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Proton T 1 and T 2 relaxation times of human brain metabolites at 3 Tesla

2001; Wiley; Volume: 14; Issue: 5 Linguagem: Inglês

10.1002/nbm.713

1099-1492

Vladimı́r Mlynárik, Stephan Gruber, Ewald Moser,

NMR spectroscopy and applications

Abstract Longitudinal and transverse relaxation times were measured for proton MRS signals from human brain metabolites at 3 T using a short‐echo STEAM protocol and a surface coil as a transmitter/receiver. Volumes of interest containing mostly grey or mostly white matter were selected in occipital lobes of healthy subjects and relaxation times for the following resonances were obtained: N ‐acetylaspartate at 2.01 ppm ( T 1 and T 2 ), glutamate at 2.35 ppm ( T 1 ), creatine at 3.03 and 3.92 ppm ( T 1 and T 2 ), choline‐containing substances at 3.22 ppm ( T 1 and T 2 ), myo ‐inositol at 3.57 and 3.65 ppm ( T 1 ) and the overlapping signals of glutamate and glutamine at 3.75 ppm ( T 1 ). The T 1 relaxation times obtained range from 0.97 to 1.47 s for grey matter and from 0.87 to 1.35 s for white matter. On the other hand, T 2 relaxation times range from 116 to 247 ms and from 141 to 295 ms in grey and white matter, respectively. Generally, the T 1 values measured at 3 T are close to the previously published data found at 1.5, 2 and 4.1 T. Also, the T 2 values confirm the previously observed decrease in transverse relaxation times with increasing static magnetic field. The proton relaxation times obtained will allow improved sequence design and spectra quantitation at 3 T, currently tested for enhanced clinical applications. Copyright © 2001 John Wiley & Sons, Ltd.