| Literature DB >> 14648578 |
Thomas Ethofer1, Irina Mader, Uwe Seeger, Gunther Helms, Michael Erb, Wolfgang Grodd, Albert Ludolph, Uwe Klose.
Abstract
In vivo longitudinal relaxation times of N-acetyl compounds (NA), choline-containing substances (Cho), creatine (Cr), myo-inositol (mI), and tissue water were measured at 1.5 and 3 T using a point-resolved spectroscopy (PRESS) sequence with short echo time (TE). T(1) values were determined in six different brain regions: the occipital gray matter (GM), occipital white matter (WM), motor cortex, frontoparietal WM, thalamus, and cerebellum. The T(1) relaxation times of water protons were 26-38% longer at 3 T than at 1.5 T. Significantly longer metabolite T(1) values at 3 T (11-36%) were found for NA, Cho, and Cr in the motor cortex, frontoparietal WM, and thalamus. The amounts of GM, WM, and cerebrospinal fluid (CSF) within the voxel were determined by segmentation of a 3D image data set. No influence of tissue composition on metabolite T(1) values was found, while the longitudinal relaxation times of water protons were strongly correlated with the relative GM content. Copyright 2003 Wiley-Liss, Inc.Entities:
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Year: 2003 PMID： 14648578 DOI： 10.1002/mrm.10640
Source DB: PubMed Journal: Magn Reson Med ISSN： 0740-3194 Impact factor: 4.668