3.0 T高分辨率MRI在肛瘘分型与内口定位中的应用价值

The value of 3.0 T high-spatial-resolution MRI in the fistula classification and internal opening location

目的研究3.0 T高分辨率MRI在肛瘘分型与内口定位中的临床应用价值。材料与方法对156例经临床确诊的肛瘘患者采用3.0 T高分辨率MRI检查,并由2名高年资放射科医生阅片,明确瘘管走向,内口位置,有无支管,有无脓肿、主要瘘管与肛门括约肌之间的关系,并与手术探查结果对照。结果根据Parks分型法分型;内口位置描述采取截石位时钟定位法,MRI内口显示位置与术中所见位于同一象限内认为显示正确。结果 (1)156例肛瘘患者的肛瘘主支Parks分型与手术探查分型符合情况:单纯性肛瘘119例,复杂性肛瘘37例,经手术探查结果符合率均为100%。MRI诊断及术后诊断Parks分型结果分别为:括约肌间型87例/85例;经肛管括约肌型52例/54例;括约肌上型10例/11例,括约肌外型7例/6例;结果符合率分别为97.70%、96.30%、90.90%和85.71%。(2)内口定位与手术探查结果符合情况:MRI诊断内口189个,术后诊断内口205个,诊断符合率92.20%。(3)MRI诊断肛瘘主、支管分别为196支、20支,术后诊断肛瘘主、支管分别为198支、24支,诊断符合率高于80%。(4)MRI诊断肛周脓肿74例,术后诊断肛周脓肿74,诊断符合率为100%。结论 3.0 T高分辨率MRI平扫及多期动态增强检查在肛瘘分型与内口定位中具有重要临床应用价值。

Objective： To evaluate the value of 3.0 T high-spatial-resolution MR imaging in the fistula classification and internal opening location. Materials and Methods： One hundred and fifty-six patients with anal fistulas underwent 3.0 T high- spatial-resolution MR imaging, and two experienced radiologists analyzed the images separatedly to identify the orientation of the fistula track, the internal opening, whether with ramifications and abscess, and the relationship between the primary track and the anal sphincter, compared with the surgical exploration. All cases were classified according to Parks classification, and the internal openings were expressed by lithotomy position of clock location method. MR imaging was correctly revealed if the internal opening was observed in the same quadrant as the surgical exploration. Results： （I） The coincidence rate was 100% of the classification according to the primary track on MR imaging, compared with surgical exploration in 156 cases： 119 samples and 37 complex anal fistula. The accuracy rates of classification by MR imaging compared with surgical exploration were： inter-sphincteric 97.70% （87/85）, trans-sphincteric 96.30% （52/54）, supra-sphincteric 90.90% （10/11）, extra-sphincteric 85.71% （7/6）, respectively. （2） The accuracy rate of internal opening was 92.20% （189/205）. （3） 196/198 primary tracks and 20/24 ramifications were identified, the accuracy rate was more than 80%. （4） Seventy- four perianal abscess were confirmed by MRI as well as surgical exploration, the accuracy was equal to 100%. Conclusions： 3.0 T high-spatial-resolution MR imaging and dynamic contrast enhancement scanning has an important clincal value in evaluating the fistula classification and internal opening location.