J. Jean Chen^1,2, Tyler D Triggs¹, H. Diana Rosas^1,3, and David H Salat^1,2
1Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, MA, United States, ²Department of Radiology, Massachusetts General Hospital, Boston, MA, United States, ³Department of Neurology, Massachusetts General Hospital, Boston, MA, United States

Spontaneous BOLD fluctuations in the resting-state have been used extensively to investigate neural connectivity, predominantly by examining the correlation between the time courses in multiple brain regions, which can be influenced by the amplitude of BOLD response. Both the amplitude and frequency traits of BOLD have been associated with vascular tone, which can be related to cerebral blood flow (CBF). In this work, we found higher BOLD fluctuation amplitudes to be associated with lower CBF and lower fluctuation frequency. These BOLD time-course parameters are potential indicators of vascular elasticity and hence of cerebrovascular changes in aging and disease.

J. Jean Chen^1,2, H. Diana Rosas^1,3, and David H Salat^1,2
1Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, MA, United States, ²Department of Radiology, Massachusetts General Hospital, Boston, MA, United States, ³Department of Neurology, Massachusetts General Hospital, Boston, MA, United States

White matter (WM) degeneration occurs in normal aging and age-related diseases, and was found to be strongly influenced by cerebrovascular health. However, it remains unclear how WM deterioration is associated with cerebral blood flow (CBF), a metric of vascular and metabolic health which has been associated with aging. In this work, we found CBF to be significantly associated with diffusion-tensor imaging-derived measures of WM integrity, demonstrating a definitive link between neurovascular factors and WM deterioration even within each age group. We also found a spatial correspondence between the effects of cortical perfusion and aging on underlying WM structural changes.

Jianli Wang¹, Megha Patel¹, Deborah Dossick¹, Michele L Shaffer², Christopher W Weitekamp¹, Xiaoyu Sun¹, Jeffrey Vesek¹, Paul J Eslinger³, David J Jill³, James R Connor⁴, and Qing X Yang^1,4
1Radiology, Penn State College of Medicine, Hershey, PA, United States, ²Public Health Sciences, Penn State College of Medicine, Hershey, PA, United States, ³Neurology, Penn State College of Medicine, Hershey, PA, United States, ⁴Neurosurgery, Penn State College of Medicine, Hershey, PA, United States

The goal of this study was to elucidate a quantitative developmental/aging characteristics and its variability on regional transverse relaxation rates (R₂) in normal human brain without a priori models. R₂ maps were acquired from seventy-seven 9 to 85 year-old healthy volunteers at 3 T. The result shows that the age dependence of R₂varied with respect to brain anatomy. The relationships between R₂ and age determined by generalized additive models were nonlinear in most of the 25 brain structures studied.

Agatha D Lee¹, Natasha Lepore², Caroline C Brun³, Marina Barysheva⁴, Arthur Toga⁴, Katie L McMaho⁵, Greig I de Zubicaray⁶, Nicholas G Martin⁶, Margaret Wright⁶, and Paul M Thompson^4
1Neurology, LONI-UCLA, Los Angeles, CA, United States, ²CHLA -USC, ³UPENN, ⁴LONI-UCLA, ⁵Centre for Magnetic Resonance, University of Queensland, ⁶Queensland Institute of Medical Research

Genetic Influences on White Matter Microstructure in 280 Twins Scanned with 4 Tesla High Angular Resolution Diffusion Imaging

Lihong Jiang¹, Barbara Gulanski², Stuart Weinzimer³, Ismene Petrakis³, Elizabeth Guidone³, Julia Koretski³, and Graeme Mason^4
1Diagnostic Radiology, Yale University School of Medicine, New Haven, CT, United States, ²Internal Medicine, Yale University School of Medicine, ³Psychiatry, Yale University School of Medicine, ⁴Diagnostic Radiology, Yale University School of Medicine

Alcohol enters the metabolic pathway by converting first to aldehyde and then to acetate through respective enzymes. Drinking alcohol leads to elevated blood acetate levels. The objective of this study is to test whether heavy alcohol use can affect brain choice of energy sources, thereby providing insight to alcohol addiction and abuse. Using 2-¹³C-acetate as metabolic tracer, combining with in vivo localized ¹³C-magnetic resonance spectroscopy, we have found that heavy drinkers have elevated resting state plasma acetate concentration, as well as transport and metabolism of acetate in brain. Our results suggest that systematic available acetate may provide reward for drinking.

Yinan Liu^1,2, Xiaoping Zhu¹, David Feinberg^2,3, Matthias Guenther^4,5, Howard Rosen⁶, Michael W Weiner^1,2, and Norbert Schuff^1,2
1Center for Imaging of Neurodegenerative Diseases, Department of Veterans Affairs Medical Center, San Francisco, CA, United States, ²Department of Radiology and Biomedical Imaging, University of California, San Francisco, CA, United States, ³Advanced MRI Technology LLC, Sebastopol, CA, United States, ⁴Mediri GmbH, Heidelberg, Germany, ⁵Department of Neurology, Klinikum Mannheim, University Heidelberg, Mannheim, Germany, ⁶Department of Neurology, University of California, San Francisco, CA, United States

While CBF reductions with advancing age have been interpreted as a consequence of reduced brain activity, there is also compelling evidence for compromised cerebrovascular integrity contributing to CBF reductions. In this study, we used ASL MRI to determine the brain perfusion as a function of aging and gender. Besides conformational findings of CBF reductions with advancing age and variations by gender, we also found prolonged arterial-arterioles transit time. The findings imply that vascular factors and gender effects cannot be neglected when evaluating age-related perfusion variations.

Tina Jeon¹, Virendra Mishra¹, Myron Weiner², Kristin Martin-Cook³, Kimmo Hatanpaa⁴, Chan Foong⁴, and Hao Huang^1
1Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, TX, United States, ²Department of Psychiatry, University of Texas Southwestern Medical Center, Dallas, TX, United States, ³Department of Neurology, University of Texas Southwestern Medical Center, Dallas, TX, United States,⁴Department of Pathology, University of Texas Southwestern Medical Center, Dallas, TX, United States

Conventional VBM (voxel-based-morphometry) approaches delineate the abnormality at the voxel level. However, it is the information reflected from whole white matter tracts that have clinical importance. In this study, with no a priori information, this novel atlas-based approach has been used to examine fractional anisotropy (FA) of DTI of all 50 major white matter tracts at the tract level to detect white matter disruption in Alzheimer disease (AD). The proposed method is highly efficient, accurate, makes comprehensive examination of all major tracts and allows comparison of disruption level of these tracts.

Ying Hao¹, Jing Liu², Yue Zhang³, Xiaoying Wang^1,4, Jue Zhang^1,3, and Jing Fang^1,3
1Academy for Advanced Interdisciplinary Studies, Peking University, Beijing, Beijing, China, People's Republic of, ²Dept. of Radiology, Peking University First Hospital, Beijing, Beijing, China, People's Republic of, ³College of Engineering, Peking University, Beijing, Beijing, China, People's Republic of, ⁴Dept. of Radiology, Peking University First Hospital, Beijing, Beijing, Beijing, China, People's Republic of

This study first depicted the effect of aging on the CBF-based correlations in DMN system. Compared with adult group, the correlation of the aging group with PCC node was found significantly decreased in the areas including right vMPFC and STG, which is in accordance with the previous BOLD-based studies. In addition, this study may shed light on the potential application of CBF signals in depicting functional connectivity mapping.

Ory Levy¹, Anat Bar-Shira², Avi Orr-Urtreger^2,3, and Yaniv Assaf^1
1Department of Neurobiology, Life Sciences Faculty, Tel aviv University, Tel Aviv, Israel, ²The Genetic Institute, Tel-Aviv Sourasky Medical Center, Tel-Aviv, Israel, ³The Sackler Faculty of Medicine, Tel aviv University, Tel Aviv, Israel

Carriers of APOE-å4 allele have a 2-3 fold risk of developing Alzheimer's. difference in APOE4 brain structure are known for 50 years old, and for glucose metabolism in 20 years old normal subjects. Here, 52 healthy Ashkenazi Jews (ages 20-35), were genotyped and underwent MRI protocol including DTI, T1 and T2. ANOVA statistics revealed that T1 VBM and DTI and T2maps VBA indicate significant differences between APOE33\23 (29,8) and APOE34 (11) in the parahippocampal gyrus, the hippocampus and the globus pallidus, the orbitofrontal cortex, and the dorsolateral prefrontal cortex. Our findings implicate that APOE affects the brain since developmental stages.

Binu P Thomas^1,2, Uma Sreekumar Yezhuvath¹, Rong Zhang^3,4, Benjamin Yichen Tseng^3,4, Benjamin Levine^3,4, and Hanzhang Lu^1,2
1Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, TX, United States, ²Biomedical Engineering, University of Texas Southwestern Medical Center/University of Texas at Arlington, TX, United States, ³Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital, Dallas, TX, United States, ⁴Internal Medicine-Cardiology, University of Texas Southwestern Medical Center, Dallas, TX, United States

This study examines benefits of long term physical exercise on brain vasculature. 10 Masters Athletes (MA) (age=75±5.8) and 10 sedentary elders (age=75±5.6) were recruited. Cerebral vascular reactivity (CVR) and baseline cerebral blood flow were measured on a 3T. CVR is the ability of vasculature to respond to CO2 which indicates vascular elasticity. MA paradoxically show lower CVR compared to SED in frontal, temporal, parietal, occipital lobes and cerebellum. Baseline CBF is increased in MA in posterior cingulate/precuneus which is a node in the default mode network indicating a protection from age related reduction in vascular function in these regions.