Labeled cortical mantle distance maps of the cingulate quantify differences between dementia of the Alzheimer type and healthy aging

doi:10.1073/pnas.2136624100

Labeled cortical mantle distance maps of the cingulate quantify differences between dementia of the Alzheimer type and healthy aging

^*Center for Imaging Science, The Johns Hopkins University, Baltimore, MD 21218; and Departments of ^‡Psychiatry, ^§Radiology, and ^¶Neurology, Washington University School of Medicine, St. Louis, MO 63110

Communicated by Ulf Grenander, Brown University, Providence, RI, October 13, 2003 (received for review May 16, 2003)

Abstract

The cingulate gyri in 37 subjects with and without early dementia of the Alzheimer type (DAT) were studied by using MRI at 1.0 mm³ isotropic resolution. Groups were segregated into young controls (n = 10), age-matched normal controls (n = 10), very mild DAT (n = 8), and mild DAT (n = 9). By using automated Bayesian segmentation of the cortex and gray matter/white matter (GM/WM) isosurface generation, tissue compartments were labeled into gray, white, and cerebrospinal fluid as a function of distance from the GM/WM isosurface. Cortical mantle distance maps are generated profiling the GM volume and cortical mantle distribution as a function of distance from the cortical surface. Probabilistic tests based on generalizations of Wilcoxon–Mann–Whitney tests were applied to quantify cortical mantle distribution changes with normal and abnormal aging. We find no significant change between young controls and healthy aging as measured by the GM volume and cortical mantle distribution as a function of distance in both anterior and posterior regions of the cingulate. Significant progression of GM loss is seen in the very mild DAT and mild DAT groups in all areas of the cingulate. Posterior regions show both GM volume loss as well as significant cortical mantle distribution decrease with the onset of mild DAT. The “shape of the cortical mantle” as measured by the cortical mantle distance profiles manifests a pronounced increase in variability with mild DAT.

Footnotes

↵ † To whom correspondence should be addressed at: Center for Imaging Science, The Johns Hopkins University, Clark 301, 3400 North Charles Street, Baltimore, MD 21218-2686. E-mail: mim{at}cis.jhu.edu.
Abbreviations: CMD, cortical mantle distance; LCMDM, labeled CMD map; DAT, dementia of the Alzheimer type; GM, gray matter; WM, white matter; YC, younger healthy control subjects; CDR, Clinical Dementia Rating Scale; MR, magnetic resonance; CSF, cerebrospinal fluid.