磁共振不同检查序列对肛瘘的诊断价值比较

Comparative study on the diagnostic values of different magnetic resonance sequences for anal fistula

目的研究对比磁共振成像(magnetic resonance imaging,MRI)不同检查序列对肛瘘的诊断价值。方法将120例疑似肛瘘患者纳入作为回顾性研究对象,所有患者均在术前接受MRI检查,分别进行MRI常规平扫、动态增强扫描(dynamic enhanced scanning,DCE)序列、三维可变翻转角快速自旋回波(3D-SPACE)序列扫描,以手术诊断结果为诊断金标准,计算和比较MRI常规平扫、DCE序列、3D-SPACE序列对肛瘘的诊断敏感度、特异度、准确率、阳性预测值、阴性预测值,分析诊断结果之间的一致性,并比较MRI常规平扫、DCE序列、3D-SPACE序列对肛瘘内口、肛瘘外口、瘘管分支的显示率。结果120例疑似肛瘘患者中,有40例经手术诊断确诊肛瘘,其余80例患者为肛周脓肿。以手术诊断结果为金标准,DCE序列、3D-SPACE序列对肛瘘的诊断敏感度、特异度、准确率、阳性预测值、阴性预测值均高于MRI常规平扫(P<0.05),而DCE序列与3D-SPACE序列的敏感度、特异度、准确率、阳性预测值、阴性预测值比较差异均无统计学意义(P>0.05)。MRI常规平扫诊断结果与手术诊断结果之间的一致性为中度,而DCE序列、3D-SPACE序列诊断结果与手术诊断结果之间的一致性均达到高度。DCE序列、3D-SPACE序列扫描对肛瘘内口、肛瘘外口、瘘管分支的显示率均高于MRI常规平扫(P<0.05),而DCE序列与3D-SPACE序列对肛瘘内口、肛瘘外口、瘘管分支的显示率比较差异均无统计学意义(P>0.05)。结论磁共振DCE序列、3D-SPACE序列扫描对肛瘘的诊断价值优于MRI平扫,临床上诊断肛瘘时推荐采取MRI多种序列扫描。

Objective To investigate the diagnostic values of different examination sequences of magnetic resonance imaging(MRI) for anal fistula. Methods A total of 120 patients with suspected anal fistula were included in the retrospective study. All patients received MRI examination before operation, and were scanned by conventional plain MRI, dynamic enhanced scanning(DCE) sequence and 3 D-SPACE sequence respectively. The diagnostic sensitivities, specificities, accuracies, positive predictive values and negative predictive values of MRI routine plain scan, DCE sequence and 3 D-SPACE sequence for anal fistula were calculated and compared, and the consistency between the diagnostic results was also analyzed. The display rates of MRI routine plain scan, DCE sequence and 3 D-SPACE sequence for anal fistula internal orifice, anal fistula external orifice and fistula branches were compared. Results Among 120 patients with suspected anal fistula, 40 patients were diagnosed as anal fistula by operation, and the remaining 80 patients were with perianal abscesses. With the surgical diagnosis results as the gold standard, the sensitivities, specificities, accuracies, positive predictive values and negative predictive values of DCE sequence and 3 D-SPACE sequence for anal fistula diagnosis were significantly higher than those of MRI routine plain scan(P<0.05), but there was no significant difference between DCE sequence and 3 D-SPACE sequence(P>0.05). The consistency between MRI conventional plain scan diagnosis results and surgical diagnosis results was moderate, while the consistencies between DCE sequence and 3 D-SPACE sequence diagnosis results and surgical diagnosis results were high. The display rates of internal anal fistula, external anal fistula and fistula branches by DCE sequence and 3 D-SPACE sequence were significantly higher than those by MRI routine plain scan(P<0.05), but there was no significant difference between DCE sequence and 3 D-SPACE sequence in displaying internal anal fistula, external anal fistula and fistula branches(P>0.05). Conclusion The diagnostic values of magnetic resonance DCE sequence and 3 D-SPACE sequence scanning for anal fistula are better than MRI plain scanning, and it is recommended to use multiple MRI sequence scanning in clinical diagnosis of anal fistula.