3.0T磁共振多序列成像在复杂肛瘘诊断中的临床应用

Clinical Application of 3.0T Magnetic Resonance Imaging in Diagnosis of Complex Anal Fistulas

目的：本研究探讨体外相位阵列线圈3.0T MRI多序列扫描对复杂肛瘘诊断的准确性及价值。方法：回顾性分析我院2014年5月至2015年11月经手术证实的18例肛瘘患者临床及影像资料,男性10例,女性8例,年龄23~83岁,平均年龄约44.8岁,病程6天-15个月,术前一周内行3.0T MRI检查。检查序列包括高分辨率横轴位抑脂、矢状位抑脂和冠状位T2WI及轴位T1WI序列、横轴位弥散加权成像（DWI）序列,10名患者行增强扫描。结果：本组18例患者手术共检出25个瘘管、其中显示12个内口、15个外口,13例肛周脓肿。瘘管于T1WI呈条状略低信号影,在T2WI序列、T2WI抑脂序列及DWI序列上呈条状或管状高信号,在T1WI增强图像上瘘管呈明显管状强化,内口多表现为圆点状强化。本组术前MRI诊断瘘管、内口、肛周脓肿显示的敏感度分别为89.2%（25/28）、80%（12/15）、100%（14/14）,特异度分别为75%（3/4）、75%（3/4）、71.4%（5/7）。结论：磁共振多序列成像对复杂肛瘘内口、外口及肛周脓肿有良好的显示,对外科手术方式选择有积极的指导作用。

Purpose：To evaluate the accuracy and clinical value of preoperative 3.0T magnetic resonance（MR） imaging multiple sequences scanning with a phased-array coil for the detection of complex anal fistulas. Methods：A total of 18 patients with surgically proved anal fistulas underwent preoperative MR imaging with phase-array coil at a 3.0T MR unit. There were 8 females and 10 males. The age of patients ranged from 23 to 83 years old. The mean age was 44.8 years old. The course of disease was ranged from two days to fifteen months. The imaging protocol included highresolution T2-weighted turbo spin echo sequence acquisition at axial, sagittal and coronal planes; T1-weighted turbo spin echo sequence acquisition and diffusion weighted imaging at axial plane; and T2-weighted sequence with fat suppression at axial and sagittal planes; 10 patients underwent post-enhanced scans. Results：Eighteen patients were found with 25 anal fistulas, 12 of them were with internal openings, 15 with external openings, and 13 with perianal abscesses. The sensitivity rate for detecting fistulas tubes, internal openings and perianal abscesses were 89.2%（25/28）, 80%（12/15）, 100%（14/14）. The specificity rate were 75%（3/4）, 75%（3/4）, 71.4%（5/7）, respectively. The anal fistula was with low intensity signal in T1 WI, and with strip-like high intensity signal in T2 WI and T2 WI with fat suppression. Conclusion：3.0T MRimaging with multiple sequences scanning is a very accurate preoperative technique for evaluating the course of fistula tubes and the presence of abscesses, thus providing important information for proper surgical treatment.