14:00         3353.     Reduced Resting CBF in the Mesolimbic-Frontal Regions in Parkinson’s Disease with Impulse Control Disorders

Hengyi Rao^1,2, Eugenia Mamikonyan³, John A. Detre¹, Andrew D. Siderowf³, Matthew B. Stern³, Daniel Weintraub³

¹Center for Functional Neuroimaging, University of Pennsylvania, Philadelphia, PA, USA; ²Department of Psychology, Sun Yat-Sen University, Guangzhou, China; ³Department of Psychiatry, University of Pennsylvania, Philadelphia, PA, USA

Dopaminergic replacement therapies may induce a range of impulse control disorders (ICDs) in Parkinson’s disease (PD), yet the neural substrates underlying ICDs in this susceptible population are unknown. Using ASL perfusion fMRI, we found that PD patients with an active ICD have significantly reduced resting CBF in striatal and prefrontal regions compared with non-ICD PD patients, indicating that impairments in mesolimbic-frontal pathway may be the neurobiological underpinning for ICDs in PD. Moreover, a significant positive correlation between resting striatal CBF and ICD duration in active ICD patients suggests an attempt to normalize some ICD-associated neural abnormalities.

14:30         3354.     Effect of Dopaminergic Drugs on Motor and Speech Tasks in PD: An FMRI Study

Mohit Saxena¹, Shanmugam Senthil Kumaran², Sumit Singh¹, Vaishna Narang³, Madhuri Behari¹

¹Neurology, All India Institute of Medical Sciences, New Delhi, Delhi, India; ²Department of NMR, All India Institute of Medical Sciences, New Delhi, Delhi, India; ³School of Languages, Jawaharlal Nehru University, New Delhi, India

Parkinson's disease (PD) is associated with tremor, bradykinesia, rigidity, postural disturbance and speech dysfunction. Using fMRI, we evaluated six PD patients with and without dopa drugs for motor (finger tapping) and speech tasks (Hindi words reading) using block design at 1.5 T. We observed Brodmann area (BA) 6 and middle temporal gyrus after drug administration and reduced activation in sensory motor cortex and middle temporal gyrus. Positive L-dopa effects were observed in right BA 4, 6 for motor tasks and BA 21, 6 for speech tasks in PD subjects. BA 44, 45 and BA 13 showed negative dopaminergic effects.

15:00         3355.     An Analysis of Working Memory in Parkinson’s Disease with Reference to Deficiency of Dopamine: An FMRI Study

Mohit Saxena¹, Shanmugam Senthil Kumaran², Sumit Singh¹, Madhuri Behari^1
1Neurology, All India Institute of Medical Sciences, New Dehli, Dehli, India; ²Department of NMR, All India Institute of Medical Sciences, New Delhi, Delhi, India

The present fMRI study observes how dopaminergic drugs may influence the areas of working memory in patients suffering from Parkinson’s disease. Memory task was recalling of scenes and everyday objects (26 in number) from among 96 images. Areas associated with memory retrieval, visual processing and episodic memory were active during ‘off’ and ‘on’ stages. Similar feedback responses or reaction times during ‘on’ and ‘off’ states show that memory was unaffected with drug administration in these subjects. L-dopa is found to increase attentional capabilities of the PD subjects, but may not have any significant role in working memory.

13:30         3357.     Studying Functional Connectivity Strength Between the Primary Motor Cortex (PMC) and the Supplementary Motor Area (SMA) in Brain Tumor Patients Using Resting State BOLD FMRI

Bob Lei Hou¹, Bharat Biswal², Henning U. Voss³, Nicole M. Petrovich Brennan⁴, Kyung Peck⁵, Andrei I. Holodny⁴

¹Medical Physics and Radiology , MSKCC, New York City, NY, USA; ²Radiology, UMDNJ, Newark, NJ, USA; ³Citigroup Biomedical Imaging Center, Weill Medical College of Cornell University, New York, NY, USA; ⁴Radiology, MSKCC, New York City, NY, USA; ⁵Medical Physics and Radiology, MSKCC, New York City, NY, USA

This study evaluated connectivity strength between PMC and SMA for healthy controls and patients with brain tumors. Results for the brain tumor patients suggest that there is a connection between the PMC and SMA irrespective of tumor type and distance between the cortics to the tumor. The tumors reduces the BOLD signal in the PMCs meanwhile increase it in the SMA.The overall mean of the SMA/PMC BOLD siganl ratio were 0.51 and 0.83 for the normal and tumor groups, respectively. The tumors seem to increase the amplitude of the low frequency fluctuations resulting from local blood flow and respiration in the SMA while decreasing the amplitude of these fluctuations in PMC.

14:00         3358.     Altered Resting State Networks in Patients with Cluster Headache

Massimo Filippi^1,2, Maria Assunta Rocca^1,2, Paola Valsasina¹, Bruno Colombo^1,2, Andrea Falini^3,4, Martina Absinta¹, Giancarlo Comi²

¹Neuroimaging Research Unit, Scientific Institute Hospital San Raffaele, Milan, Italy; ²Department of Neurology, Scientific Institute Hospital San Raffaele, Milan, Italy; ³CERMAC, Scientific Institute Hospital San Raffaele, Milan, Italy; ⁴Department of Neuroradiology, Scientific Institute Hospital San Raffaele, Milan, Italy

Aim of this study was to investigate abnormalities of brain resting state networks (RSN) in patients with chronic cluster headache (CH), outside of the attack phase, in comparison with healthy individuals. Sixteen relevant RSN were detected and significant decrease in the average percentage signal change of RS fluctuations were found in CH patients, compared to controls, for the sensorimotor network, the primary visual network and the secondary visual network. These findings suggest a diffuse dysfunction of functional connectivity which extends beyond the antinoceptive system in CH patients.

14:30         3359.     FMRI of Pain: An Analysis of the Benefits of Modelling Trial-To-Trial Pain Reports.

Eugene P. Duff¹, Stephen M. Smith¹, Mark W. Woolrich¹, Bill Vennart², Matthew A. Howard³, Steven C.R. Williams³, Steven J. Coen³

¹FMRIB, University of Oxford, Oxford, UK; ²PGRD, Pfizer, Sandwich, UK; ³Institute of Psychiatry, Kings College, London, UK

fMRI pain studies sometimes record trial-by-trial ratings of pain intensity. However, the extent to which these ratings can benefit signal modelling has not been studied in detail. This study provides such an analysis. We find that modelling trial-to-trial variations in pain provided substantial improvement in the localisation of stimulus-related effects of interest. Improvements were greatest in regions of the pain matrix known to be involved with the processing of pain. We recommend that pain ratings be recorded and modelled whenever possible.

15:00         3360.     fMRI of Patients with Acute and Chronic Low Back Pain

Harish A. Sharma¹, Gupta Rajshri², Emily Wee³, Sarah Marner⁴, William Olivero⁵

¹Biomedical Imaging Center, University of Illinois at Urbana-Champaign, Urbana, IL, USA; ²Medical College, University of Illinois, Urbana, IL, USA; ³University of Illinois at Urbana-Champaign, USA; ⁴Carle Clinic; ⁵Neurosurgery, Carle Foundation Hospital, Urbana, IL, USA

Chronic pain is a common medical problem affecting as much as 15% of the adult population. Although the treatment for acute pain is relatively successful chronic pain remains poorly treated primarily because of a lack of understanding of the primary pathophysiology. We previously presented data demonstrating the use of fMRI in imaging patients with acute low back pain and radiculopathy. Here we present some preliminary data comparing patients with lumbar pain of an acute nature (lasting less than 3 months) and compare them to patients with more chronic pain (lasting at least 1 year) and normal controls. We found more robust activation in the patients with acute pain in the S1, bilateral thalami, contralateral amygdala and cingulate gyrus as compared to patients with chronic pain and controls. Patients with chronic pain seemed to have more diffused brain activations than those with acute pain.

13:30         3361.     Effective Connectivity Analysis of Emotional Processing in Remitted Depression

Nia Goulden¹, Shane McKie¹, Emma Pegg¹, Darragh Downey², Rebecca Elliott¹, Stephen Ross Williams², Ian M. Anderson¹, John Francis William Deakin¹

¹Neuroscience and Psychiatry Unit, University of Manchester, Manchester, UK; ²Imaging Science and Biomedical Engineering, University of Manchester, Manchester, UK

We applied an effective connectivity analysis to data from healthy control and remitted depressed volunteers who had carried out an emotional face viewing paradigm. We detected differences in bottom-up and top-down processing for viewing emotional faces. There was a differential effect of happy, sad and fearful faces on remitted depressed volunteers with most differences seen during viewing sad faces. During viewing happy and sad faces a difference was seen in the connection from the fusiform gyrus to the amygdala which was also modulated by viewing sad faces. These differences potentially indicate risk factors for depression.

14:00         3362.     Predicting Treatment in Patients with Major Depression Using Granger-Based Connectivity and Support Vector Machines

Gopikrishna Deshpande¹, George Andrew James¹, Richard Cameron Craddock², Helen S. Mayberg³, Xiaoping P. Hu¹

¹Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, GA, USA; ²School of Electrical and Computer Engineering, Georgia Institute of Technology, Atlanta, GA, USA; ³Department of Psychiatry, Emory University, Atlanta, GA, USA

Variations in effective connectivity within limbic-cortical network (as modeled with structural equation modeling from PET) have been identified in different major depressive disorder (MDD) subgroups associated with differential response to antidepressants. In this study, MDD patients were randomly assigned to one of two possible treatments – cognitive behavioral therapy or a drug and treated for 12 weeks. Granger-based effective connectivity was calculated from fMRI data obtained before and during treatment. Recursive cluster elimination with support vector machines was used to predict which treatment the patients were receiving based on discriminative connectivity features. Our results show 100% accuracy in predicting treatment.

14:30         3363.     Abnormal Neural Activity in Treatment-Resistant Depression: A Resting-State FMRI Study

Qi-Zhu Wu¹, Dongming Li¹, Hong Yang¹, Long Chen¹, Xiuli Li¹, Fei Li¹, Nabin Amatya¹, Hehan Tang¹, Yu-Feng Zang², Qiyong Gong¹

¹Huaxi MR Research Center, Department of Radiology, West China Hoapital, Sichuan University, Chengdu, Sichuan, China; ²State Key Laboratory of Cognitive Neuroscience and Learning, Beijing Normal University, Beijing, China

We performed a resting-state fMRI (rfMRI) study on a group treatment resistant depressive (TRD) patients with age/sex-matched controls. Using the functional data analytical method Regional Homogeneity (ReHo), we characterized an increased ReHo value in the anterior cingulate (ACC) and decreased ReHo value in right inferior parietal lobule. The individual ReHo value in the ACC area was negatively correlated with patient's Hamilton Score. Our work suggested the usefulness of rfMRI and ReHo method in investigating psycho-pathological mechanisms of TRD.

15:00         3364.     Assessing Fit of Individuals to Group-Derived Structural Equation Models of Resting-State FMRI Data

George Andrew James¹, Richard Cameron Craddock¹, Mary Elizabeth Kelley², Paul E. Holtzheimer³, Boadie Dunlop³, Charles Nemeroff³, Helen S. Mayberg³, Xiaoping Phillip Hu¹

¹Biomedical Engineering, Emory University / Georgia Institute of Technology, Atlanta, GA, USA; ²Biostatistics and Bioinformatics, Emory University, Atlanta, GA, USA; ³Psychiatry and Behavioral Sciences, Emory University, Atlanta, GA, USA

Structural equation modeling (SEM) of PET data has shown neuroanatomic interactions to predict major depressive disorder (MDD) patients’ response to therapy. By taking advantage of fMRI’s high temporal resolution, we propose to extend this work into the domain of individual patients. Forty-six never treated MDD patients underwent resting-state fMRI scanning. The model best fitting the group was then fit to individual patients. Histogram analysis of individuals’ path coefficients demonstrate some paths (midanterior cingulate to orbitofrontal) are Gaussian distributed about the group value while others (midanterior cingulate to ventromedial prefrontal) are not, potentially indicating group commonalities and subgroup differences, (respectively).

13:30         3365.     Morphological Changes in Brain During New Language Acquisition: A VBM Study

Shilpi Modi¹, Manisha Bhattacharya¹, Pawan Kumar¹, Subash Khushu¹

¹NMR Research Centre, Institute of Nuclear Medicine and Allied Sciences, Delhi, India

Voxel Based Morphometric (VBM) studies have given evidence to ‘neuroplasticity’, with training and acquisition of new skills. In order to find the changes in brain morphometry on learning a fourth language (Japanese), VBM study was carried out on trilingual Indian students who were learning Japanese for the last 2 years. Significant increase in gray and white matter volume was obtained in language learning and processing centres of the brain suggesting use-dependent structural reorganization of the brain on acquisition of new skills.

14:00         3366.     Indications of Residual Neurovascular Function in a Case of Hemianopia Prior to Visual Field Rehabilitation.

Yi-Ching Lynn Ho^1,2, Amandine Cheze¹, Lai-Hong Dennis Cheong¹, Esben Thade Petersen^1,2, Albert Gjedde², Kong-Yong Goh³, Yih-Yian Sitoh¹, Xavier Golay¹

¹Neuroradiology, National Neuroscience Institute, Singapore, Singapore; ²Centre For Functionally Integrative Neuroscience, University of Aarhus, Aarhus, Denmark; ³Opthalmology, Tan Tock Seng Hospital, Singapore, Singapore

Visual restitution training (VRT) is a new therapy that apparently facilitates visual field recovery in patients with post-chiasmal infarcts and preserved foveal vision. However, the reasons for the apparent visual field enlargement are unclear, especially in the functional borderzone, where the improvements tend to be seen. In this case study, we aimed to track neurophysiological changes with VRT, using fMRI retinotopic mapping and a paradigm to look at borderzone-related BOLD activity, plus high-resolution DTI to assess white-matter changes. The baseline results of the case study indicate residual neurovascular function around the infarcted zone and may predict therapeutic gains.

14:30         3367.     Increased Default Mode Activity in Patients with Progressive Supranuclear Palsy

Yu-Chun Lin¹, Tien-Min Liu², Chin-Song Lu³, Yau-Yau Wai¹, Jiun-Jie Wang²

¹Department of Diagnostic Radiology, ChangGung Memorial Hospital, KweiShan, Taoyuan, Taiwan; ²Department of Medical Imaging and Radiological Science, ChangGung University, Taoyuan, Taiwan; ³Department of Neurology, ChangGung Memorial Hospital, Taoyuan, Taiwan

The present work proposed to examine the changes in the default mode network activity measured during the resting state in patients with PSP. 6 patients with PSP and 6 healthy old controls were acquired on a 3.0 Tesla MR scanner. Subjects were prompted to remain restingly awake without performing any specific task. Data were analyzed through independent component analysis. The results showed increased activations in patients in anterior cingulate and parahipocampus. It might suggest that the neural network in patients of PSP was affected such that increased amount of resources was required to maintain a similar level of performance.

15:00         3368.     A Voxel Based Morphometric Analysis of the Effect of Visual Experience on the Structural Organization of the Human Brain

Manisha Bhattacharya¹, Shilpi Modi¹, Namita Singh Saini¹, Rajendra Prasad Tripathi¹, Subash Khushu¹

¹NMR Research Centre, Institute of Nuclear Medicine and Allied Sciences, Delhi, India

Visual experience during the early stages of life effects the development of neural circuits in the visual cortex. In order to find the extent of structural reorganization with the extent of sightedness, voxel based morphometry was carried out in totally blind subjects, partially blind subjects and controls. Our study revealed gray-white matter volume loss in the parieto-occipital cortex, limbic lobe and the neo-cerebellum in total blinds as compared to controls. Morphological changes were less pronounced in the occipital lobe of partial blinds as compared to total blinds. Moreover, no changes were found in their cerebellum and the parietal cortex.

14:00         3369.     Full Brain Functional Connectivity of the Hippocampus in Temporal Lobe Epilepsy Compared to Controls

Victoria L. Morgan¹, Baxter P. Rogers¹, John C. Gore¹, Bassel Abou-Khalil²

¹Institute of Imaging Science, Vanderbilt University, Nashville, TN, USA; ²Neurology, Vanderbilt University, Nashville, TN, USA

Temporal lobe epilepsy (TLE) is typically associated with seizures generated from the anterior hippocampus. In this study we compared the functional connectivity of the left hippocampus to the rest of the brain between left TLE patients and controls, using resting-state correlations of BOLD signals. Patients had a significant decrease in connectivity between the left hippocampus and right and left thalamus, as compared to controls. Patients had only slightly increased connectivity between the left hippocampus and the right temporal tip. These findings may provide insight into the network alterations which may be related to structural changes and cognitive impairment in TLE.

14:30         3370.     Impaired Functional Connectivity and Language in Non-Symptomatic Localization-Related Epilepsy

Jacobus F.A. Jansen¹, Marielle C. Vlooswijk², H J. Majoie², Paul A. Hofman², Marc C. de Krom², Albert P. Aldenkamp², Walter H. Backes²

¹Department of Medical Physics & Radiology, Memorial Sloan-Kettering Cancer Center, New York, NY, USA; ²Maastricht University Hospital, Maastricht, Netherlands

To investigate the neuronal mechanisms underlying neuropsychological language dysfunction, activation maps and functional connectivity networks were studied by fMRI of language. 34 patients with non-symptomatic localization-related epilepsy and 20 healthy controls were included for this study. They all underwent neuropsychological assessment of IQ, word fluency, and text reading. Additionally, fMRI was performed with a standard covert word generation and text reading paradigm. Functional connectivity analysis comprised cross-correlation of signal time-series of the characteristic and most strongly activated regions involved in the language tasks. A relation between reduced functional connectivity and performance on word fluency and text reading tests was demonstrated in the patients. Impaired performance on language assessment in epilepsy patients could be attributed to loss of functional connectivity in the language networks.

15:00         3371.     A Multimodal Imaging Approach to Surgical Planning in Temporal Lobe Epilepsy

Jodie Reanna Gawryluk^1,2, Ryan C.  N. D'Arcy^3,4, David B. Clarke⁵, Kimberly D. Brewer^3,6, Steven D. Beyea^3,6, R M. Sadler⁷, Donald F. Weaver⁷

¹Institute for Biodiagnostics (Atlantic), National Research Council , Halifax, Nova Scotia, Canada; ²Psychology, Dalhousie University, Halifax, Nova Scotia, Canada; ³Institute for Biodiagnostics (Atlantic), National Research Council, Halifax, Nova Scotia, Canada; ⁴Radiology, Dalhousie University, Halifax, Nova Scotia, Canada; ⁵Surgery, QEII Health Sciences Centre, Halifax, Nova Scotia, Canada; ⁶Physics and Atmospheric Science, Dalhousie University, Halifax, Nova Scotia, Canada; ⁷Neurology, QEII Health Sciences Centre, Halifax, Nova Scotia, Canada

Neurosurgical planning can benefit greatly from functional brain imaging. Unfortunately, application in temporal lobe epilepsy must contend with the challenge of deriving clinically relevant data from the complex networks that support high level cognitive processing. The current study uses a multimodal approach that combines high-field functional magnetic resonance imaging (fMRI) and high-density event-related brain potentials (ERPs). fMRI is used in a site-directed fashion to test for spatial differences in activation across medial and lateral regions of the temporal lobes. ERPs, on the other hand, are used in a process-specific fashion to evaluate cognitive processing associated with the temporal lobes.

15:30         3372.     The Default-Mode Network Is Selectively Altered in Temporal Lobe Epilepsy

Guangming Lu¹, Zhiqiang Zhang², Qifu Tan³, Yuan Zhong², Yijun Liu⁴

¹Medical Imaging, Jinling Hospital, Clinical School of Nanjing University, Nanjing, Jiangsu, China; ²Medical Imaging, Jinling hospital, Clinical School of Nanjing University, Nanjing, Jiangsu, China; ³Neurosurgery, Jinling hospital, Clinical School of Nanjing University, Nanjing, Jiangsu, China; ⁴Psychiatry, University of Florida, Gainesville, FL, USA

The alternation of the default-mode network (DMN), being as an intrinsic low-frequency fluctuation, is remaining unknown in the medial temporal lobe epilepsy (mTLE). The resting-fMRI data of 44 patients with mTLE were investigated by using the independent component analysis (ICA) and amplitude of low-frequency fluctuation (ALFF) analysis. By comparing with the results of 27 normal controls, ICA and ALFF analysis both revealed that the patients had different changing patterns in the functional connectivity and ALFF within the regions of DMN, which implies that the alternation of DMN may play a mediating role in the process of mTLE.

13:30         3373.     Neural Correlates of Amygdala Functional Connectivity on Abstinent Heroin Addicts

Yuan Ma¹, Chunming Xie^1,2, Wenjun Li¹, Lin Ma³, Zheng Yang⁴, Shi-Jiang Li¹

¹Biophysics, Medical College of Wisconsin, Milwaukee, WI, USA; ²Neurology, School of Clinical Medicine, Nanjing, Jiangsu, China; ³Radiology, PLA Hospital, Beijing, China; ⁴Beijing Insititute of Basic Medicine Science, Beijing, China

Neuropsychological and neuroimaging studies concerning addiction have demonstrated that amygdala is instrumental in drug consumption, regulation of drug reward and craving. However, little is known about the neural correlates of heroin dosage in heroin user subjects. In this study, we utilized resting-state functional connectivity MRI (fcMRI) to investigate relationship of the alteration in the amygdala functional connectivity (AFC) and determine the associated regions with consumed heroin dosage in heroin users. This work highlights that the altered AFC network is associated with the neural process of regulating the addictive behavior. It is suggested that the fcMRI method could be applied to evaluate the consequence of heroin use and related alteration in brain circuitry.

14:00         3374.     Abnormal Diffusion and Fractional Anisotropy in the Brains of Adolescent Methamphetamine Users

Christine C. Cloak¹, Daniel Alicata², Linda Chang¹, Joanna Ng¹, Thomas Ernst¹

¹Medicine, University of Hawaii, John A Burns School of Medicine, Honolulu, HI, USA; ²Psychiatry, University of Hawaii, John A Burns School of Medicine, Honolulu, HI, USA

Abuse of stimulants like methamphetamine (METH) often begins during adolescence. We used DTI to determine whether METH use during adolescence results in altered brain microstructure. Fourty young METH users and 33 controls were evaluated. METH users showed lower diffusion in the parietal white matter and higher FA in the parietal white matter and thalamus suggesting altered tissue density and organization. However, higher diffusion in the right caudate suggests neuroinflammation and lower FA in the corpus callosum splenium may indicate axonal disruption or disorganization in these METH users. These abnormal DTI measures suggest alterations in brain development associated with METH use.

14:30         3375.     Hippocampal Gray Matter of Cannabis Users Is Correlated with Cannabidiol Obtained from Hair Analysis

Traute Demirakca¹, Gabriele Ende¹, Alexander Sartorius², Nadja Meyer¹, Helga Welzel¹, Andreas Meyer-Lindenberg², Gisela Skopp³, Karl Mann⁴, Derik Hermann⁴

¹Neuroimaging, Central Institute of Mental Health, Mannheim, Germany; ²Psychiatry, Central Institute of Mental Health, Mannheim, Germany; ³Institute of Forensic and Traffic Medicine, Heidelberg, Germany; ⁴Department of Addictive Behavior and Addiction Medicine, Central Institute of Mental Health

Studies of hippocampal volume and tissue composition in chronic cannabis users revealed divergent results. None of these studies has accounted for the proportion of delta-9-tetrahydrocannabinol (THC) and cannabidiol (CBD) included in the consumed cannabis products. We present the first voxel-based-morphometry (VBM) analysis that takes the results of a hair analysis of the cannabinoids into account. Although hippocampal volume and tissue composition showed no significant differences between groups, a significant correlation of unmodulated hippocampal gray matter and CBD was observed bilaterally, indicating a positive influence and neuroprotective properties of CBD on hippocampal neurons.

15:00         3376.     Functional Connectivity Analysis of Heroin Addicts Using the Ventral Tegmental Area as a Seed

Alexander D. Cohen¹, Chunming Xie¹, Wenjun Li¹, Zheng Yang², Lin Ma³, Shi Jiang Li^1,4

¹Biophysics, Medical College of Wisconsin, Milwaukee, WI, USA; ²Cognitive Research Laboratory, Beijing Institute of Basic Medical Sciences, Beijing, China; ³Radiology, PLA 301 Hospital, Beijing, China; ⁴Psychiatry and Behavioral Medicine, Medical College of Wisconsin

This abstract compares resting state functional connectivity (FC) in heroin addicts to matched-control subjects using the ventral tegmental area (VTA) as a seed in an attempt to better understand the underlying processes of addiction. Correlation values were obtained on a voxelwise basis for each subject and compared via t-test between groups. A decrease in FC was found between the VTA and the prefrontal cortex (PFC) and cingulate gyrus (CG). An increase in FC was found between the VTA and postcentral gyrus. The results suggest a decrease in dopamine release in the VTA may be associated with decreased FC in the PFC and CG.

13:30         3377.     Hyperoxia Calibrated FMRI of Cerebral Small Vessel Disease During a Cognitive Stroop Task

Jonathan Goodwin¹, Guy Lumley¹, Andrew Irwin¹, Hedley Emsley², Laura Michelle Parkes^1,3

¹MARIARC, University of Liverpool, Liverpool, Merseyside, UK; ²Department of Neurology, Royal Preston Hospital, Preston, UK; ³Imaging Science and Biomedical Engineering, University of Manchester, Manchester, UK

In this work we show preliminary results for a study exploring hyperoxia calibrated fMRI, as a novel imaging technique for cerebral small vessel disease (cSVD). 6 lacunar stroke patients with symptomatic cSVD, and 15 healthy aged matched control subjects performed cognitive Stroop task and hyperoxia calibration scans. We found the BOLD response to the Stroop task was higher in the frontal cortices for the SVD group, which corresponded with reduced values of bCMRO2 in those regions. We also found higher average values for the calibration parameter 'A' in all ROIs for the patients compared to the controls.

14:00         3378.     Hyperexcitability of the Motion-Sensitive Area MST in Migraineurs with Aura

Peter Dechent¹, Katharina Saller^1,2, Carmen Morawetz¹, Jürgen Baudewig¹, Walter Paulus², Andrea Antal²

¹MR-Research in Neurology and Psychiatry, University Göttingen, Göttingen, Germany; ²Department of Clinical Neurophysiology, University Göttingen, Göttingen, Germany

Differences in visual perception measures between people with/without migraine have been attributed to abnormal cortical processing. Here, we explored the dynamics of the basic interictal state regarding extrastriate, motion-responsive middle-temporal (MT) and medial-superior-temporal area (MST) using fMRI (3Tesla) with different moving dot stimuli on 18 migraine patients (with/without aura (MwA/MwoA)) and 9 controls. Compared with controls and MwoA patients, MwA patients showed higher signal changes in bilateral MST, but not in MT. This implies an enhanced responsiveness of MST of MwA patients and strengthens the hypothesis that hyperexcitability of the visual cortex in these patients goes beyond primary visual areas.

14:30         3379.     Altered Functional Connectivity in the Pain Modulatory System of Migraineurs

Caterina Mainero¹, Nils Rettby¹, Thomas Benner¹, Nouchine Hadjikhani^1,2

¹A. A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, MA, USA; ²Brain Mind Institute, Swiss Federal Institute of Technology , Lausanne, Switzerland

Recent studies have shown persistent anatomical changes in the brain white and gray matter of migraineurs, located in regions involved in pain processing/modulation including the somatosensory cortex, thalamus, and periaqueductal gray matter (PAG). We used functional connectivity during rest in migraineurs and controls to test whether the reported anatomical changes are associated with functional changes. Our preliminary results show that functional connectivity is stronger within the pain modulatory system in migraineurs than in controls. It is still unknown whether this reflects a migraine-specific process or relates to non-specific chronic pain conditions.

15:00         3380.     Effective Connectivity of Resting State Networks in Patients Prenatally Exposed to Cocaine Shows Higher Emotional Arousal

Gopikrishna Deshpande¹, Priya Santhanam¹, Zhihao Li¹, George Andrew James¹, Claire D. Coles^2,3, Mary Ellen Lynch², Stephen Hamman⁴, Xiaoping P. Hu¹

¹Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, GA, USA; ²Department of Psychiatry and Behavioral Sciences, Emory University, Atlanta, GA, USA; ³Fetal Alcohol Syndrome and Drug Exposure Clinic, Marcus Autism Center, Atlanta, GA, USA; ⁴Department of Psychology, Emory University, Atlanta, GA, USA

Previous research has led to the hypothesis that prenatal cocaine exposure (PCE) alters emotional regulation. In this study, we evaluate Granger-based resting state effective connectivity in the emotional network in PCE subjects to examine the above hypothesis. We found interhemispheric connections between homologous areas in both PCE subjects and controls, but additional bidirectional connectivity between amygdala and parahippocampal gyrus in only PCE subjects. This supports the hypothesis of emotional dysregulation in PCE subjects, wherein disinhibition of emotional arousal affects other cognitive functions leading to behavioral impairments.

13:30         3381.     Delayed Amygdala Response to Positive Emotional Stimuli in Major Depressive Disorder

Qingwei Li^1,2, Chunbo Li³, Wenyuan Wu¹, Yuan Shen¹, Peijun Wang⁴, Gonghua Dai⁴, Xuchu Weng⁵, Yijun Liu²

¹Department of Psychiatry, Tongji Hospital of Tongji University, Shanghai, China; ²Departments of Psychiatry and neuroscience, McKnight Brain Institute, University of Florida, Gainesville, FL, USA; ³Shanghai Jiaotong University, Shanghai Mental Health Center, Shanghai, China; ⁴Department of Radiology, Tongji Hospital of Tongji University, Shanghai, China; ⁵Laboratory of Brain High Function, Institute of Psychology, Chinese Academic of Science, Beijing, China

The time course of the amygdala response may be relevant to the blunted behavioral response to emotional stimuli of major depressive disorder (MDD). Functional magnetic resonance imaging was explored to the emotional pictures processing in 12 first-episode unmedicated MDD subjects and 13 healthy controls (HC). Analyses focused on the temporal dynamics of the BOLD signal change in the amygdala across blocks of positive, neutral and negative emotional pictures. MDD Individuals showed delayed response to positive emotion and blunted response to negative emotional stimuli in the amygdala, which provided an explanation of the loss of interest and pleasure in MDD.

14:00         3382.     Altered Brain Connectivity with Hippocampus in  Patients with Major Depressive Disorder

Junran Zhang¹, XiaoQi Huang^1,2, Su Liu¹, Qi-Zhu Wu¹, Dongming Li¹, Long Chen¹, Xiuli Li¹, Fei Li¹, Nabin Amatya¹, Hehan Tang¹, Weihong Kuang², QiYong Gong^1,2

¹Huaxi MR Research Center (HMRRC), Department of Radiology, West China Hospital of Sichuan University, ChengDu, SiChuan Province, China; ²Department of Psychiatry, West China Hospital of Sichuan University

In the present study we used a functional connectivity analysis toolkit REST implemented in Statistical Parametric Mapping software (SPM2) to analyze the resting state functional data obtained from patients with major depression. We chose the hippocampus as the seed region to perform the analysis to investigate its role in mediating the abnormal neural circuit underlies major depression. We identified decreased functional connectivity between the bilateral hippocampus and several cerebral regions in major depressed patients compared with healthy controls.

14:30         3383.     Resting State FMRI in Late-Life Anxious Depression

Minjie Wu^1,2, Carmen Andreescu¹, Jennifer Figurski¹, Costin Tanase³, Howard J. Aizenstein^1,2

¹Department of Psychiatry, University of Pittsburgh, Pittsburgh, PA, USA; ²Department  of Bioengineering, University of Pittsburgh, Pittsburgh, PA, USA; ³Magnetic Resonance Research Center, University of Pittsburgh Medical Center, Pittsburgh, PA, USA

Analysis of default-mode network (DMN) in clinical conditions may enhance the understanding of mental illnesses. We analyzed the DMN functional connectivity pattern in two groups: late-life depression subjects with high comorbid anxiety (LLD-HA) and late-life depression subjects with low comorbid anxiety (LLD-LA). Our results show that LLD-HA subjects display a dissociative pattern of connectivity in the DMN when compared with LLD-LA subjects. LLD-HA subjects had increased connectivity in the posterior regions of the DMN (occipital and parietal associative areas) and decreased connectivity in the anterior regions of the DMN (rostral ACC, medial prefrontal and orbito-prefrontal cortex).

15:00         3384.     Sensation Seeking and Aversive Stimulation - A Functional MRI Study at 3 Tesla

Harald Kugel¹, Christina Sehlmeyer^2,3, Sonja Schoening^2,3, Maike Kleemeyer³, Kristin Herper³, Rauch Astrid^2,3, Hagen Schiffbauer¹, Bettina Pfleiderer¹, Volker Arolt², Pienie Zwitserlood⁴, Walter Heindel¹, Carsten Konrad^2,3

¹Dept. of Clinical Radiology, University of Muenster, Muenster, NRW, Germany; ²Dept. of Psychiatry, University of Muenster, Muenster, NRW, Germany; ³Research Group 4, Interdisciplinary Center for Clinical Research (IZKF), University of Muenster, Muenster, NRW, Germany; ⁴Dept of Psychology, University of Muenster, Muenster, NRW, Germany

Sensation Seeking (SENS) is a personality trait characterized by the need for threatening stimuli even at the cost of personal risk. Low sensation seekers avoid intense and dangerous sensory stimulations. We examine the association between Sensation Seeking and the neurobiological mechanisms of fear processing with fMRI. It is suggested that the personality trait SENS correlates with neuronal responses to fear-stimuli.

14:00         3385.     Diffusion Tensor Imaging in Patients with Hallervorden-Spatz Syndrome and Their Siblings

Rishi Awasthi¹, Richa Trivedi¹, Vimal K. Paliwal², Jitesh K. Singh³, Ram K  S Rathore³, Rakesh K. Gupta¹

¹Department of Radiodiagnosis, Sanjay Gandhi Post Graduate Institute of Medical Sciences, Lucknow, Uttar Pradesh, India; ²Department of Neurology, Sanjay Gandhi Post Graduate Institute of Medical Sciences, Lucknow, India; ³Department of Mathematics and Statistics, Indian Institute of Technology, Kanpur, India

DTI was performed on 4 patients with Hallervorden Spatz syndrome (HSS), their siblings (n=2) and age matched controls (n=5). Fractional anisotropy (FA) and mean diffusivity (MD) values were measured by placing region of interests (ROIs) on globus palllidus (GP), substantia nigra (SN), putamen, and caudate (CN) in all groups. In patient group hypointense and hyperintense components of “eye of tiger sign” visible on T2* GRE were automatically segmented to obtain DTI metrics. A significant difference in FA value was observed among all groups in CN, GP and SN. Significantly high FA with low MD value in hypointense compared to hyperintense region of “eye of tiger sign” was observed in patient group. We conclude that FA is a sensitive indicator for abnormal iron accumulation in these regions.

14:30         3386.     Whole-Tract Reduction in Fractional Anisotropy in the Corticospinal Tracts of Amyotrophic Lateral Sclerosis Patients, as Measured Using a Weighted 3-D Region of Interest in Template Space After Deformable Diffusion Tensor Imaging Registration

John H. Woo¹, Elias R. Melhem¹, Sumei Wang¹, Lauren Elman², Leo McCluskey², Lisa Desiderio¹, Hui Zhang¹, James Gee¹

¹Radiology, University of Pennsylvania, Philadelphia, PA, USA; ²Neurology, University of Pennsylvania, Philadelphia, PA, USA

Amyotrophic lateral sclerosis (ALS) is a degenerative disease of motor neurons. Using diffusion tensor imaging, previous investigators have measured a reduction in fractional anisotropy (FA) in the corticospinal tract, thought to reflect axonal degeneration. However, these methods often required manual segmentation or individual fiber tractography to generate regions-of-interest (ROI). In this study, we performed whole-tract FA measurements using a deformable tensor-driven registration algorithm and a weighted 3D ROI of the CST in template space. We found a highly significant difference between 12 ALS patients and 7 controls. This method may be especially useful for evaluating whole-tract differences in large groups.

15:00         3387.     Integrity of Limbic System Network in Schizophrenia: A Tract-Specific Analysis

Akira Kunimatsu¹, Natsuko Kunimatsu², Shigeki Aoki^1,3, Osamu Abe¹, Yoshitaka Masutani¹, Hidenori Yamasue⁴, Kiyoto Kasai⁴, Harushi Mori¹, Daisuke Itoh², Kuni Ohtomo¹

¹Department of Radiology, University of Tokyo, Tokyo, Japan; ²Graduate School of Medicine, University of Tokyo, Tokyo, Japan; ³Department of Radiology, Juntendo University, Tokyo, Japan; ⁴Department of Neuropsychiatry, University of Tokyo, Tokyo, Japan

We aimed to seek diffusion abnormalities of white matter tracts included in the limbic system in schizophrenic patients on a diffusion tensor tract-specific basis. We found significant decreases of fractional anisotropy in the anterior cingulum bundles, the uncinate fasciculi, and the fornices in schizophrenic patients. Our results suggest that disintegration of limbic system network could be monitored by diffusion tensor imaging.

15:30         3388.     Application of Canonical Correlation Analysis to Identify Regions of Significant Correlation Between Symptom Scores and DTI Measures in Schizophrenia

Andrew Mario Michael^1,2, Vince D. Calhoun^1,3, Godfrey D. Pearlson^4,5, Stefi A. Baum², Arvind Caprihan¹

¹MIND Research Network, Albuquerque, NM, USA; ²Center for Imaging Science, Rochester Institute of Technology, Rochester, NY, USA; ³ECE, University of New Mexico, Albuquerque, NM, USA; ⁴Psychiatry, Yale University, New Haven, CT, USA; ⁵Olin Neuropsychiatry Research Center, Institute of Living, Hartford, CT, USA

White matter tract abnormalities are attributed as a possible marker

13:30         3389.     Static and Dynamic Visuomotor Task Performance in Children with Traumatic Brain Injury: A Diffusion Tensor Imaging Study

Karen Caeyenberghs¹, Alexander Leemans², Bouwien Smits-Engelsman³, Stephan Swinnen³

¹KULeuven, Heverlee, Belgium; ²CUBRIC, UK; ³KULeuven, Belgium

Traumatic brain injury (TBI) is a highly common form of disability in children affecting the entire lifespan. Persistent deficits in motor control have been documented following TBI. One of the major contributors to these persistent problems is diffuse axonal injury (DAI). Diffusion tensor imaging (DTI) has shown promise but has yet to be fully validated for its potential role in TBI diagnostics and evaluation.

14:00         3390.     Anatomic Vs. Functional MRI Seeding of the Corticospinal Tract in Patients with Brain Tumors

Robert J. Young¹, Tania Sierra², Valerie Lee³, Nicole Brennan¹, Kyung Peck¹

¹Radiology, Memorial Sloan-Kettering Cancer Center, New York, USA; ²Mount Sinai School of Medicine, New York; ³New York Presbyterian Hospital / Columbia University, New York

We hypothesize that fMRI driven tractography can more accurately predict the location of the corticospinal tract than anatomy driven tractography in patients with brain tumors near the motor cortex. We performed fMRI and DTI in 12 right-handed patients with brain tumors. Corticospinal tractography was similar between the anatomic and fMRI methods (p>0.06). Anatomy driven fiber tracking may be as accurate as fMRI driven fiber tracking when performed by an experienced operator, even in patients with brain tumors. Correlation of these techniques with direct cortical and subcortical stimulation during surgery is necessary for further validation of the generated fiber tracts.

14:30         3391.     Diffusion Tensor Imaging of Corticospinal Tract in Brain Neoplasms: Correlation with Motor Weakness

Naomi Morita^1,2, Sumei Wang¹, Paulomi Kadakia¹, Sanjeev Chawla¹, Myrna R. Rosenfeld³, Donald M. O'Rourke⁴, Harish Poptani¹, Elias R. Melhem¹

¹Radiology, University of Pennsylvania, Philadelphia, PA, USA; ²Radiology, Tokushima University Hospital, Tokushima, Japan; ³Neurology, University of Pennsylvania, Philadelphia, PA, USA; ⁴Neurosurgery, University of Pennsylvania, Philadelphia, PA, USA

Knowledge about the micro-structural integrity and location of motor tract, corticospinal tract (CST), is important for presurgical planning. The purpose of this study was to determine whether CST abnormality, measured by DTI, correlates with clinical motor weakness. Nineteen brain tumor patients underwent DTI. FA and ADC were measured in the segmented CSTs from the level of cerebral peduncle to internal capsule. Patients with abnormal motor function demonstrated reduced FA and increased ADC as compared to the patients with normal motor function. This study indicates that DTI has the potential to predict the degree of CST involvement in brain neoplasms.

15:00         3392.     Diffusion Tensor Imaging Study of Patterns of Tract Involvement in Diffuse Pontine Gliomas

Hoang-Vu Doan Tran^1,2, Matthew Scoggins¹, Robert Ogg¹, Nicholas Phillips¹, Kathleen Helton¹, Zoltan Patay¹, Alberto Broniscer¹, Claudia Hillenbrand¹

¹Radiological Science, St. Jude Children's Research Hospital, Memphis, TN, USA; ²Rhodes College, Memphis, TN, USA

Diffuse pontine gliomas are a heterogeneous group of lesions that account for 15% of all pediatric central nervous system tumors. Conventional MR imaging allows for the assessment of tumor location and focality but does little in terms of assessing tumor involvement in different tract compartments. This is the first study. We saw tumor involvement in tracts. The tract involvement and the ADC parameter seem to be a predictor of clinical outcome. This is an ongoing trial and we are in the process of acquiring and analyzing a larger number of patient exams in order to further assess the relationship of treatment effectiveness and tract involvement in pediatric pontine tumors.

13:30         3393.     Perioperative Changes in Diffusion Tensor Imaging of White Matter in Patients with Brain Tumors

Kyung K. Peck¹, Tania Sierra², Zhigang Zhigang¹, Raymond Baser¹, Rob Young¹

¹Memorial Sloan-Kettering Cancer Center, New York, USA; ²Mount Sinai Medical School, New York

DTI is proving to be useful in a range of applications, such as planning brain tumor surgery, glioma grading and image-modulated radiation therapy. The peritumoral region is an important area that may harbor infiltrating tumor cells in gliomas. The peritumoral region is also susceptible to mechanical and ischemic injury during surgery. DTI demonstrates changes in the peritumoral region immediately after surgery. The exact etiology of these changes remains uncertain. These changes occur in both glioma and nonglioma patients, although only the peritumoral region of gliomas reflects both edema and infiltrating tumor cells.

14:00         3394.     White Matter Damage in the Vegetative and Minimally Conscious States: Further Insights from Diffusion Tensor Imaging

Virginia Newcombe^1,2, Martin Coleman^2,3, Justin Cross⁴, John Pickard^2,5, Guy Williams², David Menon^1,3

¹Division of Anaesthesia, University of Cambridge, Cambridge, Cambridgeshire, UK; ²Wolfson Brain Imaging Centre, University of Cambridge, Cambridge, Cambridgeshire, UK; ³Cambridge Impaired Consciuosness Reasearch Group; ⁴Department of Radiology, Addenbrooke's Hospital, Cambridge; ⁵Academic Neurosurgery Unit, University of Cambridge

A better understanding of variations in neuropathology between different etiologies of the vegetative and minimally conscious states may aid diagnosis, improve prognostication and help refine the selection of patients who may benefit from particular treatment regimes. In this study we used diffusion tensor imaging to elucidate the degree and location of whole brain white matter loss in patients with disorders of consciousness secondary to traumatic brain injury (TBI) or ischaemic-hypoxic injury (IHI). While damage in the supratentorial compartment appears similar for the two groups, the TBI patients exhibited greater brainstem damage.

14:30         3395.     Diffusion Tensor Imaging Abnormalities in Children with Cerebellar Mutism After Posterior Fossa Tumor Resection

Nicholas S. Phillips¹, E. Brannon Morris², Fred H. Laningham³, Amar Gajjar⁴, Robert J. Ogg¹

¹Translational Imaging, St. Jude Children's Research Hospital, Memphis, TN, USA; ²Neurology, St. Jude Children's Research Hospital; ³Diagnostic Radiology, Children's Hospital Central California; ⁴Neuro Oncology, St. Jude Children's Reserch Hosptial

Diffusion Tensor Imaging Abnormalities in Children with Cerebellar Mutism after Posterior Fossa Tumor Resection

15:00         3396.     Diffusion Tensor Imaging of Deep Gray Matter in Children Receiving Brain Radiation Therapy.

Anna E. Nidecker¹, Firouzeh Tannazi¹, Siamak Ardekani, Moody Wharam, Jr², Mark Mahone³, Alena Horska¹

¹Radiology, Division of Neuroradiology, Johns Hopkins University, Baltimore, MD, USA; ²Radiation Oncology, Johns Hopkins University; ³Kennedy Krieger Institute

The aim of this prospective study was to evaluate FA and ADC values in specific gray matter regions among children who have received brain radiation, which is associated with toxicity which may affect learning and memory. The ADC and FA of five gray matter regions of the brain (thalamus, globus pallidus, putamen, caudate, and parahippocampal region) were calculated in five pediatric patients and five healthy controls. ADC was significantly higher in patients than controls in all five regions. These results suggest that DTI can detect changes in deep gray matter integrity associated with RT, possibly before they become clinically apparent.

13:30         3397.     Measuring Diffusion Tensor Parameters in the Human Hippocampus: Region of Interest Placement

Michael Yoong¹, Chris Clark², Rod Scott^2,3

¹Department of Neurosciences, Institute of Child Health, University College London, London, UK; ²Department of Biophysics, Institute of Child Health, University College London, London, UK; ³Department of Neurosciences, Institute of Child Health, Universitly College London, London, UK

There is inherent inaccuracy with manually placing regions of interest (ROI) within the hippocampus using diffusion images in order to measure parameters such as mean diffusivity/fractional anisotropy. Nevertheless as this remains a widely used method of analysis, it is important to maximise its reproducibility and precision. We compared several methods of ROI placement within the hippocampi of children having scans following prolonged seizures. The most precise results came from placing a small, fixed size ROI within the hippocampus. We also determined that the optimum ROI size for our scans was 12 voxels using a simple, easily reproducible technique.

14:00         3398.     Abnormal Diffusion Properties in a Rat Model of Dyslexia Revealed by Diffusion Spectrum Imaging (DSI) Tractography

Emi Takahashi¹, Glenn D. Rosen², Guangping Dai¹, Van J. Wedeen¹, Albert M. Galaburda², Ellen Grant¹

¹Radiology, Massachusetts General Hospital, Charlestown, MA, USA; ²Beth Israel Deaconess Medical Center, Boston, MA, USA

Abnormalities in brain development are increasingly reported in dyslexia. RNA interference of Dyx1c1 disrupts neuronal migration in developing embryonic neocortex in the rat and resulted in unmigrated neurons similar to those seen in the brains of dyslexics. To determine if detectable cortical and white matter organizational changes were associated with subtle heterotopia in the rat Dyx1c1 knock-down, we used diffusion spectrum imaging (DSI). DSI tractography detected abnormal tissue organization beyond the small focus of heterotopia at the white/gray matter boundary in Dyx1c1 transfected rat brains with the transfected hemisphere having fewer cortical and white matter fibers compared to control brains.

13:44         3399.     Comparison of White Matter in Normal and Dyslexic Children Using TBSS

Nancy Rollins^1,2, Michael Morriss^1,2, Jon Chia³, Barjor Gimi^1,2, Jerry Wang^1,2

¹Radiology, Children's Medical Center Dallas, Dallas, TX, USA; ²Radiology, University of Texas Southwestern Medical Center at Dallas, Dallas, TX, USA; ³Philips Healthcare Systems

: DTI at 3T using TBSS suggests lack of age-related maturational changes in dyslexic subjects beyond those reported in adults within the SLF. There are apparent alterations in white matter composition in multiple regions of the brain in children not seen in adults including a critical visual form recognition region at the left temporal-occipital junction which have not previously been reported.

15:00         3400.     White Matter and Cortical Abnormalities in Williams Syndrome Detected by Diffusion Tensor Imaging.

Andreia Vasconcellos Faria^1,2, Barbara Landau¹, Kirsten O'Hearn¹, Jiangyang Zhang¹, Kenishi Oishi¹, Xin Li¹, Hangyi Jiang¹, Kazi Akhter¹, Koji Sakai^1,3, Peter van Zijl^1,4, Susumu Mori¹, Michael I. Miller⁵

¹Johns Hopkins Medical Institutes, Baltimore, MD, USA; ²State University of Campinas, Campinas, SP, Brazil; ³ Kyoto University, Japan; ⁴Kennedy Krieger Institute, Baltimore, MD, USA; ⁵Center for Imaging Studies, Johns Hopkins University, Baltimore, MD, USA

We investigated Williams Syndrome patients’ brains using Diffusion Tensor Images (DTI) that provide suitable intra-white matter contrast. Using a nonlinear warping algorithm based on large deformation, diffeomorphic metric mapping (LDDMM) we registered participants into common coordinates. The recently established brain atlas was used to automatically segment the brains which enabled us to investigate differences in individual regions. Detected differences in size and fractional anisotropy were compatible with the physiophatological and clinical characteristics of this disease, which include impairment of functional systems responsible for abilities such as visuospatial notion, language, and socio-comportamental behavior.

14:00         3401.     Diffusion Tensor Imaging Tractography of the Corticosomatosensory Pathway in Painless Diabetic Neuropathy

Michael E. Hutton^1,2, Dinesh Selvarajah¹, Soloman Tesfaye¹, Iain D. Wilkinson^1,2

¹Sheffield Teaching Hospitals NHS Trust, Sheffield, South Yorkshire, UK; ²Academic Radiology, University of Sheffield, Sheffield, South Yorkshire, UK

Diffusion tensor imaging tractography can be used to reconstruct models of complex white matter tracts in the CNS. Quantitative measures such as the number of fibers represented in the model, the fractional anisotropy and the apparent diffusion coefficient can be used to investigate pathologies such as diabetic neuropathy (DN), which have previously been shown to have CNS involvement. In this study we compared a healthy subject group with a DN group and identified possible differences in the corticospinal pathway in the DN group.

14:30         3402.     Diffusion Anisotropy Changes in Comatose Cardiac Arrest Patients

Ona Wu¹, A Gregory Sorensen¹, Thomas Benner¹, Karen L. Furie², David M. Greer²

¹MGH Athinoula A Martinos Center, Charlestown, MA, USA; ²Neurology, MGH, Boston, MA, USA

Imaging data from comatose cardiac arrest patients who received diffusion-tensor MRI were retrospectively analyzed to examine changes in fractional anisotropy (FA) values as a function of clinical outcome. Recovery was based upon either eye opening or the six-month modified Rankin Scale (mRS) score. For patients imaged <3 days, patients without early eye opening had increased white matter FA values compared to patients with eye opening. In terms of 6 month mRS, lower FA values in the putamen and caudate at later time points were associated with a poor 6 month mRS score.

15:00         3403.     Treatment-Induced Structural Changes in Cerebral White Matter and Its Correlation with Impaired Cognitive Functioning in Breast Cancer Patients.

Sabine Deprez¹, Judith Verhoeven¹, Mathieu Vandenbulcke², Frederik Amant³, Refika Yigit³, Joris Vandenberghe², Marie-Rose Christiaens³, Caroline Sage¹, Ronald Peeters¹, Alexander Leemans⁴, Wim Van Hecke⁵, Stefan Sunaert¹

¹Department of Radiology, University Hospitals of the Catholic University of Leuven, Leuven, Belgium; ²Department of Psychiatry, University Hospitals of the Catholic University of Leuven, Leuven, Belgium; ³Multidisciplinary Breast Centre, University Hospitals of the Catholic University of Leuven, Leuven, Belgium; ⁴CUBRIC (School of Psychology), Cardiff University,, Cardiff, UK; ⁵Visionlab (Department of Physics), University of Antwerp, Antwerp, Belgium

Cognitive impairment is a potential adverse effect of systemic cancer treatment. In this study, DTI and neuropsychological testing were used to study treatment-induced structural changes in cerebral WM and correlation of DTI metrics with cognitive functioning in seventeen post-chemotherapy breast cancer patients and nineteen controls. Voxel-based two-sample T-tests revealed decreased FA in frontal, temporal and cerebellar WM and increased MD in frontal and parietal WM in patients compared to controls. FA correlated with attention tests and WAIS-Digit Symbol in the superior longitudinal fasciculus and the sagittal stratum, respectively. These results suggest a link between WM integrity and treatment-induced impaired cognition.

15:30         3404.     Neurocognitive Dysfunction in Chornic Kidney Disease (CKD) Patients - Correlations with DTI

Jiachen Zhuo¹, Stephen Seliger², David Lefkowitz¹, Joshua Betz^1,3, Steven Roys¹, Rao Gullapalli¹

¹Radiology, University of Maryland School of Medicine, Baltimore, MD, USA; ²Nephrology, University of Maryland School of Medicine, Baltimore, MD, USA; ³Statistics, University ofMaryland Baltimore County, Baltimore, MD, USA

The purpose of this study was to determine whether alterations in white matter accounts for lower neurocognitive function in CKD patients. Multiple neuro-cognitive assessment scores from 41 stage 3-4 CKD patients were correlated with DTI parameters using whole-brain/regional analysis and voxel-based morphometry. Lower FA and higher ADC were associated with poor performance on various cognitive tests. An alteration to white matter structure, possibly due to generalized microvascular disease may in part explain the observed pattern of cognitive decrement.

13:30         3405.     Effects of Brain Tumor on Corticospinal Tract and Motor Function: Analysis of Tract Stretch Using Diffusion Spectrum Imaging Tractography

Yu-Yang Yeh¹, Su-Chun Huang², W-Y. Chiang¹, F-C. Yeh¹, J-C. Tsai³, H-M. Tseng³, Wen-Yih I. Tseng^1,4

¹Center for Optoelectronic Biomedicine, National Taiwan University College of Medicine, Taipei, Taiwan; ²Institute of Biomedical Engineering, National Taiwan University, Taipei, Taiwan; ³Department of Surgery, National Taiwan University Hospital, Taipei, Taiwan; ⁴Department of Medical Imaging, National Taiwan University Hospital, Taipei, Taiwan

This study used diffusion spectrum imaging (DSI) tractography to assess the morphological change of corticospinal tracts (CST) in patients with brain tumors and investigated its correlations with the tumor properties and clinical presentation of motor function. The morphological change of CST, as quantified by tract stretch, at the internal capsule was found to be correlated with the muscle power impairment. Our results suggest that the tumor stretch of the CST at the internal capsule may impose significant impact on the motor function.

14:00         3406.     Effects of Brain Tumor on Corticospinal Tract and Motor Function: Diffusion Spectrum Imaging Tractography Analysis of Generalized Fractional Anisotropy

Yu-Yang Yeh¹, Su-Chun Huang², W-Y. Chiang¹, F-C. Yeh¹, J-C. Tsai³, H-M. Tseng³, Wen-Yih I. Tseng^1,4

¹Center for Optoelectronic Biomedicine, National Taiwan University College of Medicine, Taipei, Taiwan; ²Institute of Biomedical Engineering, National Taiwan University, Taipei, Taiwan; ³Department of Surgery, National Taiwan University Hospital, Taipei, Taiwan; ⁴Department of Medical Imaging, National Taiwan University Hospital, Taipei, Taiwan

In patients with brain tumors, microstructural integrity of the corticospinal tracts (CST), as represented by generalized fractional anisotropy (GFA), and its correlations with the muscle power and tumor properties were investigated. The results showed that GFA was significantly decreased on the tumor side as compared to the healthy side. The GFA values on the tumor side were not significantly correlated with the muscle power of the contralateral limbs. Further analysis revealed that GFA was increased as tumor volume increased, whereas it was decreased as the tumor edge distance to CST decreased. Our results suggest that GFA is changed counteractively by different tumor properties, and this may cause in part the weak relation to the muscle power impairment.

14:30         3407.     Somatotopic Organization of Hand- Feet- Lips- And Tongue-Related Fibres Identified by FMRI and DTI in Controls and Patients with Brain Tumours

Laura Mancini^1,2, Neven Moustafa Hazzaa^1,2, Mario Miranda^1,2, John S. Thornton^1,2, Tarek Yousry^1,2

¹Lysholm Dept. of Neuro-radiology, National Hospital for Neurology and Neurosurgery, University College London Hospitals NHS Trust, London, UK, UK; ²Academic Neuroradiological Unit, Institute of Neurology, University College of London, London, UK, UK

This combined DTI/fMRI study investigated the organization of the hands, feet, lips and tongue motor tracts in the brain. A probabilistic tractography approach with a 2-tensor model was used. Our results support the hypothesis of a somatotopic organization of the motor tracts, with the lips and tongue components anterior at the level of the cella media (CM) and internal capsule (IC), and medial at the level of the cerebral peduncle (CP); and the feet tracts posterior at the CM and IC and lateral at the CP. The vicinity of tumours to the tracts predominantly caused their overall displacement without affecting their relative anatomical organization.

15:00         3408.     Probabilistic Tractography of Cerebellar-Cerebral Connections in Paediatric Brain Tumor Patients

Donald Mabbott¹, Conrad Rockel¹, Nadia Scantlebury¹, Nicole Law¹, Eric Bouffet¹

¹Hospital for Sick Children, Toronto, Ontario, Canada

We used probabilistic tractography to delineate the main white matter pathways from the cerebellum to cerebral cortex for pediatric brain tumor patients treated with cranial radiation and controls. Tracts were produced that clearly replicated the cerebellar-cerebral pathways that have been delineated in prior models. Mean FA within these tracts was decreased in patients relative to controls. The ability to identify differences in the integrity of white matter for specific pathways is an important first step in localizing the regional effects of posterior fossa tumors and CRT and the subsequent impact on cognitive function.

13:30         3409.     A Diffusion Tensor Imaging Study of White Matter Integrity in Adult Major Depressive Disorder

Zhiyun Jia¹, Xiaoqi Huang¹, Tijiang Zhang¹, Qizhu Wu¹, Su Lui¹, Huijie Li², Nabin Amatya¹, Xiuli Li¹, Weihong Kuang³, Qiyong Gong¹

¹Department of Radiology, Huaxi MR Research Center (HMRRC), Chengdu, Sichuan, China; ²Institute of Psychology, Neuropsychology and Applied Cognitive Neuroscience Laboratory, Beijing, China; ³Department of Psychiatry, Chengdu, Sichuan, China

Diffusion tensor imaging was acquired using a 3.0T MR scanner in fifty one patients experiencing major depression (MDD) and fifty two normal controls. MDD exhibited lower FA values than healthy controls in multiple brain regions, and significant negative correlation between the FA value and 17-item Hamilton Depression Rating Scale were found in left caudate head and right insulae, this is the first study to investigate the whole brain abnormalities between the adult MDD and normal controls with relatively large sample size, further evidenced the microstructural white matter abnormalities in cortico-striato-limbic networks in patients with MDD.

14:00         3410.     Localization and Quantification of Injured Regions and Affected Pathways in the 3D Head-Space of Individual TBI Subjects Using DTI Tractography with Automatically Generated ROIs

Manbir Singh¹, Jeong-Won Jeong¹

¹Radiology and Biomedical Engineering, University of Southern California, Los Angeles, CA, USA

Normalized DTI tractography was conducted in the native space of 12 TBI and 10 age-matched control subjects using the same number of seeds in each subject, distributed at anatomically equivalent locations. Whole-brain tracts from the control group were mapped onto the head of each TBI subject. Differences in FA maps between each TBI subject and the control group were computed in a common space using a t-test, transformed back to the individual TBI subject’s head-space, and thresholded to form ROIs automatically that were used to sort tracts from all subjects and to compute various diffusion anisotropy metrics.

14:30         3411.     7T DTI in Mild Traumatic Brain Injury Patients and Age Matched Controls

Seongjin Choi¹, Jennifer Bogner², John Corrigan², Walter Mysiw², Dustin Cunningham¹, Cherian Renil Zachariah¹, Steffen Sammet¹, Devin Prior¹, Donald Chakeres¹, Michael Vincent Knopp¹, Petra Schmalbrock¹

¹Radiology, The Ohio State University, Columbus, OH, USA; ²Physical Medicine & Rehab, The Ohio State University, Columbus, OH, USA

Despite the presence of behavioral deficits, mild chronic traumatic brain injury (TBI) often occurs without any anatomical MRI but quantitative Diffusion Tensor Imaging (DTI) have revealed subtle differences at lower field-strengths suggesting that ultra-high field MR might have additional abilities. Ten TBI patients and ten age matched controls were scanned at 7T. Patients showed statistically significantly lower mean FA, higher ADC and shorter fibers, indicating the improved diagnostic potential of 7T.

15:00         3412.     Pericontusional and Contalateral  Tissue Show Differential Metabolism and Perfusion Changes After Traumatic Brain Injury

Kristine O'Phelan^1,2, Dalnam Park³, Thomas Ernst², Andrew Stenger², Steven Buchthal², Renat Yakupov, Linda Chang²

¹Neurology, University of Miami , Miami, Fl, USA; ²Medicine, University of Hawaii, Honolulu, HI, USA; ³Neuroscience Institute, The Queen's Medical Center, Honolulu, HI, USA

Substance abuse is common among patients with traumatic brain injury. Little is known about its effects on brain metabolism in this setting. Twelve TBI survivors were recruited. MP-RAGE, FLAIR , 1H MRS, DTI ,ASL MRI were performed. Pericontusional: rCBF was inversely correlated with post-injury day(PID). rCBF was inversely related to tensor trace. rCBF showed a trend to correlate with [NAA]. Contralateral: scans on later PIDs showed lower NAA and lactate, but higher tensor trace. [NAA] correlated with [lactate], not rCBF. Tissue ischemia may be a risk for pericontusional tissue while contralateral regions show evidence of axonal injury but not ischemia.

13:30         3413.     DTI Reveals Disease Severity Specific Nerve Fiber Impairment in Juvenile Myoclonic Epilepsy

Michael Deppe¹, Christoph Kellinghaus¹, Thomas Duning¹, Gabriel Möddel¹, Siawoosh Mohammadi¹, Katja Deppe², Harald Kugel³, Simon S. Keller⁴, E. Bernd Ringelstein¹, Stefan Knecht¹

¹Neurology, University of Münster, Münster, Germany; ²Neurology, Franz Hospital Dülmen, Germany; ³Radiology, University of Münster, Germany; ⁴MARIARC, University of Liverpool, UK

Juvenile myoclonic epilepsy (JME) is a syndrome of idiopathic generalized epilepsy (IGE) without structural brain abnormalities detectable by MRI or computed tomography. In the present study, we addressed the question of whether diffusion tensor magnetic resonance imaging (DTI) can detect disease specific white matter (WM) abnormalities in JME patients. Our results support the hypothesis that JME is associated with abnormalities of the thalamocortical network that can be detected by DTI. The alterations of the nerve fibers associated with the anterior thalamus seem to be (1) a marker for disease severity in JME and (2) no epiphenomenon of medication effects.

14:00         3414.     White Matter Tractography by Diffusion Tensor Imaging in Insular Epilepsy

Hesamoddin Jahanian^1,2, Kost Elisevich³, Azadeh Yazdan-Shahmorad², Hamid Soltanian-Zadeh⁴

¹Functional MRI Laboratory, University of Michigan, Ann Arbor, MI, USA; ²Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI, USA; ³Department of Neurosurgery, Henry Ford Health System, Detroit, MI, USA; ⁴Radiology Image Analysis Lab, Henry Ford Health System, Detroit, MI, USA

The identification of an insular origin of partial epilepsy remains a significant challenge. We hypothesized that in cases of an insular epileptogenicity, a difference in fiber density in the subinsular white matter could be measured. Therefore, a comparative hemispheric study of the subinsular white matter was performed using DTI and tractography in four patients with a unilateral partial epilepsy of insular origin, five patients with unilateral medial temporal lobe epilepsy and ten nonepileptic subjects. Measured fiber density values shows a significant difference in the insular epilepsy group but not in the medial temporal lobe epilepsy group or any difference between right and left sides in the nonepileptic group.

14:30         3415.     A Disproportionate Role for the Fornix in Recall Rather Than Recognition Memory - Tractography Evidence in Temporal Lobe Epilepsy

Mahinda Yogarajah¹, Niels Focke², Silvia Bonelli, Geoff Parker³, Daniel Alexander⁴, Pamela Thompson, Mark Symms, Matthias Koepp, John Duncan

¹MRI Unit, National Society for Epilepsy , Chalfont St Peter, Bucks, UK; ²University of Goettingen; ³University of Manchester ; ⁴University College London

Temporal lobe epilepsy is the most common cause of focal epilepsy, and over one third of patients have seizures that cannot be controlled with medications. Persisting seizures are associated with progressive memory impairment in these patients. Using diffusion tensor tractography we have demonstrated that damage to the fornix in this group, is correlated with material specific memory impairment. In addition, we have demonstrated that the fornix is critical for recall memory, rather than recognition memory. This information aids our understanding of the memory deficits observed in patients with temporal lobe epilepsy.

14:00         3416.     Tractography in the Fetal Brain with Correction of Fetal and Maternal Motion Using Model-Based Slice to Volume Registration

Alvaro Bertelsen¹, Serena Counsell¹, Joanna Allsop¹, Amy McGuinness¹, Shuzhou Jiang¹, Rita Nunes¹, Paul Aljabar², Daniel Rueckert², Mary R. Rutherford¹, Joseph V. Hajnal¹

¹Robert Steiner MRI Unit, Imaging Sciences Department, MRC Clinical Sciences Centre, Hammersmith Hospital, Imperial College London, London, UK; ²Department of computing, Imperial College London, London, UK

Diffusion tensor imaging and white matter tractography of the human brain in utero remain a substantial challenge. We have developed a model based registration algorithm that operates on single shot diffusion weighted images to achieve slice to volume registration and place all data into a single self consistent anatomical coordinate frame, so that apparent diffusion coefficient and fractional anisotropy maps can be produced even when there is substantial fetal head motion. The method has been tested on four fetal datasets and multiple tracts were successfully extracted in all. The method holds promise for systematic fetal tractography studies in the future.

14:30         3417.     Characterizing Neuronal Morphological Development Using Diffusion Tensor Imaging

Lindsey A. Leigland¹, Sune N. Jespersen², Erin N. Taber³, Anda Cornea⁴, Christopher D. Kroenke^1,4

¹Behavioral Neuroscience, Oregon Health & Science University, Portland, OR, USA; ²Center of Functionally Integrative Neuroscience, Aarhus University Hospital, Denmark; ³Advanced Imaging Research Center, Oregon Health & Science University, Portland, OR, USA; ⁴Oregon National Primate Research Center, Oregon Health & Science University, Portland, OR, USA

Abnormal morphological development of the cerebral cortex is associated with several neurodevelopmental disorders. Previously, it has been suggested that neuropil microanatomy determines water diffusion anisotropy observed in developing cerebral cortex. Here, a direct comparison is presented between post mortem diffusion tensor imaging (DTI) measurements and distributions of neuronal processes determined using rapid Golgi staining procedures in brains from postnatal day (P)13 to P31 ferrets. The results support a recently proposed theoretical model relating the neurite orientation matrix to the water diffusion tensor, providing a link between DTI measurements and specific anatomical characteristics of the developing cerebral cortex.

15:00         3418.     DTI Study of Cerebral White Matter Development in Preterm Children at Preadolescent Ages to Examine Persisting Changes

Lutfi Tugan Muftuler¹, Elysia Poggi Davis², Curt A. Sandman², Orhan Nalcioglu¹, James Fallon²

¹Center for Functional Onco-Imaging, University of California, Irvine, CA, USA; ²Psychiatry & Human Behavior, University of California, Irvine, CA, USA

We used DTI to investigate persisting changes in cerebral white matter development in preterm children at preadolescent ages. White matter deficits in preterm children were studied by others, since synaptic proliferation, pruning and ongoing myelination influence cognitive development. Most of those studies were conducted with infants at term equivalent age and there are only a few with adolescents. Their results varied significantly, possibly because of the variations in the cohorts chosen. We attempted to minimize the heterogeneity of the study cohort and used higher directional and spatial resolutions for better sensitivity. DTI parameters were compared to those of term-born controls.

15:30         3419.     White Matter Changes in Lipopolysaccharide Treated Fetal Sheep Measured by High-Field Diffusion Tensor Imaging

Yohan van de Looij^1,2, Justin M. Dean³, Grégory Lodygensky¹, Henrik Hagberg³, Petra S. Hüppi¹, Carina Mallard³, Rolf Gruetter^4,5, Stéphane V. Sizonenko¹

¹Division of Child Growth & Development, Department of Pediatrics, University of Geneva, Geneva, Switzerland; ²Laboratory for Functional and Metabolic Imaging, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland; ³Perinatal Center, Department of Neuroscience and Physiology, University of Gothenburg, Göteborg, Sweden; ⁴Laboratory for Functional and Metabolic Imaging, Ecole Polytechnique Fédérale de Lausanne , Lausanne, Switzerland; ⁵Department of Radiology, University of Geneva and Lausanne, Switzerland

White matter (WM) injury is a major cause of developmental disabilities in up to 75% infants after preterm birth. The goal of this study was to characterize changes in the fetal sheep brain following fetal lipopolysaccharide exposure by electroencephalography (EEG), DTI and neuropathology. Reduced FA correlated with histology and persistent drop in EEG amplitude revealed alterations in developing WM after fetal exposure to lipopolysaccharide. This work provides evidence of WM injuries following lipopolysaccharide detectable by DTI. This study could be of interest for clinical strategy in human preterm infants.

13:30         3420.     Measurement of Brain Development in the First Two Years of Life

Feng Shi¹, Yong Fan¹, Songyuan Tang¹, John Gilmore², Weili Lin¹, Dinggang Shen¹

¹Department of Radiology and BRIC, University of North Carolina, Chapel Hill, NC, USA; ²Department of Psychiatry, University of North Carolina, Chapel Hill, NC, USA

Major human brain structure development occurs in the first two years of life. A longitudinal MR image acquisition protocol is designed and 28 subjects were scanned at postnatal age of several weeks, one year and two years old. By using a dedicated longitudinal neonatal brain segmentation approach and 4-dimensional nonlinear registration algorithm, the anatomical correspondence among the three time points was achieved. Result showed the cerebellum grew rapidly in the first year and slow down in the second year, as well as gray matter. Different lobes manifested heterochronous growth patterns.

14:00         3421.     Longitudinal Diffusion Tensor Imaging of Healthy Brain Development in Children

Catherine Lebel¹, Christian Beaulieu¹

¹Biomedical Engineering, University of Alberta, Edmonton, Alberta, Canada

Cross-sectional DTI studies demonstrate fractional anisotropy (FA) increases during childhood and adolescence, but longitudinal DTI studies are lacking. We examined longitudinal brain development in 45 healthy children initially aged 5-12 years. Each had 2-4 MRI scans at 1-6 year intervals. Tractography was used to assess eleven major white matter tracts. The genu and splenium of the corpus callosum, and right inferior fronto-occipital fasciculus showed non-linear FA changes; all other tracts showed linear FA increases. Males had significantly greater FA in several tracts. This study provides insight into white matter maturation during childhood and adolescence, including timing and sex differences.

14:30         3422.     Study of the Development of Major Cerebral Fiber Bundles and Its Lateralization from Birth to Adulthood Using Quantitative Diffusion Tensor Tractography (DTT)

Richa Trivedi¹, Gyanendra K. Malik², Shruti Agarwal³, Sona Saksena¹, Ram K  S Rathore³, Rakesh K. Gupta¹

¹Department of Radiodiagnosis, Sanjay Gandhi Post Graduate Institute of Medical Sciences, Lucknow, Uttar Pradesh, India; ²Department of Pediatrics, Chattrapati Sahuji Maharaj Medical University, Lucknow, India; ³Department of Mathematics and Statistics, Indian Institute of Technology, Kanpur, India

The aim of our study was to compare 3 dimensional axonal growth with age among major fiber bundles using DTT and also to detect cerebral laterality in terms of anatomy, if any. DTI were performed on forty-five right-handed normal human brain with age group ranging from 10 days to 38 years. FA was highest in corpus callosum (CC) followed by inferior longitudinal fasciculus (ILF), cingulam (CNG), superior longitudinal fasciculus (SLF), and fornix (Fx). The FA value of the left CNG as well as left SLF was observed to be significantly greater than that of the right CNG and right SLF, respectively. This study demonstrates the normal development of the white matter fiber bundles as well as cerebral lateralization by using quantitative DTT that may be useful for assessing brain maturation in patients with developmental anomalies associated with cerebral white matter.

15:00         3423.     Regional Age Related Changes in Fractional Anisotropy of the Brain in Cognitively and Developmentally Normal Children and Adolescents Using Diffusion Tensor Imaging and Tract Based Spatial Statistics (TBSS) at 3T

Michael Craig Morriss¹, Jerry Wang¹, Jonathan M. Chia², Barjor Gimi¹, Nancy K. Rollins¹

¹Radiology, University of Texas Southwestern Medical School, Dallas, TX, USA; ²Philips Medical Systems, Dallas, Tx, USA

Fractional anisotropy has been considered

13:30         3424.     A Pediatric Brain Template for Diffusion Tensor Imaging

Zhiyue J. Wang^1,2, Jonathan M. Chia³, Michael C. Morriss^1,2, Hao Huang⁴, Barjor Gimi^1,2, Nancy K. Rollins^1,2

¹University of Texas Southwestern Medical Center, Dallas, TX, USA; ²Radiology, Children's Medical Center, Dallas, TX, USA; ³Philips Healthcare, Cleveland, OH, USA; ⁴Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, TX, USA

A template for diffusion tensor imaging of the brain is constructed from a group of normal children 6 to 18 years of age. The template is constructed by affine transfer of the DTI data for individual subjects to MNI152 space, and averaging the diffusion tensor. Difference maps between patients and the template can be generated to reveal abnormalities in fiber directions. It can also be used with TBSS for pediatric populations. There are clearly noticeable differences in the size of various brain structures between an adult DTI template and the pediatric DTI template in the MNI152 space.

14:00         3425.     Construction of a DTI Atlas of the Healthy Human Brain with Diffusion Full Tensor Information in ICBM-81 Space: An Application for Studying the Maturation of White Matter

Judith Verhoeven¹, Caroline A. Sage², Sabine Deprez², Paul De Cock¹, Lieven Lagae¹, Alexander Leemans³, Wim Van Hecke⁴, Stefan Sunaert²

¹Pediatrics, University Hospitals of the Catholic University of Leuven, Leuven, Belgium; ²Radiology, University Hospitals of the Catholic University of Leuven, Leuven, Belgium; ³Cubric, School of Psychology, Cardiff University, Cardiff, UK; ⁴Vision Lab, University of Antwerp, Wilrijk, Belgium

The availability of an appropriate diffusion tensor imaging (DTI) template and normative DTI data is essential for the interpretation of pathological white matter (WM) findings. In this work, we introduce a population-averaged DTI atlas that contains the complete diffusion information, which allows fiber tractography on the DTI atlas. The tract reconstructions from this DTI atlas can be used as tract masks for semi-automated ROI analyses on individual DTI datasets that have been warped to the DTI atlas. To validate this method, we assessed WM maturation and asymmetry of children aged 4 months to 18 years using these tract masks.

14:30         3426.     Enhancement of FA in Child`s Brain After Long-Term Abacus Mental Calculation Training

Yuzheng Hu¹, Fengji Geng^1,2, Feiyan chen^1,2

¹Bio-X Laboratory, Department of Physics, Zhejiang University, Hangzhou, Zhejiang, China; ²Department of Psychology, Zhejiang University, Hangzhou, Zhejiang, China

This study attempts to use Tract-Based Spatial Statistics method to explore whether there is anatomic structure alteration in brain by abacus mental training for long time. It was found that the FA intensity in middle callosum was stronger in abacus group (n = 21, age = 10.29 ± 0.54 years) than that in control group (n = 21, age = 9.98 ± 0.54 years). The result may indicate that neuronal connectivity will be enhanced by long-term training of abacus mental calculation in children.

15:00         3427.     Comparison Analysis Between Patients with Seizures and Developmental Delay: A Multiple Modality Study

Zili Chu^1,2, Elisabeth A. Wilde³, Xiaoqi Li³, Jill V. Hunter^1,2

¹Radiology, Baylor College of Medicine, Houston, TX, USA; ²Diagnostic Imaging, Texas Children's Hospital, Houston, TX, USA; ³Physical Medicine & Rehab, Baylor College of Medicine, Houston, TX, USA

DTI measures diffusion of water while MRS measures concentrations of metabolites. This study demonstrates that a modal combination of DTI and MRS reveals useful and consistent information about basal ganglia and thalami. Compared to the developmental delay group, analysis showed that NAA/Cr was significantly decreased in the seizure group on the left basal ganglia with a trend toward significant decrease on the right basal ganglia and right thalamus. In contrast, radial diffusivity was increased in the seizure group, consistent with the MRS findings. We conclude that group differences in the basal ganglia are attributable to differences in neuron density.

13:30         3428.     Role of DTI in Understanding Pathophysiology and Assessing Therapeutic Response in Patients with Tuberculous Meningitis (TBM)

Abhishek Yadav¹, Chaynika Chaudhry¹, Anuradha HK², Atul Agrawal², Sanjay Verma³, Ram K S Rathore³, Rakesh K. Gupta¹

¹Departments of Radiodiagnosis, Sanjay Gandhi Post Graduate Institute of Medical Sciences, Lucknow, Uttar Pradesh, India; ²Department of Neurology, Chhatrapati Sahuji Maharaj Medical University, Lucknow, Uttar Pradesh, India; ³Department of Mathematics and Statistics, Indian Institute of Technology, Kanpur, Uttar Pradesh, India

DTI was performed in 25 patients with TBM. The diagnosis of TBM was based on Polymerase Chain Reaction, IgM, biochemistry and cytology of cerebral spinal fluid (CSF). ELISA was used to quantify pro-inflammatory molecules (PMs) (sICAM, TNF-á, IL-1â) in CSF collected on lumber puncture of TBM patients. FA, MD and Signal intensity values were measured by placing region of interests on cortical and basal meninges of both patients and controls. Significant correlation was observed between PMs quantified from CSF and FA values and signal intensity from cerebral cortical as well as basal meninges. We conclude that DTI metrics helps in understanding the pathophysiology of the disease and may be useful in monitoring the effect of antimicrobial therapy in TBM patients.

14:00         3429.     Abnormal Age-Related Changes in Diffusion and Anisotropy in the Thalamus and Genu Suggest Abnormal Brain Development in Infants Exposed to Stimulants in Utero

Lynn Michelle Anderson¹, Linda Chang¹, Steven Buchthal¹, Christine Cloak¹, Aaron Hoo¹, Brian Keating¹, Jeffrey Sadino¹, Thomas Ernst¹

¹John A. Burns School of Medicine, University of Hawaii at Manoa, Honolulu, Hi, USA

The effects of in utero stimulant-exposure (METH and nicotine) on brain white matter microstructural development were evaluated in newborns using DTI, and without sedation. Overall, normal, age-related increases in fractional anisotropy (FA), as well as age-related decline in mean, radial and axial diffusivity were observed in both groups. However, the stimulant-exposed group showed less steep slopes in age-related development in the thalamic FA, and mean and radial diffusion, as compared to the non-exposed group. Infants exposed to stimulants in utero may have slower age-related axonal growth and myelination in the thalamus than non-stimulant exposed infants.

14:30         3430.     Diffusion Tensor Imaging of Rett Syndrome

Aigerim Djamanakova¹, SakkuBai Naidu², Genila Bibat², Kenichi Oishi³, Andreia V. Faria^3,4, Xin Li³, Michael I. Miller⁵, Peter van Zijl^3,6, Susumu Mori³

¹Biomedical Engineering, Johns Hopkins School of Medicine, Baltimore, MD, USA; ²The Kennedy Krieger Institute, Baltimore, MD, USA; ³Department of Radiology, Johns Hopkins University, Baltimore, MD, USA; ⁴State University of Campinas, Campinas, SP, Brazil; ⁵Center for Imaging Science, Johns Hopkins University, Baltimore, MD, USA; ⁶F. M. Kirby Center for Functional Magnetic Resonance Imaging, Kennedy Krieger Institute, Baltimore, MD, USA

We used diffusion tensor images (DTI) and a recently established brain atlas

15:00         3431.     Diffusion Tensor Imaging Correlates of Mathematical Ability in Children with Fetal Alcohol Spectrum Disorder

Catherine Lebel¹, Carmen Rasmussen², Katy Wyper², Gail Andrew³, Christian Beaulieu¹

¹Biomedical Engineering, University of Alberta, Edmonton, Alberta, Canada; ²Pediatrics, University of Alberta, Edmonton, Alberta, Canada; ³FASD Clinic, Glenrose Hospital, Edmonton, Alberta, Canada

Children with fetal alcohol spectrum disorder (FASD) have particular deficits in mathematics. It is speculated that this is related to abnormal parietal brain function, but math deficits in FASD have yet to be linked to brain structure. We correlated fractional anisotropy (FA) with math scores, controlling for age, in 21 children with FASD. Significant positive correlations were seen in two left parietal clusters and one left cerebellum cluster; one brain stem cluster showed negative correlations. This demonstrates that several different regions are related to math skills in children with FASD, supporting previous findings in healthy children and highlighting further areas.

14:00         3432.     Increased Cost Efficiency of Economical Brain Structural Networks in the Early Developing Brain

Yong Fan¹, Feng Shi¹, John Gilmore², Weili Lin¹, Dinggang Shen¹

¹Department of Radiology and BRIC, University of North Carolina, Chapel Hill, NC, USA; ²Department of Psychiatry, University of North Carolina, Chapel Hill, NC, USA

Brain networks are the graph representation of brain regional connectivity, often exhibiting so called small-world network properties. The small world characteristics of brain networks might be the evolutionary result of brain development. To test this hypothesis, brain structural networks were built from longitudinal MRI data of healthy pediatric subjects from 2 weeks to 2 years of age. As a function of cost, the global and local efficiency of information processing were measured. The findings suggest that the brain structural networks are economical, and their cost efficiency increases steadily and significantly with the brain development from 2 weeks to 2 years.

14:30         3433.     Frequency Dependence of the Developing Brain Functional Network: MRI-EEG?

Wei Gao¹, Hongtu Zhu², Kelly Giovanello³, Keith Smith⁴, Dinggang Shen⁵, John Gilmore⁶, Weili Lin⁵

¹Department of Biomedical Engineering, University of North Carolina-Chapel Hill, Chapel Hill, NC, USA; ²Department of Biostatistics and BRIC, University of North Carolina-Chapel Hill; ³Department of Psychology and BRIC, University of North Carolina-Chapel Hill; ⁴Department of Radiology, University of North Carolina-Chapel Hill; ⁵Department of Radiology and BRIC; ⁶Department of Psychiatry, University of North Carolina-Chapel Hill

Frequency-based brain network analysis on rsfcMRI may offer new insights into frequency dependence of brain functional network. In this study, healthy pediatric subjects at age of 2 wks to 2 yrs were recruited and rsfMRI was obtained, aiming to delineate the emerging and developing trajectory of brain functional connectivity at different frequencies of interest in a critical time period of early brain development.

15:00         3434.     Emergence of the Brain's Default Network: Evidence from Two-Week-Old to Four-Year-Old Healthy Pediatric Subjects

Wei Gao¹, Hongtu Zhu², Kelly Giovanello³, Keith Smith⁴, Dinggang Shen⁵, John Gilmore⁶, Weili Lin⁵

¹Department of Biomedical Engineering, University of North Carolina-Chapel Hill, Chapel Hill, NC, USA; ²Department of Biostatistics and BRIC, University of North Carolina-Chapel Hill; ³Department of Psychology and BRIC, University of North Carolina-Chapel Hill; ⁴Department of Radiology, University of North Carolina-Chapel Hill; ⁵Department of Radiology and BRIC; ⁶Department of Psychiatry, University of North Carolina-Chapel Hill

While most of the studies on default network have focused on adult subjects, the delineation of its developmental process may shed light on its functional evolution with age. To this end, healthy pediatric subjects from 2wks to 4yrs of age were recruited in this study and resting functional MRI (rfcMRI) were employed to acquire resting MRI images so as to gain insights into the temporal evolution of the default network in the developing brain.

15:30         3435.     fMRI of Very Premature Infants (<32 Weeks GA) at Birth

Wayne Lee¹, Drew Morris¹, Revital Nossin-Manor¹, Elizabeth J. Donner², John G. Sled^3,4, Margot J. Taylor¹, Hilary E.A. Whyte⁵

¹Diagnostic Imaging, Hospital for Sick Children, Toronto, ON, Canada; ²Division of Neurology, Hospital for Sick Children; ³Physiology Experimental Medicine, Hospital for Sick Children; ⁴Department of Medical Biophysics, University of Toronto, Toronto, ON, Canada; ⁵Division of Neonatology, Hospital for Sick Children, Toronto, ON, Canada

Roughly half of all very premature infants, born <32 weeks GA, will have cognitive deficits. Currently, there are no accurate prognostic tools for predicting which infants will suffer cognitive dysfunction. fMRI of this population could potentially aid clinicians in identifying at risk infants. However, to date there is no literature on the acquisition of fMRI data in very preterm infants. This work focuses on efforts to identify and resolve the technical challenges associated with fMRI of this population. It is the first of its kind to show BOLD activity in very preterm infants at birth.

13:30         3436.     Somatosensory Cortical Activation in the Preterm Brain Identified with a Programmable Hand Interface and Functional MRI

Tomoki Arichi^1,2, Alejandro Melendez³, Amelie Moraux³, Valentina Doria¹, Etienne Burdet³, Christian F. Beckmann⁴, D J. Larkman⁵, A D. Edwards⁶

¹Imaging Sciences Department, Imperial College , London, UK; ²Department of Neonatalogy, Imperial College , London, UK; ³Department of Bioengineering, Imperial College London; ⁴Division of Neurosciences and Mental Health, Imperial College London; ⁵Imaging Sciences Department, Imperial College, London, UK; ⁶Department of Neonatalogy, Imperial College, London, UK

We describe the first use of a programmable hand interface for functional MRI data acquisition in newborn infants. The equipment described provides a tactile and proprioceptive stimulus to the fingers of the subject, which is fully synchronised with MR image acquisition. It has been successfully used to identify well-localised functional activity in the primary somatosensory cortex of term and preterm infants. We propose that the device described will be of great value in providing reliable, reproducible results and furthermore in the investigation of sensorimotor development in the preterm brain.

14:00         3437.     Improved Slice to Volume Reconstruction of the Fetal Brain for Automated Cortex Segmentation

Alvaro Bertelsen¹, Paul Aljabar², Hui Xue³, Latha Srinivasan^1,4, Tayyib Hayat^1,5, Joanna Allsop¹, Daniel Rueckert², Mary R. Rutherford^1,5, Joseph V. Hajnal¹

¹Robert Steiner MRI Unit, Imaging Sciences Department, MRC Clinical Sciences Centre, Hammersmith Hospital, Imperial College London, London, UK; ²Department of computing, Imperial College London, London, UK; ³MR Research and Development, Siemens Medical Solutions USA, USA; ⁴Neonatal Department, Hammersmith Hospital, Imperial College London; ⁵Perinatal Imaging Group, MRC Clinical Sciences Centre, Hammersmith Hospital, Imperial College London

Analysis of adult human cortex from MRI is well established and has recently been extended to the developing cortex of neonates, but segmentation of in utero fetal cortex from MRI remains challenging. Although snapshot imaging with volume reconstruction (SVR) provides reliable 3D fetal brain reconstructions, this has not proved sufficient for automated cortex extraction. We have now improved the quality of SVR reconstructions using a temporally continuous parameterisation of motion and applied cortex segmentation methods we developed for use on neonates. The resulting extracted cortices are substantially complete, paving the way for more detailed cortical analysis of the fetal brain.

14:30         3438.     Automatic Neonatal Brain Segmentation for Nine Tissue Types Simultaneously

Petronella Anbeek¹, Britt van Kooij², Floris Groenendaal², Linda S. de Vries², Max A. Viergever¹, Manon J. Benders²

¹Image Sciences Institute, University Medical Center, Utrecht, Netherlands; ²Wilhelmina Children's Hospital, Neonatology, University Medical Center, Utrecht, Netherlands

This paper proposes a fully automated method for segmentation of brain tissue in neonatal MR imaging. The method is based on K-nearest neighbor classification and segments nine tissue types simultaneously: (un)myelinated white matter, cortical gray matter, basal ganglia, cerebro-spinal fluid, ventricles, brainstem, cerebellum, myelinated white matter in the cerebral peduncle, and the posterior limb of the internal capsule. Manual segmentations were used for training and evaluation of the results. High accuracy is reached for the segmentation results of all larger tissue types.

15:00         3439.     Automatic Regional Segmentation of Newborn Brain MRI Using Mathematical Morphology on Dual Contrast

Radoslaw Lisowski^1,2, Francois Lazeyras³, Petra Susan Hüppi⁴, Michel Kocher^5,6

¹Geneva's University of Applied Science, Geneva, Switzerland; ²Work supported in part by the Center for Biomedical Imaging (CIBM), Geneva and Lausanne, Switzerland; ³Service of Radiology, University of Geneva and University Hospital of Geneva, Geneva, Switzerland; ⁴Division of Child Growth & Development, University of Geneva, Geneva, Switzerland; ⁵School of Business and Engineering Vaud, Yverdon-les-Bains, Switzerland; ⁶Biomedical Imaging Group, EPFL, Lausanne, Switzerland

This paper describes an automatic regional tissue segmentation method for newborn brain MRI. This task is challenging due to the small size of brain structures and to

13:30         3440.     In-Vivo Proton Magnetic Resonance Spectroscopy (PMRS) Changes in Extra-Hepatic Portal Vein Obstruction (EHPVO) Induced Hepatic Encephalopathy (HE) Are Different from Chronic Liver Disease (CLD)

Santosh K. Yadav¹, Anshu Srivastava², Arti Srivastava, Michael Albert Thomas³, Surender K. Yaccha⁴, Richa Lal⁵, Rakesh K. Gupta¹

¹Radiology, Sanjay Gandhi Post Graduate Institute of Medical Sciences, Lucknow, Utter Pradesh, India; ²Pediatric Gastroenterology, Gandhi Post Graduate Institute of Medical Sciences, Lucknow, Utter Pradesh, India; ³Radiological Sciences, David Geffen Schoolof Medicine, Los Angeles, CA, USA; ⁴Pediatric Gastroenterology, Sanjay Gandhi Post Graduate Institute of Medical Sciences, Lucknow, Utter Pradesh, India; ⁵Surgical Gastroenterology, Sanjay Gandhi Post Graduate Institute of Medical Sciences, Lucknow, Utter Pradesh

In-Vivo Proton Magnetic Resonance Spectroscopy (PMRS) changes in Extra-hepatic Portal Vein Obstruction (EHPVO) induced Hepatic Encephalopathy (HE) are Different from Chronic Liver Disease (CLD)

14:00         3441.     J-Difference Editing Method to Evaluate GABA May Reveal the Mechanism of ACTH Therapy for Infantile Spasms as a Useful Predict Biomarker.

Ayumi Nose¹, Masafumi Harada², Hitoshi Kubo², Kenji Mori³, Tsuyoshi Matsuda⁴, Hiromu Nishitani¹

¹Radiology, University of Tokushima, Tokushima, Japan; ²Medical Imaging, University of Tokushima, Tokushima, Japan; ³Pediatrics, University of Tokushima, Tokushima, Japan; ⁴Imaging Application Tech Center,GE Yokokawa Medical Systems, Tokyo, Japan

Adrenocorticotropic hormone (ACTH) therapy has been used for rapid and complete elimination of infantile spasms (West syndrome) which is one of intractable epilepsies. The purposes of this study were to evaluate the metabolic changes including GABA before and after ACTH administration for infantile spasms, and to find a useful biomarkers to predict efficacy of ACTH therapy.

14:30         3442.     Functional MRI in Pediatric Cancer Survivors During Cognitive Remediation

Ping Zou¹, Raymond Mulhern¹, Robert Butler², Robert Ogg¹

¹St. Jude Children's Research Hospital, Memphis, TN, USA; ²Oregon Health & Science University, Portland, OR, USA

Patterns of brain activation during a modified Conners’ Continuous Performance Test (CPT) were measured in childhood cancer survivors who participated in a phase III clinical trial of the Cognitive Remediation Program (CRP). This pilot study showed that fMRI is feasible in childhood cancer survivors during remediation. Differences in activation between patients and healthy children and changes in patterns of activation in patients following remediation suggest that fMRI will help to understand cognitive deficits that these survivors suffer and yield insights into the neural basis of response to remediation.

15:00         3443.     Nature Vs Nurture in Newborn Voice Perception. an FMRI Comparison of  Auditory Processing Between Premature Infants at Term Age and Term Born Neonates

Stephane Simon^1,2, François Lazeyras³, Alain-Dominique Sigrist⁴, Marc Ecoffey⁵, Stefano Guatieri⁴, Dimitri Van De Ville⁶, Cristina Borradori Tolsa⁵, Marco Pelizzone⁴, Petra Hüppi⁵

¹Faculty of Medicine, University of Geneva, Geneva, Switzerland; ²Work supported in part by the Center for Biomedical Imaging CIBM, Lausanne & Geneva, Switzerland; ³Dpt of Radiology, University of Geneva and University Hospitals, Geneva, Switzerland; ⁴Romand Center for Cochlear Implants, University Hospitals, Geneva, Switzerland; ⁵Division of Child Growth & Development, University of Geneva and University Hospitals, Geneva, Switzerland; ⁶BioMedical Imaging Group, Swiss Federal Institute of Technology, Lausanne, Switzerland

This study reports the first comparison of brain functional development in premature infants at term age and term born newborns, upon auditory stimulation. Functional MRI revealed striking differences in the emergence of several bilateral temporal regions related to the processing of voice perception in the newborn, with specific differences between premature and term born infants. Since the present findings were collected at the same post-conceptional age (normal birth age), they highlight the important contribution of experience in voice recognition and possibly in language acquisition, therefore reopening the debate about the respective contributions of innate and experience shaped brain development.

13:30         3444.     Abnormalities in Regional Brain Volumes in Adolescent Methamphetamine Users

George Russell King¹, Dan Alicata², Christine Cloak¹, Thomas Ernst¹, Irene Chin¹, Linda Chang¹

¹Medicine, John A. Burns School of Medicine, Honolulu, HI, USA; ²Psychiatry, John A. Burns School of Medicine, Honolulu, HI, USA

The present study evaluates changes in cortical and subcortical brain volumes in female adolescent METH users, which represent an understudied population. Consistent with adult METH users, adolescents have enlarged striatal and limbic regions. In contrast to adults, however, adolescents show reduced cerebral gray matter volumes, with no alteration in cortical white matter. The reductions in subcortical volumes might have contributed to their poorer psychomotor performance, since we observed a correlation between putamen volume and the digit symbol task. Further analyses of the data will include a larger sample size, and comparing male and female METH users.

14:00         3445.     Systematic Investigation of Volume Changes Induced by Prenatal Alcohol Exposure in Cortical and Sub-Cortical Regions

Xiangchuan Chen¹, Mary E. Lynch², Xiaoping Hu¹, Claire D. Coles²

¹Biomedical Imaging Technology Center, Emory University, Atlanta, GA, USA; ²Department of Psychiatry and Behavioral Sciences, Emory University, Atlanta, GA, USA

Systematic investigation of volumetric brain changes induced by prenatal alcohol exposure (PAE) was performed by segmenting the cerebral cortex and the sub-cortical structures into various regions of interest with Freesurfer on T1-weighted images. Many cortical and sub-cortical regions exhibited reduced volume by PAE, suggesting that most brain structures can be affected. Our data also support that alcohol is a teratogen that may produce a spectrum of brain structural changes: from mild through moderate to severe. Moreover, gender and interhemispheric difference in PAE effect were found, which may shed some light on the special teratogenic mechanism of alcohol on human brain.

14:30         3446.     Changes in NAA and Presence of Lactate on MRS Predict Outcome in Children with Nonaccidental Trauma

Barbara Holshouser¹, Gregory Aaen², Clare Sheridan², Melinda McKenney³, Udo Oyoyo¹, Stephen Ashwal²

¹Radiology, Loma Linda University Medical Center, Loma Linda, CA, USA; ²Pediatrics, Loma Linda University Medical Center, Loma Linda, CA, USA; ³School of Medicine, Loma Linda University, Loma Linda, CA, USA

Traumatic brain injury in children under 2 years of age is attributed to non-accidental trauma (NAT) in 24% to 32% of cases. Outcome in victims of NAT is recognized to be worse possibly due to a hypoxic-ischemic component. A retrospective analysis of 109 children with confirmed NAT was performed to measure regional metabolite changes observed with single voxel and multivoxel (MRSI) proton spectroscopy through the level of the corpus callosum to determine if metabolite changes can predict long-term neurologic outcome.

15:00         3447.     Susceptibility Weighted Imaging: Microhemorrhage Prevalence and Prediction of Long Term Outcome in Pediatric Non-Accidental Brain Trauma (NAT)

Barbara Holshouser¹, Cherie Colbert¹, Gregory Aaen², Clair Sheridan², Daniel Kido³, Stephen Ashwal⁴

¹Radiology, Loma Linda University Medical Center, Loma Linda, CA, USA; ²Pediatrics, Loma Linda University Medical Center, Loma Linda , CA, USA; ³Radiology, Loma Linda University Medical Center, Loma Linda , CA, USA; ⁴Pediatrics, Loma Linda University Medical Center, Loma Linda, CA, USA

This study was done to (1) determine the prevalence of parenchymal brain microhemorrhages (MH) using susceptibility weighted imaging (SWI) in children with NAT and (2) assess whether the presence of parenchymal MH resulted in improved prediction of long-term neurologic outcome. A retrospective analysis of head CT and MRI findings in 118 pediatric NAT victims was performed. Logistic regression in patients with 6 month or greater neurologic followup was done to determine if the presence of MH on SWI was predictive of long term outcome.

14:00         3448.     Putative Links Between Fronto-Striato-Thalamic Pathways and Behavioral Phenotype in Children with Tourette Syndrome

Malek I. Makki^1,2, Rajkuma Munina-Govindan³, Benjamin Wilson³, Michael E. Behen³, Harry T. Chugani⁴

¹Radiology, Wayne State University, Detroit, MI, USA; ²Neurology, Wayne State University, Detroit, MI, USA; ³Pediatrics, Wayne State University, Detroit, MI, USA; ⁴Pediatrics and  Neurology, Wayne State University, Detroit, MI, USA

Synopsis: To determine whether abnormal connectivity of the fronto-striato-thalamic circuit underlies the morphological changes in subcortical structures of patients with Tourette syndrome, and to correlate these changes with neurobehavioral measures. Eighteen children with Tourette Syndrome and 12 age matched healthy controls underwent diffusion tensor MRI. Tractography of the fronto-striato-thalamic circuit was achieved using probability distribution function of individual voxels. Obsessive compulsive behavior was negatively associated with connectivity score of the left caudate and anterior dorsolateral frontal cortex (p=0.01), and was positively associated with connectivity score for the subcallosal gyrus (p=0.009) and for the lentiform nucleus (p=0.008).

14:30         3449.     Longitudinal Evaluation of Lactate in Children with Autism Disorder Using MR Spectroscopic Imaging

Neva M. Corrigan¹, Todd L. Richards¹, Helen Petropoulos¹, Seth D. Friedman², Stephen R. Dager^1,3

¹Department of Radiology, University of Washington, Seattle, WA, USA; ²Division of Pediatric Neurology, Children's Hospital and Regional Medical Center/University of Washington, Seattle, WA, USA; ³Departments of Bioengineering and Psychiatry, University of Washington, Seattle, WA, USA

The aim of this study is to use proton MRS to characterize cerebral lactate levels of children with autism disorder (AD) and age-matched typically developing (TD) children at three different age points (3-4, 6-7 and 9-10 years of age) to determine whether there is any evidence of mitochondrial disorder in autism during these periods of childhood development. The results show that autism children at 3 years old did not have elevated lactate compare with typically developing children. TD lactate levels were found to be higher than in the AD group in both gray and white matter.

15:00         3450.     Abnormal Cortical and Subcortical Water Diffusivity Measured in Children with Tourette Syndrome.

Malek I. Makki¹, Benjamin J. Wilson², Rajkumar Munian Govindan², Michael E. Behen³, Harry T. Chugani²

¹Radiology, Wayne State University, Detroit, Mi, USA; ²Pediatrics, Wayne State University, Detroit, Mi, USA; ³Psychology, Wayne State University, Detroit, Mi, USA

We used voxel-based-analysis to measure ADC of cortical and subcortical regions within the fronto-striato-thalmo-cortical circuit of 17 right-handed children with Tourette Syndrome and 14 age-matched right-handed controls. Tic severity, hyperactivity, attention, externalizing, internalizing, and obsessive and compulsive problems, were noted. Significant increases of ADC were observed in left and right putamen (p=0.005, p=0.039), orbitofrontal (p=0.017, p=0.007), insular (p=0.008, p=0.021) and left globus pallidus and anterior cingulate (p=0.024, p=0.046). Furthermore, the ADC from right orbitofrontal cortex showed significant positive correlation with the internalizing problem scores (p=0.006).

15:30         3451.     Comparison of Group Average and Individual Differences in Brain Morphometry in Williams Syndrome

Zhaoying Han^1,2, Tricia Thornton-Wells³, Elisabeth Dykens³, Anuj Srivastava⁴, Zhaohua Ding², John C. Gore², Benoit Dawant¹

¹Electrical Engineering and Computer Science, Vanderbilt University, Nashville, TN, USA; ²Vanderbilt University Institute of Imaging Science, Nashville, TN, USA; ³Vanderbilt Kennedy Center, Nashville, TN, USA; ⁴Department of Statistics, Florida State University, Tallahassee, FL, USA

Anatomical differences between twelve subjects with Williams Syndrome (WS) and twelve age and gender matched typically-developing (TD) subjects are characterized based on group averages. High resolution MR images were acquired and, for each group, a volume with average intensity and shape was computed iteratively using non-rigid co-registration. Qualitative analysis of central sulcus and quantitative shape analysis of brain volumes, corpus callosum parameters and contours based on group averages agree well with those of individual volumes. This analysis is fully automatic; so it can be used as an efficient technique to identify morphological differences between populations.

13:30         3452.     Perfusion Deficit in Schizophrenia and Correlation with Psychopathological Symptoms

Jinsoo Uh¹, Perry Mihalakos², Carol A. Tamminga², Hanzhang Lu¹

¹Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, TX, USA; ²Department of Psychiatry, University of Texas Southwestern Medical Center, Dallas, TX, USA

Cerebral blood volume (CBV) and cerebral blood flow (CBF) in Schizophrenia (SZ) have been assessed using recently developed MR techniques: Vascular Space Occupancy (VASO) MRI and Pseudo Continuous Arterial Spin Labeling (PCASL). Both of CBV and CBF showed deficits in frontal lobe of SZ patients compared to normal controls. The correlation study between CBV/CBF and Positive and Negative Syndrome Scale (PANSS) showed that the psychopathological symptom is negatively correlated with the perfusion of SZ in hippocampus. These results support previous PET studies and demonstrate that current MR techniques are feasible for probing cerebrovascular pathologies in SZ.

14:00         3453.     Short-Term Follow Up Study of Grey Matter Volume Changes in Antipsychotic-Naïve First Episode Schizophrenia: An Optimized VBM Study

Ling Zou¹, Deng Wei², He-Han Tang³, Li-Jun Jiang², Wei Yi⁴, Dong-Ming Li¹, Xiu-Li Li⁵, Fei Li⁵, Su Lv³, Xiao-qi Huang³, Tao Li², Qi-Yong Gong¹

¹Huaxi MR Research Center(HMRRC), West China Hospital, Sichuan Universty, Chengdu, Sichuan, China; ²Psychiatric Center,, West China Hospital, Sichuan Universty, Chengdu, Sichuan, China; ³Huaxi MR Research Center(HMRRC),, West China Hospital, Sichuan Universty, Chengdu, Sichuan, China; ⁴Radiology, West China Hospital, Sichuan Universty, Chengdu, Sichuan, China; ⁵Huaxi MR Research Center(HMRRC), , West China Hospital, Sichuan Universty, Chengdu, Sichuan, China

Decreased brain volume was reported as the common finding in schizophrenia patients. Most long-term follow up studies showed the progressive brain volume loss. Our short-term follow up optimized VBM study in antipsychotic-naive schizophrenia patients found the increase volume of left inferior frontal gyrus and right putamen, hippocampus, amygdala. It is possible that patients are sensitive to treatment in short term period, and the effects show as increase of GM volume. However, the meaning of this finding and how it can guide the clinic practices require further clarification. Serial studies are necessary to gain further insight into our findings.

14:30         3454.     Correlation Among in Vivo 1H-MRS Metabolic Profiles, Genetic and Clinical Data in Schizophrenic Patients

Bernardo Celda^1,2, Beatriz Martinez-Granados¹, MCarmen Martinez-Bisbal², Olga Brotons³, Eduardo J. Aguilar³, Luis Marti-Bonmati⁴, Rosa de Frutos⁵, Olga Rivero⁵, Julio Sanjuan⁶

¹Physical Chemistry, University of Valencia, Burjassot, Valencia, Spain; ²Physical Chemistry-UVEG, CIBER-BBN, Burjassot, Valencia, Spain; ³Clinic Hospital Valencia, Psychiatry Unit, Valencia, Spain; ⁴Radiology Unit, Dr. Peset Hospital, Valencia, Spain; ⁵Genetics, University of Valencia, Burjassot, Valencia, Spain; ⁶Department of Psychiatry, University of Valencia-CIBERSAM, Valencia, Spain

Auditory hallucinations (AH) are one of the core symptoms in Schizophrenia. A recent model suggests an alteration in language and emotional processing in which the thalamus is largely involved. In vivo thalamus metabolic modifications are larger in schizophrenic patients with AH. Likewise, it has been shown that AH can be related to genetically prone subjects (genes involved in language-FOXP2 gene and 5-HTT gene). In this communication statistical correlations have been found between in vivo metabolic profiles in thalamus and clinical data (PSYRATS) and genetic alterations in the polymorphisms of serotonine transporter gene. These results support thalamus implication in AH pathogenesis.

15:00         3455.     Evidence for Top-Down Dysregulation of Primary Visual Processes in Children and Adolescents with Schizophrenia

Tonya White^1,2, Marcus N. Schmidt¹, Steen Moeller²

¹Psychiatry, University of Minnesota, Minneapolis, MN, USA; ²Center for Magnetic Resonance Research, University of Minnesota, Minneapolis, MN, USA

Studies support disrupted neural connectivity in the pathogenesis of schizophrenia. Many of these studies focus on the functional connectivity between distant brain regions. In order to assess local connectivity in patients with schizophrenia, we studied the entrainment of neurons with differing frequencies of a flashing checkerboard fMRI paradigm. Entrainment is thought to reflect local neuronal circuitry. While we did not find abnormalities in entrainment between patients and controls, we did find decreased spatial activity of the BOLD signal in the patient group. This may reflect aberrant top-down control of primary sensory neural circuits in schizophrenia.

13:30         3456.     Working Memory Load-Related Brain Activity in Drug-Naïve, First-Episode Schizophrenia Patients

Ayna Baladi Nejad¹, Bjørn Hylsebeck Ebdrup², Birte Glenthøj², William Baaré³

¹Danish Research Centre for Magnetic Resonance, University Hospital of Copenhagen, Hvidovre, Copenhagen, Denmark; ²Center for Neuropsychiatric Schizophrenia Research, Psychiatric University Centre, Glostrup, Denmark; ³Danish Research Centre for Magnetic Resonance, University Hospital of Copenhagen, Hvidovre, Denmark

We explored BOLD-signal differences between 23 antipsychotic drug-naïve first episode schizophrenia patients and 35 age and gender matched controls performing a verbal working memory (WM) N-Back task with two WM loads (1B-0B; 2B-0B). No significant main effect for Group was found. However, there was a significant Group × WM load interaction. Certain WM-related areas (e.g. left DLPC) increased with WM load more in patients than controls despite matched performance. Patients also exhibited an inability to deactivate task-irrelevant areas with increased load. The findings suggest inefficient resource allocation in schizophrenia which could lead to the premature decline in WM performance.

14:00         3457.     Assessment of GABA and Glutamate/Glutamine at 3.0 T in Chronic Fatigue Syndrome, Major Depressive Disorder and Healthy Volunteers

Chris Kelly¹, Sanjay Johann Mathew¹, Xiangling Mao², Gizely Andrade¹, Rebecca B. Price¹, Paul S. Nestadt¹, Susan M. Levine³, Dikoma C. Shungu²

¹Psychiatry, Mount Sinai School of Medicine, New York, NY, USA; ²Radiology, Weill Medical College of Cornell University, New York, NY, USA; ³Private Practice, Infectious Diseases/Internal Medicine, New York, NY, USA

Chronic fatigue syndrome (CFS) is a controversial diagnosis due to the lack of biomarkers for the illness, and its symptom overlap with neuropsychiatric, infectious, and rheumatologic disorders. The CDC case definition requires at least 6 months of new-onset fatigue with four or more symptoms, including impaired memory or concentration, muscle pain, new headaches, unrefreshing sleep, and post-exertional malaise. Many of these symptoms are also found in patients with major depressive disorder (MDD), a much more prevalent illness, resulting in frequent misdiagnosis of CFS. Significant alterations in g-aminobutyric acid (GABA) and glutamate levels have been previously reported in symptomatic and remitted major depressive disorder (MDD) using proton magnetic resonance spectroscopy (1H MRS) in occipital cortex (OCC) and prefrontal cortical regions [1-4]. To our knowledge, no previous studies have investigated in vivo amino acid neurotransmitter function in CFS patients. OCC and anterior cingulate cortex (ACC) were selected as ROIs based on previous studies in depression and feasibility of obtaining high-quality spectroscopic data in these regions. In this pilot study, we compared cortical levels of GABA and glutamate + glutamine (Glx) levels in CFS patients and a cohort of unmedicated patients with MDD and healthy volunteers.

14:30         3458.     Cross-Sectional Grey Matter Metabolic Correlation in Adolescent with Obsessive-Compulsive Disorder and a Subgroup of Anorexia Nervosa by 1H-MR Spectroscopy

Ana Isabel Garcia¹, Luisa Lázaro^2,3, Josefina Castro-Fornieles^2,3, Susana Andrés², Carles Falcón³, Nuria Bargalló¹

¹Image Diagnostic Center, Hospital Clinic, Barcelona, Spain; ²Child and adolescent Psychiatry and Psychology, Hospital Clinic; ³IDIBAPS

1H-MR spectroscopy was performed to assess grey matter metabolic similarities in the prefrontal cortex between adolescent with obsessive-compulsive disorder (OCD) and anorexia nervosa patients (AN). Statistical analysis of the absolute metabolite concentration (AMC) did not reveal differences among groups. After the correction of the AMC in the grey matter AN group showed significant lower NAA and NAA/Cr than other groups, and lower Ins/Cr and Glx/Cr than controls but with no significant differences with the OCD patients. Although the OCD group no showed significant differences with controls, this suggest a similarity in Ins/Cr and Glx/Cr ratios among AN and OCD patients.

15:00         3459.     Macrostructural and Microstructual Abnormalities of the Neurocircuitry in Bipolar Disorder: A Study of Structural MR and Diffusion Tensor Imaging Data

Ping-Hong Yeh¹, E. Serap Monkul², Mark A. Nicoletti, John P. Hatch³, Fabiano G. Nery², Jack Lancaster³, Jair C. Soares

¹Psychiatry, University of North Carolina, Chapel Hill, Chapel Hill, NC, USA; ²Department of Psychiatry, University of Sao Paulo Medical School, Sao Paulo, Brazil; ³Department of Psychiatry, The University of Texas Health Science Center at San Antonio, U.S.A

The present study investigated the association between microstructural and macrostructural WM abnormalities and their relationships with the connectivity of WM tracts in unmedicated bipolar disorder(BD). Our results showed BD had larger white matter hyperintensitites and greater connectivity in the white matter tracts processing executive function, which may underlie the neuropsychological impairment in BD patients.

13:30         3460.     Imaging the Functional Pathology in ApoE 4 Carriers by the Hippocampus Functional Connectivity

Chunming Xie^1,2, Wenjun Li¹, Piero Antuono³, Jennifer Jones³, Zhilin Wu¹, Shi-Jiang Li¹

¹Biophysics, Medical College of Wisconsin, Milwaukee, WI, USA; ²Neurology, School of Clinical Medicine, Southeast University, Nanjing, Jiangsu, China; ³Neurology, Medical College of Wisconsin, Milwaukee, WI, USA

The allele 4 of apolipoprotein E (ApoE4) is an established susceptibility gene for late onset Alzheimer’s disease (AD). Research on the risk factor of AD in the human and animal models has highlighted the important contribution of ApoE4. Despite the extensive work dedicated to investigating the basic neurobiological mechanism of ApoE4 genotype as related to developing AD risk in younger and older populations, little is known about whether and how the ApoE4 genotype affects the functional brain network in middle-aged, cognitively healthy populations of ApoE4 carriers. In the present study, we test the hypothesis that the resting-state functional connectivity between the hippocampus and the rest of the brain regions is reduced among the middle-aged, cognitively healthy APOE4 carriers compared to that of nonAPOE4 carriers. The present results have shown that the alteration of the hippocampal functional connectivity (HFC) pattern is significantly associated with the ApoE4 genotype and that the alteration of the HFC pattern in ApoE4 carriers could serve as a surrogate biomarker for the risk of AD.

14:00         3461.     Plugged in and Switched On. the Effect of Acute Transcranial Direct Cortical Stimulation on Brain Metabolites in Healthy Controls

Caroline Rae¹, Patrick Arul-Anandam², Kirsten Moffat³, Colleen Loo²

¹POWMRI, University of New South Wales, Randwick, NSW, Australia; ²Black Dog Institute, University of New South Wales, Randwick, NSW, Australia; ³St Vincent's Hospital, Sydney, Australia

Transcranial direct cortical stimulation (DCS) is a treatment for depression, and may work by altering brain activity. Here we describe a sham-controlled pseudo randomized study of the time course of the effect of acute cathodal DCS on frontal lobe metabolite levels measured by ¹H MRS in healthy young male controls (N = 10). Elevations in Glx and myoinositol were seen which lasted up to 30 min, followed by a rapid return to baseline. No significant changes were seen in any other metabolite. DCS is inducing early and transient changes in activity in healthy brain.

14:30         3462.     Latent Volumetric Structure of Gray Matter in Adolescent Bipolar Disorder Using Factor Analysis and Structural Equation Modeling

Ping-Hong Yeh¹, Mark Nicoletti, Hongtu Zhu, Hasan Baloch, John Hatch², Giovana Zunta-Soares, Jair C. Soares

¹Psychiatry, University of North Carolina, Chapel Hill, Chapel Hill, NC, USA; ²Department of Psychiatry, The University of Texas Health Science Center at San Antonio, U.S.A

We used structural equation modeling (SEM) to assess the a priori statistical relationships among the latent variables, which may influence the volumes of other regions or structures, within the cortico-striatal-thalamic-cortical and limbic-cortico-striatal-thalamic-cortical circuits have been hypothesized in mood disorders. Our results suggest different patterns between adolescent healthy controls and bipolar disorder patients for the spatial relationships, mainly from the projection of orbitofrontal cortex to subcortical structures within the CSTC and LCSTC circuits. These differences may point to abnormalities that underlie these mood disorders.

15:00         3463.     White Matter Lesions and Cerebral Perfusion Imaging in Late-Onset Major Depression

Rikke Beese Dalby¹, Jamila Ahdidan¹, M. Mallar Chakravarty^2,3, Leif Sørensen⁴, Raben Rosenberg¹, Leif Østergaard², Poul Videbech¹

¹Centre for Psychiatric Research, Aarhus University Hospital, Risskov, Denmark; ²Center of Functionally Integrative Neuroscience, Aarhus University Hospital, Aarhus, Denmark; ³PET Center, Aarhus University Hospital, Aarhus, Denmark; ⁴Department of Neuroradiology, Aarhus University Hospital, Aarhus, Denmark

Neuroimaging studies in major depression (MD) have revealed an increased frequency of cerebral white matter lesions (WMLs) and abnormalities in regional cerebral blood flow (CBF) in multiple fronto-limbic structures, which may cause cognitive dysfunction. However, the impact of WMLs on the neuronal network and the concurrent role of cerebral perfusion are not yet fully understood.

14:00         3464.     White Matter Integrity Measured by Fractional Anisotropy Is Associated with Reading Ability in Pediatric Brain Tumor Patients: A Voxel Based Analysis Study of Cognitive Outcome

John O. Glass¹, Shawna L. Palmer², Wilburn E. Reddick¹, Dana Wallace³, Nicholas S. Phillips¹, Robert J. Ogg¹, Amar Gajjar⁴

¹Division of Translational Imaging Research, St. Jude Children's Research Hospital, Memphis, TN, USA; ²Department of Behavioral Medicine, St. Jude Children's Research Hospital, Memphis, TN, USA; ³Department of Biostatistics, St. Jude Children's Research Hospital, Memphis, TN, USA; ⁴Department of Oncology, St. Jude Children's Research Hospital, Memphis, TN, USA

This study examines the relationship between reading ability and white matter integrity among patients treated for pediatric infratentorial brain tumors. Fifty-four patients completed a neuropsychology evaluation and MR imaging at 12 months post-diagnosis. A voxel-based analysis evaluated associations between fractional anisotropy maps and Word Attack scores, identifying left and right temporal-parietal clusters. Regression models, controlling for age at treatment and risk arm, revealed significant relationships between these regions and three reading scores. The white matter integrity in these regions may contribute to the patient’s reading ability by strengthening communication between visual, auditory, and language cortical areas.

14:30         3465.     A Multicentre Study of 1H MRS for the Characterisation of Low Grade Brain Tumours of Childhood

Eleni Orphanidou-Vlachou^1,2, Dorothee Auer^3,4, Jonathan Coupland⁴, Nigel P. Davies^2,5, Tim Jaspan⁴, Lesley McPherson², Kal Natarajan^2,5, Dawn Saunders⁶, Yu Sun^1,2, Theodoros Arvanitis^1,2, Richard Grundy^3,4, Andrew Peet^1,2

¹University of Birmingham, Birmingham, UK; ²Birmingham Children's Hospital, Birmingham, UK; ³University of Nottingham, Nottingham, UK; ⁴Nottingham University Hospital, Nottingham, UK; ⁵University Hospital Birmingham, Birmingham, UK; ⁶Great Ormond Street Hospital, London, UK

This is a multicentre study of 1H magnetic resonance spectroscopy for the characterisation of low grade brain tumours of childhood. These tumours are a diverse group and present diagnostic and prognostic challenges to clinicians. Single voxel MRS was performed as part of routine clinical imaging at 3 centres. The results show that MRS has the ability to discriminate between different diagnostic groups and tumours at different brain locations. In addition, it is starting to show evidence of being a valuable non-invasive tool for predicting prognosis. MRS can be performed at multiple centres and the data combined to provide robust results.

15:00         3466.     Susceptibility Weighted Imaging (SWI) in Children with Brain Stem Glioma During Combined Antiangiogenic and Radiation Therapy.

Jan Sedlacik¹, Hoang-Vu Tran¹, Ulrike Löbel¹, Ralf Löffler¹, Jürgen Reichenbach², Alberto Broniscer¹, Zoltan Patay¹, Claudia M. Hillenbrand¹

¹St. Jude Children's Research Hospital, Memphis, TN, USA; ²Friedrich Schiller Universität, Jena, Germany

Purpose of this study was to monitor the effects of anti-angiogenesis therapy concurrently administered with local irradiation in children with diffuse brainstem glioma by using susceptibility weighted imaging, a method which is sensitive to blood oxygenation and may therefore proof useful as an early marker of tumor response to treatment.

15:30         3467.     Assessment of Vascular Supply of Hypervascular Extra-Axial Brain Tumors with MR Regional Perfusion Imaging at 3T

Akira Sasao¹, Toshinori Hirai¹, Shinichiro Nishimura¹, Mika Kitajima¹, Ryuji Murakami¹, Motohiro Morioka², Shigetoshi Yano¹, Jun-ichi Kuratsu², Yasuyuki Yamashita¹

¹Diagnostic Radiology, Graduate School of Medical Sciences, Kumamoto University, Kumamoto, Japan; ²Neurosurgery, Graduate School of Medical Sciences, Kumamoto University, Kumamoto, Japan

Assessment of vascular supply from the external carotid artery in extra-axial brain tumors with regional perfusion imaging (RPI) has not been reported. We prospectively studied conventional MR, conventional arterial spin labeling (ASL) and RPI in 7 patients with hypervascular extra-axial brain tumors. In conventional ASL images, tumor perfusion was higher than or equal to the normal-appearing cortex. In the assessment of the extent of tumor vascular territory on the conventional ASL and RPI images, the tumors were classified as coincided for 3 lesions and similar for 4. RPI was feasible for assessing the vascular supply of hypervascular extra-axial brain tumors.

13:30         3468.     Functional Diffusion Tensor Imaging in the Evaluation of Early Response After Radiosurgery in Patients with Acoustic Neuroma

Yu-Chun Lin¹, Yau-Yau Wai¹, Chun-Chieh Wang², Jiun-Jie Wang³

¹Department of Diagnostic Radiology, ChangGung Memorial Hospital, KweiShan, Taoyuan, Taiwan; ²Department of Radiation Oncology, ChangGung Memorial Hospital; ³Department of Medical Imaging and Radiological Science, ChangGung University, Taoyuan, Taiwan

This study prospectively investigated the early response after radiosurgery in patients with acoustic neuroma using functional diffusion tensor imaging (DTI). Five patients underwent longitudinal DTI studies on a 3T MR scanner up to 6 months. Posttreatment DTI data were spatially coregistered with pretreatment scans. The mean diffusivity, fractional anisotropy, and intervoxel diffusion coherence were calculated using simple average methods and functional diffusion maps. The Results showed tumors did not change in size after treatment while diffusion indices changed significantly during the study period. Functional diffusion tensor imaging provides the possibility of assessing the acute response in this patient group.

14:00         3469.     Effects of the Intravenous Contrast Agent of GD-DTPA on Time Dependent DTI on Patients with Brain Tumors

Min Sun Bae¹, Geon-Ho Jahng¹, Chang Woo Ryu¹, Hyun Cheol Kim¹, Dal Mo Yang¹, Eui Jong Kim², Woo Suk Choi²

¹Radiology, East West Neo Medical Center, Kyung Hee University, Seoul, Korea; ²Radiology, Kyung Hee Medical Center, Kyung Hee University, Seoul, Korea

To investigate the possibility of acquiring DTI data after intravenous administrations of contrast material GD-DTPA on patients with brain tumors, we acquired DTI data five times that were two DTI scans before (pre1, pre2), one DTI scan during (during3), and two DTI scans after (post4, post5) injections of the GD-DTPA agent on fourteen patients. There are significant differences between ¡°pre¡± and ¡°during¡± in ROIs of edema and tumor lesions for both Trace and FA and there are significant differences between ¡°during¡± and ¡°post¡± in ROIs of edema and tumor lesions for Trace, but not for FA.

14:30         3470.     Multispectral Analysis of Magnetic Resonance Images for Glioma Grading

Benjamín Garzón¹, Kyrre E. Emblem^2,3, Kim Mouridsen⁴, Atle Bjørnerud^2,5, Asta Håberg⁶, Yngve Kvinnsland⁷

¹Department of Circulation and Medical Imaging, NTNU, Trondheim, Norway; ²Department of  Medical Physics, Rikshospitalet University Hospital, Oslo, Norway; ³The Interventional Centre,  Rikshospitalet University Hospital , Oslo, Norway; ⁴Center of Functionally Integrative Neuroscience, Aarhus University, Aarhus, Denmark; ⁵Department of  Physics, University of Oslo , Oslo, Norway; ⁶Department of  Circulation and Medical Imaging, NTNU, Trondheim, Norway; ⁷Department of  Surgical Sciences, University of Bergen, Bergen, Norway

The purpose of the study was to investigate multiple MR-derived image features with respect to diagnostic accuracy in glioma grading. Structural and dynamic susceptibility contrast scans of 74 glioma patients (29 low grade, 45 high grade) with histologically confirmed grade were assessed. Perfusion maps were derived and a set of features was calculated at ROIs encompassing the tumor. For each combination of up to 5 features, a logistic regression model was fitted to a balanced and random training set. Model performance was assessed by applying the model to the remaining subjects and calculating the median area under the ROC curve with a bootstrap procedure. The combination yielding the best performance was maximum enhancement, roundness and skewness of time-to-peak of the first-pass perfusion curve.

15:00         3471.     Role of Functional Diffusion Maps as an Imaging Biomarker for Treatment Response Assessment in Recurrent/progressive Malignant Gliomas Treated with Bevacizumab

Rajan Jain¹, Shehanaz Ellika, Lisa Scarpace, Roy Torcuator, Lonni Schultz, David Hearshen, Tom Mikkelsen

¹Henry Ford Health System, Detroit, MI, USA

Imaging criteria of measuring tumor area/volume only, to assess treatment response may not be sufficient in patients on anti-angiogenic therapy and other functional imaging biomarkers such as ADC values can be helpful in treatment response assessment of these patients. In the present study, recurrent/progressive malignant gliomas treated with bevacizumab, CELADC (contrast enhancing lesion ADC) and NELADC (non-enhancing lesion ADC) showed a progressive increase in responders suggesting treatment response, probable tumor cell death and decreasing tumor cell density. Non-responders showed a progressive decrease of CELADC and NELADC suggesting increase of tumor cell density, hyper cellular infiltrative tumor growth and treatment failure.

13:30         3472.     Evaluating Anti-Angiogenic Therapy Response in Patients with GBM Using Homodynamic Response Imaging.

Dafna Ben-Bashat¹, Haim Ben-Ami¹, Moran Artzi^1,2, Deborah Blumenthal³, Felix Bokstein³, Orna Aizenstein⁴, Yifat Edrei⁵, Ben Corn⁶, Rinat Abramovitch⁵

¹The Wohl institute for Advanced Imaging, Tel Aviv Sourasky Medical Center, Tel-Aviv, Israel; ²Sackler Faculty of Medicine, Tel-Aviv University , Tel-Aviv, Israel; ³Neuro-Oncology Unit, Tel Aviv Sourasky Medical Center, Tel-Aviv, Israel; ⁴Radiology Department, Tel Aviv Sourasky Medical Center, Tel-Aviv, Israel; ⁵Goldyne Savad Institute of Gene Therapy, Hadassah University Medical Center, Jerusalem, Israel; ⁶Institute of Radiotherapy, Tel Aviv Sourasky Medical Center, Tel-Aviv, Israel

Currently, dynamic MR methods using contrast agent are the preferred methods for functional blood-vessel assessment. We have previously presented a novel fMRI method (hemodynamic-response-imaging HRI), using hyperoxia and hypercapnia for the evaluation of the vascular functionality and maturation. In this study, we evaluated the sensitivity of HRI in patients with GBM treated with anti-VEGF and cytotoxic chemotherapy. Three patients were scanned several times during the course of their therapy. HRI showed high sensitivity for therapy-response evaluation, demonstrating the process of blood-vessel "normalization" as a result of the antiangiogenic therapy. This novel method might have added value in clinical management.

14:00         3473.     Combining FMRI, Diffusion Tensor Tractography and Time-Resolved MRA in Pre-Operative Surgical Planning for Brain Tumors

Zhitong Zou¹, Lin Ma¹, Xianghui Meng²

¹Radiology, Chinese PLA General Hospital, Beijing, China; ²Neurosurgery, Chinese PLA General Hospital, Beijing, China

To improve residual brain function following brain tumor resection we pre-operatively mapped vascular, functional and fiber tract anatomy in 11 left frontal lobe tumor patients. Reviewing the combination of MRA/DTT/fMRI images to determine the relationship between tumor and vasculature, language areas and white matter fibers, influenced the surgical approach in 10 patients. Post-operative residual function was improved compared to historical controls.

14:30         3474.     Therapy Response in Glioblastoma Multiforme Evaluated with Diffusion/perfusion MRI

Beatrice Rositta Persson¹, Elena Steffensen¹, Mats Holmberg², Elna-Marie Larsson¹

¹Department of Radiology, Aalborg Hospital/Aarhus University Hospital, Aalborg, Denmark; ²Department of Oncology, Aalborg Hospital/Aarhus University Hospital, Aalborg, Denmark

Introduction: Tumor size, rCBV/rCBF and ADC are used for therapy monitoring in patients with brain tumors.

15:00         3475.     The ETUMOUR Database: A Tool for Annotation and Curation of Multidimensional Human Brain Tumor Data

Margarida Julià-Sapé^1,2, Mariola Mier^3,4, Miguel Lurgi^2,3, Francesc Estanyol³, Xavier Rafael^3,4, Teresa Delgado-Goñi^1,2, Miriam Camisón², Mª Carmen Martinez-Bisbal^5,6, Bernardo Celda^5,6, Carles Arús^1,2, Consortium eTUMOUR⁷

¹CIBER-BBN, UAB, Cerdanyola del Vallès, Barcelona, Spain; ²Bioquimica i Biologia Molecular, Universitat Autonoma de Barcelona, Cerdanyola del Valles, Barcelona, Spain; ³Microart SL, Barcelona, Spain; ⁴School of Informatics, The University of Edinbourgh, Edinbourgh, UK; ⁵CIBER-BBN, Universitat de Valencia, Valencia, Spain; ⁶Quimica Fisica, Universitat de Valencia, Valencia, Spain; ⁷http://www.etumour.net

The eTUMOUR database (eTDB) is a multicentre web-based, curated database of anonymized human brain tumor patient data. Strategies and database-associated tools have been developed to allow curation of the data it contains. The eTDB contains clinical, MRI, MRS (both in-vivo and in-vitro: HRMAS) and microarray data. Currently (November 5th, 2008), 1929 cases contain clinical information and 879 have consensus histopathology diagnosis. 1220 SV-spectra have been analyzed by Senior-Curator spectroscopists. eTUMOUR developed not only a database with multidimensional brain tumor patient data but also a set of strategies to ensure usability of entries for knowledge discovery and computer-assisted decision-support system development.

13:30         3476.     Correlations with Gene Expression Profile May Generate New MR Spectroscopy Markers for Glioblastoma Prognosis and Treatment Planning

Alan James Wright¹, Greg Fellows², Ken Laing³, John Griffiths⁴, Brian Anthony Bell², Franklyn Arron Howe⁵

¹Basic Medical Sciences, St. George's University of London, London, UK; ²Academic Neurosurgery Unit, St. George's University of London, London, UK; ³Cellular and Molecular Medicine, St. George's University of London, London, UK; ⁴CRUK Cambridge Research Institute, Cambridge, UK; ⁵Cardiac and Vascular Sciences, St. George's University of London, London, UK

Surgically resected gliomas were analysed for gene expression data using microarrays and for metabolite concentrations with HR-MAS NMR. Hierarchical clustering of expression data produced two distinct groups. The differential expression of genes between the two groups suggested that the glioblastomas in cluster 1 had expressed genes similarly to astrocytic tumours (also in cluster 1) and were likely to be transformed secondary glioblastomas as opposed to the more common primary glioblastomas (cluster 2). Concentrations measured by NMR showed significant differences in some metabolites between the two groups that should be investigated as novel markers for tumour prognosis and treatment planning.

14:00         3477.     TumourClassifier, a Java Tool for Fast Development and Implementation of MRS- Based Classifiers.

Sandra Ortega-Martorell^1,2, Ivan Olier^1,2, Margarida Julia-Sape^1,3, Carles Arus^1,3

¹Bioquimica i Biologia Molecular, Universitat Autonoma de Barcelona, Cerdanyola del Valles, Barcelona, Spain; ²Computing Languages and Systems, Technical University of Catalonia, Barcelona, Spain; ³CIBER-BBN, Universitat Autonoma de Barcelona, Cerdanyola del Valles, Barcelona, Spain

Nowadays, multiplatform, easy to use software programs for quick and robust classification of MRS data are scarce. TumourClassifier is a java software solution that uses statistical machine learning techniques to design and implement classifiers based on in-vivo SV 1H-MRS. TumourClassifier is a simple and robust tool for helping spectroscopists to analyze and classify single-voxel NMR spectra, minimizing the user learning process curve, and allowing users to display and evaluate the results obtained.

14:30         3478.     Differentiating Tumour vs. Pseudotumoural Disease vs. Normal Brain with SV 1H-MRS

Margarida Julià-Sapé^1,2, Carles Majós^1,3, Mònica Cos³, Carles Aguilera^1,3, Carles Arús^1,2

¹CIBER-BBN, UAB, Cerdanyola del Vallès, Barcelona, Spain; ²Bioquimica i Biologia Molecular, Universitat Autonoma de Barcelona, Cerdanyola del Valles, Barcelona, Spain; ³Hospital Universitari de Bellvitge, Institut de Diagnostic per la Imatge (IDI), L'Hospitalet de Llobregat, Barcelona, Spain

Our purpose was to differentiate tumors from pseudotumoral disease and normal brain with SV-1H-MRS at short and long TE. Inclusion criteria for tumors and pseudotumors were: 1) presence of an untreated solid non-necrotic brain mass suggesting a brain tumor, 2) diagnosis of pseudotumoral disease or glial tumor grades II or III of the WHO confidently established, 3) to have spectra available obtained at both short and long TE, and 4) the spectra to be of good quality at visual inspection. At short TE, 95.2% of cases were correctly classified whereas at long TE, 96.8% of cases were correctly classified.

15:00         3479.     In Vivo 1H MRS, Ex Vivo HR-MAS and Genetic Biomarkers for Oligodendroglial Tumours Differentiation

Bernardo Celda^1,2, Ruben Ferrer-Luna¹, Horacio Marinetto³, Jorge Calvar³, Gustavo Sevlever³, MCarmen Martinez-Bisbal², JoseM Morales⁴, Daniel Monleon⁵

¹Physical Chemistry, University of Valencia, Burjassot, Valencia, Spain; ²Physical-Chemistry, CIBER-BBN, Burjassot, Valencia, Spain; ³FLENI, Buenos Aires, Argentina; ⁴UCIM-Faculty of Medicine, University of Valencia, Valencia, Spain; ⁵FIHCUV, Valencia, Spain

Histopathological classification of Oligodendroglial tumours has a subjective component. Oligodendrogliomas are one of the most chemosensitive solid tumours and that loss of chromosome (LOH) 1p was tightly associated with chemotherapy response. The correlation between in vivo and ex vivo NMR metabolic profiles and gene expression has provided some molecular biomarkers for supporting the classification of Oligodendroglial in an objective manner. Statistical significant correlations has been found between worst prognosis and lower survival with increasing amounts of some Cholines compounds, fatty acids and alanine for ex vivo HR-MAS spectra. Likewise, a correlation between mI/Cr and LOH/ROH 1p/19 loss has been found.

14:00         3480.     HR-MAS Spectroscopic Analysis of Biopsies of Thyroid Tumors; a Pilot Study

Poonam Verma¹, R K. Singh², R Ramakant², Suresh Kumar², Surendra kumar², Nuzhat Husain³, Raja Roy¹

¹CBMR, Centre of Biomedical Magnetic Resonance, Lucknow, Uttar Pradesh, India; ²General surgery, Chhatrapati Shahuji Maharaj Medical University, Lucknow, Uttar Pradesh, India; ³Pathology, Chhatrapati Shahuji Maharaj Medical University, Lucknow, Uttar pradesh, India

Thyroid tissues were subjected to HR-MAS NMR analysis followed by histopathological examination. In malignant cases, the glutamate/alanine, choline/alanine and lactate/alanine ratios were found to be significantly reduced with respective p-values 0.01, 0.02 & 0.007 in the comparison of non-malignant cases. The tissue specimen (n=6) from Hashimoto,s thyroidites showed the presence of additional metabolite,viz. â-hydroxybutyrate which was not observed in other thyroid tumor tissue type ,can be used as fingerprint marker. We propose that thyroid tumor tissue metabolic information by NMR has a diagnostic potential along with the gold- standard histopathological examination.

14:30         3481.     Investigating the ADC Value of Neoplasm Involving the Pharynx and Oral Cavity

Chun-Jung Juan^1,2, Cheng-Yu Chen^1,2, Hing-Chiu Chang³, Chun-Jen Hsueh¹, Hung-Wen Kao¹, Hua-Shan Liu¹, Hsiao-Wen Chung^1,4, Guo-Shu Huang^1,2

¹Radiology, Tri-Service General Hospital, Taipei, Taiwan; ²Radiology, National Defense Medical Center, Taipei, Taiwan; ³Applied Science Laboratory, GE Healthcare, Taipei, Taiwan; ⁴Electrical Engineering, National Taiwan University, Taipei, Taiwan

In this study we aimed to investigate the apparent diffusion coefficient (ADC) of head and neck neoplasm focusing in the nasopharnx, oropharynx and oral tongue using PROPLLER-DWI. Our results show that PROPELLER-DWI is immune from geographic distortion and signal mis-registration in all patients. The ADC of neoplasm is significantly lower than the normal tissue and inflammatory lesions.

15:00         3482.     Imaging Distortion and Quantification Bias of Parotid ADC Measurements in EP-DWI and Fast Spin-Echo PROPELLER-DWI

Chun-Jung Juan^1,2, Hing-Chiu Chang³, Chun-Jen Hsueh¹, Hua-Shan Liu¹, Cheng-Yu Chen^1,2, Hsiao-Wen Chung^1,4, Tzu-Chao Chuang⁵, Hung-Wen Kao¹, Guo-Shu Huang^1,2

¹Radiology, Tri-Service General Hospital, Taipei, Taiwan; ²Radiology, National Defense Medical Center, Taipei, Taiwan; ³Applied Science Laboratory, GE Healthcare, Taipei, Taiwan; ⁴Electrical Engineering, National Taiwan University, Taipei, Taiwan; ⁵Electrical Engineering, National Sun Yat-sen University, Kaohsiung, Taiwan

The functionality of the parotid glands could be evaluated using diffusion-weighted imaging (DWI) noninvasively. Accurate quantification of the parotid apparent diffusion coefficient (ADC) is important not only for distinguishing pathologies but also for inter-experiment comparison. Although echo-planar DWI (EP-DWI) has been applied to measure the parotid ADC in recent decade, the results are quite discrepant due to physiological and non-physiological factors. In this study, we assessed the imaging distortion and bias in parotid ADC measurements in EP-DWI in comparison to the distortion-free technique, PROPELLER-DWI. Our results depict significant imaging distortion of EP-DWI and sequence-related biases in parotid ADC quantification.

15:30         3483.     Quantification of Parotid Fat Content and ADC Using IDEAL Gradient Echo Imaging and PROPELLER-DWI

Chun-Jung Juan^1,2, Hing-Chiu Chang³, Yin-Cheng Kris Huang^1,4, Hua-Shan Liu¹, Chun-Jen Hsueh¹, Cheng-Yu Chen^1,2, Hung-Wen Kao¹, Hsiao-Wen Chung^1,4, Guo-Shu Huang^1,2

¹Radiology, Tri-Service General Hospital, Taipei, Taiwan; ²Radiology, National Defense Medical Center, Taipei, Taiwan; ³Applied Science Laboratory, GE Healthcare, Taipei, Taiwan; ⁴Electrical Engineering, National Taiwan University, Taipei, Taiwan

Parotid fat content changes in aging process. While quantifying the parotid apparent diffusion coefficient (ADC), it is better when the parotid fat content is taken into account. The issues how parotid fat content varies with age and what impact of parotid fat content on the measurement of parotid ADC remain unclear so far. In this study, we quantified the parotid fat content using RF saturation (T1WI and PROP-T2WI) and IDEAL gradient echo imaging and measured the parotid ADC using non-fat-saturated PROP-DWI. Our results show that the parotid fat content is positively correlated with age and negatively correlated with parotid ADC.

13:30         3484.     Carotid Intima-Media Thickness and Distensibility Measured by MRI at 3T Versus High-Resolution Ultrasound

Andreas Harloff¹, Timo Zech¹, Alex Frydrychowicz², Martin Schumacher³, Joachim Schöllhorn⁴, Jürgen Hennig², Cornelius Weiller¹, Michael Markl²

¹Neurology, University Hospital Freiburg, Freiburg, Germany; ²Diagnostic Radiology, MR Physics, University Hospital Freiburg, Freiburg, Germany; ³Neuroradiology, University Hospital Freiburg, Freiburg, Germany; ⁴Cardiovascular Surgery, University Hospital Freiburg, Freiburg, Germany

The aim of this study was to evaluate the diagnostic impact of high-spatial resolution MRI for the reliable assessment of both carotid wall thickness and compliance in order to allow a comprehensive evaluation of carotid atherosclerosis. Therefore, both parameter were measured in the common carotid arteries (CCA) of 32 healthy volunteers and 20 patients with high-grade internal carotid artery stenosis and were compared with high-resolution ultrasound as the reference method.

14:00         3485.     MR Imaging of Carotid Plaque: Correlation Between Contrast-Enhancement and Inflammation at Histopathology

Francesco Sardanelli^1,2, Giacomo Davide Edoardo Papini¹, Stefania Tritella¹, Biagio Cotticelli¹, Giovanni Nano³, Claudio Clemente⁴, Giovanni Di Leo¹

¹Unit of Radiology, IRCCS Policlinico San Donato, San Donato Milanese, Milan, Italy; ²Medical and Surgical Science, University of Milan School of Medicine, Milan, Italy; ³Unit of Vascular Surgery, IRCCS Policlinico San Donato, San Donato Milanese, Milan, Italy; ⁴Unit of Pathology, Istituto Clinico Sant'Ambrogio, Milan, Italy

Twenty-two patients underwent preoperative 1.5-T MRA and unenhanced axial T1-weighted gradient-echo sequence centered on carotid bifurcation before and 3 minutes after contrast injection (gadobenate dimeglumine, 0.1 mmol/kg). Using native and subtracted images, plaque enhancement was scored as 0 (absent), 1 (focal), or 2 (extended). At histopathology, inflammatory cell infiltration was graded as 0 (absent/minimal), 1 (focal), or 2 (extended). Weighted Cohen k resulted 0.57 (moderate agreement). Sensitivity was 78%, specificity 85%, and accuracy 82%. No significant correlation was observed between stenosis degree and plaque inflammation at histopathology. Wall enhancement is a reliable marker of plaque inflammation, independently from stenosis degree.

14:30         3486.     Non-Contrast-Enhanced MR Angiography of the Carotid Arteries and Aortic Arch Using Inherent Enhancement (Inhance) Inflow IR, Adopting Peripheral-Gated Partial-Fourier Fast Spin Echo (FSE) or Steady-State Free Precession (FIESTA) : A Comparison with Contrast MRA

Kimihiko Sato¹, Takayuki Masui¹, Motoyuki Katayama¹, Hiroki Ikuma¹, Hidekazu Seo¹, Akihiko Kutsuna¹, Megumi Ishii², Masayoshi Sugimura², Naoyuki Takei³, Mitsuharu Miyoshi³, Tetsuji Tsukamoto³, Kenji Asano⁴

¹Radiology, Seirei Hamamatsu General Hospital, Hamamatsu, Shizuoka, Japan; ²Radiology Center, Seirei Hamamatsu General Hospital, Hamamatsu, Shizuoka, Japan; ³Japan Applied Science Laboratory, GE Yokogawa Medical Systems Ltd., Hino, Tokyo, Japan; ⁴MR Engineering, GE Yokogawa Medical Systems Ltd., Hino, Tokyo, Japan

Non contrast MRA of the carotid arteries and aortic arch using Inherent Enhancement (Inhance) Inflow IR (IFIR)

15:00         3487.     Nonenhanced Time-Resolved MRA Using Inflow Arterial Spin Labeling

Shinichi Kitane¹, Tokunori Kimura¹, Yuichi Yamashita², Mitsue Miyazaki³

¹MRI development department, Toshiba Medical Systems Corp., Otawara, Tochigi, Japan; ²MRI marketting department, Toshiba Medical Systems Corp., Tokyo, Japan; ³Advanced Clinical Research, MR, Toshiba Medical Research Institute USA, Inc, Vernon Hills, IL, USA

A new nonenhanced time-resolved MRA technique was proposed using inflow arterial spin labeling (ASL) with multiple non-slice selective IR pulses for suppressing background tissue signals. After saturating imaging slab, two mIR pulses tuned for nulling of brain tissues were applied, and imaging with 3D-SSFP sequence was performed on 1.5T MRI for normal volunteer brain. The stationary signal in brain tissue, gray-matter, white-matter, and CSF were well suppressed. Peripheral blood vessels were well visualized with increasing TI. Although further optimization of parameters is required, this method is promising approach for non-contrast dynamic MRA.

13:30         3488.     Blood Vessel Contrast Enhancement Using Phase Corrected Real Imaging in Flow-Sensitive Black Blood Imaging

Tokunori Kimura¹, Masato Ikedo¹

¹MRI development department, Toshiba Medical Systems Corp., Otawara, Tochigi, Japan

We have already proposed a black-blood MR angiography technique named flow-sensitive black-blood (FSBB) combining flow dephasing gradients with 3D-GRE sequence. In this study, we proposed a simple technique of improving blood to background contrast by adding signal phase contrast to signal amplitude and assessed on the volunteer brain using 1.5T MR imager. We demonstrated that the wraparound artifacts appeared on the vessels when the phase difference from the background was over pi/2 were eliminated, and thus the blood to background contrasts were increased. This correction was useful for slow-flow vessels particularly when the surrounding background signal was smaller such as CSF.

14:00         3489.     Detection of 100% Oxygen Induced Changes in Retina Using Magnetic Resonance Imaging: A Human Study

Xu qinggang¹, Chen qinghua, Wang zhenchang, Xian junfang

¹Radiology, Beijing Tongren Hospital,Capital Medical University, Beijing, China

Initially insufficient supply of oxygen with the following metabolic dysfunction may lead to neovascularization and irreversible retinal damage in the late period. We speculate that both of these effects are consistent with impaired autoregulation. Based on MRI research on animal experiments, our study supports that ¦¤PO2 in preretinal vitreous water following 100% oxygen inhalation detected by MRI are in accordance with the retinal blood flow distribution, and it is a foundation for further research on retinal oxygenation response to a hyperoxic inhalation challenge in healthy humans as well as in patients with diabetes. In addition, our study also supports that MRI is a valuable, noninvasive tool for investigation of retinal physiology and function in vivo.

14:30         3490.     Delineation of Draining Veins in Arteriovenous Malformations on Susceptibility Weighted Imaging: Impact of Magnitude Images

Toshiteru Miyasaka¹, Toshiaki Taoka¹, Toshiaki Akashi¹, Kaoru Myouchin¹, Masahiko Sakamoto¹, Katsutoshi Takayama¹, Horoyuki Nakagawa¹, Kimihiko Kichikawa¹

¹Dep. of Radiology, Nara Medical University, Kashihara, Nara, Japan

The magnitude image, which is one of the sources of SWI, seems useful to assess the draining vein of AVM, especially on follow-up. This is because, while draining veins of AVM depicted as low signal structure on SWI, the magnitude image depicts draining veins of AVM as high signal, due to higher concentration of oxy-Hb and higher flow speed within draining vein of AVM.

15:00         3491.     TOF-MRA Measurements of Cranial Arteries in Cholesterol-Fed Rabbits

Susan K. Lemieux^1,2, Carrie A. Smith-Bell³, Jeffrey S. Carpenter², Bernard G. Schreurs³

¹Social & Life Science Imaging Center, The Pennsylvania State University, State College, PA, USA; ²Radiology, West Virginia University, Morgantown, WV, USA; ³Blanchett Rockefeller Neurosciences Institute, Morgantown, WV, USA

Our purpose was to determine if a 2% cholesterol diet alters vessel diameter in rabbit cranial arteries including common and internal carotids, basilar, posterior communicating, and ophthalmic arteries. Further to test if vessel size changes were associated with beta-amyloid accumulation in the temporal lobes or hippocampus. Four groups of cholesterol-fed New Zealand white rabbits were studied by TOF-MRA. Vessel diameters were measured on the TOF gradient echo source images. Vessel diameters of the basilar artery and both posterior communicating arteries decreased with duration of the cholesterol diet. The amount of beta-amyloid that accumulated was inversely correlated with vessel size.

13:30         3492.     Simultaneous Measurement of Glutathione and Other Metabolites in Stroke Patients by J-Difference Spectroscopy

Li An¹, Larry L. Latour¹, Krishna A. Dani², Jun Shen³, Steven Warach¹

¹National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, USA; ²University Medical Unit, Glasgow Royal Infirmary, Glasgow, UK; ³National Institute of Mental Health, National Institutes of Health, Bethesda, MD, USA

In this study, a J-difference spectroscopy technique was used to investigate the changes in brain glutathione (GSH) occurring after stroke, with respect to changes in other commonly measured metabolites: choline, creatine/phosphocreatine, N-acetyl-aspartate, and lactate. The ratio between the GSH levels in lesion and control regions was computed and represented by rGSH. A correlation between rGSH and lactate level in the lesion was found to be significant at 0.05 level with Pearson¡¯s correlation coefficient r = 0.59 and p = 0.042 (two-tailed). This is consistent with findings from clinical studies where blood GSH levels were found to be increased in the first 48 hours post ictus.

14:00         3493.     Sodium MRI of Core and Penumbra in Ischemic Stroke Patients

Adrian Tsang¹, Rob Stobbe¹, Ken Butcher², Shazam Hussain, Yusuf Bhagat¹, Derek Emery³, Christian Beaulieu¹

¹Biomedical Engineering, University of Alberta, Edmonton, Alberta, Canada; ²Neurology, University of Alberta, Edmonton, Alberta, Canada; ³Radiology, University of Alberta, Edmonton, Alberta, Canada

Sodium imaging may complement both diffusion- and perfusion-weighted proton imaging in the assessment of ischemic stroke patients. The purpose of this study is to evaluate the relative tissue sodium intensity in the penumbra defined by PWI-DWI mismatch and core infarct regions defined by DWI from acute to subacute times. Preliminary results based on 4 longitudinal subjects demonstrated that mean relative sodium intensity increases with time only in the infarct core but does not change in the penumbra.

14:30         3494.     Diffusional Kurtosis Imaging in Acute Human Stroke

Joseph A. Helpern^1,2, Calvin Lo¹, Caixia Hu¹, Maria F. Falangola¹, Otto Rapalino¹, Jens H. Jensen¹

¹Radiology, NYU School of Medicine, New York, NY, USA; ²Medical Physics, The Nathan Kline Institute, Orangeburg, NY, USA

Diffusional Kurtosis Imaging (DKI) is a new technique for quantifying non-Gaussian diffusion yielding conventional diffusion metrics as well as a new metric, the mean kurtosis (MK). In human stroke, the MK identified ischemic brain regions that correlated with DWI and ADC maps, but in several cases MK also identified affected regions adjacent to acute infarct not apparent on other images. Within the region of ischemia MK maps were heterogeneous in appearance, and the temporal behavior of MK was different than DWI or ADC. The fact that MK identifies brain regions affected by ischemia not identified by conventional DWI is encouraging.

15:00         3495.     Evaluation of the SWAN Pulse Sequence: A Novel Technique for Susceptibility Enhanced Imaging

David W. Stanley¹, E Paul Lindell², John D. Port², Norbert G. Campeau², Heidi A. Ward², Marilyn R. Wood², Ravi Bhardwaj³, Anthony T. Vu⁴

¹GE Healthcare, Proctor, MN, USA; ²Mayo Clinic, Rochester, MN, USA; ³MR Engineering, GE Healthcare, Bangalore, Karnataka, India; ⁴MR Engineering, GE Healthcare, Waukesha, WI, USA

Use of magnetic susceptibility effect as an image contrast is relatively new technique that has proven useful for evaluation iron containing tissues, cerebral microvasculature, and pathologic processes resulting in susceptibility changes (hemorrhage, metastasis, traumatic brain injury, metabolic disorders). The purpose of this work is to evaluate SWAN (T2Star Weighted ANgiography) a new susceptibility enhanced imaging sequence [1], and compare this technique to conventional gradient echo imaging.

14:00         3496.     Susceptibility Weighted MRI of Ferumoxytol at 3T and 7T in Human Brain

John Grinstead¹, Seymur Gahramanov², Csanad Varallyay², Vladimir Jellus³, Edward A. Neuwelt², William D. Rooney⁴

¹Siemens Medical Solutions USA, Inc., Portland, OR, USA; ²Department of Neurology, Oregon Health and Science University, Portland, OR, USA; ³Siemens AG Healthcare Sector, Erlangen, Germany; ⁴Advanced Imaging Research Center, Oregon Health and Science University, Portland, OR, USA

Susceptibility weighted imaging (SWI) relies on susceptibility effects which increase with the magnetic field strength. The recent availability of Ultrasmall Superparamagnetic Iron-Oxide contrast agents (FeO) may increase the sensitivity of SWI. The combination of SWI and FeO contrast agents were studied in brain tumors at 3T and 7T. Extremely small blood vessels were visible following FeO injection. The increased magnetic susceptibility effects, high SNR, and low specific absorption rate (SAR) make SWI an attractive technique at 7T, especially in combination with FeO contrast agents.

14:30         3497.     High Contrast and High Resolution in Vitro Susceptibility Weighted Imaging (SWI) at 7 Tesla

Guenther Grabner^1,2, A-M van Cappellen van Walsum^3,4, Siegfried Trattnig¹, Markus Barth^2,5

¹Department of Radiology, Medical University of Vienna, Vienna, Austria; ²Donders Institute for Brain, Cognition and Behaviour, Radboud University Nijmegen, Nijmegen, Netherlands; ³Department of Anatomy, Radboud University Nijmegen Medical Centre, Nijmegen, Netherlands; ⁴University of Twente, Institute of Technical Medicine, Enschede, Netherlands; ⁵E.L. Hahn Institute for Magnetic Resonance Imaging, University Duisburg-Essen

Within this study we exploited the rich anatomical information that is present in the contrast of high resolution 7 Tesla SWI scans with the main focus on visualization of small anatomical structures and vessels of a formalin-fixed human brain and the comparison to a standard anatomical atlas. Very detailed anatomical structures such as the internal/external separation of the globus pallidus and automatically segmentation of small veins are shown.

15:00         3498.     Gradient Echo Versus Spin Echo T2-Weighted Imaging of Deep Brain Structures of the Human Brain at 7 Tesla

Stephane Lehericy^1,2, Eric Bardinet^1,3, Jerome Yelnik⁴, Fabrice Poupon⁵, Kamil Ugurbil⁶, Pierre-Francois Van de Moortele⁶, Cyril Poupon⁵

¹Center for NeuroImaging Research - CENIR, University Pierre and Marie Curie - Paris 6, Paris, France; ²Neuroradiology, Inserm U610, Pitie-Salpetriere Hospital, Paris, France; ³CNRS UPR 640 - LENA, University Pierre and Marie Curie - Paris 6, Paris, France; ⁴INSERM U679, Pitie-Salpetriere Hospital, University Pierre and Marie Curie - Paris 6, Paris, France; ⁵NeuroSpin, CEA, Saclay, France; ⁶Center for Magnetic Resonance Research and Department of radiology, University of Minnesota, Minneapolis, MN, USA

In this work, we compared spin echo and gradient echo 7T images to depict the normal anatomy of deep brain nuclei in the human brain. Six human volunteers were included. T2*- and T2-weighted images showed improved contrast at 7T as compared to lower field strength and better detection of deep brain structures. Several fiber pathways were also detected using either 7T images confirming that very high field magnets provide new contrast.

15:30         3499.     Resolving White Matter Structures of Human Hippocampus in Vivo with High Resolution DTI at 3 T

Dimitrios C. Karampinos^1,2, Anh T. Van³, Brian D. Gonsalves^2,4, John G. Georgiadis^1,2, Bradley P. Sutton^2,5

¹Mechanical Science and Engineering Department, University of Illinois at Urbana-Champaign, Urbana, IL, USA; ²Beckman Institute, University of Illinois at Urbana-Champaign, Urbana, IL, USA; ³Electrical and Computer Engineering Department, University of Illinois at Urbana-Champaign, Urbana, IL, USA; ⁴Psychology Department, University of Illinois at Urbana-Champaign, Urbana, IL, USA; ⁵Bioengineering Department, University of Illinois at Urbana-Champaign, Urbana, IL, USA

The hippocampus is a small structure, which is challenging to image in vivo with a clinical scanner. Many studies of hippocampal diseases rely on measurements of hippocampal volume, but the derived metrics are not specific to tissue microanatomy. Diffusion tensor imaging (DTI) can probe the microanatomy, but its application on the hippocampus is hindered by the technical limitations of single-shot EPI. In this work, a multi-shot variable density spiral encoding is implemented for high resolution DTI of the hippocampus at 3 T. The results show the ability of the technique to resolve the hippocampus white matter structures of fimbria and alveus.

13:30         3500.     Ultra-High Resolution 7.0T MRI of Medial Temporal Lobe Epilepsy

Michael Maroun Zeineh¹, Josef Parvizi¹, Priti Balchandani¹, Chunlei Liu¹, Gary Glover¹, Anne Sawyer¹, Robert Fisher¹, Scott William Atlas¹

¹Stanford University School of Medicine, Stanford, CA, USA

Ultra-high field human brain imaging holds the promise to visualize with great precision the biological substrates of medial temporal lobe (MTL) epilepsy. We performed 7.0T MRI brain scanning on 6 volunteers with medial temporal lobe epilepsy who had concurrent 1.5T or 3.0T MRIs. Compared to the lower field imaging, the 7.0T images demonstrated superior visualization of both the microscopic anatomy of the normal contralateral medial temporal lobe as well as atrophy of hippocampal cell fields in the abnormal hemisphere. High-field imaging has the potential to characterize and detect microscopic pathology associated with MTL epilepsy.

14:00         3501.     Comparison of SNR and Contrast in FLAIR at 3T and 7T

Jaco J.M. Zwanenburg¹, Fredy Visser^1,2, Jerhoen Hendrikse¹, Taro Takahara¹, Peter R. Luijten¹

¹Dept. of Radiology, University Medical Center Utrecht, Utrecht, Netherlands; ²Philips Healthcare, Best, Netherlands

FLAIR imaging at the ultra-high field strength of 7 Tesla has been challenging. This work compares the SNR and contrast of the multislice FLAIR sequence at two different field strengths 3T and 7T, and shows that SNR increases approximately linear with field strength, while relative contrast between gray and white matter is maintained.

14:30         3502.     Attenuation of Cerebral Venous Contrast in Susceptibility Weighted Imaging (SWI) in Pediatric Patients Under General Anesthesia.

Jan Sedlacik¹, Ulrike Löbel¹, Alberto Broniscer¹, Zoltan Patay¹, Claudia M. Hillenbrand¹

¹St. Jude Children's Research Hospital, Memphis, TN, USA

Pediatric patients have to be anesthetized during the MRI exam which can lead to a considerable attenuation of the contrast of cerebral veins in SWI. It is known that the deepness of the anesthesia raises the blood CO2 level which in turn increases the cerebral blood flow (CBF). Furthermore, it was shown in healthy adults that an increased level of CO2 in the breathing gas causes a loss of venous contrast in SWI. Purpose of this study was to investigate how anesthesia impacts the venous contrast in SWI.

15:00         3503.     Anatomical Identification of V5 in Humans at 7 T

Robert Trampel¹, Robin Heidemann¹, Dimo Ivanov¹, Robert Turner¹

¹Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany

The goal of this study was the structural identification of the visual motion area V5, which is known to have regionally increased myelination. The earliest studies to show myeloarchitectural differences in grey matter demonstrated that the densely myelinated stria of Gennari (V1) is MR visible. The present study was performed at a field strength of 7 T. A high-resolution Turbo-Spin Echo sequence with an isotropic resolution of 0.5 mm was used to identify V5 anatomically. The location of V5 was confirmed by means of a functional MRI scan in which a moving star field paradigm activated this visual motion sensitive area.

13:30         3504.     Diagnosis of Dental Abnormalities in Children Using MRI

Olga Tymofiyeva¹, Kurt Rottner², Peter Christian Proff³, Ernst-Juergen Richter², Peter Michael Jakob¹

¹Dept. of Experimental Physics 5, University of Würzburg, Würzburg, Bavaria, Germany; ²Dept. of Prosthodontics, Dental School, University of Würzburg, Würzburg, Bavaria, Germany; ³Dept. of Orthodontics, Dental School, University of Regensburg, Regensburg, Germany

Genetic and environmental factors can cause abnormalities in tooth development that manifest as change of the size, shape, position and number of teeth. The purpose of this study was to assess the feasibility of MRI of dental abnormalities in children. The study included 38 orthodontic patients of mean age 12.4. Supernumerary teeth were diagnosed in 26% of the patients, gemination in 3%, dilaceration in 3%, transposition in 3% and various tooth impactions in 63%. MRI was shown to be a well-tolerated imaging modality for diagnosis of dental abnormalities in children as well as for orthodontic treatment and surgery planning.

14:00         3505.     MRI as a Diagnostic Tool in Conservative Dentistry

Olga Tymofiyeva¹, Julian Boldt², Kurt Rottner², Ernst-Juergen Richter², Peter Michael Jakob¹

¹Dept. of Experimental Physics 5, University of Würzburg, Würzburg, Bavaria, Germany; ²Dept. of Prosthodontics, Dental School, University of Würzburg, Würzburg, Bavaria, Germany

Quantification of carious lesions and measurement of the distance to the pulp is an important task in conservative dentistry. This information can improve identification of cases with the potential for maintaining pulp vitality and monitor treatment success of indirect pulp capping. The presented results demonstrate feasibility of dental MRI to visualize and quantify the distance between the carious cavity and dental pulp in all three spatial directions. To the authors’ knowledge, MRI is the only modality that can perform this task non-invasively.

14:30         3506.     Dental Restorations – Crowns, Bridges and Inlays – Produced Using in Vivo Dental MRI

Olga Tymofiyeva¹, Kurt Rottner², Julian Boldt², Ernst-Juergen Richter², Peter Michael Jakob¹

¹Dept. of Experimental Physics 5, University of Würzburg, Würzburg, Bavaria, Germany; ²Dept. of Prosthodontics, Dental School, University of Würzburg, Würzburg, Bavaria, Germany

The MRI-based contrast-enhanced method of tooth surface digitization was recently suggested as an alternative way of making dental impressions. The negative impression of the tooth surface can be directly used for production of dental restorations by means of CAD/CAM technology. For the first time dental restorations were produced using in vivo MRI-based tooth surface digitization. The resulting fit of the restorations demonstrates feasibility of the technique.

15:00         3507.     3D Visualization of Endolymphatic Hydrops After Intratympanic Injection of Gd-DTPA; Optimization of 3D-Real IR TSE Sequence and Utilization of 32ch Head Coil at 3T

Shinji Naganawa¹, Minako Kawamura¹, Tsutomu Nakashima²

¹Department of Radiology, Nagoya University Graduate School of Medicine, Nagoya, Aichi, Japan; ²Department of Otorhinolaryngology, Nagoya University Graduate School of Medicine, Nagoya, Aichi

Optimized 3D-real IR TSE, 32ch coil, 3T and intratympanic injection of Gd-DTPA synergetically allowed the clear 3D visualization of endolymphatic hydrops in the patients with Meniere's disease for the first time. This will allow the volume quantification of each lymph space and will serve a new biomaker of Meniere’s disease in the future.

13:30         3508.     T1 and Volumetric Q-MRI of the Major Salivary Glands: Effects of Aging (Preliminary Results in 41 Subjects Over the Human Lifespan)

Naoko Saito¹, Hernan Jara¹, Osamu Sakai¹

¹Boston Medical Center, Boston University School of Medicine, Boston, MA, USA

Purpose: To study the T1 relaxation times and volume changes of the three major salivary glands; parotid, submandibular, and sublingual glands over the full human lifespan using quantitative MRI. Methods: Forty-one subjects (0.5-87 years) scanned with the mixed-TSE pulse sequence were segmented manually into bilateral three salivary glands leading to the T1 histograms. Results: All the major salivary glands showed very subtle age-related changes in T1 relaxometry, however showed clear aging growth in volumetry. Furthermore, two volumetric aging patterns were observed after 60 years of age. Conclusion: Age-related T1 and volume changes of the major salivary glands have been studied.

14:00         3509.     7 Tesla in Vivo of the Human Eye: A SNR and CNR Optimization Study

Peter A. Wassenaar¹, Kathryn Richdale², Katharine Teal Bluestein¹, John Christoforidis³, Titus Lanz⁴, Michael Vincent Knopp¹, Petra Schmalbrock¹

¹Radiology, The Ohio State University, Columbus, OH, USA; ²Optometry, The Ohio State University, Columbus, OH, USA; ³Ophthalmology, The Ohio State University, Columbus, OH, USA; ⁴Rapid MR International, LLC, Columbus, OH, USA

High quality imaging is critical for examining changes in the fine structures of the human eye. Increased signal at 7T with a custom coil is uniquely suited for this task. Ten healthy subjects were imaged. Motion and susceptibility artifacts were minimized by patient preparation, minimum slice thickness and 35 second scan times. Optimal images were obtained using 3D SPGR with flip angles of 10-20° and IR-TFE with TS/TI=2000/1000ms. Multiple images with voxel volumes of 0.15x0.25x1.0 were obtained and registered for final SNRs of 30-40.

14:30         3510.     High Resolution MRI and CT Investigation of Laryngeal Soft Tissues and Skeletal Structures

Michael Hofer¹, Bernhard Neumayer², Markus Gugatschka³, Philipp Juergens⁴, Rudolf Stollberger², Erich Sorantin⁵, Franz Ebner⁵, Gerhard Friedrich³, Claudio Storck⁶

¹Institute of Medical Engineering, Graz University of Technology , Graz, Austria; ²Institute of Medical Engineering, Graz University of Technology, Graz, Austria; ³Department of Phoniatrics, Medical University of Graz, Graz, Austria; ⁴Department of Craniomaxillary Surgery, University Hospital Basel, Basel, Switzerland; ⁵Department of Radiology, Medical University Graz, Graz, Austria; ⁶Department of Phoniatry, University Hospital Basel, Basel, Switzerland

Functional biomechanics of laryngeal cartilages and soft tissues is difficult to visualize by MRI and CT. The aim of the study was to visualize and compare skeletal structures and soft tissues in detail by MRI and CT. 20 human cadaveric larynges were examined by MRI and CT and visualized by post-process imaging software. In all 20 human cadaveric larynges, the laryngeal cartilages could be visualized clearly. The assessment of the thyroid and cricoid is dependent of the ossification. The ossification of the hyaline cartilages increases with advanced age where male larynges ossify more than female larynges.

15:00         3511.     A Method for MR Imaging of Head and Neck Cancer Patients in the Radiotherapy Treatment Position Without Loss of Image Quality

Scott Hanvey¹, John Foster², Martin Glegg¹

¹Beatson West of Scotland Cancer Centre, Glasgow, UK; ²Glasgow Cardiac Magnetic Resonance Unit, Western Infirmary, Glasgow, UK

Imaging head and neck patients in the radiotherapy treatment planning position using MRI is desirable, since MR image registration with CT in different positions introduces errors, which can potentially lead to inaccuracies in the delineation of the target volume. Positioning patients in the treatment position using immobilisation and a head rest is not generally possible in MRI without incurring an unacceptable loss in image quality as immobilisation and multi-channel head coils are not compatible. This study describes a method for using immobilisation in MR while maintaining the diagnostic image quality necessary for successful radiotherapy treatment planning.

14:00         3512.     Estimation of Local Tissue Diffusion Anisotropy with Hyperecho Coherence Pathway Selective (HyperCOPS) Diffusion Tensor Imaging

Lawrence R. Frank^1,2, J Michael Tyszka³

¹Radiology, UCSD, La Jolla, CA, USA; ²Radiology, VASDHS, La Jolla, CA, USA; ³Biology, Caltech Brain Imaging Center, Pasadena, CA, USA

The assessment of local diffusion anisotropy using DTI is problematic in regions containing multiple fiber orientations. Recently, this problem has been approached with "multiple scattering" methods that employ multiple q-space encoding gradients between successive refocusing pulses so the net signal is sensitive to local variations diffusion. We present a novel method for imaging of local diffusion anisotropy based on the integration of the multiple scattering concept within the framework of a hyperecho diffusion weighted sequence. We present the basic theory of hyperecho diffusion weighting with COherence Pathway Selection (hyperCOPS) and preliminary results obtained on fixed mouse brains at 11.7T.

14:30         3513.     Optimization of Diffusion Encoding Gradients in Axisymmetric Diffusion Tensor Imaging Using A Priori Structure Information

Shantanu Majumdar¹, David C. Zhu^2,3, L. Guy Raguin^3,4, Satish S. Udpa¹

¹Electrical and Computer Engineering, Michigan State University, East Lansing, MI, USA; ²Psychology, Michigan State University, East Lansing, MI, USA; ³Radiology, Michigan State University, East Lansing, MI, USA; ⁴Mechanical Engineering, Michigan State University, East Lansing, MI, USA

In Diffusion Tensor Imaging, an assumption of isotropic diffusivity in the direction transverse to fiber orientation can be applied to the diffusion model to create an axisymmetric DTI model. An optimization procedure for the selection of diffusion encoding gradients by using a priori information of the anatomical structure has been presented for the axisymmetric DTI model. The optimization applies a priori information to a D-optimality based method to compute a set of gradient directions that reduce the uncertainty in the estimate of ADTI model parameters. In this work, a region of the cervical spinal cord has been imaged with an optimized gradient scheme. The data was used to estimate the covariance matrix of the estimation error for the model parameters. It was demonstrated that the optimized scheme provides a lower overall variance in the estimates than that offered using a standard scheme.

15:00         3514.     Reduction of Signal Loss in Diffusion-Weighted Imaging of the Upper Abdomen:motion Correction Using Bipolar Motion Probing Gradients

Isao Muro¹, Tetso Ogino², Tomohiko Horie¹, Taro Takahara³, Thomas Kwee³, Yutaka Imai¹, Marc Van Cauteren⁴

¹Department of Radiology, Tokai University, Isehara, Japan; ²Philips Electronics Japan, Shinagawa, Japan; ³Department of Radiology, University Medical Center Utrecht, Utrecht, Netherlands; ⁴Philips Healthcare Asia Pacific, Shinagawa, Japan

In diffusion-weighted imaging (DWI) of the body, cardiac motion gives signal loss in the adjacent left lobe of the liver, causing poor visibility of lesions and overestimation of apparent diffusion coefficient (ADC) measurements. Motion correction (MC) using dual bipolar motion probing gradients may solve this issue. We conducted phantom and volunteer studies using DWI with and without MC and showed MC is effective in preventing signal loss and reducing falsely increased ADCs in the left lobe of the liver.

15:30         3515.     Study of Aliasing Error with SENSE in Body Diffusion Image Using Single Shot EPI at 3T

Isao Muro¹, Tomohiko Horie¹, Yutaka Imai¹

¹Department of Radiology, Tokai University, Isehara, Japan

In SENSE, a reference scan usually needs to be performed to create a sensitivity profile of each receiver channel. Gradient echo (GRE) sequences are often used in the reference scan. In diffusion weighted imaging (DWI) using single shot EPI with SENSE, non-negligible aliasing artifacts often remain in the reconstructed images. We suppose that these artifacts result from misregistration between the reference images acquired using GRE sequences and the DW images acquired using EPI. In this study, we have used two types of acquisition methods to create sensitivity profiles: GRE sequences and EPI, and compared the residual artifacts in the reconstructed images.Our study suggests that EPI sensitivity profiles be used when imaging data are acquired using a sigle shot EPI with SENSE although GRE sensitivity profiles have often been used in practice.

13:30         3516.     Robust Diffusion-Weighted Imaging Using Split-Blade PROPELLER and LRX Phase Modulation

Zhiqiang Li¹, Xiaoli Zhao¹, Donglai Huo², James Pipe², Patrick Le Roux³

¹GE Healthcare, Waukesha, WI, USA; ²Barrow Neurological Institute, Phoenix, AZ, USA; ³GE Healthcare, Paleiseau, France

To address the non-CPMG condition, diffusion-weighted (DW) PROPELLER uses an XY2 phase modulation. However, it still has some constraints such as high refocusing flip angle, limited echo train length, high SAR and sensitivity to dielectric effect at 3T. A quadratic phase modulation strategy was proposed by Le Roux allowing the use of low flip angle and long echo train with SSFSE, but requires double encoding. We adapted this novel strategy in DW-PROPELLER with the split blade method, producing more stable signal with less decay. In vivo images demonstrate the advantages of this new technique.

14:00         3517.     Diffusion-Weighted PROPELLER with a Novel Unaliasing Technique for Small Field of View Imaging

Zhiqiang Li¹, Donglai Huo², Xiaoli Zhao¹, Ajeetkumar Gaddipati¹, James Pipe²

¹GE Healthcare, Waukesha, WI, USA; ²Barrow Neurological Institute, Phoenix, AZ, USA

Split-blade PROPELLER was introduced for diffusion-weighted (DW) imaging to avoid image distortion. When imaging a small field of view of a large object, No-Phase-Wrap (NPW) is usually applied to remove aliasing, with a trade off in blade width and scan time. In this work a new method based on parallel imaging techniques was proposed to effectively eliminate the aliasing for DW-PROPELLER. The feasibility is demonstrated in phantom and spine imaging with image quality comparable to conventional NPW but without the loss of scan time or blade width.

14:30         3518.     PROPELLER DUO: Applied to Diffusion-Weighted Imaging

Xiaoli Zhao¹, Zhiqiang Li¹, Ajeetkumar Gaddipati¹

¹GE Healthcare, Waukesha, WI, USA

A novel pulse sequence, PROPELER DUO is presented to address the non-CPMG issue of diffusion-weighted (DW) PROPELLER. By the synchronized play-out of readout gradients, RF pulses and “phaser” gradients, PROPELLER DUO splits all the echoes in pathways into two self-coherent echo groups (E1 and E2) to form two perpendicular blades in a single k-space. This sequence is named as PROPELLER DUO, based on the facts that “two” echo groups are separated and form “two” blades in a single shot. Distortion-free DW imaging with whole brain coverage can be completed within 1 minute 30 seconds.

15:00         3519.     New Horizons in Diffusion Weighted Imaging: A Comprehensive Evaluation of a Fast Spin Echo DWI Sequence with Radial K-Space Sampling at 3T Using a 32-Channel Head Coil in Acute Brain Ischemia.

Ulrike Irmgard Attenberger¹, Val M. Runge², K D. Williams², Alto Stemmer³, Henrik J. Michaely⁴, Stefan O. Schoenberg⁴, Maximilian F. Reiser¹, Bernd J. Wintersperger¹

¹Department of Clinical Radiology, Munich University Hospitals - Grosshadern, Ludwig-Maximilians-University, Munich, Germany; ²Department of Radiology, Scott & White Clinic and Hospital, Texas A&M University Health Science Center, Temple, TX, USA; ³Siemens Medical Solutions, Erlangen, Germany; ⁴Department of Clinical Radiology and Nuclear Medicine, University Medical Center Mannheim, Medical Faculty Mannheim – University of Heidelberg, Mannheim, Germany

Diffusion weighted MR imaging became widely accepted as reliable method for the diagnosis of brain ischemia early after stroke onset. Single-shot spin echo echoplanar imaging is most commonly used for acquisition of diffusion weighted scans but relatively low resolution, low SNR and bulk susceptibility artifacts decrease their diagnostic value. A promising new scan technique (`BLADE` DWI) is now available for diffusion imaging using a fast spin echo sequence (FSE) with radial k-space sampling that could help overcome susceptibility artifacts. A FSE BLADE diffusion weighted imaging was evaluated at 3 T in combination with a 32-channel head coil in this study.

13:30         3520.     Measuring Small Compartmental Dimensions with Low-Q Angular Double-PGSE NMR

Noam Shemesh¹, Evren Özarslan², Peter J. Basser², Yoram Cohen¹

¹School of Chemistry, Tel Aviv University, Tel Aviv, Israel; ²Section on Tissue Biophysics and Biomimetics, NICHD, National Institute of Health, Bethesda, MD, USA

In this study, we presented a method employing low amplitude gradients to estimate the pore dimension in restricted compartments, circumventing the need for high q values. We have shown that we can accurately estimate the dimensions of even small pores (5ìm) when the timing parameters of the low-q angular double-PGSE experiments are incorporated into our simulations, provided that the diffusion times are long enough to probe the boundaries. This experimental study validates the theory that was previously published. Low-q angular d-PGSE NMR may fill an important niche in characterizing compartment sizes in which restricted diffusion occurs.

14:00         3521.     Partial Volume Averaging and Contrast-To-Noise Ratios in Diffusion Tensor MRI: Effects of Using Multiple B-Values

Marta Morgado Correia¹, Virginia FJ Newcombe², Thomas Adrian Carpenter¹, Guy B. Williams¹

¹Wolfson Brain Imaging Centre, University of Cambridge, Cambridge, UK; ²Wolfson Brain Imaging Centre, University of Cambridge , Cambridge, UK

A two-tensor compartment model was used to simulate simple partial volume effects, and the data generated was used to compare the performance of different DTI acquisition schemes in estimating ADC and FA. Results show that the use of multiple b-values increases the accuracy of the measurements, as well as their stability in the presence of noise. Simulations and experimental data also show that the ability to differentiate between tissue types increases with the number of b-values used.

14:30         3522.     Diffusion-Sensitive Single-Shot Proton-Echo-Planar-Spectroscopic-Imaging (PEPSI) in Human Brain

Stefan Posse^1,2, Akio Ernesto Yoshimoto², Ricardo Otazo³, Andre van der Kouwe^4,5, Fa-Hsuan Lin^4,5, Lawrence L. Wald^4,5

¹Neurology, U. New Mexico, Albuquerque, NM, USA; ²Electrical and Computer Engineering, U. New Mexico, Albuquerque, NM, USA; ³New York University Medical Center, New York, NY, USA; ⁴MGH-HMS-MIT Athinoula A. Martinos Center for Biomedical Imaging, Charlestown, MA, USA; ⁵Radiology, Massachusetts General Hospital, Boston, MA, USA

Metabolite diffusion coefficients reflect intra-cellular viscosity, restriction in subcellular structures and cytoplasmic streaming. However, spatial mapping of metabolite diffusion in vivo is not feasible with conventional phase encoded MRSI techniques due to the strong motion sensitivity. We are showing proof-of-concept of single-shot MRSI with SENSE and Superresolution reconstruction in human brain using 32-channel head coil. Clinical applications, such as the study of intra-cellular changes in Multiple Sclerosis, ischemia and tumors, for diagnostic and treatment monitoring may become feasible.

15:00         3523.     Do We Need Cardiac Gating in Brain-DTI at High (3T) and Ultra-High (7T) Field Strengths?

Josef Habib^1,2, Richard Bowtell², Dorothee P. Auer¹, Paul S. Morgan^1,3

¹Academic Radiology, University of Nottingham, Nottingham, Nottinghamshire, UK; ²Physics and Astronomy, University of Nottingham, Nottingham, Nottinghamshire, UK; ³Radiology & Radiological Sciences, Medical University of South Carolina, Charleston, SC, USA

This work aims to address a number of outstanding issues to determine whether or not cardiac gating should be used as a standard practice in DTI at 3T and 7T. To this end, repeated DTI-scans of a heavily affected region were acquired, and datasets of larger populations simulated via Bootstrapping. In the FA-values of 3T-scans cardiac pulsation was found to result in potentially significant artefacts in certain individuals. On a group level, however, the observed errors were small compared to scanner instabilities. At 7T, the even lower scan-rescan stability completely masked cardiac pulsation effects in all observed volunteers.

13:30         3524.     Stimulated-Echo DTI with Magnetization Transfer Contrast for Myelin Specificity

Alexandru Vlad Avram¹, Arnaud Guidon¹, Allen W. Song¹

¹Brain Imaging and Analysis Center, Duke University, Durham, NC, USA

We present a stimulated echo DTI sequence with magnetization transfer capable of imaging the diffusion anisotropy of proton pools in myelin water. Moreover, we establish a theoretical model for estimating the anisotropy of the low T2 (myelin) and high T2 (axonal) water compartments in the white matter. Results confirm that the anisotropy of the exchanged magnetization is more similar to that of the low T2 compartment, and appears to be the main contributor to the anisotropy of the myelin water. We anticipate that this new technique will be used clinically for early diagnosis of white matter pathology (e.g. demyelination).

14:00         3525.     Discarded Image Volumes and Gradient Table Alignment: How Much Do They Affect DTI Tensor Calculations?

Lutfi Tugan Muftuler¹, Orhan Nalcioglu¹

¹Center for Functional Onco-Imaging, University of California, Irvine, CA, USA

DTI image volumes are preprocessed prior to the calculation of tensor model parameters. Before the preprocessing, it is common to discard some of the image volumes (or slices) if there are artifacts. The second step is to align all diffusion images. This corrects both the image deformations due to eddy current effects and the head motions. Sometimes the motion corrections are also applied to the gradient tables to ensure accuracy. In this study, we investigated the impact of these correction steps on the quality of FA maps, which are the most commonly used DTI parameter maps.

14:30         3526.     Non-Gaussian Diffusion MR Maps of Human Brain

Silvia De Santis^1,2, Silvia Capuani³

¹Physics Department Sapienza University Rome, Rome, Italy; ²CNR-INFM SOFT , Physics Department Sapienza University Rome, Rome, Italy; ³CNR-INFM SOFT, Physics Department Sapienza University Rome, Rome, Italy

Our goal was to investigate the potential role of non-gaussian diffusion methods in discriminating among the different cerebral tissues (i.e. WM, GW, CSF) and in detecting differences into a selected tissue characterized by a known MR-parameter. This preliminary study shows a different pattern of ã values when considering WM and GM tissues. Moreover, a different pattern of change is detectable for WM regions with a higher (i.e., corpus-callosum) as compared to those with a lower level of fiber tracts coherency (i.e., corona radiata). ã values might be suitable for detecting subtle changes in neurological disorders not associated with macroscopic tissue-damages.

15:00         3527.     Does Kurtosis or Stretched-Exponential Model Fit Experimental Diffusion-Weighted Data Better?

Edward S. Hui^1,2, Abby Y. Ding^1,2, Ed X. Wu^1,2

¹Laboratory of Biomedical Imaging and Signal Processing, The University of Hong Kong, Hong Kong SAR, China; ²Department of Electrical and Electronic Engineering, The University of Hong Kong, Hong Kong SAR, China

Diffusion-weighted (DW) signal dependence on b-value in neural tissues deviates from monoexponential decay. As a result, numerous models have been proposed to characterize such non-monoexponential decay. Two of them, namely kurtosis and stretched-exponential model, are of special interest. This study aimed to evaluate the performance of these two models in describing the experimental DW signals obtained from rodent brains in vivo. Our analysis demonstrates that the quadratic diffusion kurtosis model provides better fitting of DWI data, suggesting that DKI is a more accurate and robust diffusion model for characterizing the complex diffusion processes in vivo in neural tissue.

14:00         3528.     Anatomical Cortico-Cortical Networks of the Human Brain Based on Diffusion Probabilistic Tractography

Ruiwang Huang¹, N Jon Shah^1,2, Lars Hoemke¹, Oleg Posnansky¹, Karl Zilles^1,3, Katrin Amunts^1,4

¹Institute of Neuroscience and Biophysics - Medicine, Research Centre Juelich, Juelich, Germany; ²Department of Neurology, RWTH Aachen University, Aachen, Germany; ³C. and O. Vogt Institute for Brain Research, Heinrich-Heine-University of Duesseldorf, Duesseldorf, Germany; ⁴Department of Psychiatry and Psychotherapy, RWTH Aachen University, Aachen, Germany

The identification and quantification of networks in the human brain is a key issue in neuroscience. Here, we construct an anatomical cortico-cortical connectivity (CCC) matrix based on diffusion-weighted imaging (DWI) and diffusion probabilistic tractography (DPT) in 14 subjects. The cortical networks corresponding to symmetric and antisymmetric CCC-matrices were constructed with respect to Brodmann areas (BA) as vertices. With the application of an unsupervised learning network approach on the cortical network, the cortex was partitioned into seven major subdivisions. Several highly connected cortical areas were detected from the CCC-network such as BA8, BA22 and BA42 as well as the insular and periinsular cortex.

14:30         3529.     Feasibility of Prefronto-Caudate Pathway Tractography Using High Resolution Diffusion Tensor Tractography Data at 3 T

Arash Kamali¹, Larry A. Kramer², Khader M. Hasan²

¹Diagnostic and Interventional Imaging, University of Texas Health Science Center at Hosuton, Houston, TX, USA; ²Diagnostic and Interventional Imaging, University of Texas Health Science Center at Houston, Houston, TX, USA

We demonstrate the feasibility of in vivo delineation and 3D reconstruction of the prefronto-caudate pathway using high resolution DTI data on 3.0 T and also the ability to separate and quantify the diffusion tensor metrics of anterior thalamic radiation (ATR) and prefronto-caudate pathways.

15:00         3530.     Kiss to Cross ! Non-Invasive Mapping of Cerebellar Dentate Nucleus Projections to the Cerebral Cortex

vinod kumar^1,2, Michael Erb¹, Sudhir Pathak³, Wolfgang Grodd¹

¹Section Exp. MR of the CNS, Universtiy of tuebingen, Tuebingen, Germany; ²Graduate School of Neural & Behavioural Sciences | International Max Planck Research School, Universtiy of tuebingen, Tuebingen, Germany; ³LRDC, Universtiy of Pittsburgh, Pittsburgh, USA

Post-mortem connectivity based methods demonstrate that the cerebellar dentate nuclei act as the main center of communication to the cerebral cortex. Dentate nuclei have a contralateral connection with the cerebral cortex. However, direct invivo diffusion imaging of this crossing and of the dentate projections to the cortex via crossing is lacking. diffusion-tractography with integration of resting-state-fMRI is used to investigate the dentate-thalamocortical circuit. The results inflect the dentate nuclei connectivity with the contralateral cortical regions via the thalamic nuclei i.e. motor, posterior-parietal, frontal, and temporal regions. In the study, connectivity based organization about the output-channels within the dentate is introduced. The study holds promise for clinical applications.

15:30         3531.     In Vivo Diffusion Spectrum Imaging Shows the Structural Basis of the “Papez Circuit”

Cristina Granziera¹, Reto Meuli², Gunnar Krueger³

¹CHUV, Dpt of Neurology , Lausanne, VD, Switzerland; ²CHUV, Dpt of Radiology, Lausanne, VD, Switzerland; ³Siemens Switzerland SA - CIBM, Advanced Clinical Imaging Technology, Switzerland

The “Papez circuit” is an important anatomical substrate of memory and emotion. To date, however, no attempt has been done to show the structural basis of this circuit in-vivo, probably due to its convoluted shape and complex nature. In this investigation, we disentangled the anatomical structure of the “Papez Circuit” in humans using high-angular resolution diffusion spectrum imaging tractography. In six subjects, we could consistently map the hippocampus-mamillary body pathway, the pathway connecting the lateral subiculum to the cingulated cortex and the tract connecting the mamillary body to the thalamus, where higher level integration of cognition is performed.

13:30         3532.     Diffusion Tensor Tractography of the Somatosensory System in the Human Brainstem: Initial Findings Using High Isotropic Spatial Resolution at 3.0 T

Arash Kamali¹, Larry A. Kramer², Ian J. Butler³, Khader M. Hasan²

¹Diagnostic and Interventional Imaging, University of Texas Health Science Center at Hosuton, Houston, TX, USA; ²Diagnostic and Interventional Imaging, University of Texas Health Science Center at Houston, Houston, TX, USA; ³Pediatrics, University of Texas Health Science Center at Hosuton, Houston, TX, USA

Lack of adequate spatial resolution has impeded depiction of different somatosensory pathways with unique sensory functions such as spinal lemniscus (SL) and medial lemniscus (ML). The purpose of this study is to demonstrate that a reliable delineation of the ML and SL on Diffusion Tensor Imaging (DTI) requires higher spatial resolution combined with accurate ROI placement. This is the first study to demonstrate the feasibility of in vivo delineation and reconstruction of the two major somatosensory pathways with unique sensory functions using high spatial resolution DTI data on 3.0 T.

14:00         3533.     In Vivo Fiber Tracking in the Rabbit Brain on a Clinical 3T MRI System

Daniel Güllmar¹, Stephan Lau^2,3, Lars Flemming⁴, Jens Haueisen³, Jürgen R. Reichenbach¹

¹Medical Physics Group, University Hospital Jena, Jena, Germany; ²Neuroengineering Group, Electrical and Electronic Engineering, University of Melbourne, Melbourne, Australia; ³Institute of Biomedical Engineering and Informatics, TU Ilmenau, Ilmenau, Germany; ⁴Biomagnetic Center, University Hospital Jena, Jena, Germany

This study shows the feasibility of in vivo fiber tracking of the rabbit brain using DTI-MRI on a clinical whole-body 3T MRI system. Applying in-plane interpolation and overlapping interleaved slices resulted in a dataset with isotropic resolution of 0.6 mm³. Seventy different diffusion weighted directions and six b0-images were scanned in less than 20 minutes. The applied deterministic tracking of the tensor data revealed well defined major tracts in good agreement with the anatomic structure.

14:30         3534.     Addressing the Problem of Path-Length Dependency in Probabilistic Tractography – the ICE-T Framework

Matthew George Liptrot¹, Karam Sidaros¹, Tim Bjørn Dyrby¹

¹DRCMR, MR dept. 340, Copenhagen University Hospital Hvidovre, Hvidovre, Denmark

One of the primary hurdles to the quantitative interpretation of probabilistic tractography results is the path-length dependency problem. Here we present a novel framework, Iterative Confidence Enhancement for Tractography (ICE-T), which addresses the issue and can be implemented with any conventional probabilistic tractography method. Fibre-tracking was performed from a somatosensory seed region, and whereas a traditional approach with 60,000 streamlines failed to penetrate far into the contralateral hemisphere, the ICE-T version succeeded with good agreement with in-vivo tracer results. We hope that ICE-T will allow future comparison of quantitative fibre-tracking results across subjects.

15:00         3535.     Evaluation of DTI Tractography at Long and Short Diffusion Times in ex Vivo and in Vivo Rhesus Macaques

Swati Rane^1,2, Timothy Q. Duong³

¹Georgia Institute of Technology, Atlanta, GA, USA; ²Yerkes Imaging Center, Emory University, Atlanta, GA, USA; ³Research Imaging Center, University of Texas Health Science Center at San Antonio, San Antonio, TX, USA

This study investigated DTI tractography using long diffusion time (t_diff) to improve tracking of smaller fibers in fixed and in vivo rhesus monkey brains. By comparison with short diffusion time, DTI at long t_diff increased fractional anisotropy and tracked longer fiber connections in regions of low diffusion anisotropy at the same statistical thresholds. These results together offer encouraging data that DTI at long diffusion time could improve the ability of DTI tractography to trace smaller fibers.

13:30         3536.     High Resolution Ex-Vivo Diffusion Imaging and Fiber Tracking

Thomas Benner¹, Akram Bakkour², Ruopeng Wang¹, Bradford Clark Dickerson²

¹Radiology, Athinoula A. Martinos Center, Charlestown, MA, USA; ²Gerontology Research Unit, Massachusetts General Hospital, Charlestown, MA, USA

The feasibility of high resolution ex-vivo diffusion-weighted steady state free procession (DW-SSFP) imaging with tensor based fiber tracking was examined. One hemisphere was scanned for 60 hours at 3 T using a 3-D DW-SSFP sequence at a spatial resolution of 0.5x0.5x0.5 mm³ isotropic. We found that DW-SSFP data can be used with standard fiber tracking software. Spatial resolution and SNR are high enough to allow fiber tracking in gray matter.

14:00         3537.     ExploreDTI: A Graphical Toolbox for Processing, Analyzing, and Visualizing Diffusion MR Data

Alexander Leemans¹, Ben Jeurissen², Jan Sijbers², Derek K. Jones¹

¹CUBRIC, School of Psychology, Cardiff University, Cardiff, Wales, UK; ²Visionlab - Department of Physics, University of Antwerp, Antwerp, Belgium

Diffusion tensor imaging is becoming a standard addition to routine MR imaging for investigating microstructural tissue properties. With this research field rapidly evolving, the need for efficient and user-friendly diffusion MR processing/analysis software packages is also increasing. Here, a new MR diffusion toolbox – dubbed ExploreDTI – is officially presented for the first time. ExploreDTI is a non-commercial package that combines many of the key MR diffusion processing tools that have appeared in the recent literature, but which have not necessarily been widely available. The package will be made freely available to academic institutions following the ISMRM meeting in Hawaii. The main features of ExploreDTI are summarized.

14:30         3538.     A Comparative Study Between 4 Optimal DWI Gradient Sampling Schemes: Simulations Based on Constrained Spherical Deconvolution (CSD)

Shiou-Ping Lee¹, Jacques-Donald Tournier², Christopher-P Hess³, Chung-Ming Chen¹, Wen-Yih Isaac Tseng⁴

¹Institute of Biomedical Engineering, National Taiwan University, Taipei, Taiwan; ²Brain Research Institute, Florey Neuroscience Institutes, Austin, Melbourne, Australia; ³Department of Radiology, University of California-San Francisco, San Francisco, California,, USA; ⁴Center for Optoelectronic Biomedicine, National Taiwan University Medical College, Taipei, Taiwan

The constrained spherical deconvolution (CSD) approach has been shown to be robust to resolve fibers crossing at small angles. Nevertheless, the DW gradient sampling scheme is also crucial to obtain an accurate reconstruction of the fiber orientation distribution (FOD), although the optimal scheme to use with high angular resolution DW imaging (HARDI) methods has not been fully investigated. The goal of this study is to determine the optimal sampling scheme for use with CSD, in terms of the precision of the estimated fiber orientations. This will improve the reliability of performing white matter tractography through crossing fiber regions.

15:00         3539.     Optimal Real-Time Q-Ball Imaging with Incremental Recursive Orientation Sets

Maxime Descoteaux¹, Jeff Calder², Cyril Poupon¹, Fabrice Poupon¹, Rachid Deriche²

¹NeuroSpin, IFR 49, CEA Saclay, Gif-sur-Yvette, France; ²Odyssee Projet, INRIA, Sophia Antipolis, France

We propose an optimal real-time system for q-ball imaging using a regularized Kalman filtering framework and incremental orientation sets. We show that the ODF reconstruction for every incoming diffusion measurements. We also show that the orientation set can be computed on the fly with an efficient recursive algorithm.

13:30         3540.     An Interface for DTI Tractography

Shruti Agarwal¹, Rakesh K. Gupta², RKS Rathore¹, Sanjay Kumar Verma¹, Richa Trivedi², Manoj Verma², Prativa Sahoo¹

¹Mathematics & Statistics, Indian Institute of Technology, Kanpur, UP, India; ²Department of Radiodiagnosis, Sanjay Gandhi Post Graduate Institute of Medical Sciences, Lucknow, UP, India

We have developed a cross-platform graphical user environment using JAVA. Maps necessary for evaluating fiber tract architecture in the brain were computed. From a given volume data, multiple ways for selecting ROI (Region of Interest), from which user can reconstruct various fiber tracts have been provided. The interface incorporates operations of add/delete selected fibers, morphological trimming operations, boolean set operations on fiber bundles and gathering statistics on the obtained fiber volume or parts of it.

14:00         3541.     Robust Extraction of Fiber Skeleton Based on Whole Fiber Tensor Information and Active Contour Method

Wu Li¹, Xiaoping P. Hu¹

¹Department of Biomedical Engineering, Georgia Tech and Emory University, Atlanta, GA, USA

In DTI data analysis fiber-based quantitative analyses are becoming more widely used for cross subject comparison. To detect the fiber trajectory, tractography methods or skeleton extracted from FA are usually used. However, fiber tracking methods track fibers according to local diffusion orientation, which are highly sensitive to noise and leading to cumulative errors. We proposed an approach to extract fiber trajectory based on an active contour model, taking into account both fiber regularity and measured DTI data. Results show that this method leads to improved fiber trajectory, which can potentially improve the accuracy of fiber based analysis.

14:30         3542.     Diffusion Sensitization Direction Dependence of Biexponential Diffusion Decay Parameters in the Splenium

Robert Vincent Mulkern¹, Richard Lee Robertson¹, Stephen John Haker², Dimitrios Mitsouras², Stephan E. Maier²

¹Radiology, Children's Hospital, Boston, MA, USA; ²Radiology, Brigham and Women's Hospital, Boston, MA, USA

The dependence of biexponential parameters characterizing diffusion decay curves from the splenium on the angle between fiber direction and diffusion sensitization direction was examined. An angular dependence of the slow diffusion coefficient consistent with current models was obtained. A similar angular dependence for the fast fraction amplitude and the fast diffusion coefficient was also found, features which are not explained by current models.

15:00         3543.     White Matter Fiber Tractography with Genetic Algorithm

Xi Wu^1,2, Qing Xu³, Jiliu Zhou¹, Adam W. Anderson^2,4, Zhaohua Ding^2,3

¹School of Electronics and Information Engineering, Sichuan University, Chengdu, Sichuan, China; ²Institute of Imaging Science, Vanderbilt University, Nashville, TN, USA; ³Department of Electrical Engineering and Computer Science, Vanderbilt University, Nashville, TN, USA; ⁴Department of Biomedical Engineering, Vanderbilt University, Nashville, TN, USA

Diffusion tensor imaging based fiber tractography has become a primary tool for non-invasive exploration of white matter structures in the human brain. To reliably track fiber pathways, a novel technique based on well established genetic algorithms was proposed in this work. Compared to existing methods, the new tracking algorithm incorporates a global constraint, thus making it insusceptible to image noise and other local artifacts. In addition, it generates fiber pathways that are independent of the tracking direction – this greatly benefits subsequent quantitative characterization of structure connectivity between two regions.

14:00         3544.     Estimation of Multiple Fibre Orientations Using Convex Optimization

Jaime E. Cisternas¹, Tim B. Dyrby², Takeshi Asahi³, Marcelo Galvez⁴, Gonzalo Rojas⁵

¹Engineering School, Universidad de los Andes, Santiago, RM, Chile; ²Danish Research Centre for Magnetic Resonance, Copenhagen University Hospital Hvidovre, Hvidovre, Denmark; ³Center for Mathematical Modelling, Universidad de Chile, Santiago, Chile; ⁴Neurosurgery Institute, Universidad de Chile, Santiago, Chile; ⁵Clinica Santa Maria, Radiology, Santiago, Chile

A method is presented that is capable of determining more than one fibre orientation within a single voxel from diffusion weighted MR images of the brain. The method can identify voxels with directional heterogeneity and assess the relevance of each direction in the signal. The method describes the diffusion weighted dataset as a combination of one isotropic compartment and a large pre-specified set of anisotropic compartments, and uses regularized least squares to find the amplitude of each component, reducing overfitting i.e. the use of unnecessary degrees of freedom. The result is a sparse representation of the diffusion signal in terms of a few anisotropic compartments. Using diffusion weighted MR datasets, we show that the multiple orientation method gives robust results across a wide range of b-values, and can be further enhanced using multi-channel denoising on the raw datasets. The method is fast and uses standard optimization algorithms. Results of this methodology can potentially improve results of multi-fibre tractography.

14:30         3545.     Dataset-Independent Reconstruction of High Angular Resolution Diffusion Sampling Schemes by Generalized Q-Space Imaging

Fang-Cheng Yeh¹, Van Jay Wedeen², Wen-Yih Isaac Tseng^1,3

¹Center for Optoelectronic Biomedicine, National Taiwan University College of Medicine, Taipei, Taiwan; ²MGH Martinos Center for Biomedical Imaging, Harvard Medical School, Charlestown, MA, USA; ³Department of Medical Imaging, National Taiwan University Hospital, Taipei, Taiwan

We propose a novel q-space imaging method derived from the Fourier transform relationship between the MR signals and diffusion displacement probability density function. The method is featured by being independent of the q-space sampling schemes, such as high angular resolution images (HARDIs) and diffusion spectrum imaging (DSI) grid dataset. The accuracy of the method is examined in comparison with q-ball imaging (QBI) and DSI.

15:00         3546.     Dual Q-Ball Imaging Reveals Intravoxel Orientation Distribution Functions for Laminar Structures in the Heart.

Hans Dierckx¹, Alan P. Benson^2,3, Stephen H. Gilbert^2,3, Mike E. Ries^3,4, Arun V. Holden^2,3, Henri Verschelde¹, Olivier Bernus^2,3

¹Department of Mathematical Physics and Astronomy, Ghent University, Gent, Belgium; ²Institute of Membrane and Systems Biology, University of Leeds, Leeds, UK; ³Multidisciplinary Cardiovascular Research Centre, University of Leeds, Leeds, UK; ⁴School of Physics and Astronomy, University of Leeds, Leeds, UK

Knowledge of both fiber and sheet organization is crucial for understanding of mechanical and electrophysiological processes in heart tissue. Diffusion tensor imaging is able to provide this information in regions where a single dominant fiber or sheet structure is present. For probing more complex fiber architecture, one needs high angular resolution methods such as Q-Ball Imaging (QBI).

15:30         3547.     The Effect of the Acquisition Parameters for High Angular Resolution Diffusion Imaging

Vesna Prckovska¹, Alard F. Roebroeck², Pim W.L.P.M. Pullens^3,4, Anna Vilanova, Bart M. ter Haar Romeny

¹Biomedical Engineering, Technical University of Eindhoven, Eindhoven, Netherlands, Netherlands; ²Maastricht Brain Imaging Center, Dept. of Cognitive Neuroscience, Faculty of Psychology, Maastricht University, Maastricht, Netherlands; ³Maastricht Brain Imaging Center, Dept. of Cognitive Neuroscience, Faculty of Psychology, Maastricht University,, Maastricht, Netherlands; ⁴Brain Innovation B.V., Maastricht, Netherlands

High Angular Resolution Diffusion Imaging is an emerging area that overcomes the known limitations in Diffusion Tensor Imaging. One of the recent challenges in HARDI is to find acquisition schemes that can correctly represent non-Gaussian profiles in a clinical setting. This study investigates the effect of the b value and the number of gradient vector directions for Q-ball imaging and Diffusion Orientation Transform. Extensive quantitative analysis is given on synthetic software and hardware phantom data, as well as qualitative analysis on in-vivo data. Our results suggest that over a wide range of acquisition schemes DOT can outperform Q-ball.

13:30         3548.     Application of Automated Fiber Tract Identification and Restriction Spectrum Imaging to Study Microstructural Changes in White Matter Tracts Associated with Temporal Lobe Epilepsy.

Donald Joseph Hagler¹, Nathan S. White², Christopher J. Pung¹, Carrie R. McDonald³, Eric Halgren^1,4, Anders M. Dale^1,4

¹Radiology, UCSD, La Jolla, CA, USA; ²Cognitive Science, UCSD; ³Psychiatry, UCSD; ⁴Neurosciences, UCSD

Diffusion Imaging can probe microstructural changes caused by a variety of diseases and disorders. Diffusion tensor analysis, and the derived fractional anisotropy measure, is often used to quantify such changes; however, FA depends on a number of factors. We have used a multi-compartment fiber orientation distribution model to derive more sensitive and specific measures of the coherence of fiber orientations and the relative volume fraction of isotropic tissue and free water. We averaged these measures within fiber tract ROIs generated with a probabilistic-atlas based method to study differences in tissue properties associated with temporal lobe epilepsy.

14:00         3549.     Mixture Model for Estimating Fiber ODF and Multi-Directional Tractography

Yogesh Rathi¹, James Malcolm², Sylvain Bouix¹, Gordon Kindlmann³, Carl-Fredrik Westin³, Marek Kubicki¹, Martha E. Shenton¹

¹Psychiatry, Harvard Medical School, Boston, MA, USA; ²Psychiatry, Brigham and Women's Hospital; ³Radiology, Harvard Medical School

In this work, we propose to use a mixture model of Watson directional functions for representing the signal and computing the diffusion ODF and fiber ODF. The parameters of the model can be directly used for multi-directional streamline tractography, which allows to track fibers not possible with single-tensor tractography methods. In addition, the model parameters live in a vector space and hence interpolation between ODF's is straightforward. The number of parameters required to represent each fiber is 3 (2 for direction in spherical coordinates and 1 scaling). Thus, the representation is also concise.

14:30         3550.     Evaluation of Angular Uncertainties of Q-Space Diffusion MRI Under Finite Gradient Pulse Widths : A Phantom Study

Chun-Hung Yeh¹, Jacques-Donald Tournier², Kuan-Hung Cho³, Cyril Poupon⁴, Ching-Po Lin⁵

¹Department of Biomedical Imaging and Radiological Sciences, National Yang-Ming University, Taipei, Taiwan; ²Brain Research Institute, Melbourne, Australia; ³Department of Electrical Engineering, National Taiwan University, Taipei, Taiwan; ⁴CEA Neurospin, Gif-sur-Yvette cedex, France; ⁵Institute of Neuroscience, National Yang-Ming University, Taipei, Taiwan

Prolonging diffusion pulse duration (£_) has been found to be beneficial for fibre orientation estimation, however a longer £_ also leads to a longer echo time, which should be considered for setting the optimal imaging parameters. We therefore compare both the DW signal and the angular accuracy of diffusion imaging using various £_ with the corresponding minimum TE from DW phantom models. The results demonstrate that for most current DW MRI techniques to map complex fibre architecture, which utilize intermediate to high b-values, the application of a long £_ may not be problematic for the purpose of fibre orientation estimation.

15:00         3551.     Effects of Coregistration for the Reconstruction of High Angular Resolution Diffusion Imaging

Yi-Ping Chao¹, Kun-Hsien Chou², Kuan-Hung Cho¹, Chun-Hung Yeh³, Jyh-Horng Chen¹, Ching-Po Lin^3,4

¹Department of Electrical Engineering, National Taiwan University, Taipei, Taiwan; ²Institute of Biomedical Engineering, National Yang-Ming University, Taipei, Taiwan; ³Institute of Biomedical Imaging and Radiological Sciences, National Yang-Ming University, Taipei, Taiwan; ⁴Institute of Neuroscience, National Yang-Ming University, Taipei, Taiwan

High angular resolution diffusion imaging (HARDI) has been proposed for resolving heterogeneity of white matter fibers within an MR voxel. Long acquisition time of HARDI would lead to image distortion caused by head motion during the scan sessions. Here, we present that initial coregistration step for the high b-value DWIs might be beneficial for the reconstruction of dODFs and subsequent fiber tractography with experimental data. According to the results, it is shown clearly that non-coregistered QBI were influenced more easily by the partial volume effect of adjacent microstructures, especially within the region with tract of single orientation.

13:30         3552.     A Web-Based Probabilistic Tractography Database

Chris James Rose¹, David Ellard¹, David Morris¹, Hamied Haroon¹, Karl Embleton^1,2, Nikos K. Logothetis^1,3, Matthew A. Lambon Ralph², Geoffrey J. Parker¹

¹Imaging Science and Biomedical Engineering, School of Cancer and Imaging Sciences, The University of Manchester, Manchester, UK; ²School of Psychological Sciences, The University of Manchester, Manchester, UK; ³Max Planck Institute for Biological Cybernetics, Tübingen, Germany

Diffusion tensor imaging (DTI) and probabilistic tractography allow inferences to be made about connectivity in the brain. Tractography results are useful to a range of communities, from those working in MR, through biologists, psychologists and physicians. However, few who stand to benefit have ready access to the requisite MR scanners, sequences and tractography software. This abstract describes a new Internet-based system that allows researchers to obtain anatomical connectivity information—derived from DTI and probabilistic tractography—for a number of human and animal subjects. We provide a web browser-based interface suited to manual browsing, and a programmatic interface suited to batch processing.

14:00         3553.     Probabilistic Tractography Driven White Matter Width Measurement

Hojjatollah Azadbakht¹, David Mark Morris¹, Hamied Ahmed Haroon¹, Karl V. Embleton^1,2, Brandon J. Whitcher³, Julie Snowden⁴, Geoff J. Parker¹

¹Imaging Science and Biomedical Engineering, School of Cancer and Imaging Sciences, University of Manchester, Manchester, UK; ²School of Psychological Science, University of Manchester, Manchester, UK; ³Clinical Imaging Centre, GlaxoSmithKline, London, UK; ⁴Greater Manchester Neuroscience Centre, Hope Hospital, Salford, UK

This work introduces a novel approach to quantify the width of the White Matter (WM) structures in the brain. The PICo tractography method was used to extract the Uncinate Fasciculus (UF) from both hemispheres of 10 normal datasets. An electric field model was used to generate the curve-skeletons of the extracted tracts. Subsequently, using the generated electro-static vector fields, for each point along the curve-skeletons, the mean geodesic distance from the surface to the skeleton was computed. Seven of the subjects demonstrated right hemisphere lateralization, where the right UF had a higher mean width score than the left.

14:30         3554.     Regional Microstructural Differences of the Corpus Callosum Using Cytoarchitectural Parcellation and DT-MRI

Yi-Ping Chao¹, Kuan-Hung Cho¹, Chun-Hung Yeh², Kun-Hsien Chou³, Jyh-Horng Chen¹, Ching-Po Lin^2,4

¹Department of Electrical Engineering, National Taiwan University, Taipei, Taiwan; ²Institute of Biomedical Imaging and Radiological Sciences, National Yang-Ming University, Taipei, Taiwan; ³Institute of Biomedical Engineering, National Yang-Ming University, Taipei, Taiwan; ⁴Institute of Neuroscience, National Yang-Ming University, Taipei, Taiwan

In this study, population-based probabilistic connection topographies of the CC, in the standard MNI space, were estimated by incorporating anatomical cytoarchitectural parcellation with high angular resolution diffusion imaging (HARDI) tractography. Using q-ball imaging (QBI) with MFACT algorithm, a more detailed CC subdivision according to 27 selected Brodmann¡¦s areas (BAs) was demonstrated. Further, it allowed an assignment of the quantitative distribution of fractional anisotropy (FA) values derived from diffusion tensor imaging (DTI) data of 20 normal healthy subjects to evaluate the correlation with neural composition in distinct CC regions explored by previous postmortem study.

15:00         3555.     Quantitative Tractography Metrics of White Matter Integrity in Diffusion-Tensor MRI Using Diffusivity Scalars

Eni Halilaj¹, Cagatay Demiralp², Stephen Correia³, David H. Laidlaw¹

¹Computer Science, Brown University, Providence, RI, USA; ²Computer Science, Brown University, Providence , RI, USA; ³Department of Psychiatry and Human Behavior, Warren Alpert Medical School of Brown University, Providence, RI, USA

We present six new quantitative tractography metrics for the assessment of white matter integrity in diffusion-tensor MRI. These metrics calculate a weighted total length of fiber tracts in brain tractography models. The weighting factors we use are well-established diffusion scalars, such as mean, axial, and radial diffusivity. The rationale for using these weighting factors is the fact that radial diffusivity is affected by demyelination whereas axial diffusivity is affected by axonal drop-out. Our findings suggest that these metrics can give hints on the nature of axonal damage, besides quantifying white matter deterioration.

13:30         3556.     Optimization of Diffusion Sequences Using Bootstrap Algorithms

Carolin Reischauer¹, Robert Stefan Vorburger¹, Philipp Staempfli¹, Peter Boesiger¹

¹Institute for Biomedical Engineering, ETH and University of Zurich, Zurich, Switzerland

The experimental optimization of diffusion sequences is crucial with respect to prospective clinical studies. But up to now it has not been possible to quantify measurement precision of diffusion parameters in-vivo. Recently, bootstrap techniques have been introduced which overcome the necessity of a large number of scan repetitions. So far, the performances of these algorithms have only been analyzed using Monte Carlo simulations. The present work investigates and compares the predicted measurement precision of two model-based and two non-model-based bootstrap algorithms experimentally and demonstrates that using this approach diffusion sequences can be effectively optimized.

14:00         3557.     An Evaluation of Contrast-To-Noise Ratios for Diffusion Anisotropy Metrics in the Presence of Multiple Fibres

Marta Morgado Correia¹, Virginia FJ Newcombe¹, Thomas Adrian Carpenter¹, Guy B. Williams¹

¹Wolfson Brain Imaging Centre, University of Cambridge, Cambridge, UK

Despite the undeniable successes of FA (fractional anisotropy), DTI derived anisotropy metrics can be inaccurate in the presence of orientational heterogeneity. The present study compared the performance of alternative metrics of anisotropy, both using simulated and experimental data. Results show that most alternative metrics result in less significant drops of values between one and two-fibre populations. In addition, the use of a higher rank tensor results in increased ability to differentiate between tissue types, for both simulated and experimental data.

14:30         3558.     Making the Robust Tensor Estimation Approach: "RESTORE" More Robust

Lin-Ching Chang¹, Lindsay Walker², Carlo Pierpaoli²

¹Department of Electrical Engineering and Computer Science  , The Catholic University of America, Washington, DC, USA; ²National Institutes of Health, Bethesda, MD, USA

The Robust Estimation of Tensors by Outlier Rejection (RESTORE) has been demonstrated to be an effective method for improving tensor estimation on a voxel by voxel basis in the presence of artifactual data points in the diffusion weighted images. Despite the very good performance of the RESTORE algorithm, there are some limitations and opportunities for improvement. This paper extends our previous work of improving diffusion tensor estimation by proposing two practical constraints in the outlier rejection process that make the RESTORE method more robust.

15:00         3559.     Investigation of DTI Bootstrap Reproducibility in the Human Brain

Robert Stefan Vorburger¹, Carolin Reischauer¹, Katerina Dikaiou¹, Philipp Staempfli¹, Peter Boesiger¹

¹Institute for Biomedical Engineering, University and ETH Zurich, Zurich, Switzerland

Bootstrap methods were recently introduced in diffusion tensor imaging (DTI) to quantify the uncertainty in derived parameters. In this study, four different bootstrap algorithms were investigated with respect to their reproducibility in in-vivo measurements. Therefore, the bootstrap techniques were applied to selected regions of interest in the human brain. The reproducibility was demonstrated in a clinical measurement setup in-vivo. A difference concerning the reproducibility between the model based and non-model based techniques cannot be distinguished. Therefore, the model based bootstrap methods provide powerful techniques to quantify the uncertainty of DTI parameters and offer supplementary information without requiring additional measurements.

14:00         3560.     Probabilistic Corticocortical Connectivity Maps of Human Brain Based on DTI Tractography and Cortical Parcellation

Hao Huang¹, Jerry L. Prince², Aaron Carass², Bennett Landman³, Peter C.M. van Zijl^4,5, Susumu Mori^4,5

¹Advanced Imaging Research Center, UT Southwestern Medical Center, Dallas, TX, USA; ²Electrical and Computer Engineering, Johns Hopkins University, Baltimore, MD, USA; ³Biomedical Engineering, Johns Hopkins University, Baltimore, MD, USA; ⁴Radiology, Johns Hopkins University, Baltimore, MD, USA; ⁵F.M. Kirby Functional MRI Center, Kennedy Krieger Institute, Baltimore, MD, USA

Corticocortical connectivity is correlated with many neurological or psychiatric diseases and brain functions. With the fused information from cortical parcellation and DTI-based tractography, the mapping of corticocortical tracts from a specific cortical lobe to other cortical areas can be used to set up quantitative connectivity maps. Cortical parcellation was used to localize the cortical lobes for regions of interests in DTI tractography. Probabilistic corticocortical connectivity maps were established by nonlinearly registering the connectivity results from ten subjects to a template space. These probabilistic connectivity maps can serve as important structural connectivity reference for fMRI and disease study.

14:30         3561.     Sex Differences in the Human Corpus Callosum Microstructure: T2 Myelin-Water Imaging Versus Diffusion Tensor Imaging

Logi Vidarsson¹, Fang Liu², Andrea Kassner^2,3

¹Diagnostic Imaging, The Hospital for Sick Children and the University of Toronto, Toronto, ON, Canada; ²Physiology and Experimental Medicine, Hospital for Sick Children, Toronto, ON, Canada; ³ Medical Imaging, The University of Toronto, Toronto, ON, Canada

The corpus callosum plays an important role in relaying sensory, motor and cognitive function between cerebral hemispheres. Females seem to employ a greater degree of bilateral hemispheric activity than males and also have a larger callosal area in proportion to brain volume, which suggests that a larger number of fibres are passing through. In this study we have compared short T2 myelin-water imaging to DTI in the corpus callosum of healthy volunteers. Our findings suggest that male fibers are less densely packed compared to female fibres but contain more myelin as reflected by the difference in myelin-water values.

15:00         3562.     Summary Statistics for Diffusion Tensor Imaging Brain Templates: Mean Vs. Median Tensors

Huiling Peng¹, Shengwei Zhang¹, Robert John Dawe¹, Anton Orlichenko², Gady Agam³, Konstantinos Arfanakis¹

¹Department of Biomedical Engineering, Illinois Institute of Technology, Chicago, IL, USA; ²Department of Electrical and Computer Engineering, Illinois Institute of Technology, Chicago, IL, USA; ³Department of Computer Science, Illinois Institute of Technology, Chicago, IL, USA

Human brain diffusion tensor imaging (DTI) templates developed to date use the mean tensor to summarize the DTI information from a group of subjects. However, spatial normalization of DTI data between subjects contains inaccuracies, and the mean of imperfectly matched tensors may have significantly different characteristics than the individual tensors. It is well known that, in distributions with statistical outliers, the median may be a more accurate summary statistic than the mean. The purpose of this work was to investigate the role of the mean and median tensors in summarizing the DTI information from a group of subjects.

15:30         3563.     Mapping Crossing Fibres of the Human Brain with Spherical Deconvolution: Towards an Atlas for Clinico-Anatomical Correlation Studies

Flavio Dell'Acqua^1,2, Joan Coward², Andy Simmons², Declan Murphy¹, Steve Williams², Marco Catani^1,2

¹Natbrainlab, Section of Brain Maturation, Institute of Psychiatry, King’s College London, London, UK; ²Centre for NeuroImaging Sciences, Institute of Psychiatry, King’s College London, London, UK

The development of MRI-derived quantitative measurements of fibre damage could have important applications for prognosis and treatment planning. In this work we have used the information from the Spherical Deconvolution approach to quantify the number of distinct fibre orientations in each voxel. Maps of the Number of Fibres Orientations (NuFO) were created from a central region of the cerebral hemispheres and compared with fractional anisotropy maps. We propose that these maps may be used to create an atlas for clinico-anatomical correlation studies in a number of conditions including, multiple sclerosis, brain tumours, vascular dementia and other stroke-related disorders.

13:30         3564.     Implications of Physiological Motion on DTI Values in the Cervical Spinal Cord

Celina Nahanni¹, Patrick W. Stroman^1,2

¹Centre for Neuroscience Studies, Queen's University, Kingston, Ontario, Canada; ²Departments of Diagnostic Radiology and Physics, Queen's University, Kingston, Ontario, Canada

Recent studies suggest that DTI values in the human cervical spinal cord may be susceptible to motion related noise caused by the flow of the CSF. It has been established that the cervical spinal cord pulsates with the cardiac cycle displacing 0.6 mm on average following systole. In the current study, corruption due to motion is observed in ADC values of the cervical spinal cord compared to values collected in the lumbar cord where motion is negligible. DTI data has been binned at consistent phases of the cardiac cycle and consistent cord position therefore minimizing the effects due to motion.

14:00         3565.     Effect of Reference Template Selection in Diffusion Tensor Based Voxel-Wise Analysis

Hsuan-Hui Wang¹, Kun-Hsien Chou², Pei-Chin Chen¹, I-Yun Chen³, Ching-Po Lin^1,3

¹Institute of Biomedical Imaging and Radiological Sciences, National Yang-Ming University, Taipei, Taiwan; ²Institute of Biomedical Engineering, National Yang-Ming University, Taipei, Taiwan; ³Institute of Neuroscience, National Yang-Ming University, Taipei, Taiwan

Diffusion tensor based voxel-wise analysis (DT-VBA) has been increasingly used to investigate subtle inter-group differences in brain white matter integrity on a voxel-wise basis in a standardized space. However, varieties of reference template and procedures of processing exist in the implementation of DT-VBA. In order to realize the effect of different DT-VBA procedures, the purpose of this study is to systematically evaluate the effects and accuracy of varying reference template and image preprocessing procedure of the DT-VBA. The results indicate that using the modality-matched template for normalization could diminish the distortion and improve the accuracy for spatial normalization in DT-VBA.

14:30         3566.     Population Based Probabilistic Neural Tracts Atlas of Human Brain

Chun-Yi Lo¹, Yi-Ping Chao², Ke-Hsin Chen³, Kun-Hsien Chou⁴, Ching-Po Lin^3,5

¹Institute of Biomedical Imaging and Radiological Sciences, National Yang Ming University, Taipei, NA, Taiwan; ²Institute of Electrical Engineering, National Taiwan Univeristy, Taipei, Taiwan; ³Institute of Neuroscience, National Yang Ming Univeristy, Taipei, Taiwan; ⁴Institute of Biomedical Engineering, National Yang Ming Univeristy, Taipei, Taiwan; ⁵Institute of Biomedical Imaging and Radiological Sciences, National Yang Ming Univeristy, Taipei, Taiwan

Diffusion tensor MRI (DTI) has shown its feasibility in white matter connectivity. In this study, a probabilistic connectivity atlas was presented with the tract-based transformation into MNI152 space. The white matter tractography was based on FACT (fiber assignment by continuous tracking) algorithm with fractional anisotropy (FA) threshold of 0.2 and angular threshold of 60 degrees. By calculating the neural bundles in MNI152 coordinate, the probabilistic tract atlas was regarded as a new template which can provide the correct location of neural bundles. The results can facilitate further studies on neural connectivity, brain mapping, and diffusion indices analysis for clinical applications.

15:00         3567.     Functional MRI Results Guided ROI Selection & Probability Map Making on DTI Study: The White Matter Route for Orthography-To-Phonology Transformation in Chinese

Ke-Hsin Chen¹, Yi-Ping Chao², Chun-Yi Lo³, Ching-Po Lin¹

¹Institute of Neuroscience, National Yang-Ming University, Taipei, Taiwan; ²Institute of Electrical Engineering, National Taiwan University, Taipei, Taiwan; ³Institute of Biomedical Imaging and Radiological Science, National Yang-Ming University, Taipei, Taiwan

The present study tried to use diffusion tensor imaging (DTI) to delineate the possible white matter track for the cognitive processes on normal healthy subjects. The results of previous fMRI study were used to guide ROI selection for tractography. In order to increase the reliability of tracking results, all the track data were then transformed to standard space to make probability maps. Finally, we performed correlation test to test whether the tracks play important roles in the information processing of the cognitive function.

13:30         3568.     A New Quality Measure for Gradient Encoding Schemes

Sarah C. Mang^1,2, Daniel Gembris^2,3, Wolfgang Grodd¹, Uwe Klose¹

¹Section Exp. MRI of CNS, Diagnostic and Interventional Neuroradiology, Tübingen, Germany; ²Institute for Computational Medicine, University of Mannheim, Mannheim, Germany; ³Bruker Biospin MRI GmbH, Ettlingen, Germany

We present a new method for the evaluation of gradient encoding scheme quality. The “signal deviation” compares the input signal derived from a chosen tensor with the signal synthesized from a tensor fitted to this input signal. An encoding scheme of high quality has a low “signal deviation”. This encoding scheme quality measure is applicable to different kinds of diffusion representation. Here we did focus on higher order diffusion tensor models. We could show that a pair wise force minimizing direction set gives the best quality for all evaluated tensor models.

14:00         3569.     A Tensor Approach for Double Wave Vector Experiments on Microscopic Anisotropy

Marco Lawrenz^1,2, Martin A. Koch^1,2, Jürgen Finsterbusch^1,3

¹Dept. of Systems Neuroscience, University Medical Center Hamburg-Eppendorf, Hamburg, Germany; ²Neuroimage Nord, Hamburg-Kiel-Lübeck, Germany; ³Neuroimage, Hamburg-Kiel-Lübeck, Germany

A theoretical approach to the double wave-vector experiment aiming at the examination of microscopic anisotropy in tissue is presented for fully restricted diffusion. A detailed analysis of the generalized tensor expression in the fourth order for long mixing times does not only hold for the characterization of non-isotropically oriented pores but deduces also a measure for microscopical anisotropy on the pore size level. Monte Carlo simulations confirm the observed signal behavior for arbitrary distributed pore populations. It is shown that the derived anisotropy parameter allows for a direct derivation of the pore anisotropy.

14:30         3570.     Optimized Measurement of Anomalous Diffusion

Justin P. Haldar¹, Qing Gao², Xiaohong Joe Zhou^2,3, Zhi-Pei Liang¹

¹Beckman Institute, Electrical and Computer Engineering, University of Illinois at Urbana-Champaign, Urbana, IL, USA; ²Center for MR Research, University of Illinois Medical Center, Chicago, IL, USA; ³Radiology, Neurosurgery, and Bioengineering, University of Illinois at Chicago, Chicago, IL, USA

The stretched exponential curve has recently been proposed to model the non-exponential diffusion-induced signal attenuation observed in biological tissues at large b-values. In this work, we propose two techniques to help improve the robustness of the experiment to measure the parameters of this model. First, using the Cramér-Rao bound, we optimize the set of b-values acquired during the experiment. Second, we make use of a regularized joint image reconstruction technique to help mitigate the effects of measurement noise. The combination of these two techniques enables efficient and robust characterization of anomalous diffusion.

15:00         3571.     On the Problem of Gradient Calibration in DWI

Oleg P. Posnansky¹, Yuliya Kupriyanova¹, N. Jon Shah^1,2

¹Institute of Neuroscience and Biophysics 3 - Medicine, Research Centre Juelich, Juelich, Germany; ²Faculty of Medicine, Department of Neurology, RWTH Aachen University,  JARA, Aachen, Germany

A calibration method for diffusion weighted imaging using an isotropic phantom is proposed. The key point of the method consists in finding the correction curve and followed by retrospective rescaling of the diffusion weighted signal distributed among the different diffusion encoding directions. The correction protocol was applied to produce improved FA maps which were analyzed with statistical histograms. The results demonstrate that described scheme of systematic error reduction is a valid approach for quality control studies of gradient system performance for diffusion weighted imaging.

13:30         3572.     Generalized MAGSTE with Improved Diffusion-Weighting Efficiency

Jürgen Finsterbusch^1,2

¹Dept. of Systems Neuroscience, University Medical Center Hamburg-Eppendorf, Hamburg, Germany; ²Neuroimage Nord, Hamburg-Kiel-Lübeck, Germany

Cross terms of background gradients with diffusion gradients often hamper the accurate determination of diffusion coefficients in MR experiments, in particular if microscopic background gradients are present which vary within a voxel. For diffusion weighting based on a stimulated echo preparation several approaches that inherently null these cross terms have been presented in the past. The generalized MAGSTE technique is the most appropriate for echo-planar imaging acquisitions because it takes long fill time contributions of the echo train into account. Here, an extension of the generalized MAGSTE technique is presented that increases the diffusion-weighting efficiency without sacrificing the cross-term compensation.

14:00         3573.     Double-Wave-Vector Diffusion-Weighting Experiments with Multiple Concatenations

Jürgen Finsterbusch^1,2

¹Dept. of Systems Neuroscience, University Medical Center Hamburg-Eppendorf, Hamburg, Germany; ²Neuroimage Nord, Hamburg-Kiel-Lübeck, Germany

An extension of the double wave vector diffusion-weighting experiment with short mixing time that involves multiple concatenations of the two diffusion-weighting periods in a single experiment is proposed. A generalized tensor model is presented to describe the signal behaviour for arbitrary orientation distributions and number of concatenations. The absolute and relative signal modulation increases with the number of concatenations approaching twice the value observed for the un-concatenated experiment. Thus, multiple concatenations may help to improve the detectability of the signal modulation on whole-body MR systems. These results are confirmed by numerical simulations using a Monte-Carlo algorithm.

14:30         3574.     Optimal Strategy for B-Values Selection for Lung Morphometry with Hyperpolarized 3He Diffusion MRI

Alexander L. Sukstanskii¹, Jim D. Quirk¹, Mark S. Conradi², Dmitriy A. Yablonskiy^1,2

¹Mallinckrodt Institute of Radiology, Washington University, St. Louis, MO, USA; ²Physics, Washington University, St. Louis, MO, USA

Lung morphometry with hyperpolarized 3He diffusion MRI allows estimation of lung microstructural parameters. Herein Bayesian analysis is used to analyze how the accuracy of this technique depends on data sampling strategy, generalizing the previous theory of equidistant sampling. We demonstrate that the optimum strategy requires three samples with b-values of 0, 2 and 8 s/cm2. This 3b-value sequence results in the relative errors in the parameter estimate smaller than that can be achieved by means of a longer 6b-value approach with equidistant sampling. This reduced imaging time can be harnessed to increase the number of acquired slices.

15:00         3575.     A New and Versatile Gradient Encoding Scheme for DTI: A Direct Comparison with the Jones Scheme

Rüdiger Stirnberg¹, Tony Stöcker¹, N. Jon Shah^1,2

¹Institute of Neurosciences and Biophysics, Research Centre Juelich, Juelich, Germany; ²Faculty of Medicine, Department of Neurology, RWTH Aachen University,  JARA, Aachen, Germany

An important issue in Diffusion Tensor Imaging (DTI) is the use of a well-chosen gradient encoding scheme. The most established schemes, minimising the orientational dependence of the reliability of DTI, are the Jones schemes. Here, a geometrical, point-symmetric method has been developed and implemented which mimics the Jones schemes successfully for an arbitrary number of directions. Appropriately describing their underlying construction, the resulting schemes are entitled DISCOBALL schemes. Using simulations, previously performed by Skare, Jones and Landmann et al., it is shown that the proposed versatile schemes perform as well as the computationally demanding Jones schemes.

14:00         3576.     Regularisation of Fractional Anisotropy Using Neighbourhood Information

Marta Morgado Correia¹, Virgina FJ Newcombe¹, Thomas Adrian Carpenter¹, Guy B. Williams¹

¹Wolfson Brain Imaging Centre, University of Cambridge, Cambridge, UK

Notwithstanding its successes, the traditional tensor model for diffusion imaging is a very simple model which ignores the uncertainty associated to the data caused by noise and partial volume averaging. In this study we propose the use of Bayes decision rule in a regularisation algorithm which takes into consideration this uncertainty and aims at producing more reliable and robust measures of fractional anisotropy (FA). Results show that the proposed method reduces the variability observed between voxels belonging to the same population of fibres, and it increases FA’s ability to differentiate between tissue types.

14:30         3577.     Effective Reduction of CSF Partial Volume Effect in DTI by Acquiring Additional DWIs with Smaller B-Value

Edward S. Hui^1,2, Joseph A. Helpern^3,4, Ed X. Wu^1,2

¹Laboratory of Biomedical Imaging and Signal Processing, The University of Hong Kong, Hong Kong SAR, China; ²Electrical and Electronic Engineering, The University of Hong Kong, Hong Kong SAR, China; ³Department of Radiology, New York University School of Medicine, New York, NY 10016, USA; ⁴Centre for Advanced Brain Imaging, The Nathan Lkine Institute, Orangeburg, NY 10962, USA

One of the major limitations of DTI is its vulnerability to CSF contamination. To remove such effect, FLAIR preparation and the two-compartment tensor model have been proposed. However, they require substantially increased scan time (and lead to reduced brain tissue SNR in the former case). A simple and effective approach is proposed in the current study. Diffusion tensor (DT) was computed from diffusion-weighted images acquired with b-value=500 and 1000s/mm2. Experiments were performed in volunteers and rodents to compare this approach and conventional DTI, demonstrating effective reduction of CSF contamination.

15:00         3578.     Effects of Voxel Size, B-Factor and Averaging on the Test-Retest Reproducibility of DTI-Derived Fractional Anisotropy at 4T

Nico Dario Papinutto¹, Jorge Jovicich¹

¹Center for Mind/Brain Sciences, University of Trento, Mattarello (TN), Italy

Diffusion tensor imaging of in-vivo human brain provides insights into normal and abnormal white matter anatomical connectivity, but little is known about measurement reliability at very high magnetic field systems (> 3T). Here we assess the impact of acquisition variables (voxel size: 1.8^3 , 2.0^3 , and 2.5^3 mm^3 , b-value: 700, 1000, 1300 s/mm^2, number of acquisitions: 1, 2) on test-retest reproducibility of fractional anisotropy (FA) estimates in a group of healthy subjects at 4T. We found good consistency both in FA values and reproducibility reported from clinical scanners, even a the higher spatial resolution of (1.8 mm)^3.

15:30         3579.     Effect of Voxel Size on DTI Fractional Anisotropy

Ramtilak Gattu¹, Z Latif², Zhifeng Kou³, Ewart M. Haacke³, Randall R. Benson⁴

¹Radiology, Wayne State University/MR Research Facility, Detroit, MI , USA; ²Radiology, Wayne State University/MR Research Facility, Detroit, MI, USA; ³MR Research Facility, Wayne State University, Detroit, MI, USA; ⁴Neurology, Wayne State University, Detroit, MI, USA

DTI Fractional Anisotropy (FA) is sensitive to white matter pathology. Maximal sensitivity to pathology requires understanding the MR parameters which affect both sensitivity to diffusion and FA. We investigated the effect of voxel size on FA in five healthy subjects using seven different voxel dimensions. Identical brain volumes were imaged in order to isolate the effect of resolution. We found a logarithmic relationship between voxel size and FA. The data suggest that it is necessary to use the same imaging resolution when comparing FA between time points or between subjects.

13:30         3580.     Metric Selection and Variability Maps for Diffusion Tensor Data

Ofer Pasternak¹, Nir Sochen², Peter Joel Basser³

¹Blavatnik School of Computer Science, Tel Aviv University, Tel Aviv, Israel; ²Department of Applied Mathematics, Tel Aviv University, Tel Aviv, Israel; ³Section on Tissue Biophysics & Biomimetics, Eunice Kennedy Shriver National Institute of Child Health and Human Development, NIH, Bethesda, MD, USA

We study the question of metric selection for diffusion tensors by applying a tensor-variate statistical framework. The Log-Euclidean metric, which represent the affine-invariant metric family, is compared with the conventional Euclidean distance. By calculating variability maps for synthetic and real DTI data we show that the Log-Euclidean distance does not adequately model the effect of Rician noise in diffusion weighted imaging data. We suggest that the Euclidean metric provides variability maps in coherence with the expected type of noise.

14:00         3581.     Quantitative Tissue Structure Characterization with Temporal Diffusion Spectroscopy

Junzhong Xu¹, Mark D. Does¹, Ke Li¹, Daniel F. Gochberg¹, John C. Gore¹

¹Institute of Imaging Science, Vanderbilt University, Nashville, TN, USA

In the present work, we provide analytical expressions for MR signals with OGSE methods for restricted diffusion based on the theory of temporal diffusion spectroscopy. A novel model is developed to interpret DWI data obtained from OGSE measurements to quantitatively characterize tissue structures. Compared with other models with conventional PGSE methods, this model has the ability to quantitatively extract tissue structural information including cell nuclear sizes which are usually not obtainable using conventional methods. This approach provides new structural parameters which may be helpful to follow intracellular changes in tissues and potentially can be used for applications such as monitoring tumor response to treatment in vivo.

14:30         3582.     Diffusion in Brain Tissue Modelled as Random Walks Under Confinements and Trapping Constraints

Farida Grinberg¹, A. M. Oros-Peusquens¹, Yuliya Kupriyanova¹, Oleg Posnansky¹, N. Jon Shah^1,2

¹Institute of Neurosciences and Biophysics, Research Centre Juelich, Juelich, Germany; ²Faculty of Medicine, Department of Neurology, RWTH Aachen University,  JARA, Aachen, Germany

Diffusion MRI has established itself as an invaluable tool for the non-invasive probing of tissue microstructure and function. The sensitivity of water molecular dynamics to the local geometrical and physiological environment gives rise to unique options in brain diagnostics. Simplified geometrical models from studies of confined diffusion in porous media, where the pore walls are usually regarded as non-interacting geometrical barriers, are often invoked. In contrast, cellular membranes tend to influence water dynamic properties not only by merely obstructing diffusion pathways, but also via interactions in the interfacial region (“bound water”). In this work, Monte Carlo simulations of random walks in restricted geometries were performed taking account of such interactions. The latter were modelled in terms of “orienting” and “trapping” (or adsorbing) properties of the confining surface.

15:00         3583.     Estimation of Cell Membrane Permeability and Intracellular Diffusion Coefficient of the Gray Matter in the Normal Human Brain

Toshikazu Imae¹, Hiroyuki Shinohara², Masaki Sekino, Hiroyuki Ohsaki, Shoogo Ueno³, Kazuo Mima¹, Kuni Ohtomo¹

¹University of Tokyo Hospital, Bunkyo-ku, Tokyo, Japan; ²Tokyo Metropolitan University; ³Kyushu University

Diffusion-weighted imaging reflects the influence of the intra- and extracellular diffusion coefficient of water and membrane permeability. The purpose of this study is to non-invasively estimate membrane permeability and intracellular diffusion coefficient of normal human gray matter. Membrane permeability and intracellular diffusion coefficient were estimated in three normal volunteers through a comparison of theoretically predicted signals and experiment results using a 1.5 T MRI system. The estimated membrane permeability and intracellular diffusion coefficient were 76±9 μm and (1.0±0.0) mm²/s, respectively. The estimated value of membrane permeability was the criterion value for the diagnosis of brain diseases in gray matter.

13:30         3584.     Procrustes Analysis of Diffusion Tensor Data

Diwei Zhou^1,2, Ian L. Dryden^1,2, Alexey Koloydenko³, Li Bai^2,4

¹School of Mathematical Sciences, University of Nottingham, Nottingham, UK; ²CMIAG Research Group, University of Nottingham, Nottingham, UK; ³Mathematics Department, Royal Holloway University of London, London, UK; ⁴School of Computer Science and IT, University of Nottingham, Nottingham, UK

Since the diffusion tensor (DT) is a symmetric, positive-definite matrix, we consider an alternative non-Euclidean metric for statistical analysis based on the weighted Procrustes mean. By computing the full Procrustes metric from a diffusion tensor to isotropy, we find an alternative measure of anisotropy called Procrustes anisotropy. For comparison, we plot geodesic paths between two DT’s with Euclidean, Log-Euclidean, Cholesky, Procrustes, Riemannian and root-Euclidean metrics. We find that FA and PA maps from smoothed and interpolated tensor fields with Procrustes analysis provide an improved method to investigate the diffusion anisotropy in human brain compared to using the raw DT images.

14:00         3585.     A Voxel-Based Analysis of SNR Effect on Diffusion Tensor Imaging

Lian Xue¹, Liangsuo Ma², Khader M. Hasan

¹University of Texas Medical School at Houston, Houston, TX, USA; ²Department of Psychiatry and Behavioral Sciences, University of Texas Medical School at Houston, Houston, TX, USA

The study of fractional ansiotropy (FA) mean group differences between healthy and patients has been the primary focus of various diffusion tensor imaging (DTI) investigations, although the accuracy of FA needs to studied due to signal-to-noise ratio (SNR) effects in diffusion-encoded measurements, in particular in regions with low anisotropy such as gray matter. However, there is no systematic study of the influence of SNR in DTI on the estimated FA on a voxel-by-voxel basis for all brain regions. This work is the first report of SNR effects using an unbiased voxel based morphometry (VBM) approach. The comparison of diffusion weighted SNR is realized by selecting different icosahedral schemes from same DTI data set to isolate measurement noise introduced by inter-session factors. The normalization for VBM is completed using the DARTEL technique in SPM5. The group comparison of segmented gray and white matter from different encoding schemes is performed on the same healthy adult controls. The VBM results confirm that FA of GM is effected with lower SNR while FA of white matter is more immune to SNR effects. The multi-faceted encoding scheme approach adopted for comparison gives insight on the choice of encoding scheme in DTI experimental design and the analysis of the minimal scan time needed to provide unbiased measurements to SNR effects.

14:30         3586.     Voxel Based Topometry: Collapse Onto a Sphere or an Ellipsoid?

Oleg P. Posnansky¹, N. Jon Shah^1,2

¹Institute of Neuroscience and Biophysics 3 - Medicine, Research Centre Juelich, Juelich, Germany; ²Faculty of Medicine, Department of Neurology, RWTH Aachen University,  JARA, Aachen, Germany

We explore the complex geometry of the apparent diffusion coefficient (ADC) profiles and discuss the blowing compact-surface method. Completely isotropic and anisotropic characteristic cases are considered. As a probing surface the blowing sphere is chosen in the isotropic case. For the anisotropic case, an ellipsoid built on eigenvectors with kept eigenvalues ratios is chosen. Using the step-by-step scaling procedure, we investigate the collapse of topological indices and demonstrate geometrical contrast. For the sphere and ellipsoid cases sets of non-integer indices are mapped. The maps correlate with the anatomical structure of the brain to different extents and provide more detailed non-Gaussian information about brain architecture.

15:00         3587.     Improved Results of Voxel-Based DTI Analyses by Using Non-Rigid Coregistration and a Population-Based DTI Atlas

Caroline A. Sage¹, Wim Van Hecke², Ronald Peeters¹, Jan Sijbers², Wim Robberecht³, Judith Verhoeven⁴, Sabine Deprez¹, Paul Parizel⁵, Guy Marchal¹, Alexander Leemans⁶, Stefan Sunaert¹

¹Radiology, University Hospitals of the Catholic University of Leuven, Leuven, Belgium; ²Vision Lab, University of Antwerp, Wilrijk, Belgium; ³Neurology, University Hospitals of the Catholic University of Leuven, Leuven, Belgium; ⁴Pediatrics, University Hospitals of the Catholic University of Leuven, Leuven, Belgium; ⁵Radiology, University of Antwerp, Antwerp, Belgium; ⁶CUBRIC, School of Psychology, Cardiff University, Cardiff, UK

Results of voxel-based analyses of DTI data are dependent on various factors such as the coregistration technique and choice of reference system. In this study, non-rigid coregistration and a population-based DTI atlas that contains the complete diffusion information are used to validate our previously published results of voxel-based analyses in which DTI data of 28 patients with amyotrophic lateral sclerosis were compared to those of 26 healthy controls. We demonstrate that, as the residual variance after spatial normalization to the atlas is lowered, the results of the voxel-based analyses are improved, especially for the mean diffusivity.

13:30         3588.     Supertoroid-Based Characterization of Cardiac Diffusion Tensor Fields

Choukri Mekkaoui¹, Marcel P. Jackowski², Albert J. Sinusas¹

¹Yale University, New haven, CT, USA; ²University of Sao Paulo, Brazil

The aim of this study is to introduce a novel supertoroid-based representation of the diffusion tensor fields to improve myofiber visualization. The supertoroids address the limitations of the superquadrics and toroidal glyphs, by unifying the specific advantages of each representation. Supertoroids incorporate the visual features conveyed by the increase in genus inherent to the toroids and a continuum that fully encodes the local eigensystem intrinsic to the superquadrics. The methodology was applied on DT-MRI datasets of a normal and infarcted canine hearts. Results indicate that supertoroids enhance cardiac myofiber structure characterization compared to ellipsoidal, superquadrics and toroids.

14:00         3589.     Analytic Description of MR Diffusion Indices in Ex-Vivo Human Hypertrophic Cardiomyopathy

Eric Stephant¹, Carole Frindel¹, Marc Robini¹, Laurent Fanton², Magalie Viallon³, Pierre Croisille⁴

¹Creatis-LRMN, Université Lyon 1, INSA Lyon, Lyon, France; ²Institut de Médecine Légale, Université Lyon 1, Lyon, France; ³Hopital Cantonal Universitaire de Genève, Genève, Switzerland; ⁴Hopital Cardiologique et Pneumologique L. Pradel, Lyon, France

Hypertrophic cardiomyopathy (HCM) is the most common genetic heart disease and the leading cause of sudden death in the youngs. HCM is well known to contain major changes at the structural level with myocytes disarray, increase in collage content and modification of the extracellular matrix (ECM), that can only be determined using invasive focal myocardial biopsy or after death. In-vivo Diffusion Weighted Imaging (DWI) of the heart remains very challenging due to cardiac and respiratory motion. Most of the cardiac DWI studies have been performed with animals using a high-field scanner or extra-long time acquisition but that will never be applicable to in-vivo imaging. Our objective is therefore to study hypertrophic cardiomyopathy in human and to find MR diffusion indices that reflect the myocardial fiber disarray and ECM changes.

14:30         3590.     Measuring Axial and Radial Diffusivities in the Brain.

Claudia A.M. Wheeler-Kingshott¹, Daniel C. Alexander², Torben Schneider¹, Mara Cercignani³

¹Department of Neuroinflammation, UCL Institute of Neurology, London, UK; ²Dept. Computer Science, University College London, Centre for Medical Image Computing, London, UK; ³Neuroimaging Laboratory , Fondazione Santa Lucia, Rome, Italy

The diffusion coefficient along and across white matter fibers is a useful biomarker for tissue changes, such as axonal loss and demyelination. Axial and radial diffusivities have been associated with the DT eigenvalues, but crossing fibers, pathology and noise can affect the orientation of the corresponding eigenvectors. Here we present a method for calculating the axial and radial diffusivities in the brain based on the directionality of the structures in a healthy “super-dataset” representing the average diffusion properties of the population under sample. The use of this “super-dataset” helps overcoming the issues of pathology, noise and potentially of crossing fibers.

15:00         3591.     The Relationship Between "axial" and "radial" Diffusivities and the Eigenvectors of the Diffusion Tensor in the Brain.

Claudia A.M. Wheeler-Kingshott¹, Daniel C. Alexander², Mara Cercignani³

¹Department of Neuroinflammation, UCL Institute of Neurology, London, UK; ²Dept. Computer Science, University College London, Centre for Medical Image Computing, London, UK; ³Neuroimaging Laboratory , Fondazione Santa Lucia, Rome, Italy

Axial and radial diffusivities reflect the diffusion coefficient along and across white matter fibres and are potential biomarkers of axonal integrity and myelination. The principal eigenvalue of the diffusion tensor (DT) has been associated with axial diffusivity and the average of the second and third eigenvalues with radial diffusivity. Here we challenge this assumption, underlying the importance of analysing the DT eigenvalues together with their eigenvectors. We present simulations to illustrate the effect of pathology and compare the DT eigenvalues in two healthy controls and two patients with MS, using non-linear registration and the preservation of principal direction algorithm.

14:00         3592.     White Matter Injury in Germinal Matrix Hemorrhage in Rabbit Pup Model Detected by DTI

Halima Chahboune¹, Caroline Chua², Praveen Ballabh^2,3, Fahmeed Hyder^4,5

¹Diagnostic Radiology  , Yale University School of Medicine  , New HAven, CT, USA; ²Pediatrics, New York Medical College - Westchester Medical Center, Valhalla, NY, USA; ³Cell Biology, New York Medical College - Westchester Medical Center, Valhalla, NY, USA; ⁴Diagnostic Radiology, Yale University School of Medicine, New HAven, CT, USA; ⁵Biomedical Engineering, Yale University School of Medicine  , New HAven, CT, USA

DTI is used as a noninvasive diagnostic marker to characterize perinatal brain injury in animal model. The goal of this study was to use ex vivo DTI to evaluate the long-term consequences of germinal matrix hemorrhage-intraventricular hemorrhage (GMH-IVH) in rabbit pup. This study shows injury to the corpus callosum, corona radiate and fimbria fornicis caused by GMH-IVH. This injury to white matter is in agreement with histological and neurobehavioral evaluation. These results in the GMH-IVH model are important for understanding neurodevelopmental difficulties found in low birth weight preterm infant, and evaluate strategies in prevention and/or treatment of post-hemorrhagic complications

14:30         3593.     DTI Detects FA Changes in the Internal Capsule and Thalamus in Rat After Traumatic Brain Injury - Comparison with Histology

Teemu P. Laitinen¹, Alejandra Sierra Lopez¹, Tamuna Bolkvadze¹, Asla Pitkänen¹, Olli H. Gröhn¹

¹Dept. of Neurobiology, A. I. Virtanen Institute for Molecular Sciences, University of Kuopio, Kuopio, Finland

The ability of diffusion tensor imaging to detect neurobiological alterations after traumatic brain injury was studied in rats with TBI induced by lateral percussion injury. Our results show that the fractional anisotropy was increased in the ipsilateral laterodorsal thalamic nuclei and in the ipsilateral ventral posterolateral and -medial thalamic nuclei, and that FA was decreased in the ipsilateral internal capsule six months after the induction of TBI when compared to control animals. Preliminary results from histology showed structural changes as well as demyelination in these areas, consistent with the DTI results.

15:00         3594.     Fractional Anisotropy Correlates with Social Behavior Symptoms in a Mouse Model Relevant to Autism

Sungheon Kim¹, Steve Pickup², Andrew H. Fairless³, Ranjit Ittyerah², Holly C. Dow³, Ted Abel⁴, Edward S. Brodkin³, Harish Poptani²

¹Department of Radiology, New York University, New York, NY, USA; ²Department of Radiology, University of Pennsylvania, Philadelphia, PA, USA; ³Department of Psychiatry, University of Pennsylvania, Philadelphia, PA, USA; ⁴Department of Biology, University of Pennsylvania, Philadelphia, PA, USA

The purpose of this study was to evaluate the feasibility of diffusion tensor imaging (DTI) in detecting abnormal brain regions associated with reduced sociability in juvenile BALB/cJ mice. Sociability was measured in terms of the time a 31-day-old BALB/cJ test mouse spent sniffing a stimulus mouse. Ex vivo DTI data on fifteen BALB/cJ mouse brains were acquired and were co-registered to a template brain generated from four C57BL/6J mouse brains. Using regression analysis, positive relationships between the sociability and fractional anisotropy were found in the white matter regions, whereas negative relationships were found in the gray matter regions.

15:30         3595.     Characterization of Cortex and White Matter Injury in a Mild Hypoxic-Ischemic Neonatal Rat Model by Diffusion Tensor MR Imaging

Silun Wang¹, Ed. X. Wu^2,3, Ho-Fai Lau^2,3, Pek-Lan Khong¹

¹Department of Diagnostic Radiology, The University of Hong Kong, Hong Kong, Hong Kong; ²Laboratory of Biomedical Imaging and Signal Processing, The University of Hong Kong, Hong Kong; ³Department of Electrical and Electronic Engineering, The University of Hong Kong

We evaluated hypoxic-ischemic (HI) induced cortex and white matter (WM) damage in a mild HI neonatal rat model at 24h post HI by diffusion tensor MR imaging (DTI) and correlated the DTI indices with histological evaluations. Results showed that significantly decreased FA and ¦Ë// reflected HI induced astrogliosis in the injured cortex, whereas significantly decreased FA with increased ¦Ë¡Í indicated dysmyelination in the WM. Our results demonstrated that early mild HI induced cortex and WM damage could be reflected by DTI indices and these may be potentially useful biomarkers to non-invasively monitor mild HI induced neonatal brain damage.

13:30         3596.     Design and Setup of Dynamic Contrast Enhanced Experiments for Longitudinal Preclinical Studies of Tumor Response to Anti-Angiogenic Therapy

Jan Sedlacik¹, Regan Williams¹, Melissa Johnson¹, Chris Calabrese¹, Andrew M. Davidoff¹, Claudia M. Hillenbrand¹

¹St. Jude Children's Research Hospital, Memphis, TN, USA

DCE measurements are able to detect, quantify and monitor tumor response on anti-angiogenic agents by assessing changes in the contrast agent’s permeability of the tumor vascular system. Especially DCE experiments in mice can help to better verify effects of anti-angiogenic drugs on tumors. Unfortunately, the design and setup of DCE experiments in small animals are reported only fragmentally. However, a reasonable setup is crucial to conduct reliable DCE experiments. The purpose of this work was to report in detail the design and setup of DCE experi¬ments of our institution to monitor treatment of anti-angiogenic drugs in tumor bearing mice.

14:00         3597.     Evaluation of Interleukin-2 Neurovascular Toxicity Using DCE-MRI

Yetty Yennawati Irwan^1,2, H. Michael Gach³, Yi Feng⁴, Gopalkrishna Veni³, Wolfram E. Samlowski¹

¹Melanoma, Nevada Cancer Institute, Las Vegas, NV, USA; ²Pathology, University of Utah, Salt Lake City, UT, USA; ³Research Imaging, Nevada Cancer Institute, Las Vegas, NV, USA; ⁴Drug Development, Nevada Cancer Institute, Las Vegas, NV, USA

Interleukin-2 (IL-2) therapy causes neuropsychiatric toxicity in cancer patients. The mechanism is currently not well understood. We developed an experimental protocol to evaluate changes in the brain vasculature of mice induced by IL-2 using DCE-MRI. Using a two-compartment model, we were able to show that IL-2 induced changes in the brain vasculature include vasodilation and fluid extravasation into the brain extravascular space. This model provides the opportunity to evaluate potential pharmacologic inhibitors of cytokine-induced neurologic toxicity.

14:30         3598.     Functional Bolus-Tracking Arterial Spin Labeling; a New Approach to Quantitative FMRI

Michael Edward Kelly¹, Christoph Wolfgang Blau², Oliviero Leopoldo Gobbo², Karen Mary Griffin³, James Francis Xavier Jones³, Christian Mattheis Kerskens²

¹Trinity College Institute of Neuroscience, Trinity College Dublin, Dublin , Ireland; ²Trinity College Institute of Neuroscience, Trinity College Dublin, Dublin, Ireland; ³School of Medicine and Medical Science, University College Dublin, Dublin, Ireland

Alterations in cerebral blood flow and volume can present a considerable obstacle when interpreting BOLD fMRI studies. The purpose of this study is to develop a new fMRI technique, bolus-tracking arterial spin labeling (ASL) fMRI, which provides a quantitative assessment of blood perfusion during activation. A novel Fokker-Planck equation was derived to describe the physiological processes involved in cerebral perfusion. The new model was fitted to ASL data and the mean transit time (MTT) and capillary transit time (CTT) were calculated. A rat fMRI study was performed and a significant difference in MTT and CTT during activation was identified.

15:00         3599.     Fast Bolus-Tracking FMRI in Medetomidine-Sedated Rats Using Intravascular Tracer: Towards Quantitative FMRI

Christoph Wolfgang Blau¹, Karen Mary Griffin², Oliviero Leopoldo Gobbo¹, James Francis Xavier Jones², Christian Matthias Kerskens¹

¹Trinity College Institute of Neuroscience, Trinity College Dublin, Dublin, Ireland; ²School of Medicine and Medical Science, University College Dublin, Dublin, Ireland

We show that neuronal activation of the rat primary somatosensory cortex can be clearly visualised by fast T1-weighted gradient-echo contrast MRI in the medetomidine-sedated rat. We describe the course of the bolus through the activated region and compare it to a cortical control region. Our results show a difference in bolus dispersion between the active and control regions. The work has the potential to provide new quantitative information on the haemodynamic response due to activation.

13:30         3600.     High-Field Diffusion Tensor Imaging on a Mouse Model of Leukoencephalopathy

Yohan van de Looij^1,2, Géraldine Favrais³, Pierre Gressens³, Petra S. Hüppi¹, Rolf Gruetter^4,5, Stéphane V. Sizonenko¹

¹Division of Child Growth & Development, Department of Pediatrics, University of Geneva, Geneva, Switzerland; ²Laboratory for Functional and Metabolic Imaging, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland; ³INSERM-UMR676, France; ⁴Laboratory for Functional and Metabolic Imaging, Ecole Polytechnique Fédérale de Lausanne , Lausanne, Switzerland; ⁵Department of Radiology, University of Geneva and Lausanne, Switzerland

On early preterm infants, diffuse and focal white matter injury is one of the predominant forms of brain damage. Leukoencephalopathy occurs primarily in the white matter and involves defects in either the formation or the maintenance of the myelin sheath. The aim of this work was to study mechanisms of leukoencephalopathy on a mouse model obtained by interleukin (IL-1β) injection by the way of DTI and histopathology. DTI results correlated with histology provide evidence for a quantitative and diffuse myelination defect as well as a decrease of axonal diameter. IL-1β mouse model gives a better understanding of LEP mechanisms.

14:00         3601.     Explanation of High Fractional Anisotropy Value in the Wall and Cavity of the Brain Abscess Differs as Evident by Histology and Immunohistochemistry

Rakesh K. Gupta¹, Sona Saksena¹, Nuzhat Husain², Mazhar Husain³, Savita Srivastava², Mahesh Ramola³, Rishi Awasthi¹, Kashi N. Prasad⁴, Ram K.S. Rathore⁵

¹Radiodiagnosis, Sanjay Gandhi Post Graduate Institute of Medical Sciences, Lucknow, Uttar Pradesh, India; ²Pathology, Chhatrapati Shahuji Maharaj Medical University, Lucknow, Uttar Pradesh, India; ³Neurosurgery, Chhatrapati Shahuji Maharaj Medical University, Lucknow, Uttar Pradesh, India; ⁴Microbiology, Sanjay Gandhi Post Graduate Institute of Medical Sciences, Lucknow, Uttar Pradesh, India; ⁵Mathematics and Statistics, Indian Institute of Technology, Kanpur, Uttar Pradesh, India

DTI data were acquired from eight patients with brain abscess (BA) with an aim to see the difference in the relationship between intercellular cell adhesion molecule-1 (ICAM-1) and lymphocyte function-associated antigen-1 (LFA-1) expression and fractional anisotropy (FA) in the BA wall and cavity and its possible explanation vis-à-vis histology. Quantitative immunohistochemical analysis was performed for ICAM-1 and LFA-1 in the wall showing maximal positive staining. Higher FA values in the wall compared to the cavity even when ICAM-1 and LFA-1 were not expressed in the collagen fibers suggest that the concentrically laid collagen fibers provide structural orientation and are responsible for increased FA. In the BA, there are different explanations for increased FA in cavity and wall substantiated by histology and immunohistochemistry.

14:30         3602.     Time-Dependent Diffusion MRI in the Neocortex of Aquaporin-4 Deficient and Normal Mice in the Resting State at 7T

Tina Pavlin¹, Christian Brekken¹, Pål Erik Goa², Anna Thoren³, Ole Petter Ottersen³, Erlend A. Nagelhus³, Asta Håberg¹

¹Circulation and Medical Imaging, NTNU, Trondheim, Norway; ²Medical Imaging, St.Olavs Hospital HF, Trondheim, Norway; ³University of Oslo, Oslo, Norway

We use time-dependent diffusion MRI to investigate how complete depletion of aquaporin-4 affects water diffusion in the mice brain. Our measurements show no difference in time-dependent diffusion between knockouts and controls in the resting state. We obtain a bulk diffusion constant of 1x10-5 cm2/s and the tortuosity value of 1.6. Furthermore, the diffusion is monoexponential over the entire range of diffusion times used (from 7 ms to 149 ms) due to the small gradient strengths (and thus q-values) used in these measurements.

15:00         3603.     DTI Abnormalities in Anterior Corpus Callosum of Rats with Spike-Wave Epilepsy

Halima Chahboune¹, Asht Mishra², Matthew Desalvo², Lawrence Staib^1,3, Magor Lorincz⁴, Vincenzo Crunelli⁴, Fahmeed Hyder^1,5, Hal Blumenfeld^2,6

¹Diagnostic Radiology  , Yale University School of Medicine  , New Haven, CT, USA; ²Neurology, Yale University School of Medicine, New Haven, CT, USA; ³Biomedical Engineering, Yale University School of Medicine  , New HAven, CT, USA; ⁴School of Biosciences, Cardiff University, Cardiff, UK; ⁵Biomedical Engineering, Yale University School of Medicine  , New Haven, CT, USA; ⁶Neurobiology, Yale University School of Medicine  , New HAven, CT, USA

DTI has provided unique insights into human epilepsy, and albeit to a lesser extent, animal models of seizure disorder. The aims of this study were to use DTI in WAG/Rij rats, an animal model of absence epilepsy, at two different developmental stages to first identify DTI changes related to epileptogenesis and to then use a different animal model of absence (GAERS) to determine the specificity of DTI changes. This study shows impairment in animal models of epilepsy. These abnormalities are not present early in life before development of seizures and are not specific to one animal model of spike-wave epilepsy.

13:30         3604.     Hemodynamics of the Hippocampus and Perilesional Cortex in the Acute and Sub-Acute Phases After Traumatic Brain Injury in Rats

Nick Mark Edward Alexander Hayward¹, Riikka Immonen¹, Asla Pitkänen¹, Olli Gröhn¹

¹University of Kuopio, AIV Institute, Kuopio, Savo, Finland

Traumatic brain injury (TBI) is a leading cause of mortality and morbidity. We assessed the hemodynamics within the hippocampus and perifocal area surrounding the trauma lesion after TBI in rats. Cerebral blood flow (CBF) was quantified using continuous arterial spin labelling. Cerebral blood volume was calculated by measuring MION induced changes in T2 relaxation, all at 4.7 T. Acutely, initial hypoperfusion and CBF recovery was observed in both subregions. Over two subsequent weeks, hippocampal CBF normalized, yet CBF declined gradually in the perifocal cortex. Hemodynamic changes may influence secondary injury cascades as they precede TBI-induced structural changes.

14:00         3605.     Age-Dependent Impairment of the Cerebrovascular Reactivity to CO2 in Spontaneously Hypertensive Rats: An ASL Study

Renata F. Leoni^1,2, Fernando F. Paiva¹, Draulio B. de Araujo², Afonso C. Silva¹

¹Cerebral Microcirculation Unit, NINDS, NIH, Bethesda, MD, USA; ²Departamento de Fisica e Matematica, FFCLRP, Universidade de Sao Paulo, Ribeirao Preto, SP, Brazil

Arterial spin labeling (ASL) has been used to measure cerebral blood flow (CBF) noninvasively, and has become useful for the diagnosis of cerebrovascular diseases. Since hypertension is an important risk factor for stroke, CBF maps and perfusion territories were obtained in two groups of spontaneously hypertensive rats (SHR), differing in age, under normo- and hypercapnia using continuous ASL. Reduced CBF and cerebral CO2 reactivity has been observed in the older SHR group, so age can influence the ability of the cerebrovascular system to autoregulate. Moreover, perfusion maps showed asymmetries probably due to anatomic variations of the Circle of Willis.

14:30         3606.     A DTI Study of Diffusion Anisotropy on CRMP-1 Knockout Mice

Kuan-Hung Cho¹, Bing-Hsuan Lei¹, Jyh-Horng Chen¹

¹Department of Electrical Engineering, National Taiwan University, Taipei, Taiwan

Collapsin response mediator protein-1 (CRMP-1) has been identified in brain and implicated in plexin-dependent neuronal function. CRMP-1 knock-out mice exhibited impaired performance in hippocampal-dependent spatial learning and memory tests, and disorganized MAP2 staining in the distal dendrites of hippocampal CA1 pyramidal cells. In this study we use diffusion tensor imaging (DTI) to noninvasively and quantitatively investigate the change of diffusion properties of the knock-out of the CRMP-1.

15:00         3607.     Absolute Cerebral Volume Quantification by Vascular Space Occupancy Technique on Rat Model with Optimized Inversion Time

Chien-Chung Chen¹, Yi-Chun Wu¹, Chou-Ming Cheng², Tzu-Chen Yeh³, Fu-Nien Wang¹

¹Biomedical Engineering and Environmental Sciences, National Tsing Hua University, Hsinchu, Taiwan; ²Integrated Brain Research Laboratory, Department of Medical Research and Education, Taipei Veterans General Hospital, Taipei, Taiwan; ³Integrated Brain Research Laboratory, Department of Medical Research and Education, Taipei Veterans General Hospital, Taiwan

A TI optimization method for vascular space occupancy (VASO) technique was implemented to quantification the absolute cerebral blood volume (CBV) on a rat model. The information of relative CBV from dynamic susceptibility contrast (DSC) imaging is included to find the optimized TI which maximize the R square between relative CBV from DSC method and absolute CBV from VASO method. It is also noted that when using VASO technique with a TI apart from the optimized one, the R square is significantly reduced between DSC and VASO methods, which could reduce the accuracy of absolute CBV measurement.

14:00         3608.     Errors in DCE MRI Measurements Due to Errors in Gd Concentration Estimates

Vishal Patil¹, Glyn Johnson¹

¹Radiology, NYU School of Medicine, New York, USA

Dynamic Contrast-Enhanced MRI (DCE-MRI) is used to characterize the microcirculation in pathologies ranging from cancer to multiple sclerosis. Previous studies have shown that in tissue, the change in relaxation rate is not linearly proportional to gadolinium concentration, [Gd]. In this study we used computer simulations to investigate the effect of non-linearities on the accuracy of first-pass, T2* weighted DCE-MRI parameter estimates. Results show fractional error increasing approximately linearly with Gd dose in all estimated parameters with the error ranging from 5 – 10% in meningioma and 1-5% in glioma for a single dose and from 20 – 30% and 5 – 15% for triple dose.

14:30         3609.     3D Sequences Used for DCE-MRI Can Exhibit Initial Instabilities That Will Affect T1 Quantification

Michael Germuska¹, James A. d'Arcy¹, Keiko Miyazaki¹, Matthew R. Orton¹, Geoffrey S. Payne¹, Martin O. Leach¹, David J. Collins¹

¹CRUK Clinical Magnetic Resonance Group, Institute of Cancer Research & Royal Marsden NHS Trust, Sutton, Surrey, UK

Modelling pharmacokinetic behaviour with DCE-MRI experiments requires precise and accurate T1 estimates. Any short-term instability of the dynamic data would adversely affect T1 estimates and the resulting pharmacokinetic model accuracy. Phantom experiments were performed to assess the accuracy and short-term stability of a number of sequences. We found that changes in acquisition parameters had a significant effect on the short-term stability of dynamic data. In particular, we observed a significant initial signal drift for certain gradient echo sequences. We feel it is essential to perform this level of quality assurance in order to have the required confidence in DCE-MRI data.

15:00         3610.     Analytical Equation of State for Rapid and Direct Quantification of Longitudinal Relaxation Time (T1) in Look-Locker Sequences

Hassan Bagher-Ebadian^1,2, Ramesh Paudyal^1,2, James Russel Ewing^1,2

¹Neurology, Henry Ford Hospital, Detroit, MI, USA; ²Physics, Oakland University, Rochester, MI, USA

In this study an analytical equation of state is derived and extracted from Look-Locker (LL) inversion recovery formula to construct an accurate algorithm

15:30         3611.     Dynamic Contrast Enhanced MRI Parameters Independent of Baseline T1 Values

Junyu Guo¹, Wilburn E. Reddick¹

¹Radiological Sciences, St. Jude Children's Research Hospital, memphis, TN, USA

In this abstract, we systematically investigate the baseline T1 independence of the commonly used DCE-MRI kinetic parameters (Ktrans, kep, ve and IAUC) and the new-defined parameters (the normalized ratios (NR) of the corresponding kinetic parameters) for a gradient-echo pulse sequence using simulations and in vivo studies. We found that DCE-MRI parameters, kep and its NR, are approximately independent of the baseline T1 and the T1 difference between pre- and post-treatment. The other kinetic parameters and their NRs have to be carefully used when the baseline T1 measurement is not available or not accurate.

13:30         3612.     Mri Surrogates of Blood Flow Estimates in the Malignant Prostate Gland

Roberto Alonzi¹, Peter Hoskin¹, N Jane Taylor², J James Stirling², James A. d'Arcy³, David J. Collins³, Anwar R. Padhani²

¹Mount Vernon Cancer Centre, Northwood, London, UK; ²Paul Strickland Scanner Centre, Mount Vernon Cancer Centre, Northwood, London, UK; ³CRUK Clinical MR Research Group, Institute of Cancer Research, Sutton, Surrey, UK

The purpose of this study was to assess clinically useful MRI derived kinetic parameters as surrogates for prostate cancer blood flow. Results demonstrated significant correlations between relative blood flow (rBF) derived from dynamic susceptibility-contrast enhanced MRI (DSC-MRI) and the T1-weighted parameters Ktrans, kep and IAUGC60. The strongest correlation in tumour was noted for IAUGC60 (r = 0.62, p=0.006). This provides evidence that T1-weighted Dynamic Contrast Enhanced MRI could provide a clinically feasible, multislice, whole gland blood flow imaging protocol.

14:00         3613.     Pre-Bolus Quantification of Arterial Input Functions by Non-Steady-State Analysis of Gradient-Echo Dynamic Imaging

Matthew R. Orton¹, Michael Germuska¹, Keiko Miyazaki¹, Dow-Mu Koh², David J. Collins¹, Martin O. Leach¹

¹Clinical Magentic Resonance Research Group, Institute of Cancer Research, Sutton, Surrey, UK; ²Academic Department of Radiology, Royal Marsden Hospital, Sutton, Surrey, UK

Use of a spoiled gradient echo dynamic imaging sequence is proposed for use with a pre-bolus of contrast to estimate the arterial input function (AIF) in the descending aorta with a single coronal slice. This approach avoids many of the problems associated with obtaining the AIF from the main dynamic data, particularly temporal resolution and partial volume issues with small vessels. Due to the flow speed of aortic blood, the steady-state assumption for signal quantification no longer applies. Non-steady-state estimation results in an increase in the concentration estimates of around 25% compared to steady-state estimation.

14:30         3614.     Onset Estimation for Dual Input DCE-MRI Liver Data : Information Criteria Used to Determine Statistical Optimality of Global or Pixel-Wise Onset Estimation

Matthew R. Orton¹, Keiko Miyazaki¹, Dow-Mu Koh², David J. Collins¹, David Atkinson³, David J. Hawkes³, Martin O. Leach¹

¹Clinical Magentic Resonance Research Group, Institute of Cancer Research, Sutton, Surrey, UK; ²Academic Department of Radiology, Royal Marsden Hospital, Sutton, Surrey, UK; ³Centre for Medical Image Computing, Univeristy College London, London, UK

The onset time of contrast enhancement is typically estimated pixel-wise when analysing DCE-MRI data. We have developed an algorithm for estimating the onset time as a single global parameter, which has the benefit of reducing the variability in such estimates. This is particularly beneficial when a dual-input liver model is used as the arterial-portal fraction is highly correlated with the onset time. Statistical information criteria are used to determine whether global or pixel-wise onset estimation is optimal when applied to data acquired from patients with liver metastases. This analysis suggests that in this case global estimation is optimal.

15:00         3615.     Novel Method of Portal Delay and Dispersion Estimation for Dual-Input Kinetic Modelling of DCE-MRI Liver Data

Matthew R. Orton¹, Keiko Miyazaki¹, Dow-Mu Koh², David J. Collins¹, David Atkinson³, David J. Hawkes³, Martin O. Leach¹

¹Clinical Magentic Resonance Research Group, Institute of Cancer Research, Sutton, Surrey, UK; ²Academic Department of Radiology, Royal Marsden Hospital, Sutton, Surrey, UK; ³Centre for Medical Image Computing, Univeristy College London, London, UK

Kinetic modelling of DCE-MRI liver data requires portal and arterial input functions. Patient specific portal input functions are necessary for accurate kinetic estimation, but direct measurement is challenging, and often highly variable. We present a methodology whereby the portal input function is derived from the arterial input function by applying a delay and a dispersion factor to the first-pass bolus. These parameters are estimated from the tissue data itself, thus avoiding many of the pitfalls of direct measurement. Results from 10 cases of patients with liver metastases are presented demonstrating a correlation between the estimated portal delay and dispersion.

13:30         3616.     Quantitative Mapping of Cerebral Blood Flow Change Using Phase Information of SWI

Yuri Zaitsu¹, Kohsuke Kudo², Rie Yazu¹, Kinya Ishizaka³, Noriyuki Fujima¹, Khin Khin Tha¹, Satoshi Terae¹, Makoto Sasaki², Hiroki Shirato¹

¹Radiology, Hokkaido University  Graduate School of Medicine, Sapporo, Hokkaido, Japan; ²Advanced Medical Research Center, Iwate Medical University, Japan; ³Radiology, Hokkaido University Hospital, Japan

Phase image of susceptibility weighted imaging (SWI) offers information of oxygen saturation by using the phase shift of the spin derived from the paramagnetic substances. It is possible to achieve automated calculation to make a whole brain mapping of cerebral blood flow (CBF) changes. Our automated method to calculate blood flow changes (&#8710;ƒ) yields stable and reliable &#8710;ƒ value, compared to the manual measurements. Moreover, the good agreement between &#8710;ƒ of SWI and &#8710;CBF of arterial spin labeling data with respiratory challenge suggests that our automated map could be an alternative and non-invasive tool for CBF measurement.

14:00         3617.     Bolus Perfusion-Weighted Imaging Measurement of Quantitative Cerebral Blood Flow Can Be Improved Using an Arterial Spin Label Derived Scaling Factor:  a Comparative Xenon CT Study

Greg Zaharchuk¹, Matus Straka¹, Ajit Shankaranarayan², David C. Alsop³, Michael E. Marks¹, Michael E. Moseley¹, Roland Bammer¹

¹Department of Radiology, Stanford University, Stanford, CA, USA; ²Appled Sciences Laboratory - West, GE Healthcare, Menlo Park, CA, USA; ³Department of Radiology, Beth Israel Deaconess Hospital, Boston, MA, USA

Arterial spin labeling and bolus dynamic susceptibility contrast perfusion-weighted imaging are two methods to measure CBF quantitatively with MRI. While ASL can measure normal CBF well, it is prone to errors at low flow rates. We propose using as ASL-based correction factor in regions with short Tmax, to scale bolus PWI CBF maps. We found that the combined PWI-ASL method was more accurate than either method used separately in 16 patients with cerebrovascular disease, using xenon CT CBF as a gold standard.

14:30         3618.     SCALE PWI: A Pulse Sequence for Quantitative Cerebral Perfusion Imaging

Jessy J. Mouannes¹, Saurabh Shah², Wanyong Shin³, Octavia Biris¹, Timothy J. Carroll^1,4

¹Biomedical Engineering, Northwestern University, Chicago, IL, USA; ²Siemens Medical Solutions USA, Inc, Chicago, IL, USA; ³National Institute on Drug Abuse, National Institute of Health, Baltimore, MD, USA; ⁴Radiology, Northwestern University, Chicago, IL, USA

CALibrated Epi Perfusion Weighted Imaging (SCALE-PWI) is a new sequence that produces an absolute scale for the quantification of cerebral perfusion. This sequence implements the Bookend technique, a reproducible and reliable MRI method for quantitative cerebral perfusion, in a single push-button scan. This eliminates the need for multiple Bookend scans which requires special technologist training, is less prone to motion artifacts, and, ultimately, produces quantitative images of cerebral perfusion without the need for offline post-processing. A validation of this sequence is presented for 19 healthy subjects at 1.5 T.

15:00         3619.     Reference-Based CBF Index of Maximum Upslope Without Using Arterial Input Function in Dynamic Susceptibility Contrast MRI: Comparison with Deconvolution Method

Tokunori Kimura¹, Hiroshi Kusahara¹

¹MRI development department, Toshiba Medical Systems Corp., Otawara, Tochigi, Japan

The purpose was to assess errors in CBF indexes in dynamic susceptibility contrast (DSC) MRI obtained from our proposed reference-based quantification without using an arterial input function (AIF). By simulation and clinical study, CBF and the referential tissue-related ratio (CBFratio) were compared between methods of maximum upslope (US) and block-circulant SVD deconvolution (cSVD). The errors in the CBFratio obtained using US (Ref-US) compared to cSVD were almost equivalent but smaller in lower CBF. Correlation of clinical CBFratio maps between US and cSVD provided r>0.9. We can conclude that the Ref-US is a valuable index from the viewpoint of balancing robustness against errors and simplicity.

13:30         3620.     Prediction of Hemorrhagic Transformation in Acute Ischemic Stroke: A Comparison of DSC Surrogate Measures of Permeability

Rebecca E. Thornhill^1,2, Shuo Chen¹, Wael Rammo¹, David J. Mikulis^1,3, Andrea Kassner^1,2

¹Medical Imaging, University of Toronto, Toronto, Ontario, Canada; ²Physiology and Experimental Medicine, Hospital for Sick Children, Toronto, Ontario, Canada; ³Medical Imaging, Toronto Western Hospital, Toronto, Ontario, Canada

The use of thrombolysis is known to increase the risk of hemorrhagic transformation (HT) in acute ischemic stroke (AIS). What is needed for successful treatment guidance is a method for predicting HT. An alternative to DCE-MRI and subsequent permeability estimation is a model-free approach to measure T2* contrast recirculation abnormalities associated with permeability. The purpose of this study was to compare four different T2* measures in AIS (relative recirculation (rR), Peak Height, %Recovery, and Slope). Only rR and %Recovery were significantly different in HT patients, suggesting that the measurement of either metric could have the potential to predict HT.

14:00         3621.     Unique Thalamic Perfusion Abnormalities in Painful But Not Painless Diabetic Peripheral Neuropathy.

Dinesh Selvarajah¹, Celia Emery², Rajiv Gandhi², Paul Griffiths¹, Solomon Tesfaye², Iain Wilkinson¹

¹Academic Department of Radiology, University of Sheffield, Sheffield, UK; ²Diabetes Research Department, University of Sheffield, Sheffield, UK

Painful diabetic neuropathy is a common complication of diabetes with serious consequences. Its pathogenesis, however, remains unknown. Using a new technique to analyze dynamic contrast enhanced MR perfusion imaging, we demonstrate unique thalamic microvascular abnormalities in painful but not painless neuropathy. This may provide important clues to the pathogenesis of pain in diabetes.

14:30         3622.     Quantification of Brain Perfusion in Patients with Internal Carotid Stenosis and Perfusion Change After Carotid Stenting Based on Dynamic Susceptibility Contrast-Enhanced MRI

Mao-Yuan Su¹, H-L Kao², Y-W Wu², H-Y Yu³, W-C Chu, W-Y Isaac Tseng⁴

¹Institute of Biomedical Engineering, Natioanl Yang-Ming University, Taipei, Taiwan; ²Internal Medicine, National Taiwan University Hospital; ³Surgery, Natioanl Taiwan University Hospital; ⁴Center for Optoelectronic Biomedicine, National Taiwan University College of Medicine

In patients with internal carotid artery (ICA) stenosis, the risk of stroke is associated with reduction of brain perfusion. To reduce the risk, carotid stenting has been considered a treatment of choice. The change in the brain perfusion after stenting, however, still remains unclear. In this study, we used dynamic susceptibility contrast-enhanced MRI to measure brain perfusion change post carotid stenting. In six patients with ICA stenosis, mean transit time (MTT) showed the most significant change, followed by cerebral blood volume (CBV) in the hemispheres ipsilateral to the ICA stenosis. These abnormal perfusion indices returned to normal after carotid stenting.

15:00         3623.     Estimation of Contrast Agent Extravasation from the Tissue Residue Function: Application to Tumor Perfusion Imaging

Atle Bjornerud^1,2, Kyrre E. Emblem¹

¹Department of Medical Physics, Rikshospitalet University Hospital, Oslo, Norway; ²Dept of Physics, Univ of Oslo, Oslo, Norway

We propose a new method to estimate contrast agent extravasation directly from the tissue residue function derived from dynamic susceptibility contrast (DSC) MR imaging. The method is insensitive to variations in mean transit times and can correct both CBV, CBF and MTT directly from the estimated tissue residue function. Using the method, both T1-dominant and T2* dominant extravasation (resulting in both positive and negative leakage constant K1) was detected in a population of 21 contrast enhancing gliomas using a standard GRE-EPI DSC sequence at 1.5 T.