Résumé
Objective To investigate the application value of multimodal MRI in complex anal fistula.Methods The clinical and MRI data of 50 cases with complex anal fistula confirmed by surgery were collected.All patients were examined with 1.5T MR before surgery,including three major modules of conventional MRI,diffusion weighted imaging(DWI)and dynamic contrast-enhanced magnetic resonance imaging(DCE-MRI).Finally,the diagnostic efficacy of different MRI modules in complex anal fistula was evaluated based on the surgical results.Results The surgery detected 73 internal orifices,81 external orifices,58 main fistulas,47 branch fistulas and 37 abscesses.Before the surgery,there were 63 internal orifices(86.3%),75 external orifices(92.6%),53 main fistulas(91.4%),40 branch fistulas(85.1%),and 37 abscesses(100%)correctly diagnosed by conventional MRI.Sixty internal orifices(82.2%),75 external orifices(92.6%),51 main fistulas(87.9%),37 branch fistulas(78.7%),and 37 abscesses(100%)were correctly diagnosed by conventional MRI+DWI,while 68 internal orifices(93.2%),78 external orifices(96.3%),56 main fistulas(96.6%),44 branch fistulas(93.6%),and 37 abscesses(100%)were correctly diagnosed by conventional MRI+DCE-MRI.There were 68 internal orifices(93.2%),78 external orifices(96.3%),56 main fistulas(96.6%),44 branch fistulas(93.6%),and 37 abscesses(100%)correctly diagnosed by conventional MRI+DWI+DCE-MRI.Compared with conventional MRI,conventional MRI+DWI or conventional MRI+ DCE-MRI,conventional MRI+DWI+DCE-MRI could find more internal orifices,main fistulas and branch fistulas,and the difference was statistically significant.The multimodal MRI had the highest consistency with the surgical results(Kappa=0.734,P<0.001).Conclusion MRI can accurately estimate the information of internal orifices,external orifices,main fistula,branch fistula and abscess of cases with complex anal fistula.The diagnostic accuracy of multimodal joint application is superior than that of single-modal and dual-modal application.