title: Region and tissue differences of metabolites in normally aged brain using multislice 1H magnetic resonance spectroscopic imaging.
abstract: Quantitative measurements of regional and tissue specific concentrations of brain metabolites were measured in elderly subjects using multislice proton magnetic resonance spectroscopic imaging ((1)H MRSI). Selective k-space extrapolation and an inversion-recovery sequence were used to minimize lipid contamination and linear regression was used to account for partial volume problems. The technique was applied to measure the concentrations of N-acetyl aspartate (NAA), and creatine (Cr)- and choline (Cho)-containing compounds in cortical gray and white matter, and white matter lesions of the frontal and the parietal lobe in 40 normal elderly subjects (22 females and 18 males, 56-89 years old, mean age 74 +/- 8). NAA was about 15% lower in cortical gray matter and 23% lower in white matter lesions when compared to normal white matter. Cr was 11% higher in cortical gray matter than in white matter, and also about 15% higher in the parietal cortex than in the frontal cortex. Cho was 28% lower in cortical gray matter than in white matter. Furthermore, NAA and Cr changes correlated with age. In conclusion, regional and tissue differences of brain metabolites must be considered in addition to age-related changes when interpreting (1)H MRSI data.
authors.affiliation: DVA Medical Center, San Francisco, California 94121, USA. nschuff@itsa.ucsf.edu
authors.forename: N
authors.initials: N
authors.lastname: Schuff
authors.forename: F
authors.initials: F
authors.lastname: Ezekiel
authors.forename: A C
authors.initials: AC
authors.lastname: Gamst
authors.forename: D L
authors.initials: DL
authors.lastname: Amend
authors.forename: A A
authors.initials: AA
authors.lastname: Capizzano
authors.forename: A A
authors.initials: AA
authors.lastname: Maudsley
authors.forename: M W
authors.initials: MW
authors.lastname: Weiner
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000378:metabolism*; D000704:Analysis of Variance; D001224:Aspartic Acid / Q000031:analogs & derivatives / Q000378:metabolism; D001921:Brain / Q000378:metabolism* / Q000473:pathology; D001927:Brain Diseases / Q000378:metabolism* / Q000473:pathology; D002794:Choline / Q000378:metabolism; D003401:Creatine / Q000378:metabolism; D005260:Female; D006801:Humans; D006859:Hydrogen; D016014:Linear Models; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D008297:Male; D008875:Middle Aged; D012815:Signal Processing, Computer-Assisted
chemical_list: D001224:Aspartic Acid; D006859:Hydrogen; C000179:N-acetylaspartate; D003401:Creatine; D002794:Choline