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Signal modulation in 1 H magnetic resonance spectroscopy using contrast agents: Proton relaxivities of choline, creatine, and N ‐acetylaspartate
Author(s) -
Murphy Philip S.,
Leach Martin O.,
Rowland Ian J.
Publication year - 1999
Publication title -
magnetic resonance in medicine
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.696
H-Index - 225
eISSN - 1522-2594
pISSN - 0740-3194
DOI - 10.1002/(sici)1522-2594(199912)42:6<1155::aid-mrm21>3.0.co;2-n
Subject(s) - creatine , choline , nuclear magnetic resonance , chemistry , gadolinium , nuclear magnetic resonance spectroscopy , metabolite , proton , in vivo , spectroscopy , relaxation (psychology) , biochemistry , physics , medicine , biology , microbiology and biotechnology , organic chemistry , quantum mechanics
The effect of gadolinium diethylenetriaminepentaacetic acid (Gd‐DTPA) on the proton relaxation properties of choline, creatine and N ‐acetylaspartate has been assessed quantitatively. The compounds studied, either directly or indirectly as chemical constituents of other compounds, contribute to proton MR spectroscopy observable metabolite resonances. The longitudinal and transverse Gd‐DTPA proton relaxivities of the methyl groups of choline, creatine, and N ‐acetylaspartate have been determined at 1.5 T. The longitudinal relaxivity of lactate has also been measured. Longitudinal and transverse relaxivity values were found to vary in the order N ‐acetylaspartate < creatine < choline. Using choline as an example, the maximum possible signal enhancement predicted in vivo in the presence of 0.5 mM Gd‐DTPA (using a T 1 ‐weighted sequence, TR = 888 msec, TE = 20 msec) was found to be approximately 100 %. For a T 2 ‐weighted sequence (TR = 3000 msec, TE = 270 msec) a maximum signal loss of 53 % was calculated. The present study indicates why the use of contrast agents in spectroscopic investigations may lead to significant changes in signal intensities. Magn Reson Med 42:1155–1158, 1999. © 1999 Wiley‐Liss, Inc.