胎儿磁共振成像序列的对比研究及应用

目的:比较单次激发快速自旋回波序列(SSFSE)和快速成像稳态采集序列(FIESTA)对胎儿解剖结构和病变的显示能力,探讨两种快速成像序列在胎儿MRI中的临床应用价值。方法:82例中晚期妊娠孕妇行单次激发快速自旋回波序列和快速成像稳态采集序列扫描,并根据图像平均信号强度、图像质量和图像伪影等方面对两个序列在胎儿解剖结构和病变的显示能力方面做出统计学分析。结果:两种序列对胎儿解剖结构和异常病变的显示各有优点和不足,SSFSE和FIESTA均能清楚显示胎儿正常脏器的解剖结构和异常病变。SSFSE的平均信号强度和分辨力要高于FIESTA序列,但其呼吸伪影要比FIESTA序列明显,而对于液体的显示FIESTA要优于SSFSE。结论:SSFSE序列和FIESTA序列对胎儿的不同组织其显示能力不同,所以根据病情做出不同的选择是非常重要的。

Comparative Study and Evaluation of MR Sequences in Fetus Imaging:SSFSE versus FIESTA

Objective:To compare the application of single-shot fast spin-echo (SSFSE) sequence with fast imaging employing steady-state acquisition (FIESTA) sequence for the delineation of anatomic structure and disease in fetus and to explore the clinical value of two series of fast imaging for MRI of fetus.Methods:82 women with middle and late pregnancies were imaged with SSFSE and FIESTA sequences.All the images were statistical analyzed with regard to average signal intensity,imaging quality and artifacts.Results:With both sequences,both merits and shortage were found in the delineation of anatomic structures and disease in fetus,respectively.Normal anatomy and lesions can be clearly displayed with both series.The average signal intensity and resolution of images with SSFSE were higher than that of FIESTA,but with more respiratory blurring;while FIESTA was much better than SSFSE for the detection of fluid.Conclusion:SSFSE and FIESTA have different ability for demonstration of different tissues of the fetus,so it is important to select the imaging sequences reasonably according to the specific diseases to be detected.