盆底动态磁共振成像诊断不协调性排便

目的 利用盆底动态MRI观察不协调性排便（DD）患者肛直肠解剖及功能特点。方法 对90例出口梗阻型便秘患者（其中48例诊断为DD，DD组）及60名健康志愿者（对照组）行盆底动态MRI，观察肛提肌的MRI解剖表现，并对耻骨直肠肌（PRM）厚度行定量分析，分析两组PRM厚度的差异。结果 MRI示肛提肌由PRM、耻尾肌和髂尾肌3部分组成。静息时，DD组左右侧PRM厚度分别为（7.83±1.10）mm和（6.64±1.73）mm，而对照组分别为（5.96±1.27）mm和（5.43±1.15）mm（P均<0.05）；DD组力排前后左右侧PRM厚度分别为（10.70±1.80）mm和（12.40±2.00）mm（P<0.05）。结论 盆底动态MRI直观显示肛提肌的解剖特点，可定量及定性分析DD患者的异常解剖及功能特点，为术前选择手术方式及术后评估提供依据。

Pelvic dynamic MRI in diagnosis of dyssynergic defecation

Objective To observe anatomy and functional features of dyssynergic defecation (DD) with pelvic dynamic MRI. Methods Pelvic dynamic defecation was performed in 90 outlet obstruction constipation patients (48 were diagnosed as DD named DD group) and 60 healthy volunteers (control group). The anatomy of the levator ani muscle in MRI imaging were observed, and the thickness of puborectalis muscle (PRM) was quantitatively analyzed. Results The levator ani muscle was composed of PRM, pubococcygeus muscle and the ileoccygeus muscle in MRI. At rest, the thickness of left and right side of PRM in DD group was (7.83±1.10)mm and (6.64±1.73)mm, respectively, while in control group was (5.96±1.27)mm and (5.43±1.15)mm, respectively (all P<0.05). In DD group, the thickness of PRM during rest and straining was (10.70±1.80)mm and (12.40±2.00)mm, respectively (P<0.05). Conclusion Pelvic dynamic MRI can display the anatomical features as well as quantitatively and qualitatively analyze the abnormal anatomical and functional characteristics of levator ani muscle, therefore providing information in the choice of surgical approach and postoperative evaluation of dyssynergic defecation.