PT  - JOURNAL ARTICLE
AU  - Ge, Yulin
AU  - Grossman, Robert I.
AU  - Babb, James S.
AU  - Rabin, Marcie L.
AU  - Mannon, Lois J.
AU  - Kolson, Dennis L.
TI  - Age-Related Total Gray Matter and White Matter Changes in Normal Adult Brain. Part I: Volumetric MR Imaging Analysis
DP  - 2002 Sep 01
TA  - American Journal of Neuroradiology
PG  - 1327--1333
VI  - 23
IP  - 8
4099  - http://www.ajnr.org/content/23/8/1327.short
4100  - http://www.ajnr.org/content/23/8/1327.full
SO  - Am. J. Neuroradiol.2002 Sep 01; 23
AB  - BACKGROUND AND PURPOSE: A technique of segmenting total gray matter (GM) and total white matter (WM) in human brain is now available. We investigated the effects of age and sex on total fractional GM (%GM) and total fractional WM (%WM) volumes by using volumetric MR imaging in healthy adults.METHODS: Fifty-four healthy volunteers (22 men, 32 women) aged 20–86 years underwent dual-echo fast spin-echo MR imaging. Total GM, total WM, and intracranial space volumes were segmented by using MR image-based computerized semiautomated software. Volumes were normalized as a percentage of intracranial volume (%GM and %WM) to adjust for variations in head size. Age and sex effects were then assessed.RESULTS: Both %GM and %WM in the intracranial space were significantly less in older subjects (≥50 years) than in younger subjects (<50 years) (P < .0001 and P = .02, respectively). Consistently, %GM decreased linearly with age, beginning in the youngest subjects. %WM decreased in a quadratic fashion, with a greater rate beginning only in adult midlife. Although larger GM volumes were observed in men before adjustments for cranium size, no significant differences in %GM or %WM were observed between the sexes.CONCLUSION: GM volume loss appears to be a constant, linear function of age throughout adult life, whereas WM volume loss seems to be delayed until middle adult life. Both appear to be independent of sex. Quantitative analysis of %GM and %WM volumes can improve our understanding of brain atrophy due to normal aging; this knowledge may be valuable in distinguishing atrophy of disease patterns from characteristics of the normal aging process.