@article {1086, title = {Imaging cerebral blood flow in the cognitively normal aging brain with arterial spin labeling: implications for imaging of neurodegenerative disease.}, journal = {J Neuroimaging}, volume = {19}, year = {2009}, month = {2009 Oct}, pages = {344-52}, abstract = {

INTRODUCTION: Arterial spin labeling (ASL) is a safe, noninvasive imaging method for evaluating cerebral blood flow (rCBF). The purpose of this article is to present ASL imaging features of 38 elderly cognitively normals (CN) with their rCBF values and an averaged profile of targeted anatomic regions rCBF values.

METHODS: Thirty-eight CN underwent MR imaging especially ASL with voxel morphometric techniques fusing the MR anatomical and ASL images to a standard reference brain (colin27). The ASL images were fused to echo planar images, which were then coregistered to high-resolution anatomical SPGR images. rCBF was calculated per region of interest using a modified continuous arterial spin labeling (CASL) convolutional method. Anatomical regions were selected and identified by the Talairach atlas in SPM2.

RESULTS: We identified areas of decreased and increased perfusion (compared to the averaged rCBF of all 38 CN) corresponding to decreased and increased quantified rCBF. The most common sites for decreased perfusion were precuneus (53\%), superior temporal (48\%), and orbitofrontal (37\%), and for increased perfusion the caudate (39\%), posterior cingulate (34\%), anterior cingulate (32\%), and amygdala (32\%).

CONCLUSION: There are regional variations in rCBF both increased and decreased with the posterior cingulate and precuneus cortex showing the highest averaged values and signal intensity (bright spots). These variations represent the normal profile of a CN elderly brain, with higher perfusion in areas associated with cognition, memory, and behavior. It is necessary to understand these normal variations in order to determine if there are perfusion changes in ASL detected in neurodegenerative disorders such as Alzheimer{\textquoteright}s disease.

}, keywords = {Aged, 80 and over, Aging, Brain, Brain Mapping, Cerebrovascular Circulation, Female, Humans, Magnetic Resonance Imaging, Male, Neurodegenerative Diseases, Signal Processing, Computer-Assisted, Spin Labels}, issn = {1552-6569}, doi = {10.1111/j.1552-6569.2008.00277.x}, author = {Lee, Charles and Lopez, Oscar L and Becker, James T and Raji, Cyrus and Dai, Weiying and Kuller, Lewis H and Gach, H Michael} } @article {6773, title = {Voxel Level Survival Analysis of Grey Matter Volume and Incident Mild Cognitive Impairment or Alzheimer{\textquoteright}s Disease.}, journal = {J Alzheimers Dis}, volume = {46}, year = {2015}, month = {2015}, pages = {167-78}, abstract = {

The purpose of this study was to identify, at the voxel level, brain regions associated with the time to develop mild cognitive impairment (MCI) or Alzheimer{\textquoteright}s disease (AD) from normal cognition. We analyzed incident MCI (n = 58) or AD (n = 151) in 292 cognitively normal participants in the Cardiovascular Health Study-Cognition Study (mean age = 79.2 {\textpm} 3.6 years). We used segmented, modulated grey matter maps from 3D (spoiled gradient echo) MRI scans obtained in 1998/99 (with clinical follow-up through 2012) that were smoothed with a 3-D 4 mm Gaussian filter. We fit approximately 1.92 million voxel-level Cox proportional hazard models to examine the grey matter volume effect on time to event, adjusting for age, sex, and diabetes. We used the significance threshold of p <  0.005 with contiguity threshold of at least 68 voxels (false detection probability <2.5{\texttimes}10 -8). Areas within the mesial temporal lobe (MTL), anterior temporal lobe, hippocampus, and posterior cingulate gyrus were associated with time to MCI or AD. The presence of white matter lesions (a marker of small vessel disease in the brain) was associated with the volumes of the MTL and precuneus; MRI-identified infarcts also predicted MTL volume. These findings are important because we identified critical brain regions that predict a person{\textquoteright}s increased likelihood of developing MCI or AD over a decade prior to the onset of clinical symptoms; these critical brain regions were themselves affected by the presence of vascular disease.

}, keywords = {Aged, Aged, 80 and over, Alzheimer Disease, Chi-Square Distribution, Disease Progression, Female, Gray Matter, Humans, Incidence, Magnetic Resonance Imaging, Male, Mild Cognitive Impairment, Neuropsychological Tests, Psychiatric Status Rating Scales, Survival Analysis}, issn = {1875-8908}, doi = {10.3233/JAD-150047}, author = {Zeifman, Lubov E and Eddy, William F and Lopez, Oscar L and Kuller, Lewis H and Raji, Cyrus and Thompson, Paul M and Becker, James T} }