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Comparison of T 1 and T 2 metabolite relaxation times in glioma and normal brain at 3T
Author(s) -
Li Yan,
Srinivasan Radhika,
Ratiney Helene,
Lu Ying,
Chang Susan M.,
Nelson Sarah J.
Publication year - 2008
Publication title -
journal of magnetic resonance imaging
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.563
H-Index - 160
eISSN - 1522-2586
pISSN - 1053-1807
DOI - 10.1002/jmri.21453
Subject(s) - metabolite , glioma , creatine , nuclear magnetic resonance , white matter , nuclear medicine , voxel , chemistry , in vivo magnetic resonance spectroscopy , choline , medicine , magnetic resonance imaging , physics , radiology , biochemistry , cancer research
Purpose To measure T 1 and T 2 relaxation times of metabolites in glioma patients at 3T and to investigate how these values influence the observed metabolite levels. Materials and Methods A total of 23 patients with gliomas and 10 volunteers were studied with single‐voxel two‐dimensional (2D) J‐resolved point‐resolved spectral selection (PRESS) using a 3T MR scanner. Voxels were chosen in normal appearing white matter (WM) and in regions of tumor. The T 1 and T 2 of choline containing compounds (Cho), creatine (Cr), and N‐acetyl aspartate (NAA) were estimated. Results Metabolite T 1 relaxation values in gliomas were not significantly different from values in normal WM. The T 2 of Cho and Cr were statistically significantly longer for grade 4 gliomas than for normal WM but the T 2 of NAA was similar. These differences were large enough to impact the corrections of metabolite levels for relaxation times with tumor grade in terms of metabolite ratios ( P < 0.001). Conclusion The differential increase in T 2 for Cho and Cr relative to NAA means that the ratios of Cho/NAA and Cr/NAA are higher in tumor at longer echo times (TEs) relative to values in normal appearing brain. Having this information may be useful in defining the acquisition parameters for optimizing contrast between tumor and normal tissue in MR spectroscopic imaging (MRSI) data, in which limited time is available and only one TE can be used. J. Magn. Reson. Imaging 2008;28:342–350. © 2008 Wiley‐Liss, Inc.