title: A longitudinal study of brain morphometrics using serial magnetic resonance imaging analysis in a canine model of aging.
abstract: Longitudinal changes in cortical atrophy, ventricular enlargement, and lesion development in serial MRI scans collected from 47 healthy dogs from 1999 (8-11 years old) to 2002 (11-14 years old) were studied. The first method involved manual region of interest volumetric analysis to examine changes in cerebral and ventricular volume during the three years. No change in cerebral volume was detected but ventricular volume increased significantly each year in 2000, 2001, and 2002. Increased ventricular volume parallels early studies of age-dependent ventricular enlargement in the brain of aging beagle dogs. The second method involved a visual analysis of co-registered serial MRIs for each subject. Consistent with the volumetric results, there was no visible change in cortical thickness indicating no cerebral atrophy, but a significant increase in ventricular size was noted. Visual examination also revealed a significant increase in number of dogs who developed aging lesions over the last 2 years in 2001 and 2002. Additionally, a disproportionate number of lesions were recorded in the frontal cortex and caudate nucleus compared to other brain regions. These lesion findings are consistent with other studies in the aging dog that suggest that the frontal lobes may be particularly vulnerable to age-related changes.
authors.affiliation: John Tu and Thomas Yuen Center for Functional Onco-Imaging, University of California Irvine, CA 92697-5020, USA. msu@uci.edu
authors.forename: Min-Ying
authors.initials: MY
authors.lastname: Su
authors.forename: P Dwight
authors.initials: PD
authors.lastname: Tapp
authors.forename: Long
authors.initials: L
authors.lastname: Vu
authors.forename: Ya-Fang
authors.initials: YF
authors.lastname: Chen
authors.forename: Yong
authors.initials: Y
authors.lastname: Chu
authors.forename: Bruce
authors.initials: B
authors.lastname: Muggenburg
authors.forename: Jr-Yuan
authors.initials: JY
authors.lastname: Chiou
authors.forename: Changqing
authors.initials: C
authors.lastname: Chen
authors.forename: Jun
authors.initials: J
authors.lastname: Wang
authors.forename: Christian
authors.initials: C
authors.lastname: Bracco
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Head
mesh_terms: D000375:Aging / Q000502:physiology*; D000818:Animals; D001284:Atrophy / Q000473:pathology; D001921:Brain / Q000033:anatomy & histology*; D001931:Brain Mapping; D002552:Cerebral Ventricles / Q000473:pathology; D016009:Chi-Square Distribution; D003430:Cross-Sectional Studies; D004285:Dogs; D005260:Female; D007091:Image Processing, Computer-Assisted; D008137:Longitudinal Studies; D008279:Magnetic Resonance Imaging; D008297:Male; D023421:Models, Animal; D013997:Time Factors