30例肛瘘患者不同序列扫描MR诊断分析

目的分析不同MR序列扫描在30例肛瘘患者临床诊断中的应用价值。方法对我院2014年3月至2015年9月收治的肛瘘疑似患者30例进行MR检查,行轴面SE T_1WI平扫、冠状面TIRM、轴面SE T_1WI增强扫描、3D-FLASH减影扫描。以SE T_1WI增强序列结果为基准,统计TIRM、SE T_1WI平扫及3D-FLASH减影对肛瘘患者外瘘口、内瘘口及瘘管分支的显示率。结果肛瘘瘘管MRI平扫轴位T_1WI、T_2WI示环状低信号影,T_1WI低信号环内呈近似肌肉信号影,T_2WI低信号环内呈高信号影。冠状面TIRM示片状高信号影下行,与括约肌关系不清;矢状位增强扫描可见瘘管呈管状强化、细小分支及周围软组织小炮絮状强化影。内瘘口的TIRM、SE T_1WI平扫、3D-FLASH显示情况均较差,3DFLASH对外瘘口及瘘管分支的显示情况均优于TIRM与SE T_1WI平扫。结论 3D-FLASH序列的应用诊断肛瘘有较高敏感性,结合轴面3D-FLASH与冠状面TIRM序列可提高MRI对肛瘘内、外瘘口及肛瘘瘘管的显示率,还可缩短检查时间,尤其适用于因肛瘘而而无法耐受长时间卧床检查的患者,具有显著临床应用价值。

Analysis of Different MR Sequences Scanning in Diagnosis of 30 Cases with Anal Fistula

Objective To analyze the application value of different MR sequences scanning in the clinical diagnosis of 30 cases with anal fistula.Methods Thirty patients with suspected anal fistula who were admitted to our hospital between March 2014 and September 2015 were given MR examination. Axial SE T1WI scan, coronal TIRM, axial T1WI enhanced scan and 3D-FLASH subtraction scan were performed. With the results of SE T1WI enhanced sequence as standard, the display rates of TIRM, SE T1WI scan and 3D-FLASH subtraction for external fistula, internal fistula and fistula branch in patients with anal fistula were statistically analyzed.Results Axial T1WI and T2WI of MRI scan for anal fistula canal showed ring-like low signal shadow and approximate muscular signal shadow in T1WI low signal ring and high signal in T2WI low signal ring. Coronary TIRM showed patchy high signal shadow down, and the relationship with sphincter is not clear; Sagittal scan showed fistula with tubular enhancement, small branches and surrounding soft tissue with small flocculent enhancement. The display of TIRM, SE T1WI scan and 3D-FLASH for internal fistula was poor. The display of 3D-FLASH for external fistula and fistula branch was superior to TIRM and SE T1WI scan.Conclusion 3D-FLASH sequence is of high sensitivity in diagnosis of anal fistula. Combination of axial 3D-FLASH and coronary TIRM sequence can improve the display rate of MRI for internal and external fistula of anal fistula, and shorten the examination time, especially for patients who can not tolerate anal fistula and stay in bed. It is of significant value in clinical application.