title: Quantitative 1H spectroscopic imaging of human brain at 4.1 T using image segmentation.
abstract: Metabolic differences in the content of N-acetylaspartate (NAA), creatinine (CR), and choline (CH) in cerebral gray and white matter can complicate the interpretation of 1H spectroscopic images. To account for these variations, the gray- and white-matter content of each voxel must be known. To provide these data, a T1-based image segmentation scheme was implemented at 4.1 T. The tissue composition of each voxel was determined using the point-spread function of the spectroscopic imaging acquisition and the segmented anatomical image. Pure gray- and white-matter values for CR/NAA and CH/NAA, and the content of CR, CH, and NAA, were determined using a linear-regression analysis of 984 voxels acquired from 10 subjects using white-matter CR as an internal standard. This information was used to establish means and confidence intervals for CR/NAA and CH/NAA from a voxel of arbitrary tissue composition. Using a single-tailed t test, the extent and locations of the metabolic abnormalities (P < 0.05) in a patient with multiple sclerosis were identified.
authors.affiliation: Department of Medicine, University of Alabama at Birmingham, USA.
authors.forename: H P
authors.initials: HP
authors.lastname: Hetherington
authors.forename: J W
authors.initials: JW
authors.lastname: Pan
authors.forename: G F
authors.initials: GF
authors.lastname: Mason
authors.forename: D
authors.initials: D
authors.lastname: Adams
authors.forename: M J
authors.initials: MJ
authors.lastname: Vaughn
authors.forename: D B
authors.initials: DB
authors.lastname: Twieg
authors.forename: G M
authors.initials: GM
authors.lastname: Pohost
mesh_terms: D001224:Aspartic Acid / Q000031:analogs & derivatives / Q000378:metabolism; D001479:Basal Ganglia / Q000378:metabolism; D001921:Brain / Q000033:anatomy & histology / Q000378:metabolism*; D002540:Cerebral Cortex / Q000378:metabolism; D002555:Cerebrospinal Fluid / Q000378:metabolism; D002794:Choline / Q000378:metabolism; D016001:Confidence Intervals; D003401:Creatine / Q000378:metabolism; D006179:Gyrus Cinguli / Q000033:anatomy & histology; D006801:Humans; D006859:Hydrogen; D007089:Image Enhancement / Q000379:methods*; D016014:Linear Models; D050356:Lipid Metabolism; D008279:Magnetic Resonance Imaging / Q000379:methods*; D009103:Multiple Sclerosis / Q000378:metabolism; D010296:Parietal Lobe / Q000378:metabolism; D013702:Temporal Lobe / Q000378:metabolism; D013788:Thalamus / Q000378:metabolism
chemical_list: D001224:Aspartic Acid; D006859:Hydrogen; C000179:N-acetylaspartate; D003401:Creatine; D002794:Choline