The aim of this study was to evaluate transverse relaxation time of methylene resonance compared to other lipid resonances.
The examinations were performed using a 3.0 T scanner with a point — resolved spectroscopy (PRESS) sequence. Lipid relaxation time in a lipid phantom filled with canola oil was estimated considering repetition time (TR) as 6000 msec and echo time (TE) as 40 — 550 msec. For in vivo proton magnetic resonance spectroscopy (1H — MRS), eight male Sprague — Dawley rats were given free access to a normal - chow (NC) and eight other male Sprague-Dawley rats were given free access to a high — fat (HF) diet. Both groups drank water ad libitum. T2 measurements in the rats’ livers were conducted at a fixed TR of 6000 msec and TE of 40 – 220 msec. Exponential curve fitting quality was calculated through the coefficients of determination (R2).
A chemical analysis of phantom and liver was not performed but a T2 decay curve was acquired. The T2 relaxation time of methylene resonance was estimated as follows: NC rats, 37.07 ± 4.32 msec; HF rats, 31.43 ± 1.81 msec (p < 0.05). The extrapolated M0 values were higher in HF rats than in NC rats (p < 0.005).
This study of 1H-MRS led to sufficient spectral resolution and signal — to — noise ratio differences to characterize all observable resonances for yielding T2 relaxation times of methylene resonance. 1H — MRS relaxation times may be useful for quantitative characterization of various liver diseases, including fatty liver disease.
This study was supported by grant (2012-007883 and 2014R1A2A1A10050270) from the Mid-career Researcher Program through the NRF funded by Ministry of Science. In addition, this study was supported by the Industrial R&D of MOTIE/KEIT (10048997, Development of the core technology for integrated therapy devices based on real-time MRI-guided tumor tracking).
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This article by K-H Song, D-W Lee and B-Y Choe originally appeared on scitation.aip.org on June 26, 2015 at 06:44PM
