뇌의 고속스핀에코 T2강조영상에서 지방조직 억제를 위한 SPAIR의 반전시간(TI) 결정 및 STIR 영상과의 비교 연구

Abstract

The purpose of this research is to seek SPAIR’s reversal time (TI) which satisfies two conditions ; maintaining the suppression ability of fat tissue and simultaneously minimizing the inhomogeneity of fat tissue in T2 high-speed spin echo 3.0T magnetic resonance image (MRI) of the brain, and to compare SPAIR with STIR which is fat-suppression technique. The reversal times (TI) of SPAIR protocol are set to 1/2, 1/3, 1/6 and 1/12 of SPAIR TR (420msec), namely 210msec (8 people), 140msec (26 people), 70msec (26 people) and 35msec (18 people) and STIR TI is set with 250msec (26 people). With these parameter sets, we acquired the axis direction 104 images of the brain. In ROI (50㎟) of output image, signal intensities of the fatty tissue, the muscular tissue, and the background were measured and the CNRs of fatty tissue and the muscular tissue were calculated. The inhomogeneity of the fatty tissue is SD/mean, where SD is the standard deviation and ‘mean’ is a average fatty tissue signal. Consequently, SPAIR TI is determined on either 1/3 or 1/6 of TR (420ms) ; 140ms or 70ms. Because the difference of statistics in fat-suppression ability and inhomogeneity of fatty tissue is very small (p<0.001), Selecting 140ms seems to be better choice for the image quality. Meanwhile, Comparing SPAIR (TI : 140ms) with STIR, the fat-suppression is not able to be considered statistically (p<0.252), but the image quality is able to be considered statistically (p<0.01). In conclusion, SPAIR is better than STIR in the image quality.