MRI动态排粪造影在出口梗阻性便秘诊断中的应用

Application of dynamic MRI defecography in diagnosis of outlet obstructive constipation

目的探讨磁共振成像(magnetic resonance imaging, MRI)动态排粪造影在出口梗阻性便秘(outlet obstructive constipation, OOC)诊断中的应用价值.方法选择2016-03/2018-02南昌大学第三附属医院接诊的疑似OOC患者48例为研究对象,均接受动态MRI排粪造影和X线片排粪造影检查,记录动态MRI排粪造影和X线片排粪造影检查情况,以X线片排粪造影检查为对照,评估动态MRI排粪造影检查的特异度、敏感度、阴性预测值和阳性预测值.结果动态MRI排粪造影检查对乙状结肠疝、耻骨直肠肌痉挛、小肠疝、内痔诊断与X线片排粪造影比较,差异无统计学意义(P>0.05);动态MRI排粪造影对直肠前突、直肠黏膜脱垂、会阴下降、直肠内套叠、乙状结肠盘曲检出率低于X线片排粪造影,差异具有统计学意义(P<0.05);动态MRI排粪造影能发现X线片排粪造影无法显示的病变,包括肌肉断裂、子宫肌瘤、宫颈纳氏囊肿、骶骨囊肿、苗勒管囊肿;以X线片排粪造影检查为金标准,动态MRI排粪造影检查对直肠黏膜脱垂、直肠前突、耻骨直肠肌痉挛、直肠内套叠、乙状结肠疝、小肠疝、乙状结肠盘曲、会阴下降的特异度和阳性预测值均为100%,不同疾病的敏感度与阳性预测值存在明显差异,阳性预测值整体较高,而敏感度相对较低.结论 MRI与X线片排粪造影对OOC诊断方面各有优势,动态MRI排粪造影能提供盆腔脏器和盆壁、盆底功能与形态结构信息,是X线片排粪造影的很好补充,对OOC伴盆腔多室病变的整体评估与全面诊断具有较好的指导价值.

AIM To assess the application value of dynamic magnetic resonance imaging(MRI)defecography in the diagnosis of outlet obstructive constipation(OCC).METHODS Forty-eight patients with suspected OOC at Third Affiliated Hospital of Nanchang University from March 2016 to February 2018 were selected,and they underwent dynamic MRI defecography and X-ray defecography.The situations of dynamic MRI defecography and X-ray defecography were recorded.Using X-ray defecography as the standard,the specificity,sensitivity,negative predictive value,and positive predictive value of dynamic MRI defecography were calculated.RESULTS There was no statistical difference in the diagnosis of intersigmoid hernia,puborectalis spasm,hernia,or internal hemorrhoid between dynamic MRI defecography and X-ray defecography(P>0.05).The detection rates of dynamic MRI defecography in the diagnosis of rectocele,rectal mucosal prolapse,perinaeum descent,intrarectal invaginate,and sigmoid colon zigzagging were lower than those of X-ray defecography(P<0.05).Dynamic MRI defecography could find lesions that cannot be displayed by X-ray defecography,including muscular rupture,uterine fibroid,cervical accepts cyst,sacral cyst,and mullerian duct cyst.Using X-ray defecography as the gold standard,the specificity and positive predictive value of dynamic MRI defecography in the diagnosis of rectal mucosal prolapse,rectocele,puborectalis spasm,intrarectal invaginate,intersigmoid hernia,hernia,sigmoid colon zigzagging,and perinaeum descent were all 100.00%;the sensitivity and positive predictive value for different diseases had a significant difference,the positive predictive value was generally higher,and the sensitivity was usually lower.CONCLUSION MRI and X-ray defecography have their own advantages in the diagnosis of OOC.Dynamic MRI defecography can provide information on the pelvic organ and pelvic wall,pelvic floor function,and morphological structure,and it is a good supplement to X-ray defecography.Dynamic MRI defecography can provide guidance for overall evaluation and comprehensive diagnosis of OOC with pelvic multiple-organ lesions.