[Effects of echo time on the liver fat quantification using proton magnetic resonance spectroscopy]

This study was aimed to evaluate the effects of different echo time (TE) on the liver fat quantification using proton magnetic resonance spectroscopy (1H-MRS). Liver 1H-MRS was performed on 24 adult male wistar rats on a 1.5 T superconductor MR scanner. Spectrums were collected with a TR of 1500 ms and different TE of 35, 45, 55, 65, 75, 85, 95, 105, 144 ms, respectively. The water and lipid peaks, baseline of the spectrum and lipid to water ratio were evaluated. With the increment of TE, the amplitude and integrated area of the water and lipid peaks decreased, and the baseline of the spectrum and the lipid to water ratio became unstable. The lipid to water ratio determined by 1H-MRS was highly correlated with the liver fat content determined by pathological analysis at TE between 35 and 55 ms (r > 0.9) and poorly to moderately correlated at TE > or =65 ms (r < 0.9). The results indicated that long TE would compromise the liver fat quantification using 1H-MRS, and therefore short TE was strongly recommended for liver fat quantification.