目的:评估MR排粪造影结果在协同排便(DD)诊断中的诊断性能。
方法:这项回顾性研究纳入了46例符合罗马IV诊断标准的慢性便秘患者,这些患者在2015年1月至2020年6月期间接受了MRI检查。患者分为DD组(n=24)和非DD组(n=22)。由两名放射科医生分析了9个参数:肛门直肠角度(ARA)和静止时的M线,排便,和两个阶段之间的变化;肛管宽度;突出的耻骨直肠肌;异常疏散。绘制受试者工作特征(ROC)曲线以提取最佳截止值和曲线下面积(AUC)。进行多因素分析。
结果:7项研究结果显示,DD组和非DD组之间存在统计学上的显著差异。排便时M线的赔率比最高,随后是ARA的变化,ARA在排便时,M线变化,突出的耻骨直肠肌,异常疏散和肛管宽度,分别。ARA改变和突出的耻骨直肠肌具有最高的特异性(95.5%和100%,分别)。排便时ARA的最佳截止值,ARA改变,排便时M线,M线变化和肛管宽度为122°,1.5°,3.25cm,1.9厘米和8.5毫米,分别。多因素logistic回归分析显示,在区分DD和非DD方面有两个显著发现,包括排便时的M线(OR23.31,95%CI3.10-175.32)和排便时的ARA(OR13.63,95%CI1.94-95.53),特异性,PPV,NPV和AUC为79.2%,95.5%,95%,80.8%和0.87(95%CI0.78-0.97),分别。
结论:MR排粪造影在DD诊断中具有较高的诊断效能。尽管排便时的M线和ARA是多变量分析的两个重要发现,ARA改变小于1.5度和突出的耻骨直肠肌在DD诊断中具有良好的特异性。
OBJECTIVE: To assess diagnostic performance of MR defecographic findings in diagnosis of dyssynergic defecation (DD).
METHODS: This retrospective study included 46 patients with chronic constipation who met the Rome IV criteria for diagnosis of present or absent DD and underwent MRI between Jan 2015 and June 2020. Patients were divided into DD group (n = 24) and non-DD group (n = 22). Nine parameters were analyzed by two radiologists: anorectal angle (ARA) and M line at rest, defecation, and change between 2 phases; anal canal width; prominent puborectalis muscle; abnormal evacuation. Receiver operating characteristic (ROC) curves were plotted to extract the optimal cut-offs and area under the curve (AUC). Multivariate analysis was performed.
RESULTS: Seven findings showed statistically significant difference between DD and non-DD groups. M line at defecation had highest odds ratio, followed by ARA change, ARA at defecation, M line change, prominent puborectalis muscle, abnormal evacuation and anal canal width, respectively. ARA change and prominent puborectalis muscle had highest specificity (95.5% and 100%, respectively). The optimal cut-offs of ARA at defecation, ARA change, M line at defecation, M line change and anal canal width were 122°, 1.5°, 3.25 cm, 1.9 cm and 8.5 mm, respectively. Multivariate logistic regression revealed two significant findings in differentiating between DD and non-DD, including M line at defecation (OR 23.31, 95% CI 3.10-175.32) and ARA at defecation (OR 13.63, 95% CI 1.94-95.53) with sensitivity, specificity, PPV, NPV and AUC of 79.2%, 95.5%, 95%, 80.8% and 0.87(95% CI 0.78-0.97), respectively.
CONCLUSIONS: MR defecography has high diagnostic performance in diagnosis of DD. Although M line and ARA at defecation are two significant findings on multivariate analysis, ARA change less than 1.5 degrees and prominent puborectalis muscle have good specificity in DD diagnosis.