MRI测量肛提肌裂孔前后径和面积对产后盆底肌收缩力低下的诊断价值

Value of levator hiatal antero-posterior diameter and area measured by MRI in diagnosis of postpartum low pelvic floor muscle contraction

目的探讨MRI测量肛提肌裂孔前后径(LH ap)和肛提肌裂孔面积(LH area)对产后盆底肌收缩力低下(LPFMC)的诊断价值。方法选取2019年1月至2022年5月在金华市中心医院经阴道分娩或剖宫产分娩的102例产妇为研究对象,按照分娩后1个月经盆底肌触诊改良牛津评分(MOS)分为LPFMC组(MOS 0~3分)39例,正常组(MOS 4~5分)63例。采用3.0T T_(2)WI快速自旋回波序列(TSE)静息态和单次激发TSE动态MRI成像,在静息态和最大Valsalva动作时测量肛提肌裂孔形态(包括V形、U形、O形和不规则形4种)、髂尾肌形态(包括穹隆状、漏斗状和凹槽状3种)以及MRI参数[包括LH ap、LH area、肛提肌裂孔横径(LH-W)、肛提肌起始处距耻骨联合下缘距离(LH-S)、肛提肌板角度(LPA)以及各参数最大Valsalva动作时的拉长百分比]。采用ROC曲线分析LH ap和LH area对LPFMC的诊断效能。结果LPFMC组患者静息态及最大Valsalva动作时MRI成像显示肛提肌裂孔形态U+O以及髂尾肌形态漏斗+凹槽的比例均明显高于正常组(均P<0.05),且最大Valsalva动作时的比例均明显高于静息态(均P<0.05)。LPFMC组静息态和最大Valsalva动作时LH ap、LH area以及两者拉长百分比均明显高于正常组(均P<0.05);两组患者静息态和最大Valsalva动作时LH-W、LH-S、LPA以及3者拉长百分比比较,差异均无统计学意义(均P>0.05)。ROC曲线分析显示,静息态及最大Valsalva动作时LH ap、LH area诊断LPFMC的AUC分别为0.656、0.798和0.689、0.836,LH ap、LH area拉长百分比诊断LPFMC的AUC分别为0.869和0.923。结论静息态和动态MRI是评估产后LPFMC的重要无创检查方法,其中LH ap和LH area拉长百分比具有较高的诊断效能。

Objective To analyze the clinical value of levator hiatal antero-posterior diameter(LH ap)and area(LH area)measured by MRI for the diagnosis of low pelvic floor muscle contraction(LPFMC)of patients with postnatal pelvic floor dysfunction(PFD).Methods one hundred and two postpartum women who underwent vaginal or cesarean delivery at Jinhua Central Hospital from January 2019 to May 2022 were selected as the study subjects.According to the modified Oxford score(MOS)of pelvic floor muscle palpation at the first month after delivery,they were divided into 39 cases of LPFMC group(MOS 0-3 points)and 63 cases of normal group(NPFMC group,MOS 4-5 points).Using 3.0T T_(2)WI turbo spinecho(TSE)sequence static and single-shot TSE dynamic MRI imaging,the shapes of levator hiatus(including"V"-,"U"-,"O"-and irregular shapes)and iliac tail muscle(including"dome","funnel"and"groove"like shapes)were measured at rest and during the maximum Valsalva maneuver,as well as relevant MRI parameters,including LH ap,LH area,levator hiatal width(LHW),distance between levator hiatus and symphysis(LH-S),levator muscle plate angle(LPA),and additionally elongated percentage of each parameter at the maximum Valsalva maneuver.The receiver operator characteristic(ROC)curve was used to analyze the diagnostic efficiency of LH ap and LH area for LPFMC.Results MRI imaging at rest and during maximum Valsalva maneuver showed that the abnormal"U"and"O"shapes of levator hiatus and the abnormal"funnel"and"groove"shapes of iliococcus muscle in LPFMC group were significantly more than those of NPFMC group(all P<0.05),and these shapes in LPFMC group during maximum Valsalva maneuver were significantly more than those at rest(both P<0.05).The LHap and LH area in LPFMC group were significantly larger than those in NPFMC group at rest and during maximal Valsalva maneuver,and the elongated percentages of LH ap and LH area were significantly higher than that of NPFMC group(all P<0.05).However,there were no statistical differences in LH-W,LH-S and LPA,as well as elongated percentages of the three,between the two groups at rest and during maximal Valsalva maneuver(all P>0.05).According to ROC curve,the area under the curve(AUC)of LH ap and LH area at rest state and during maximum Valsalva maneuver for diagnosing LPFMC was 0.656 and 0.798,0.689 and 0.836,respectively,and the AUC of LH ap and LH area elongated percentages was 0.869 and 0.923,respectively.Conclusion Rest and dynamic MRI is an important non-invasive method to evaluate LPFMC in postpartum PFD patients,among which,LH ap and LH area elongated percentages have better diagnosing performance.