3.0T MR不同扫描序列对肛瘘的诊断

Diagnosis of perianal fistula with different MR sequences at 3.0 Tesla

目的比较不同磁共振成像(MR)序列对肛瘘病变的显示,探讨其在临床诊治中的应用价值。方法收集15例临床疑诊为肛瘘的患者,于术前行MR扫描,MR扫描序列包括矢状T2WI(SAGT2WI)、冠状T2脂肪抑制序列(CORT2FS),轴位FSET1WI(AXT1WI),轴位FRFSET2WI(AXT2WI),轴位T2脂肪抑制序列(AXT2FS)和动态增强(DCE),检查结果与手术结果对照。结果15例患者术中共发现内口16个,瘘管14个。根据JohnMorris等的分类方法,15例患者中,1级肛瘘3例,2级肛瘘6例,3级肛瘘3例,4级肛瘘2例,5级肛瘘1例,其中2例为单纯肛周脓肿。在内口的显示率上,动态增强扫描高于其他扫描序列,但与轴位T2脂肪抑制序列相比无统计学意义(P>0.05)。在瘘管的显示率上,动态增强扫描亦高于其他扫描序列,但仅与轴位T1WI序列相比有统计学意义(P<0.05)。结论动态增强扫描结合冠状面扫描可以较好地显示肛瘘病变,能够为外科手术方式的选择提供较详尽的影像资料。

Objective To explore the clinical value of different MR sequences in the diagnosis of perianal fistula. Methods MRI was perfonned on fifteen cases of clinically suspected perianal fistula. The MR pulse sequences included sagittal T2 WI （ SAG T2 WI）, coronal T2 WI with fat suppression （ COR T2 FS）, axial T1 WI （AX T1 WI）, axial T2 WI（ AX T2WI）, axial T2WI with fat suppression（AX T2 FS） and dynamic contrast enhancement（DCE）. The MR findings were compared with the surgical results. Results 16 internal opening and 14 tracks were found in 15 cases. Based on John Morris＇s study, 3 cases were gradel, 6 cases were grade2, 3 cases were grade3, 2 cases were grade 4, and 1 case was grade 5. Only 2 cases had a perianal abscess. The internal opening display rate of the DCE imaging was much higher than that of other sequences, but there were no statistical differences between the DCE and AX T2 FS（P 〉 0.05）. The fistula track display rate of the DCE imaging was also much higher than that of the other sequences, and there were statistical differences only between the DCE and AX T1WI （ P 〈 0.05）. Conclusion Optimized coronal T2 fat suppression and dynamic contrast enhanced MR imaging are critical for perianal fistula, which provides great help for surgical planning and treatment.