3.0T磁共振扩散张量成像在正常女性盆底肌肉的应用

Application of 3.0T MR Diffusion Tensor Imaging in Normal Female Pelvic Floor Muscles

目的探讨3．0TMR扩散张量成像（DTI）在正常女忖：盆底肌肉纤维束的三维显示及参数特点，为DTI在盆腔器官脱垂患者的应用提供参考。资料与方法50例未生育和经剖寓产分娩的女性，按年龄分为20～29岁（15例）、30～39岁（15例）、40-49岁（12例）、50～54岁（8例）。于3．0T MRI上首先行常规矢状位、横轴位、冠状位T2WI、横轴何T1WI柃查；然后行动态正中矢状位Fiesta序列检查．排除盆腔器订脱垂；最后采用二维扩散加权横断自旋甲丽嘲波（SE-EPI）脉冲序列对盆底DTI柃查，对DTI图像进行后处理获得正常女性盆底肌肉纤维束图像，并测量对应肌肉的表观扩散系数（ADC）值和备向异性分数（FA）值。结果所有受枪暂禽底耻骨内脏肌、盆晕闭孔内肌均获得满意的三维肌肉纤维束图像及对应的ADC值、FA值；同一年龄组内在、右侧耻骨内脏肌及闭孔内肌ADC值、FA值比较，砖异无统计学意义（P〉0．05）；不同年龄组间耻骨内脏肌及闭孔内肌ADC值、FA值比较，差异无统计学意义（P〉0．05）。结论3．0T MR DTI纤维束成像可以三维观察史性盆底复杂肌肉纤维束结构，并且获得其正常ADC值和FA值。

Purpose To explore the three-dimensional display and parameter features of 3.0T MR diffusion tensor imaging （DTI） in the imaging of normal female pelvic floor muscle fiber bundles, and to provide a reference standard for the application of DTI in patients with pelvic organ prolapse. Materials and Methods Fifty cases of females who had not given birth or had given birth by cesarean delivery were divided into lbur groups： 20 to 29 years （15 cases）, 30 to 39 years （15 cases）, 40 to 49 years （12 cases） and 50 to 54 years （8 cases）. First, the conventional sagittal, axial, coronal T2W1 and axial T1WI images were acquired with a 3.0T MRI scanner; then a dynamic sagittal fiesta sequence was executed to exclude pelvic organ prolapse; at last, the transverse two-dimensional diffusion-weighted spin echo-echo planar imaging （SE-EPI） pulse sequence was executed to acquire pelvic floor DTI data, through the post-processing of the data, normal female pelvic floor muscle fiber bundle images can be obtained and apparent diffusion coeFficient （ADC） value and fractional anisotropy （FA） value were calculated. Results Content three- dimensional muscle fiber bundle images and corresponding ADC and FA values of the pubic visceral muscles in pelvic wall and obturator muscles in pelvic wall were acquired in all subjects; there was no statistically significant difference （P〉0.05） for the ADC and FA values between the left and right side of the pubic visceral muscles and obturator muscles within the same age group; and the difference of ADC and FA values of pubic visceral muscles and obturator muscles among different age groups were not statistically significant （P〉0.05）, either. Conclusion 3.0T MR DTI fiber tracking imaging can be applied for the three-dimensional observation of the complicated muscle fiber bundle structures in female pelvic floor, through the measurement of ADC and FA value changes, functional abnormity can be suggested before the anatomy structure changes of the pelvic muscles occurs, thus provides an important new approach for further study of pelvic organ prolapse.