经相位纠正的稳态自由进动相位敏感压脂技术的研究  

Phase-sensitive Fat Suppression Steady-state Free Procession Sequence with Phase Correction

作　　者：白国刚[1] 俎中良[2] 刘亚军[1] 

机构地区：[1]解放军总医院第二附属医院医务部,北京100091 [2]北京大学物理学院重离子物理研究所,北京100871

出　　处：《中国医疗设备》2008年第12期17-19,38,共4页China Medical Devices

摘　　要：目的稳态自由进动序列(SSFP)可在非常短的时间内获得高对比度和高信噪比效率的图像。但是由于其亮的脂肪信号,SSFP成像的临床应用价值受到严重影响。本文目的在于消除SSFP图象亮的脂肪信号。方法单采集相位敏感SSFP通过适当选择重复时间(TR)来获得相位差180°的水脂信号,利用此相位信息,可以快速而有效的获得压脂图像。结果人体和体模试验得出了很好的水脂分离图像,证明了采用此相位纠正算法的单采集相位敏感SSFP成像技术可以获得非常好的压脂图像。结论经相位纠正的稳态自由进动相位敏感压脂技术,可以在非常短的时间内获得压脂图象,避免了运动伪影,具有一定的临床应用价值。Objective Balanced steady-state free precession （SSFP） sequences use fully refocused gradient waveforms to provide high contrast images with high signal to noise ratio （SNR） efficiency within short scan times. However, SSFP is limited by the fact that fat appears bright, possibly obscuring underlying pathology. The purpose of this article is to eliminate bright fat signal in SSFP imaging. Methotis Single-acquisition phase-sensitive SSFP is a rapid and efficient fat suppression method depending on a 180° phase difference between lipid and water signals with the appropriate selection of the sequence repetition time （TR）, while phase errors, especially spatially-dependent phase shift, caused by a variety of factors may result in misplacement of fat and water voxels. In this paper, a novel phase correction algorithm is used to calibrate those phase errors during image reconstruction.Conclusion Phase-sensitive fat suppression steady-state free procession sequence with phase correction can acquire images without fat signal in short scan time, which eliminate motion artifact and is practical in clinical application.

关 键 词：稳态自由进动 压脂技术 相位敏感 相位纠正 

分 类 号：R319[医药卫生—基础医学]