title: Maturational and aging effects on human brain apparent transverse relaxation.
abstract: The goal of this study was to address the need for comprehensive reference data regarding maturational and aging effects on regional transverse relaxation rates (R(2)) of the brain in normal humans. Regional R(2)s were measured in twenty-five brain structures from a sample of seventy-seven normal volunteers 9 to 85 years of age. The relationships between regional R(2) and age were determined using generalized additive models, without the constraint of a specified a priori model. Data analysis demonstrated that the brain tissue R(2)-age correlations followed various time courses with both linear and non-linear characteristics depending on the particular brain structure. Most anatomical structures studied exhibited non-linear characteristics, including the amygdala, hippocampus, thalamus, globus pallidus, putamen, caudate nucleus, red nucleus, substantia nigra, orbitofrontal white matter and temporal white matter. Linear trends were detected in occipital white matter and in the genu of corpus callosum. These results indicate the complexity of age-related R(2) changes in the brain while providing normative reference data that can be utilized in clinical examinations and studies utilizing quantitative transverse relaxation.
authors.affiliation: Department of Radiology, Pennsylvania State University College of Medicine, Hershey, Pennsylvania, United States of America. jxw73@psu.edu
authors.forename: Jianli
authors.initials: J
authors.lastname: Wang
authors.forename: Michele L
authors.initials: ML
authors.lastname: Shaffer
authors.forename: Paul J
authors.initials: PJ
authors.lastname: Eslinger
authors.forename: Xiaoyu
authors.initials: X
authors.lastname: Sun
authors.forename: Christopher W
authors.initials: CW
authors.lastname: Weitekamp
authors.forename: Megha M
authors.initials: MM
authors.lastname: Patel
authors.forename: Deborah
authors.initials: D
authors.lastname: Dossick
authors.forename: David J
authors.initials: DJ
authors.lastname: Gill
authors.forename: James R
authors.initials: JR
authors.lastname: Connor
authors.forename: Qing X
authors.initials: QX
authors.lastname: Yang
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000502:physiology*; D001921:Brain / Q000502:physiology*; D002648:Child; D015331:Cohort Studies; D005260:Female; D006262:Health; D006801:Humans; D016014:Linear Models; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009928:Organ Specificity; D012741:Sexual Maturation / Q000502:physiology*; D055815:Young Adult