心脏MRI检查中自由呼吸单次激发FIESTA序列的应用

Myocardial delayed enhancement using a single shot free-breathing FIESTA sequence

目的:研究SS-SSFP序列在心脏MRI检查中从图像质量和扫描时间方面与IR-FGRE、3DIR-FGRE序列的优势。方法:本文搜集疑似或确诊心脏病患者52例进行心脏MRI检查,延迟期扫描采用SS-SSFP、IR-FGRE、3DIRFGRE序列。通过测量扫描时间和图像质量相关参数评价新序列与传统序列的差别。结果:SS-SSFP序列(24~36s)和3DIR-FGRE序列(27~35s)扫描时间明显低于IR-FGRE序列(116~154s),两者有统计学差异(P<0.001)。统计学结果显示SS-SSFP序列图像质量、异常强化体积及百分比与IR-FGRE序列相比较无差异,而心肌信噪比、强化心肌与心肌对比信噪比有差异,SS-SSFP序列高于IR-FGRE序列(P<0.001)。3DIR-FGRE序列的所有测量值均高于IR-FGRE序列,由于有更多的呼吸运动伪影,二者在图像质量方面有统计学差异(P<0.001)。结论:SS-SSFP序列加快扫描时,由于其较高的信噪比、对比信噪比,且图像质量与IR-FGRE序列无统计学差异,SS-SSFP序列更适合患有严重心脏病和不能屏气的患者。

Objective To study the steady-state free precession （SS-SSFP） sequence in the MRI examination of theheart and to study its advantages in image quality and scanning time as compared to IR-FGRE and Cardiac MRI examination data of 52 patients with suspected or confirmed heart disease were collected. For the SS-SSFP sequence, the ir-fgre sequence, and the 3D ir-fgre sequence were used. The difference between the new sequence and the traditional sequence was evaluated by measuring the time of the scan and the quality of the image. Results ：The scan-ning time of the SS-SSFP sequence （24- 36s） and 3DIR-FGRE （2 7- 35s） were significantly lower FGRE sequence （116- 154 s ） ,with statistical differences （ P 〈0. 001） ;The statistical results showed that thequence image quality,anomalous enhanced volume and percentage were not different from the IR-FGRE sequence. However, the signal noise ratio of myocardium, enhanced myocardium and myocardial contrast to noise ratio were different, the CNRof SS-SSFP sequence is higher than that of the IR-FGRE sequence （P 〈0. 0001）. All measurements of the 3D IR-FGRE se-quence were higher than that of the IR-FGRE sequence. Because of more respiratory artifacts, there was a statistical differ-ence in image quality （P〈0. 0001）. Conclusions ： When the SS-SSFP sequence was used to speed up due to its higher SNR and CNR,and no statistical significant difference of image quality SS-SSFP sequence is more suitable for patients with severe heart disease and unable to breath-holding in clinical treatment.