@article {1519, title = {A brain image database for structure/function analysis.}, journal = {AJNR Am J Neuroradiol}, volume = {19}, year = {1998}, month = {1998 Nov-Dec}, pages = {1869-77}, abstract = {

BACKGROUND AND PURPOSE: Lesion-deficit-based structure-function analysis has traditionally been empirical and nonquantitative. Our purpose was to establish a new brain image database (BRAID) that allows the statistical correlation of brain functional measures with anatomic lesions revealed by clinical brain images.

METHODS: Data on 303 participants in the MR Feasibility Study of the Cardiovascular Health Study were tested for lesion/deficit correlations. Functional data were derived from a limited neurologic examination performed at the time of the MR examination. Image data included 3D lesion descriptions derived from the MR examinations by hand segmentation. MR images were normalized in-plane using local, linear Talairach normalization. A database was implemented to support spatial data structures and associated geometric and statistical operations. The database stored the segmented lesions, patient functional scores, and several anatomic atlases. Lesion-deficit association was sought by contingency testing (chi2-test) for every possible combination of each neurologic variable and each labeled atlas structure. Significant associations that confirmed accepted lesion-deficit relationships were sought.

RESULTS: Two-hundred thirty-five infarctlike lesions in 117 subjects were viewed collectively after mapping into Talairach cartesian coordinates. Anatomic structures most strongly correlated with neurologic deficits tended to be situated in anatomically appropriate areas. For example, infarctlike lesions associated with visual field defects were correlated with structures in contralateral occipital structures, including the optic radiations and occipital gyri.

CONCLUSION: Known lesion-deficit correlations can be established by a database using a standard coordinate system for representing spatial data and incorporating functional and structural data together with appropriate query mechanisms. Improvements and further applications of this methodology may provide a powerful technique for uncovering new structure-function relationships.

}, keywords = {Brain, Brain Mapping, Cerebral Infarction, Databases as Topic, Humans, Image Processing, Computer-Assisted, Magnetic Resonance Imaging, Neurologic Examination}, issn = {0195-6108}, author = {Letovsky, S I and Whitehead, S H and Paik, C H and Miller, G A and Gerber, J and Herskovits, E H and Fulton, T K and Bryan, R N} } @article {1140, title = {Age, Alzheimer disease, and brain structure.}, journal = {Neurology}, volume = {73}, year = {2009}, month = {2009 Dec 01}, pages = {1899-905}, abstract = {

BACKGROUND: Lack of clear understanding remains on the overlapping atrophy patterns of aging and early Alzheimer disease (AD) pathology in gray matter (GM) of the brain in vivo.

OBJECTIVE: To evaluate the independent and overlapping patterns of GM atrophy in normal aging and AD.

METHODS: A total of 169 cognitively normal subjects and 33 persons with probable AD enrolled in the longitudinal Cardiovascular Health Study-Cognition Study underwent 3-dimensional volumetric MRI scans. Controls remained cognitively normal for at least 5 years after their MRI scans and the probable AD subjects were relatively early in their clinical course with an average modified Mini-Mental State Examination score of 76/100. The scans were analyzed using voxel-based morphometry adjusting for total intracranial volume, gender, education, and race.

RESULTS: With older age, GM volume was lower in the sensorimotor and heteromodal association areas in frontal, temporal, occipital, and parietal lobes, as well as in the cerebellum (false discovery rate p = 0.05). Additional atrophy was observed in the posterior hippocampus, thalamus, and middle cingulate gyrus. By contrast, atrophy was seen in subjects with AD in the anterior hippocampal/parahippocampal regions and the precuneus. Normal aging and AD overlapped in the hippocampal body and the entorhinal cortex.

CONCLUSION: Brain atrophy with aging was observed in supratentorial and infratentorial areas, as well in primary motor, sensory, and heteromodal association regions. Age and Alzheimer disease exert independent gray matter atrophy patterns but these effects overlapped substantially in the hippocampus and entorhinal cortex.

}, keywords = {Aged, Aged, 80 and over, Aging, Alzheimer Disease, Brain, Brain Mapping, Cognition Disorders, Female, Humans, Image Processing, Computer-Assisted, Linear Models, Magnetic Resonance Imaging, Male, Neuropsychological Tests, Retrospective Studies}, issn = {1526-632X}, doi = {10.1212/WNL.0b013e3181c3f293}, author = {Raji, C A and Lopez, O L and Kuller, L H and Carmichael, O T and Becker, J T} } @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 {1239, title = {Physical activity predicts gray matter volume in late adulthood: the Cardiovascular Health Study.}, journal = {Neurology}, volume = {75}, year = {2010}, month = {2010 Oct 19}, pages = {1415-22}, abstract = {

OBJECTIVES: Physical activity (PA) has been hypothesized to spare gray matter volume in late adulthood, but longitudinal data testing an association has been lacking. Here we tested whether PA would be associated with greater gray matter volume after a 9-year follow-up, a threshold could be identified for the amount of walking necessary to spare gray matter volume, and greater gray matter volume associated with PA would be associated with a reduced risk for cognitive impairment 13 years after the PA evaluation.

METHODS: In 299 adults (mean age 78 years) from the Cardiovascular Health Cognition Study, we examined the association between gray matter volume, PA, and cognitive impairment. Physical activity was quantified as the number of blocks walked over 1 week. High-resolution brain scans were acquired 9 years after the PA assessment on cognitively normal adults. White matter hyperintensities, ventricular grade, and other health variables at baseline were used as covariates. Clinical adjudication for cognitive impairment occurred 13 years after baseline.

RESULTS: Walking amounts ranged from 0 to 300 blocks (mean 56.3; SD 69.7). Greater PA predicted greater volumes of frontal, occipital, entorhinal, and hippocampal regions 9 years later. Walking 72 blocks was necessary to detect increased gray matter volume but walking more than 72 blocks did not spare additional volume. Greater gray matter volume with PA reduced the risk for cognitive impairment 2-fold.

CONCLUSION: Greater amounts of walking are associated with greater gray matter volume, which is in turn associated with a reduced risk of cognitive impairment.

}, keywords = {Aged, Aged, 80 and over, Brain, Brain Mapping, Cardiovascular Diseases, Cognition Disorders, Female, Humans, Longitudinal Studies, Magnetic Resonance Imaging, Male, Mental Status Schedule, Motor Activity, Neuropsychological Tests, Odds Ratio, Predictive Value of Tests, Surveys and Questionnaires}, issn = {1526-632X}, doi = {10.1212/WNL.0b013e3181f88359}, author = {Erickson, K I and Raji, C A and Lopez, O L and Becker, J T and Rosano, C and Newman, A B and Gach, H M and Thompson, P M and Ho, A J and Kuller, L H} } @article {1225, title = {The effects of physical activity, education, and body mass index on the aging brain.}, journal = {Hum Brain Mapp}, volume = {32}, year = {2011}, month = {2011 Sep}, pages = {1371-82}, abstract = {

Normal human aging is accompanied by progressive brain tissue loss and cognitive decline; however, several factors are thought to influence brain aging. We applied tensor-based morphometry to high-resolution brain MRI scans to determine whether educational level or physical activity was associated with brain tissue volumes in the elderly, particularly in regions susceptible to age-related atrophy. We mapped the 3D profile of brain volume differences in 226 healthy elderly subjects (130F/96M; 77.9 {\textpm} 3.6 SD years) from the Cardiovascular Health Study-Cognition Study. Statistical maps revealed the 3D profile of brain regions whose volumes were associated with educational level and physical activity (based on leisure-time energy expenditure). After controlling for age, sex, and physical activity, higher educational levels were associated with ~2-3\% greater tissue volumes, on average, in the temporal lobe gray matter. After controlling for age, sex, and education, greater physical activity was associated with ~2-2.5\% greater average tissue volumes in the white matter of the corona radiata extending into the parietal-occipital junction. Body mass index (BMI) was highly correlated with both education and physical activity, so we examined BMI as a contributing factor by including physical activity, education, and BMI in the same model; only BMI effects remained significant. This is one of the largest MRI studies of factors influencing structural brain aging, and BMI may be a key factor explaining the observed relationship between education, physical activity, and brain structure. Independent contributions to brain structure could not be teased apart as all these factors were highly correlated with one another.

}, keywords = {Aged, Aged, 80 and over, Aging, Analysis of Variance, Body Mass Index, Brain, Brain Mapping, Educational Status, Female, Humans, Image Processing, Computer-Assisted, Magnetic Resonance Imaging, Male, Motor Activity, Neuropsychological Tests, Statistics as Topic}, issn = {1097-0193}, doi = {10.1002/hbm.21113}, author = {Ho, April J and Raji, Cyrus A and Becker, James T and Lopez, Oscar L and Kuller, Lewis H and Hua, Xue and Dinov, Ivo D and Stein, Jason L and Rosano, Caterina and Toga, Arthur W and Thompson, Paul M} }