Figure 1.
A typical three-dimensional region of interest created by manually outlining the hippocampal formation in consecutive T2-weighted sagittal images of a human cerebral hemisphere.
Image A corresponds to the most lateral slice and image I to the most medial slice. The hemisphere remained immersed in formaldehyde solution during the MRI scan. In-plane resolution was 0.3125×0.3125 mm2 after zero-padding of the k-space acquisition matrix.
Table 1.
Selected demographic, clinical, and neuropathologic characteristics of subjects from the Memory and Aging Project (MAP) and the Religious Orders Study (ROS) included in this work.
Table 2.
Selected characteristics of groups of subjects with no cognitive impairment (NCI) and clinical diagnoses of mild cognitive impairment (MCI) and Alzheimer's disease (AD).
Figure 2.
Box plot of hippocampal volumes for clinically diagnosed Alzheimer's disease, mild cognitive impairment, and no cognitive impairment subjects.
The horizontal line through each box indicates the median. The ends of each box indicate the 25th and 75th percentile locations, and the lines indicate the range of the data. Hippocampal volume was significantly smaller in Alzheimer's disease than in cases of mild cognitive impairment or no cognitive impairment.
Figure 3.
Plots of the hippocampal volume as a function of the z-score for global cognition, episodic memory, semantic memory, working memory, perceptual speed, and visuospatial ability.
Clinical diagnosis for each subject is indicated by marker type.
Table 3.
Coefficient values for linear regression models of postmortem hippocampal volume as a function of global cognition and other covariates, and the corresponding P-values.
Table 4.
Effects of different types of neuropathology on hippocampal volume, assessed individually using analysis of covariance, and the corresponding P-values.
Table 5.
Effect of AD pathology and hippocampal sclerosis on hippocampal volume, assessed simultaneously using analysis of covariance, and the corresponding P-values.
Table 6.
Selected demographic, clinical, and neuropathologic characteristics of subjects with no histopathologically diagnosed Alzheimer's disease (AD) or hippocampal sclerosis (HS), with AD only, with HS only, and with both AD and HS.
Figure 4.
Shape analysis of (A) hippocampi affected by Alzheimer's disease (AD) and not hippocampal sclerosis (HS) compared to controls, (B) hippocampi most severely affected by AD compared to controls, and (C) hippocampi affected by HS with or without AD compared to controls.
The top row of images contains the superior view of the hippocampus, while the bottom row contains the inferior view. Within each comparison, the left side shows a map of the difference in distance between points on the surface mesh of the first group versus the corresponding points on the surface mesh of the second group, projected along a unit vector that is normal to the surface. Thus, red shading shows areas of inward deformation of the first group relative to the second group, and green shading shows areas of outward deformation. The right side of each comparison shows significance maps with color indicating P-value. The significance maps show regions where points on the surface mesh of the first group are significantly displaced from the corresponding points on the surface mesh of the second group in any direction.
Figure 5.
The average shapes of hippocampi affected by neither Alzheimer's disease (AD) or hippocampal sclerosis (HS) (N = 47), AD only (N = 40), and HS (N = 13, 9 with AD and 4 with HS only), viewed from the superior direction.
The dashed line is the outline of the control hippocampal surface mesh.