Junjie Wu¹, Seena Dehkharghani¹, Tyler Gleason¹, Fadi Nahab², and Deqiang Qiu^1
1Department of Radiology and Imaging Sciences, Emory University, Atlanta, GA, United States, ²Department of Neurology, Emory University, Atlanta, GA, United States

In this paper we applied a temporal-shift analysis of the BOLD signal to delineate regions with abnormal perfusion in patients with chronic steno-occlusive disease of the cerebrovascular system. We proposed an improved method of analysis based on an iterative approach for the temporal shift analysis. We further explored the effects of acetazolamide, a vasodilator, on the assessment of hemodynamic compromise using temporal-shift analysis and functional connectivity.

Khin Khin Tha^1,2, Ulrich Katscher³, Shigeru Yamaguchi⁴, Shunsuke Terasaka⁴, Toru Yamamoto⁵, Kohsuke Kudo^2,6, and Hiroki Shirato^1,2
1Department of Radiobiology and Medical Engineering, Hokkaido University Graduate School of Medicine, Sapporo, Japan, ²Global Institution for Quantum Medical Science and Engineering, Hokkaido University, Sapporo, Japan, ³Research Laboratories, Hamburg, Germany, ⁴Department of Neurosurgery, Hokkaido University Graduate School of Medicine, Sapporo, Japan, ⁵Graduate School of Health Sciences, Sapporo, Japan, ⁶Hokkaido University Hospital, Sapporo, Japan

Electric Properties Tomography was performed in 24 glioma patients, and the electrical conductivity characteristics of glioma were determined noninvasively. Diagnostic performance of electrical conductivity in distinguishing glioma grades was also evaluated. Validity of noninvasive electrical conductivity measurement was proved by correlating with the conductivity values measured ex vivo by a dielectric probe.

Virendra R Mishra¹, Karthik Sreenivasan¹, Xiaowei Zhuang¹, Zhengshi Yang¹, Sarah Banks¹, Dietmar Cordes¹, and Charles Bernick^1
1Cleveland Clinic Lou Ruvo Center for Brain Health, Las Vegas, NV, United States

The professional fighters brain health study (PFBHS) is a longitudinal study of active professional fighters with age-matched healthy controls using multimodal MRI methods. Using ASL-MRI, we report for the first time that cerebral blood flow (CBF) is significantly lower in boxers and mixed-martial-arts fighters (MMA) than age-matched healthy controls. Most of the clusters were located in the fronto-temporal lobe, cerebellum and thalamus. No significant difference in perfusion between boxers and MMA suggests that type of combat sports have an indiscernible effect on CBF, further suggesting that perfusion may not account for different patterns of cognitive decline observed later in the life of these athletes.  

Yossi Yovel¹, Omri Zomet¹, Arieli Bonzach², Assaf Marom¹, and Yaniv Assaf^1
1Tel Aviv University, Tel Aviv, Israel, ²Beit Dagan Veterinary institute, Beit Dagan, Israel

Despite its importance, little is known on the evolution of the mammalian brain. Previous work suggests that body size and behavioral function are intertwined in their influence on the evolution of the brain. Most previous studies focused on examining gray matter. Because the underlying white matter connectome facilitates the connections between gray matter areas, it must have simultaneously evolved to support gray matter evolution. In this work we used a wide comparative approach relying on diffusion MRI based fiber-tracking to reconstruct whole-brain structural connectomes and explore its evolution. 

Jiaying Zhang¹, Catherine F Slattery², Ross W Paterson², Alexander JM Foulkes², Laura Mancini², David L Thomas², Marc Modat¹, Nicolas Toussaint², David M Cash², John S Thornton², Daniel C Alexander¹, Sebastien Ourselin¹, Nick C Fox², Jonathan M Schott², and Hui Zhang^1
1Department of Computer Science and Centre for medical image computing, University College London, London, United Kingdom, ²Department of Neurodegenerative disease, Institute of Neurology, University College London, London, United Kingdom

Alzheimer's disease (AD) is now increasingly considered as a disorder of brain networks. Therefore, it is important to quantify the integrity of white matter (WM) connections in AD populations. Previous DTI studies have shown WM breakdown in patients with young onset AD (YOAD), but DTI parameters are not specific to any tissue property. Here we investigated WM changes using NODDI and DTI in YOAD patients using TBSS and explored whether unique patterns of WM changes exist in YOAD subtypes. We found NODDI was more sensitive than DTI and demonstrated different profiles of WM damage in YOAD syndromic subgroups.

Xianjun Li^1,2, Jie Gao¹, Yumiao Zhang¹, Yanyan Li¹, Huan Li¹, Mingxi Wan², and Jian Yang^1,2
1Radiology Department of the First Affiliated Hospital, Xi'an Jiaotong University, Xi'an, China, People's Republic of, ²Department of Biomedical Engineering, the Key Laboratory of Biomedical Information Engineering of the Ministry of Education, School of Life Science and Technology, Xi'an Jiaotong University, Xi'an, China, People's Republic of

To distinguish axon-related and myelin-related developmental processes, we tried to find a strategy for assessing white matter developmental processes by using white matter tract integrity (WMTI) metrics derived from diffusion kurtosis imaging (DKI). The method was used on 41 neonates. The proposed strategy provided more processes than conventional diffusion tensor imaging (DTI) method. Five change patterns were found for WMTI metrics, while 2 patterns for DTI metrics. WMTI metrics derived from DKI could provide more detailed developmental processes on neonatal white matter.

Xiaozhen Li^1,2, Peter van Gelderen², Pascal Sati³, Jacco de Zwart², Daniel Reich³, and Jeff Duyn^2
1Dept. NVS, Karolinska Institutet, Stockholm, Sweden, ²Advanced MRI Section, LFMI, NINDS, National Institutes of Health, Bethesda, MD, United States, ³Translational Neuroradiology Unit, NINDS, National Institutes of Health, Bethesda, MD, United States

Multiple sclerosis (MS) is a chronic demyelinating disease characterized by focal lesions.  Recent studies suggest the possibility of obtaining cellular microcompartment-specific information from three-component fitting of the T₂^* relaxation decay curve, allowing determination of the relative fractions of myelin water, axonal water and interstitial water. The microcompartment-specific T₂^* relaxation values of initially enhancing lesions were followed serially on 7T at approximately 3, 6, and 12 months. The changes over time that we observed in enhancing lesions are consistent with the presence of ongoing remyelination. This may lead to a better understanding of, and prognostic ability for, this complex disease.

Vadim Zotev¹, Raquel Phillips¹, Masaya Misaki¹, Chung Ki Wong¹, Brent Wurfel¹, Matthew Meyer^1,2, Frank Krueger^1,3, Matthew Feldner^1,4, and Jerzy Bodurka^1,5
1Laureate Institute for Brain Research, Tulsa, OK, United States, ²Laureate Psychiatric Clinic and Hospital, Tulsa, OK, United States, ³Neuroscience Dept., George Mason University, Fairfax, VA, United States, ⁴Dept. of Psychological Science, University of Arkansas, Fayetteville, AR, United States, ⁵College of Engineering, University of Oklahoma, Tulsa, OK, United States

We have performed a study of emotion regulation training in veterans with combat-related PTSD using real-time fMRI neurofeedback (rtfMRI-nf) with simultaneous EEG. Fifteen PTSD patients learned to upregulate their left amygdala activity using rtfMRI-nf during a positive emotion induction task based on retrieval of happy autobiographical memories. Individual session-to-session variations in frontal EEG asymmetry (FEA) changes during the rtfMRI-nf task significantly correlated with variations in PTSD severity (CAPS) and co-morbid depression severity (HDRS). These results suggest that variations in task-specific FEA changes during rtfMRI-nf training provide a sensitive measure of individual response to treatment in PTSD patients.

Yuhui Chai¹, Guoqiang Bi², Liping Wang³, Fuqiang Xu⁴, Xin Zhou⁴, Bensheng Qiu², Hao Lei⁴, Bing Wu⁵, Yang Fan⁵, and Jia-Hong Gao^1
1Center for MRI Research, Peking University, Beijing, China, People's Republic of, ²University of Science and Technology of China, Hefei, China, People's Republic of, ³Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China, People's Republic of, ⁴Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan, China, People's Republic of, ⁵GE Healthcare, MR Research China, Beijing, China, People's Republic of

In-vivo detection of neuronal current remains a challenging and promising goal in fMRI. Previous work has demonstrated its feasibility in phantom and cell culture studies, but attempts in in-vivo studies remain few and far between. As neuronal current is usually comprised of a series of oscillatory waveforms rather than being a direct current, it is most likely to be detected using oscillatory current sensitive sequences. In this study, we explored the potential of using the spin-lock oscillatory excitation (SLOE) sequence to directly detect optogenetically evoked oscillatory neuronal current in vivo for the first time.

Emil Ljungberg¹, Irene Vavasour², Roger Tam^2,3, Youngjin Yoo³, Alexander Rauscher⁴, David Li², Anthony Traboulsee⁵, Alex MacKay^1,2, and Shannon Kolind^5
1Physics and Astronomy, University of British Columbia, Vancouver, BC, Canada, ²Radiology, University of British Columbia, Vancouver, BC, Canada, ³Electrical and Computer Engineering, University of British Columbia, Vancouver, BC, Canada, ⁴Pediatrics, University of British Columbia, Vancouver, BC, Canada, ⁵Medicine, University of British Columbia, Vancouver, BC, Canada

Myelin water imaging can quantify myelin in the cervical cord in vivo. However, the established 3D Turbo Spin Echo (TSE) approach has a lengthy scan time. We used a 3D Gradient Spin Echo (GRASE) sequence to speed up cervical cord myelin water acquisition by a factor of three. Average GRASE and TSE myelin water estimates were similar (GRASE: 23±1.5%; TSE: 24±3%) and significantly correlated (R²=0.69, p<0.001). 3D-GRASE showed good reproducibility with an average myelin water coefficient of variation of 6%. Our findings demonstrate that cervical cord myelin water data can reliably be collected in clinical feasible scan times. 

Christian Federau¹, Maged Goubran¹, Jason Su¹, Jaimie Henderson¹, Veronika Santini¹, Casey Harrison Halpern¹, Brian Rutt¹, Kim Butts Pauly¹, and Pejman Ghanouni^1
1Stanford University, Stanford, CA, United States

Transcranial MR-guided high-intensity focused ultrasound ablation of the ventral division of the ventral lateral posterior thalamic nucleus (VLpv) is a promising, minimally invasive treatment method for essential tremor. We report our initial clinical experience in 11 patients, and correlate clinical outcome with lesion size, location, and thermal dose during treatment. We found a correlation between clinical outcome at 1 year follow-up and lesion size  (r = 0.73), as well as thermal dose in the VLpv (r = 0.65).

Margaret R. Lentz¹, Jeffery R. Solomon², Srikanth Yellayi¹, Richard Bennett¹, Dawn Traynor¹, David Thomasson¹, Anna Honko¹, Lisa Hensley¹, and Peter B. Jahrling^1,3
1Integrated Research Facility, NIAID, National Institutes of Health, Frederick, MD, United States, ²Clinical Research Directorate/Clinical Monitoring Research Program, Frederick National Laboratory for Cancer Research, Leidos Biomedical Research, Inc., Frederick, MD, United States, ³Emerging Viral Pathogens Section, NIAID, National Institutes of Health, Frederick, MD, United States

The purpose of this study was to use MRI to assess alterations in the brain that occur in rhesus macaques infected with a variant of the Ebola virus (EBOV) isolated from the most recent outbreak. EBOV was found to induce signal alterations in susceptibility weighted imaging (SWI) along vasculature that correlate to venous congestion and perivascular hemorrhage. The use of SWI or other gradient echo based methods to examine vascular changes may be of interest when examining survivors of Ebola. Additionally, the identification of non-invasive imaging biomarkers of EBOV disease progression could help in development of medical countermeasures.

Gwenaelle Douaud¹, Eugene Duff¹, Adrian Groves¹, Thomas Nichols^1,2, Saad Jbabdi¹, Christian Tamnes³, Lars Westlye³, Andreas Engvig³, Kristine Walhovd³, Anders Fjell³, Heidi Johansen-Berg¹, and Steve Smith^1
1FMRIB Centre, University of Oxford, Oxford, United Kingdom, ²University of Warwick, Coventry, United Kingdom, ³University of Oslo, Oslo, Norway

It is believed that the resting-state networks closely relate to the underlying anatomical connectivity and grey matter structure but cannot be understood in those terms alone. Here, we show that a purely data-driven approach used to co-model three complementary types of grey matter information on a large, healthy population covering most of the lifespan uncovers the entire repertoire of canonical functional networks. We further demonstrate that the modes of variation of grey matter volume across all participants forming these structural networks spatially co-vary with cortical area, except in primary sensory areas where they also partially co-vary with cortical thickness.

Xingfeng Shao¹, Yi Wang¹, and Danny J.J. Wang^1
1Laboratory of FMRI Technology (LOFT), Department of Neurology, University of California Los Angeles, Los Angeles, CA, United States

Compared to standard two-dimensional (2D) arterial spin labeling (ASL), simultaneous multi-slice (SMS) ASL imaging techniques can reduce T1 relaxation effect of the label; improve spatial coverage and resolution. However, existing 2D SMS ASL techniques are sub-optimal for the background suppression (BS) technique since multiple SMS excitations are required. In this study, we propose a novel constrained slice-dependent BS scheme for 2D multi-slice pseudo-continuous ASL (pCASL) with SMS-EPI acquisition, to suppress background signal across a wide range of T1s. In vivo experiment showed that the BS scheme can increase temporal SNR of perfusion images 1.5-2 folds.

Mathieu David Santin^1,2, Marc Herbin³, and Roberto Toro^4
1Centre de NeuroImagerie de Recherche - CENIR, Paris, France, ²Inserm U 1127, CNRS UMR 7225, Sorbonne Universités, UPMC Univ Paris 06 UMR S 1127, Institut du Cerveau et de la Moelle épinière, ICM, Paris, France, ³Muséum National d'Histoire Naturelle, Paris, France, ⁴Institut Pasteur, Paris, France

We present here an example of one of the application of the Brain Catalogue with an MRI of an extinct species: the Thylacine