Elsevier

Academic Radiology

Volume 19, Issue 7, July 2012, Pages 785-793
Academic Radiology

Original investigation
Healthy Aging: An Automatic Analysis of Global and Regional Morphological Alterations of Human Brain

https://doi.org/10.1016/j.acra.2012.03.006Get rights and content
Under a Creative Commons license
open access

Rationale and Objectives

Morphologic changes of the human brain during healthy aging provide useful reference knowledge for age-related brain disorders. The aim of this study was to explore age-related global and regional morphological changes of healthy adult brains.

Materials and Methods

T1-weighted magnetic resonance images covering the entire brain were acquired for 314 subjects. Image processing of registration, segmentation, and surface construction were performed to calculate the volumes of the cerebrum, cerebellum, brain stem, lateral ventricle, and subcortical nuclei, as well as the surface area, mean curvature index, cortical thickness of the cerebral cortex, and subjacent white matter volume using FreeSurfer software. Mean values of each morphologic index were calculated and plotted against age group for sectional analysis. Regression analysis was conducted using SPSS to investigate the age effects on global and regional volumes of human brain.

Results

Overall global and regional volume loss was observed for the entire brain during healthy aging. Moderate atrophy was observed in subcortical gray matter structures, including the thalamus (R2 = 0.476, P < .001), nucleus accumbens (R2 = 0.525, P < .001), pallidum (R2 = 0.461, P < .001), and putamen (R2 = 0.533, P < .001). The volume of hippocampus showed a slight increase by 40 years of age, followed by a relatively faster decline after the age of 50 years (R2 = 0.486, P < .001). Surface area and mean curvature were less affected by aging relative to cortical thickness and subjacent white matter volume. Significant cortical thinning was mainly found in the parietal (R2 = 0.553, P < .001) and insula regions (R2 = 0.405, P < .001).

Conclusions

Morphologic alterations of human brain manifested regional heterogeneity in the scenario of general volume loss during healthy aging. The age effect on the hippocampus demonstrated a unique evolution. These findings provide informative reference knowledge that may help in identifying and differentiating pathologic aging and other neurologic disorders.

Key Words

Aging
morphology
cortex
subcortical nuclei
magnetic resonance imaging

Cited by (0)

The image data in this study were provided by the Open Access Series of Imaging Studies (grants P50 AG05681, P01 AG03991, R01 AG021910, P20 MH071616, and U24 RR021382 from the National Institutes of Health, Bethesda, MD).