Mohammad Rakeen Niaz¹, Yingjuan Wu¹, Abdur Raquib Ridwan¹, Xiaoxiao Qi¹, Shengwei Zhang¹, David A. Bennett², and Konstantinos Arfanakis^1,2
1Biomedical Engineering, Illinois Institute of Technology, Chicago, IL, United States, ²Rush Alzheimer's Disease Center, Rush University Medical Center, Chicago, IL, United States

A high-resolution older adult brain template containing full diffusion tensor (DT) information has not been constructed. Available DT templates of low spatial resolution lack fine details, and most are not representative of the older adult brain. Both factors limit spatial normalization accuracy in studies of aging. This work a) introduced a novel approach for constructing a DT template with high spatial resolution based on principles of super-resolution, and using this technique, b) developed and quantitatively evaluated a DT template of the older adult brain with high spatial resolution using high-quality data from 202 non-demented older adults.

Taylor Swift-LaPointe¹, Irene M. Vavasour^2,3, Lisa Eunyoung Lee⁴, Shawna Abel⁴, Bretta Russell-Schulz², Carina Graf^1,3, Anika Wurl¹, Hanwen Liu^1,3, Cornelia Laule^1,2,3,5, David K.B. Li^2,4, Anthony Traboulsee⁴, Roger Tam^2,6, Lara A. Boyd⁷, Alex L. MacKay^1,2, Shannon H. Kolind^1,2,3,4, and Adam V. Dvorak^1,3
1Physics and Astronomy, University of British Columbia, Vancouver, BC, Canada, ²Radiology, University of British Columbia, Vancouver, BC, Canada, ³International Collaboration on Repair Discoveries (ICORD), Vancouver, BC, Canada, ⁴Medicine (Neurology), University of British Columbia, Vancouver, BC, Canada, ⁵Pathology and Laboratory Medicine, University of British Columbia, Vancouver, BC, Canada, ⁶Biomedical Engineering, University of British Columbia, Vancouver, BC, Canada, ⁷Department of Physical Therapy, University of British Columbia, Vancouver, BC, Canada

Data from 100 healthy volunteers (58F/42M, mean age 41 years, range 20-78 years) scanned at 3.0T were used to create a structural template. Voxel-wise mean myelin water fraction (MWF) and intra/extracellular T₂ (IET2) atlases were created, and 19 regions of interest were obtained using the joint label fusion framework. Pearson correlations with both age and sex were calculated for MWF and IET2. Mean MWF and IET2 demonstrated clear ranking between brain structures for different age groups, indicating that relative metric values are generally consistent between ROIs. There were no significant correlations between MWF or IET2 and sex.

Mustapha Bouhrara¹, Joseph E. Alisch¹, Nikkita Khattar¹, Abinand C. Rejimon¹, Luis E. Cortina¹, and Richard G. Spencer^1
1NIA, NIH, Baltimore, MD, United States

Little is known about the relationship between white matter (WM) perfusion and microstructure across cognitively normal or impaired subjects. WM maintenance through oligodendrocyte metabolism is an energy-intensive process, so that myelin homeostasis is particularly sensitive to hypoxia, ischemia, or hypoperfusion. In addition to substrate delivery, adequate cerebral blood flow (CBF) is crucial for removal of metabolic byproducts. We investigated associations between CBF deficits and myelin loss in multiple brain regions in a cohort of cognitively unimpaired participants across a wide age range. We show significant correlations between CBF deficits and myelin loss in critical brain structures.
 

Mustapha Bouhrara¹, Nikkita Khattar¹, Luis E. Cortina¹, Abinand C. Rejimon¹, Elango Palchamy¹, and Richard G. Spencer^1
1NIA, NIH, Baltimore, MD, United States

Microstructural white matter (WM) degeneration has been shown to have a direct impact on mobility performance. However, the association between speed gait and myelin changes is less clear. This study examines the effect of myelin degeneration measured using myelin water fraction (MWF), a specific proxy of myelin content, and relaxation rates, sensitive but non-specific measures of myelin, on rapid gait speed (RGS), which represents an integrated metric of physiologic function. Our study is conducted on a large age-range cohort of cognitively unimpaired participants. We show statistically significant correlations between MWF loss and RGS decline in several WM structures.
 

Mustapha Bouhrara¹, Abinand C. Rejimon¹, Luis E. Cortina¹, Nikkita Khattar¹, and Richard G. Spencer^1
1NIA, NIH, Baltimore, MD, United States

Changes in brain myelination with age and sex have been the subject of intense MRI study. However, most studies have used nonspecific methods to probe myelin, including DTI and relaxation times. We investigated age- and sex-related differences in brain myelin water fraction (MWF), a surrogate of myelin content, in a large cohort of unimpaired participants, spanning a wide age range. We observed a quadratic relationship between MWF and age in all brain regions investigated, suggesting that myelination continues until middle age followed by a decrease through older age.  Sexual dimorphism in this process was observed in several brain regions.
 

Wenshu Qian¹, Nikkita Khattar¹, Abinand C. Rejimon¹, Mustapha Bouhrara ¹, and Richard G. Spencer^1
1National Institute on Aging, Baltimore, MD, United States

While sensitive to microstructural changes, conventional quantitative MR techniques, such as diffusion tensor imaging, are not specific to underlying physiological mechanisms. Advanced multi-shell diffusion and multicomponent relaxometry analyses have been shown to provide more specific insights regarding microstructural differences with age and disease. In this study, we combined our multicomponent relaxometry method for myelin mapping and the neurite orientation dispersion and density imaging (NODDI) method to investigate neurite myelination and density in a cohort of cognitively unimpaired participants. Quadratic relationships were observed between neurite density and myelination, and age, in critical brain regions.

Zheng Li¹, Zongpai Zhang¹, Wenna Duan¹, Lissa Riley², Adam K. Anderson², Eve DeRosa², and Weiying Dai^1
1Computer Science, State University of New York at Binghamton, Binghamton, NY, United States, ²Human Development, Cornell University, Ithaca, NY, United States

Disrupted CBF-related measures in clinical diseases has highlighted the importance of reliable baseline data from normal controls. We characterized CBF-related measures in normal aging by acquiring PCASL images in 11 young and 12 elderly subjects. We found that the elderly exhibited longer ATT in the frontal, parietal, temporal, and subcortical regions, reduced CBF in the prefrontal and parietal regions and increased CBF in the subcortical regions, and increased LFF in the superior frontal and paracentral region, compared to the young. This work sets the stage for a larger scale use of PCASL to investigate CBF-related alterations in neurological diseases.

Marie-Pier McSween^1,2, Megan L. Isaacs^1,2, David A. Copland^1,2, Jeff S. Coombes³, Amy D. Rodriguez⁴, Kirk I. Erickson⁵, and Katie L. McMahon^6
1The University of Queensland School of Health and Rehabilitation Sciences, Brisbane, Australia, ²University of Queensland Centre for Clinical Research, Brisbane, Australia, ³The University of Queensland School of Human Movement and Nutrition Sciences, Brisbane, Australia, ⁴Centre for Visual and Neurocognitive Rehabilitation, Atlanta, GA, United States, ⁵University of Pittsburgh, Pittsburgh, PA, United States, ⁶Queensland University of Technology School of Clinical Sciences, Brisbane, Australia

High-intensity interval exercise (HIIE) can benefit word learning in young adults, however this is yet to be investigated in older adults and the neural mechanisms responsible have not been directly examined. Twenty-six older adults participated in this study and engaged in stretching or HIIE prior to performing an in-scanner (fMRI) associative new word learning task. Results showed increased activation after HIIE, in the left middle temporal gyrus, and right inferior occipital gyrus in addition to better word recognition accuracy, suggesting benefits of HIIE on word learning that may be attributed to increased activation in key language and visual processing areas.

Jason Langley¹, Sana Hussain², Justino J Flores³, Daniel E Huddleston⁴, Ilana Bennett³, and Xiaoping Hu^1,2
1Center for Advanced Neuroimaging, University of California Riverside, Riverside, CA, United States, ²Bioengineering, University of California Riverside, Riverside, CA, United States, ³Psychology, University of California Riverside, Riverside, CA, United States, ⁴Neurology, Emory University, Atlanta, GA, United States

Characterization of age-related alterations in microstructure of locus coeruleus and its projections will aid in the development of new biomarkers and may provide insight in the development of novel interventions to arrest progression of Alzheimer's disease or Parkinson's disease. Imaging locus coeruleus with diffusion-weighted images is difficult due to its small stature (locus coeruleus is 1.5 mm in diameter and 15 mm long) and location in the brain stem. In this abstract, we utilize a high resolution diffusion-weighted protocol to examine age-related microstructural changes in locus coeruleus and examine its effect on age-related cognitive decline.

Stephan Kaczmarz^1,2, Jens Göttler^1,2,3, Andreas Hock⁴, Claus Zimmer¹, Fahmeed Hyder², and Christine Preibisch^1,5
1School of Medicine, Department of Neuroradiology, Technical University of Munich, Munich, Germany, ²MRRC, Yale University, New Haven, CT, United States, ³School of Medicine, Department of Radiology, Technical University of Munich, Munich, Germany, ⁴Philips Healthcare, Hamburg, Germany, ⁵School of Medicine, Clinic of Neurology, Technical University of Munich, Munich, Germany

White matter lesions (WML) are detected as hyperintensities on clinically frequently used T₂-weighted FLAIR-images and can manifest as cognitive decline. Though most elderly subjects show WML, the pathogenesis is still unclear. Potential causes are small vessel damages and myelin-sheath deformations. We present data from 30 healthy elderly and 29 carotid stenosis patients measuring WML, individual watershed areas (iWSA), capillary transit-time heterogeneity (CTH) and DTI-based structural parameters. We hypothesize increased lesion load inside iWSAs and capillary dysfunction with structural damages in WML. Our results confirm those hypotheses and furthermore, indicate similar WML formation mechanisms in healthy aging and carotid artery stenosis.

Tae Kim¹, Annie Cohen¹, and James T Becker^1
1University of Pittsburgh, Pittsburgh, PA, United States

Brain atrophy is highly associated with cardiac pulsatility in the brain. The reduction of brain regional volumes was correlated with increased pulsatility of its supply arteries and a decrease of sinus and CSF. The regional volume reduction was affected by the pulsatility of different vessels.

Kathryn Broadhouse¹, Natalie Winks¹, and Jim Lagopoulos^1
1University of the Sunshine Coast, Sunshine Coast, Australia

Current markers of early neurodegeneration include β-amyloid plaque accumulation and Tau-mediated neuronal injury; both of which are thought to emerge prior to significant cognitive deficits and measurable brain atrophy. Unfortunately, the role of these biomarkers within the cascade of pathophysiological processes of AD remains poorly understood. Impairment in the glymphatic clearance system has garnered attention and is thought to represent a pathway to decline. Here we demonstrate that quantification of glymphatic clearance measures are feasible in healthy controls. Combining these measures with cognitive performance scores and diagnosis will provide insight into the role of the glymphatics system with decline.

Mayu Iida^1,2, Junichi Hata^2,3,4, Yawara Haga^1,4, Akiko Uematsu^4,5, Fumiko Seki^2,4, Daisuke Yoshimaru^2,3,4, Kei Hagiya⁴, Hirotaka James Okano^3,4, Hideyuki Okano⁴, and Takako Shirakawa^1
1Department of Radiological Sciences, Human Health Sciences, Tokyo Metropolitan University Graduate School, Tokyo, Japan, ²Live Imaging Center, Central Institute for Experimental Animals, Kanagawa, Japan, ³Division of Regenerative Medicine, Jikei University School of Medicine, Tokyo, Japan, ⁴Laboratory for Marmoset Neural Architecture, Center for Brain Science, RIKEN, Saitama, Japan, ⁵Center of Evolutionary Cognitive Sciences, Tokyo University Graduate School, Tokyo, Japan

MRI data of 204 large common marmoset colonies were obtained and analyzed regarding brain volume. Marmosets have a brain structure and nerve paths are similar to those in humans compared to other experimental animals. The volume from puberty to old age in six regions (gray matter, deep gray matter, white matter, brainstem, cerebellum, and CSF) could be evaluated. From the viewpoint of volume and variability when performing brain image analysis, it was suggested that marmosets are experimental animals that can evaluate the effects of individual differences at the same level as humans or with slightly less variation than humans.

SAMUEL BARNES¹, SHILPY CHOWDHURY², JENNIFER GARCIA-CANO³, NICOLE M GATTO⁴, and GRACE J LEE^3
1RADIOLOGY, LOMA LINDA UNIVERSITY HEALTH, Loma Linda, CA, United States, ²LOMA LINDA UNIVERSITY, LOMA LINDA, CA, United States, ³PSYCHOLOGY, LOMA LINDA UNIVERSITY SCHOOL OF BEHAVIORAL HEALTH, LOMA LINDA, CA, United States, ⁴School of Community and Global Health, Claremont Graduate University, CLAREMONT, CA, United States

Dynamic-contrast enhanced (DCE) MRI can detect changes in the blood brain barrier integrity which can be associated with cognitive changes in aging populations. 40 participants from a large cohort underwent contrast MRI and battery of neuropsychological tests. DCE K_trans values showed a negative correlation with verbal learning and memory testing (RAVLTIR and RAVLTSD). Blood brain barrier disruption, defined by higher K_trans values, is associated with worse performance on verbal learning, memory and category fluency tests.

Soroush Heidari Pahlavian^1,2, Xinhui Wang ², Samantha Ma^1,2, John Ringman², Helena Chui², Danny J.J. Wang^1,2, and Lirong Yan^1,2
1USC Stevens Neuroimaging and Informatics Institute, Keck School of Medicine, University of Southern California, Los Angeles, CA, United States, ²Department of Neurology, University of Southern California, Los Angeles, CA, United States

Elevated cerebroarterial pulsations due to arterial stiffness can impart abnormal forces to downstream capillary/tissue leading to microvascular damage, which are thought to be a contributing factor in the pathogenesis of neurodegenerative disorders such as Alzheimer’s disease and small vessel disease. In this study, we assessed the utility of two-dimensional (2D) phase-contrast MRI (PC-MRI) in quantifying cerebroarterial pulsations and evaluated the associations of pulsatile and non-pulsatile hemodynamic measures with cognitive performance and white matter hyperintensity (WMH). Our results indicated significant associations of PC-MRI derived pulsatility metrics with cognitive performance and WMH.

Austin Bazydlo¹, Sigan Hartley¹, Minjie Wu², Patrick Lao³, Douglas C Dean, III¹, Matthew Zammit¹, Sterling Johnson¹, Dana Tudorascu², Annie Cohen², Karly Cody¹, Charles Laymon², William Klunk², Shahid Zaman⁴, Benjamin Handen², Andrew Alexander¹, and Bradley Christian^1
1University of Wisconsin-Madison, Madison, WI, United States, ²University of Pittsburgh Medical Center, Pittsburgh, PA, United States, ³Columbia University, New York, NY, United States, ⁴University of Cambridge, Cambridge, United Kingdom

People with Down Syndrome (DS) are at an increased risk of developing Alzheimer’s Disease (AD), due to an overproduction of β-amyloid resulting from triplication of the amyloid precursor protein (APP) gene located on chromosome 21. The effect of white matter degradation on early AD-related cognitive decline in the DS population is not known. In this work, we present results from a study of non-demented adults with DS showing correlations between increased mean diffusivity (MD), derived using diffusion tensor imaging (DTI), within several white matter regions of interest and poorer performance on measures of episodic memory.

Remika Mito^1,2, Robert Smith¹, Thijs Dhollander¹, Christopher Rowe^3,4, Victor Villemagne^3,4, Amy Brodtmann^1,3, and Alan Connelly^1,2
1Florey Institute of Neuroscience and Mental Health, Melbourne, Australia, ²Florey Department of Neuroscience and Mental Health, University of Melbourne, Melbourne, Australia, ³Department of Medicine, Austin Health, University of Melbourne, Melbourne, Australia, ⁴Department of Molecular Imaging & Therapy, Centre for PET, Austin Health, Heidelberg, Australia

Alzheimer’s disease (AD) is characterised by degeneration of specific white matter tracts, however the longitudinal trajectory of tract-specific decline has not yet been well described. In this work, we utilise a longitudinal fixel-based analysis framework to investigate specific fibre tracts that exhibit accelerated decline in AD and mild cognitive impairment (MCI). Whole-brain analysis revealed that select fixels exhibit accelerated rates of decline in AD compared to healthy elderly controls, while MCI patients did not exhibit accelerated decline in any fibre structures. Tract-of-interest analysis revealed group differences in tract trajectories over time.

Judith Harrison¹, Xavier Caseras², Sonya Foley¹, Emily Baker², David Linden³, Peter Holmans², Derek Jones¹, and Valentina Escott-Price^2
1CUBRIC, CUBRIC, Cardiff University, Cardiff, United Kingdom, ²MRC Centre for Neuropsychiatric Genetics and Genomics, Cardiff University, Cardiff, United Kingdom, ³School for Mental Health and Neuroscience, Maastricht University, Maastricht, Netherlands

This study explores the relationship between structural brain measurements and novel pathway-specific polygenic scores for Alzheimer’s Disease (AD). We observed associations between the pathway-polygenic profiles, cortical thinning, and changes in white matter signal particularly in the fornix, which have been shown to be markers of Alzheimer’s degeneration, in our sample of healthy young adults. Surprisingly, despite the contribution of APOE to AD risk, the signal in the white matter was stronger when APOE was excluded from the polygenic scores.        

Harald Kugel¹, Jonathan Repple², Janik Goltermann², Ronny Redlich², Katharina Dohm², Claas Kaehler^2,3, Dominik Grotegerd², Katharina Foerster², Susanne Meinert², Verena Enneking², Tim Hahn², Andreas Jansen⁴, Axel Krug⁴, Igor Nenadic⁴, Simon Schmitt⁴, Frederike Stein⁴, Tina Meller⁴, Dilara Yueksel⁴, Elena Fischer⁴, Marcella Rietschel⁵, Stephanie Witt⁵, Andreas J Forstner^6,7, Markus Noethen⁶, Andreas Johnen⁸, Tilo Kircher⁴, Bernhard T Baune², Udo Dannlowski², and Nils Opel^2
1Institute of Clinical Radiology, University of Muenster, Muenster, Germany, ²Department of Psychiatry, University of Muenster, Muenster, Germany, ³Department of Mathematics and Computer Science, University of Muenster, Muenster, Germany, ⁴Department of Psychiatry, University of Marburg, Marburg, Germany, ⁵Department of Genetic Epidemiology in Psychiatry, University of Heidelberg, Mannheim, Germany, ⁶Institute of Human Genetics, University of Bonn, Bonn, Germany, ⁷Centre for Human Genetics, University of Marburg, Marburg, Germany, ⁸Department of Neurology, University of Muenster, Muenster, Germany

Apoliprotein E (APOE) genotype status, a predictor of Alzheimer's disease, has been associated with brain structural alterations. Supplementing previous research that primarily focused on hippocampal morphometry, we found a widespread effect of APOE allele status on cortical surface area and white matter microstructure. There is a significant cortical surface area decrease in 57 out of 68 cortical brain regions in APOE ε4 homozygous carriers. Furthermore, APOE ε4 homozygous carriers showed significant and widespread reductions in fractional anisotropy in corpus callosum, right internal and external capsule, left corona radiata and right fornix.

Yangyingqiu Liu¹, Junyi Dong¹, Yanwei Miao¹, Ailian Liu¹, Qingwei Song¹, and Lizhi Xie^2
1Department of Radiology, First Affiliated Hospital of Dalian Medical University, Dalian, China, ²GE healthcare, Beijing, China

Blood oxygen level of the cerebral vein is quantitatively assessed by magnetic sensitivity value (MSV)using quantitative susceptibility mapping (QSM), and its’correlation to cognitive scores is also analyzed in patients with Alzheimer's disease (AD).The results show that increased MSV value of cerebral vein in AD patients may affect cognitive scores.

Arun Venkataraman¹, Zachary Christensen², and Jianhui Zhong^3
1Physics, University of Rochester, Rochester, NY, United States, ²Translational Biomedical Sciences, University of Rochester, Rochester, NY, United States, ³Imaging Sciences, University of Rochester, Rochester, NY, United States

Frontotemporal Dementia (FTD) and Early-Onset Alzheimer's Dementia (EOAD) can occur in the same age group and have overlapping symptoms, often complicating diagnosis. In this study, we focused on trying to understand cortical thickness as a biomarker of dementia type. More specifically, we wanted to classify EOAD vs FTD using only data from T1w MRI. We found that classification of FTD vs EOAD using FreeSurfer and ANTs cortical thickness data is highly dependent on the type of classifier used. In addition, it seems that ANTs is better suited than FreeSurfer independent of classification model.

Dongxue Li¹, Yuancheng Liu¹, Zhenliang Xiong¹, Xianchun Zeng¹, Lisha Nie², Pu-Yeh Wu², and Rongpin Wang^1
1Department of Radiology, Guizhou Provincial People's Hospital, Guiyang, China, ²GE Healthcare, MR Research, Beijing, China

The CBF and iron deposition evaluation are commonly used in alzheimer's disease. we analyzed the changes and correlations of CBF and iron deposition in different stages of AD. ASL and QSM identified several abnormal brain regions of interest, which were sensitive to tissue alterations in each stage. This study found QSM was detected in the early stage of AD, which is expected to be an effective tool for early AD diagnosis and timely intervention. Additionally, the iron deposition and CBF in the globus pallidum and putamen flow negatively correlated in the AD group that may be relevant to pathologic changes.

Dengrong Jiang¹, Zixuan Lin¹, Peiying Liu¹, Sandeepa Sur¹, Cuimei Xu¹, George Pottanat¹, Kaisha Hazel¹, Sevil Yasar², Paul Rosenberg³, Marilyn Albert⁴, and Hanzhang Lu^1
1Department of Radiology, Johns Hopkins University School of Medicine, Baltimore, MD, United States, ²Department of Medicine, Johns Hopkins School of Medicine, Baltimore, MD, United States, ³Department of Psychiatry and Behavioral Sciences, Johns Hopkins School of Medicine, Baltimore, MD, United States, ⁴Department of Neurology, Johns Hopkins School of Medicine, Baltimore, MD, United States

Alzheimer’s disease (AD) and vascular dementia (VD) are the two most common types of cognitive impairment. However, there is still a lack of effective tools for their differential diagnosis. In this work, we demonstrated that OEF is differentially (in opposite direction) affected by AD and vascular pathology. Among patients with cognitive impairment, patients with low OEF are associated with more AD pathology and less vascular pathology; and the opposite can be said for patients with high OEF. These findings suggest that OEF may provide valuable information in differentiating AD and VD.

Yurui Gao^1,2, Anirban Sengupta¹, Muwei Li^1,3, Zhongliang Zu^1,3, Baxter P Rogers^1,3, Adam W Anderson^1,2,3, Zhaohua Ding^1,4, and John C Gore^1,2,3
1Vanderbilt University Institute of Imaging Science, Vanderbilt University Medical Center, Nashville, TN, United States, ²Biomedical Engineering, Vanderbilt University, Nashville, TN, United States, ³Radiology and Radiological Sciences, Vanderbilt University Medical Center, Nashville, TN, United States, ⁴Electrical Engineering and Computer Science, Vanderbilt University, Nashville, TN, United States

Pathological alterations of white matter (WM) have been reported during the development of Alzheimer’s disease (AD). This study extended our previous rsfMRI analyses of WM tract BOLD correlations to evaluate WM functional connectivity (FC) in 383 subjects at different stages of cognitive impairment and found that WM FCs 1) decline regionally in late AD groups relative to a control group, 2) are related to cognitive behavioral scores, and 3) are well-performing features for distinguishing AD patients from controls. These findings suggest the potential of WM FC, which has been overlooked, as a novel neuroimaging biomarker to assess AD progression.

Yi-Fen Yen¹, Mary Kate Manhard¹, Annie G. Bryant², Rachel E. Bennett², Kimberly A. Stephens¹, David H. Salat^1,3, Keith A. Johnson², Bradley T. Hyman², Kawin Setsompop¹, and Susie Huang^1
1Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Charlestown, MA, United States, ²Department of Neurology, Massachusetts General Hospital, Boston, MA, United States, ³VA Boston Healthcare System, Neuroimaging Research for Veterans Center, Boston, MA, United States

We have identified reduced cerebral blood flow, abnormally long mean transit time, and large capillary transit time heterogeneity in seven individuals with mild cognitive impairment or Alzheimer’s disease as compared to healthy subjects by using a highly accelerated dynamic susceptibility enhanced (DSC) MRI technique. This perfusion imaging technique provides whole brain coverage using simultaneous multi-slice acquisition and collects spin and gradient echo in one dynamic scan. The spin-echo and gradient-echo DSC-MRI acquisition enables probing and potentially distinguishing micro- and macro-vascular contributions to perfusion in older adults using a single injection of gadolinium.

Xingjuan Li¹, Jurgen Fripp¹, Samantha Burnham², Vincent Doré², and Pierrick Bourgeat^1
1Australian eHealth Research Center, CSIRO, Brisbane, Australia, ²Australian eHealth Research Center, CSIRO, Melbourne, Australia

Understanding the heterogeneity in atrophy changes from Alzheimer's disease (AD) can be an important factor to develop effective drugs and improve patients' outcomes [7]. In this study, we propose a deep learning approach to identify AD subtypes based on T1w magnetic resonance images (MRI). Experimental results show that the proposed method can accurately identify four AD subtypes exhibiting a distinctive cortical atrophy pattern.

Huaiqiang Sun¹, Lin Zou¹, Haoyang Xing¹, Min Wu¹, Lei Chen², Qing Li³, and Qiyong Gong^1
1Huaxi MR Research Center (HMRRC), West China Hospital of Sichuan University, Chengdu, China, ²Department of Neurology, West China Hospital of Sichuan University, Chengdu, China, ³MR Collaborations, Siemens Healthcare Ltd., Shanghai, China

A preliminary study that apply geometric deep learning to brain morphometry analysis of Alzheimer’s disease, the results show promising prediction accuracy suggesting geometric deep learning opens new prespectives for  brain morphometry analysis of neurological and psychiatric disorders.

Catherine A Morgan^1,2, Zichang Dong³, David Lythgoe⁴, Lynette Tippett^1,2, and Tracy Melzer^5,6
1School of Psychology and Centre for Brain Research, University of Auckland, Auckland, New Zealand, ²Brain Research New Zealand, Auckland, New Zealand, ³Department of Physics, University of Auckland, Auckland, New Zealand, ⁴Institute of Psychiatry, Psychology & Neuroscience, King's College London, London, United Kingdom, ⁵University of Otago, Christchurch, New Zealand, ⁶Brain Reserach New Zealand, Christchurch, New Zealand

There is a growing body of work (post-mortem and in vivo) to support the link between iron and the pathophysiology of neurodegenerative disorders. While much of the current literature has focused on later stages of diseases such as Parkinson’s and Alzheimer’s disease (AD), how iron may contribute to early pathology is less well understood. We employed QSM and R2* mapping in a group of mild cognitive impairment and early AD subjects along with age-matched controls. Our pilot results suggest that magnetic susceptibility is higher in the cortex of the cognitively impaired group and is negatively correlated with cognition.

Siriwan Piyapittayanan¹, Sahutchadech Tangisarapap¹, Chanon Ngamsombat¹, Orasa Chawalparit¹, Weerasak Muangpaisan², and Suwit Charoensak^3
1Radiology, Faculty of Medicine Siriraj Hospital, Bangkok, Thailand, ²Geriatric Medicine, Faculty of Medicine Siriraj Hospital, Bangkok, Thailand, ³Psychiatry, Faculty of Medicine Siriraj Hospital, Bangkok, Thailand

The brain circuit pathways of major depressive disorder (MDD) and Alzheimer’s disease (AD) could overlap. The authors hypothesized that AD and MDD subjects would have different diffusion parameters compared to healthy elderly controls (HE). Forty-seven age-matched subjects (AD=19, MDD=11, HE=20) were enrolled and performed MRI included structural brain imaging and diffusion kurtosis imaging (DKI) and then diffusional parameters were compared to differentiate between the three groups. Caudate nucleus and thalamus revealed significant different of diffusion parameters between AD and HE, and between AD and MDD but no significant different between MDD and HE. Diffusion imaging can demonstrate microstructural change in AD.

Kay Jann¹, Hosung Kim¹, Danny JJ Wang¹, and for the Alzheimer's Disease Neuroimaging Initiative^2
1USC Stevens Neuroimaging and Informatics Institute, Keck School of Medicine at USC, Los Angeles, CA, United States, ²http://adni.loni.usc.edu/wp-content/uploads/how_to_apply/ADNI_Acknowledgement_List.pdf, Los Angeles, CA, United States

Recently entropy measures have been explored as indices of the complexity of rs-fMRI time-series which decrease in aging and dementia. Here, we compared multi-scale entropy (MSE) of rs-fMRI with tau PET measures of neurofibrillary tangles in a cohort of 50 aged subjects in the ADRC database, through correlational and machine learning approaches. We show that the complexity of BOLD signals provides an index of the information processing capacity of regional neuron populations, and is associated with tau-related neuronal injury and cognitive decline in the AD processes. 

Nazanin Makkinejad¹, Arnold M. Evia², Ashish A. Tamhane², David A. Bennett², Julie A. Schneider², and Konstantinos Arfanakis^1,2
1Biomedical Engineering, Illinois Institute of Technology, Chicago, IL, United States, ²Rush Alzheimer's Disease Center, Rush University Medical Center, Chicago, IL, United States

Arteriolar sclerosis and small vessel atherosclerosis are two age-related neuropathologies that are common in older adults and have been linked to cognitive decline and dementia. Definitive diagnosis of either pathology is only possible at autopsy. In this work, a novel MRI-based classifier was developed for predicting the presence of arteriolar sclerosis or small vessel atherosclerosis in-vivo. The classifier was first developed based on ex-vivo MRI and pathology data from a large community-based cohort of older adults and was then translated in-vivo. The performance of the classifier was assessed both ex-vivo and in-vivo.

Sung-Jong Eun¹, Sang-Young Kim², Young Noh³, and Eung-Yeop Kim^4
1Health IT Research Center, Gil Medical Center, Gachon University College of Medicine, Incheon, Korea, Republic of, ²Center for Parkinson's Disease and Dementia, Neuroscience Research Institute, Gachon University, Incheon, Korea, Republic of, ³Department of Neurology, Gil Medical Center, Gachon University of College of Medicine, Incheon, Korea, Republic of, ⁴Department of Radiology, Gil Medical Center, Gachon University of College of Medicine, Incheon, Korea, Republic of

Locus coeruleus (LC) is involved in regulating working memory, learning, attention, and arousal/wakefulness in the brain and accumulating evidence suggest that the LC is the initial brain region that the earliest pathological changes occur in Alzheimer’s disease (AD). We employed neuromelanin-sensitive MRI to detect the changes of LC volumes in AD. Automatic segmentation of the LC revealed profound reductions in LC volumes in AD dementia as compared to prodromal AD and/or healthy controls. Our finding suggests that volumetric reduction of the LC would be a non-invasive biomarker for detecting early pathological changes in AD. 

Christian Tinauer¹, Stefan Heber¹, Lukas Pirpamer¹, Anna Damulina¹, Martin Soellradl¹, Maximilian Sackl¹, Edith Hofer¹, Marisa Koini¹, Reinhold Schmidt¹, Stefan Ropele¹, and Christian Langkammer^1
1Medical University of Graz, Graz, Austria

Using R2* maps we separated Alzheimer's patients (n=119) from healthy controls (n=131) by using a deep neural network and found that the preprocessing steps might introduce unwanted features to be used by the classifier. We systematically investigated the influence of registration and brain extraction on the learned features using a relevance map generator attached to the classification network. The results were compared to our relevance-guided training method. While the resulting classification accuracy on the testset was similar for all training configurations, the relevance-guided method identified anatomical regions, which are known to have higher R2* values.

Wenliang Fan¹, Jia Liu¹, Jiazheng Wang², and Jing Wang^1
1Radiology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China, ²Philips Healthcare, Beijing, China

The dynamic longitudinal change of brain in progression of AD is still unknown. We analyzed the brain networks of AD patients at different stages. We found in global network properties, most differences only existed between healthy people and patients, and few were discovered between patients at different stages. However, nearly all subnetwork properties showed significant differences between patients at different stages. Moreover, we found two different functional evolving patterns of cortical networks in progression of AD, named ‘Temperature inversion’ and “Monotonous decline”, but not the same monotonous decline trend as the external functional assessment observed in disease progression.

Marianna Inglese¹, Haonan Lu^2,3, Matthew Grech-Sollars^1,4, and Eric O Aboagye^1
1Surgery and Cancer, Imperial College, London, United Kingdom, ²Cancer Imaging Centre, Imperial College, London, United Kingdom, ³Ovarian Cancer Action Research Centre, Imperial College, London, United Kingdom, ⁴Department of Imaging, Imperial College Healthcare NHS Trust, London, United Kingdom

Alzheimer’s disease(AD) is the most common form of dementia. In the past few decades, great advances have been made in the understanding of its pathophysiology due to the use of biomarkers. Imaging biomarkers, either based on structural brain changes and metabolic alterations alone, or in conjunction with cerebrospinal fluid(CSF) biomarkers, can be informative of the ongoing pathological processes occurring in a patient with AD. In our method, we propose a novel MRI biomarker that is based on the extraction of structural features from a T1-w MRI scan, and it provides biological characterization of early and later forms of AD.

Shuyue Wang¹, Xiao Luo¹, Kaicheng Li¹, Qingze Zeng¹, Yeerfan Jiaerken¹, Hui Hong¹, Yong Zhang², Peiyu Huang¹, and Minming Zhang^1
1Radiology, The 2nd Affiliated Hospital of Zhejiang University, School of Medicine, Hangzhou, China, ²MR Research, GE Healthcare, Shanghai, China

For the first time, we applied fixel-based analysis (FBA) to investigate fibre tract-specific WM changes in early-onset Alzheimer’s disease (EOAD) and late-onset AD (LOAD). To test the repeatability of the results, we repeated the analysis in two independent cohort. We demonstrated that EOAD in two cohorts had more widespread WM tracts loss than LOAD. The different FD extended from the limbic system to long posterior projection regions. Further, we found that FD, rather than FC, had a higher sensitivity in detecting WM loss of EOAD, and vice versa in LOAD.  Results may provide clinical clues for  early diagnosis of EOAD.

Zhao Qing¹, Feng Chen¹, Jilei Zhang², and Bing Zhang^1
1Nanjing Drum Tower Hospital, Nanjing, China, ²Clinical science, Philips Health Care, Shanghai, Shanghai, China

We used independent components analysis to analysis the inter-subject variation of the voxel-based morphometry results of 446 subjects of Alzheimer's spectrum. 20 components which reflect the inter subject volume variation were extracted and used as features in SVM.  We observed better performance in SVM classification by these features than those using atlas-based method. These findings might be helpful for classification of AD, MCI and NC populations, which provide assistance to the early diagnosis and intervention of Alzheimer’s disease.    

Sena Tunçer¹, Dilek Betul Arslan¹, Tanya Ipek Deniz², Oznur Aslan ³, Ani Kiçik^4,5, Kardelen Eryürek^4,6, Emel Erdoğdu^4,7, Zerrin Yildirim⁸, Zeynep Tüfekcioglu⁸, Basar Bilgic⁸, Hasmet Hanagasi⁸, Hakan Gürvit⁸, Tamer Demiralp^4,9, and Esin Ozturk-Isık^1
1Institute of Biomedical Engineering, Bogazici University, Istanbul, Turkey, ²Department of Electrical and Electronic Engineering, Bogazici University, Istanbul, Turkey, ³Department of Biomedical Engineering, Namik Kemal University, Tekirdağ, Turkey, ⁴Neuroimaging Unit, Hulusi Behcet Life Sciences Research Center, Istanbul University, Istanbul, Turkey, ⁵Department of Physiology, Faculty of Medicine, Demiroglu Bilim University, Istanbul, Turkey, ⁶Department of Neuroscience, Aziz Sancar Institute of Experimental Medicine, Istanbul University, Istanbul, Turkey, ⁷Department of Psychology, Faculty of Arts and Sciences, Isik University, Istanbul, Turkey, ⁸Behavioral Neurology and Movement Disorders Unit, Department of Neurology, Istanbul Faculty of Medicine, Istanbul University, Istanbul, Turkey, ⁹Department of Physiology, Istanbul Faculty of Medicine, Istanbul University, Istanbul, Turkey

This study aims to find cerebral blood flow (CBF) deficits in Parkinson’s disease dementia (PDD). ASL-MRI was utilized to obtain CBF values in PD patients with different stages of cognitive decline at 3T. The CBF values were compared using a whole brain voxel-based analysis. The findings of this study revealed that the PDD group had significant CBF reductions in posterior cerebral areas, mostly in visual cortices, but also in medial parietal areas, and cortical and thalamic components of dorsolateral prefrontal fronto-striatal circuit as compared to both PD group with mild cognitive impairment (PD-MCI) and the cognitively normal PD group (PD-CN). 

Xueling Suo^1,2, Du Lei^1,2,3, Wenbin Li^1,2,3, Jing Yang^1,2, Nannan Li⁴, Lan Cheng⁴, Rong Peng⁴, and Qiyong Gong^1,2
1Huaxi MR Research Center (HMRRC), Department of Radiology, West China Hospital of Sichuan University, Chengdu, China, ²Psychoradiology Research Unit of Chinese Academy of Medical Sciences (2018RU011), West China Hospital of Sichuan University, Chengdu, China, ³Department of Psychiatry and Behavioral Neuroscience, University of Cincinnati, Cincinnati, OH, United States, ⁴Department of Neurology, West China Hospital of Sichuan University, Chengdu, China

To use graph theory approaches and high resolution T1-weighted structural MRI to explore the brain grey matter (GM) morphological network in patients with Parkinson's disease (PD) with and without mild cognitive impairment (MCI). The individual morphological brain networks were constructed by estimating interregional similarity in the distribution of regional GM volume of 116 brain regions. The lower path length were found in both patients relative to healthy controls. Altered morphological connection primarily in default mode network were common deficits, while different connectivity characteristic in widespread regions involving temporal and subcortical regions, and cerebellum were observed between the patient groups.

Hanyu Wei¹, Le He¹, Rongsong Zhou², Xuesong Li³, Shuo Chen¹, Yu Ma², and Rui Li^1
1Center for Biomedical Imaging Research, Department of Biomedical Engineering, Tsinghua University, Beijing, China, ²Department of Neurosurgery, Tsinghua University Yuquan Hospital, Beijing, China, ³School of Computer Science and Technology, Beijing Institute of Technology, Beijing, China

The aim of this study was to investigate the white matter hyperintensities (WMH) on FLAIR MRI in patients of Parkinson’s disease (PD) with questionable mild cognitive impairment (PD-Q) and without MCI (PD-N). Automatic segmentation and artificial localization of WMH were done to accurately describe WMH characteristics. By the Clinical Dementia Rating (CDR) staging dementia in PD patients, the WMH showed more in the region of bilateral cornu occipital in PD-Q than PD-N. This finding may initially improve understanding about the association between WMH and PD cognitive dysfunction.

Virendra R Mishra¹, Jessica Caldwell¹, Karthik R Sreenivasan¹, Xiaowei Zhuang¹, Zhengshi Yang¹, Dietmar Cordes^1,2, Jeffrey Cummings^1,3, Zoltan Mari¹, Aaron Ritter¹, and Irene Litvan^4
1Cleveland Clinic Lou Ruvo Center for Brain Health, Las Vegas, NV, United States, ²University of Colorado, Boulder, Boulder, CO, United States, ³Department of Brain Health, University of Nevada, Las Vegas, Las Vegas, NV, United States, ⁴University of California, San Diego, San Diego, CA, United States

Mild Cognitive Impairment (MCI) affects approximately 30% of individuals with Parkinson’s disease (PD). However, no reliable imaging methodology currently exists to identify PD-MCI within PD. We hypothesized that multivariate analysis of sophisticated diffusion-MRI (dMRI) voxelwise measures, volumetric measures, and dMRI-derived graph-theoretical network measures will provide a set of imaging measures that are both sensitive and specific to PD-MCI. Our preliminary analysis with 22 PD-MCI and 15 PD-non-MCI participants suggest that beyond single tensor dMRI voxelwise measures, network measures, and structural MRI-derived measurements might provide both sensitive and specific measures for further multivariate analysis to identify imaging markers corresponding to PD-MCI.

Christian Langkammer¹, Anna Damulina¹, Lukas Pirpamer¹, Martin Soellradl¹, Edith Hofer^1,2, Christian Tinauer¹, Maximilian Sackl¹, Christian Enzinger^1,3, Stefan Ropele¹, and Reinhold Schmidt^1
1Department of Neurology, Medical University of Graz, Graz, Austria, ²Institute for Medical Informatics, Statistics and Documentation, Medical University of Graz, Graz, Austria, ³Department of Radiology, Medical University of Graz, Graz, Austria

Using R2* relaxation rate mapping we found higher iron concentrations in the deep grey matter and neocortical regions in 101 patients with Alzheimer’s disease compared to 101 age-matched community-dwelling individuals. AD patients had significantly higher R2* in the temporal and occipital lobes and caudate nuclei. Independently of brain volume loss, changes in cortical iron levels over time were associated with cognitive decline in participants with Alzheimer's disease.

Yasuhiro Fujiwara¹, Tetsuyoshi Hirai², Tomohiro Ueda², Hiroyuki Kumazoe², and Shigeki Ito^3
1Department of Medical Image Sciences, Faculty of Life Sciences, Kumamoto University, Kumamoto, Japan, ²Department of Radiology, National Hospital Organization Omuta National Hospital, Omuta, Japan, ³Department of Medical Radiation Sciences, Faculty of Life Sciences, Kumamoto University, Kumamoto, Japan

We estimated the T1 values of the SN in healthy subjects and clarified its correlation with the SN characteristics obtained in neuromelanin (NM) images to identify an imaging biomarker for early diagnosis of PD.  In healthy adults, the area and T1 value of the SN, measured quantitatively from PSIR images, has different characteristics from those obtained from NM images, and may help assess SN degeneration.

Junye Yao¹, Qiqi Tong¹, Ting Gong¹, Qiuping Ding¹, Yi Sun², Peipeng Liang³, Kuncheng Li⁴, Hongjian He¹, and Jianhui Zhong^1,5
1Center for Brain Imaging Science and Technology, College of Biomedical Engineering and Instrumental Science, Zhejiang University, Hangzhou, China, ²MR Collaboration, Siemens Healthcare Ltd, Shanghai, China, ³School of Psychology, Capital Normal University, Beijing, China, ⁴Department of radiology, Xuanwu Hospital Capital Medical University, Beijing, China, ⁵Department of Imaging Sciences, University of Rochester, Rochester, NY, United States

Magnetic resonance structural images of 902 Chinese subjects were used to study the change of myelin content with the age based on the T1-weighted/T2-weighted ratio. Significant quadratic age effects were observed in white matter tracts and subcortical areas. The gender difference was reflected in the results that the myelin content levels are higher and begin to decline earlier in women. The inverted U-shape myelin-vs-age curve accords with the existing research literature. However, the age of the observed peaks may have been delayed by iron deposition in basal ganglia.

Guiling Zhang¹ and Wenzhen Zhu^1
1Tongji hospital, Wuhan, China

Atherosclerosis is the predominant risk factor of ischemic stroke. Age and location are intrinsic factors in the development of carotid artery plaque. Therefore, the relationship between hemodynamic changes and location/age in healthy subjects can help understand how the hemodynamic states influence carotid incidents. Our study found velocity/WSS/PG decreased with age. And proximal ICA, the most common point arising atherosclerotic plaque, displayed the lowest velocity/WSS/PG. It may imply this state of hemodynamics are more likely to cause atherosclerotic plaques. The multi-parameter analysis of 4D flow MRI may  offer suggestions for choosing age and location matched control cohorts in future study.

Kathryn Broadhouse¹, Natalie Winks¹, and Mathew Summers^1
1University of the Sunshine Coast, Sunshine Coast, Australia

Recent work suggests that aberrant functional neurocircuitries arise prior to significant structural atrophy and clinically cognitive deficits in dementia. Using a rigorous, longitudinally confirmed multi-domain amnestic MCI cohort we show that functional decoupling of networks implicated in memory and executive function, occur prior to measurable MTL atrophy in this population. Moreover, we show that decreased functional connectivity in these networks is associated with poorer cognitive performance. Further longitudinal studies investigating the neuronal underpinnings of disease progression will provide insight into potential functional biomarkers and establish significance of functional decoupling within the sequential model of dynamic biomarkers of Alzheimer’s pathological cascade.

Yuan Luo¹, Chunchao Ma², Xianchang Zhang³, Xiuwei Fu⁴, and Hongyan Ni^5
1Department of Radiology, First Central Clinical College, Tianjin Medical University, Tianjin, China, ²Department of Neurology, Tianjin First Central Hospital, Tianjin, China, ³MR Collaboration, Siemens Healthcare Ltd., Beijing, China, ⁴Department of Radiology, Tianjin Medical University General Hospital, Tianjin, China, ⁵Department of Radiology, Tianjin First Central Hospital, Tianjin, China

Brain network alterations remain poorly understood in mild cognitive impairment (MCI). This functional magnetic resonance imaging (fMRI) study aimed to investigate the degree centrality alterations in patients with Alzheimer's disease (AD) and MCI using graph theory analyses based on a population-specific template, as well as associations with neuropsychological test scores. The degree centrality of the left middle frontal gyrus and left medial superior frontal gyrus increased as patients’ cognitive function and daily activities declined. These findings suggest that abnormalities in the network topology progress in the prodromal and clinical stages of AD and are associated with clinical manifestations.

Virendra R Mishra¹, Karthik R Sreenivasan¹, Xiaowei Zhuang¹, Zhengshi Yang¹, Dietmar Cordes^1,2, Jeffrey Cummings^1,3, Jessica Caldwell¹, and Aaron Ritter^1
1Cleveland Clinic Lou Ruvo Center for Brain Health, Las Vegas, NV, United States, ²University of Colorado, Boulder, Boulder, CO, United States, ³Department of Brain Health, University of Nevada, Las Vegas, Las Vegas, NV, United States

We hypothesized that diffusion-MRI (dMRI)-derived free-water fraction (f_iso) will show a significantly lower and a faster change over time in mild cognitive impaired (MCI) participants who progressed to Alzheimer’s disease (AD) dementia in various cortical, subcortical, and white-matter fiber tracts compared to those who did not progress to AD dementia. Utilizing five β-Amyloid (Aβ) positive (+)/ApoE-4 carriers MCI participants who progressed to AD dementia within one-year, and thirteen Aβ+/ApoE-4 carriers MCI participants who did not progress to AD dementia within one-year, we showed that although the relationship between various cortical/subcortical volume and f_iso is complex, it was distinct between groups.

Lydia M Le Page^1,2, Soo Hyun Shin³, Kai Qiao^1,2, and Myriam M Chaumeil^1,2
1Physical Therapy and Rehabilitation Science, University of California, San Francisco, San Francisco, CA, United States, ²Radiology and Biomedical Imaging, University of California, San Francisco, San Francisco, CA, United States, ³Bioengineering, University of California, Berkeley, Berkeley, CA, United States

As ketogenic diets have been shown to elicit cognitive improvements in Alzheimer’s disease (AD) patients, non-invasive methods allowing for in vivo monitoring of brain ketone metabolism are critically needed to understand and monitor these observations. We hypothesized that ¹³C magnetic resonance spectroscopy of hyperpolarized (HP) [1-¹³C] beta-hydroxybutyrate (BHB) could be used to monitor response to ketogenic diets in health and AD. Here, we characterized HP [1-¹³C] BHB and validated an AD mouse model for application of our HP probe. We also carried out the first proof-of-concept acquisition of data showing in vivo metabolism of HP BHB in the mouse brain.

Tracy Ssali^1,2, Lucas Narciso^1,2, Justin Hicks^1,2, Matthias Günther³, Frank Prato^1,2, Udunna Anazodo^1,2, Elizabeth Finger⁴, and Keith St Lawrence^1,2
1Lawson Health Research Institute, London, ON, Canada, ²Department of Medical Biophysics, Western University, London, ON, Canada, ³Fraunhofer Institute for Medical Image Computing MEVIS, Bremen, Germany, ⁴Department of Clinical Neurological Sciences, Western University, London, ON, Canada

The ability of arterial spin labeling (ASL) to detect perfusion abnormalities in clinical populations, such as frontotemporal dementia, can be limited by poor signal to noise and transit-time artefacts. Recent advances in ASL imaging protocols should enable detection of more subtle perfusion abnormalities. This study presents a head-to-head comparison of regional hypoperfusion detected by ASL and PET with radiolabeled water (¹⁵O-water) - the gold standard for measuring CBF in humans. While ¹⁵O-water PET data showed greater sensitivity, as identified by larger and focal clusters on the t-maps, similar areas of hypoperfusion were identified by ASL, particularly with relative CBF.

Doonyaporn Wongsawaeng¹, Chanon Ngamsombat¹, Tanyaluck Thientunyakit¹, Weerasak Muangpaisan², Suwit Charoensuk³, Panida Charnchaowanish¹, and Orasa Chawalparit^1
1Department of Radiology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand, Bangkok, Thailand, ²Department of Geriatric Medicine, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand, Bangkok, Thailand, ³Department of Psychiatry, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand, Bangkok, Thailand

    Hippocampus is a part of limbic system involving both neurodegenerative disease and emotional regulation circuit. This study aimed to use MRI automated subfield hippocampal volumetric analysis to differentiate mild cognitive impairment (MCI) from major depressive disorder (MDD) and age-matched healthy elderly (HE) subjects. We found a trend of relative smaller size in several subfield hippocampal regions in MCI than MDD patients. Even though, there were no statistical significance. These may raise possibility of MRI volumetry to be the tool for discriminating early neurodegenerative disease from major depressive disorder. 

Won-Jin Moon¹, Ilheon Ha¹, Changmok Lim¹, Yaehoon Kim¹, Yeolsil Moon², and Seol-Heui Han^2
1Radiology, Konkuk University Medical Center, Seoul, Republic of Korea, ²Neurology, Konkuk University Medical Center, Seoul, Republic of Korea

In normal and cogntively impaired subjects, BBB permeability of hippocampus is increased in APOE4 carrier group than in APOE4 non-carrier group. After adjusting for education years, and medial temporal lobar atrophy, the only valuable predicting factor for predicting cognitive function was BBB permeability of hippocampus. Our study indicates that BBB permeability imaging can be a distinct imaging phenotype of APOE4 mutation as well as an early imaging marker for clinical decline in cognitive impaired subjects. 

Hongyuan Ding ¹, Yi Zhu ², Han Wu ³, Ling Zhang ¹, Yaxin Gao ⁴, Qian Zhong ⁴, Qiumin Zhou ², Ming Qi ¹, Long Qian ⁵, Weiqiang Dou⁵, and Tong Wang^2
1Radiology department, The First Affiliated Hospital of Nanjing Medical University, Nanjing, China, ²Rehabilitation Department, The First Affiliated Hospital of Nanjing Medical University, Nanjing, China, ³Rehabilitation Department, Nanjing Drum Tower Hospital, The Affiliated Hospital of the Medical School at Nanjing University, Nanjing, China, ⁴Nanjing Medical University, Nanjing, China, ⁵MR Research China, GE Healthcare, Beijing, China

In this study, the whole brain cerebral blood perfusion (CBF) values have been respectively investigated for patients with subjective cognitive decline (SCD) and mild cognitive impairment (MCI) and healthy controls (HCs). Significantly lower CBF values for the left superior frontal gyrus, left middle frontal gyrus, and left caudate nucleus regions have been shown in SCD patients than HCs. Additionally, the CBFs at these regions also showed strong correlations with multiple clinical scales. Therefore, CBF can be considered an effective tool in the early detection of SCD patients.

Jonas Richiardi^1,2, Bénédicte Maréchal^1,2,3, Ricardo Corredor², Mazen Mahdi², Reto Meuli¹, and Tobias Kober^1,2,3
1Department of Radiology, Lausanne University Hospital and University of Lausanne, Lausanne, Switzerland, ²Advanced Clinical Imaging Technology, Siemens Healthcare, Lausanne, Switzerland, ³LTS5, Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland

Estimating clinical significance of changes in regional brain volumetry using only two consecutive  images is difficult because algorithmic measurement error dominates actual biological changes in short-term (less than a year) follow-up imaging. Here, we evaluate an approach to compute reference ranges from image pairs, using empirical Bayesian regularization. With over 6400 image pairs, we evaluate the impact of regularization strength and time between images. Regularization is essential; optimal regularization amount depends on brain region. Increased time between pairs of images improves clinical discrimination in dementia. We recommend a minimum of eight months to one year to obtain discriminative atrophy estimates.

Lingfei Guo^1,2, Liangdong Zhou¹, Thanh D. Nguyen¹, Weiyuan Huang¹, Junghun Cho¹, and Yi Wang^1
1Weill Cornell Medicine, Cornell University, New York, NY, United States, ²Shandong Medical Imaging Research Institute Affiliated to Shandong University, Jinan, China

Quantitative susceptibility mapping (QSM) was used to evaluate and compare the characteristics of iron deposition in gray matter nuclei of the brain between patients with cerebral small-vessel disease and cerebral microbleeds (CSVD-CMBs) and those with CSVD and no CMBs（CSVD–no CMBs). The susceptibility values of the bilateral caudate nucleus, putamen, red nucleus, and substantia nigra were significantly higher in patients with CSVD-CMBs than in those with CSVD–no CMBs and in healthy controls. The change in the susceptibility values of these regions may be an imaging marker of cognitive decline in patients with CSVD.