ABSTRACT
Objective To evaluate the application value of high resolution MRI fat suppression T2WI combined with DWI in anal fistula and its activity. Methods We analyzed the clinical data and MRI findings of 59 patients who received high resolution MRI from January 2016 to November 2017. According to the clinical and surgical results,anal fistulas were divided into positive inflammatory activity(PIA)and negative inflammatory activity(NIA). ADC values of anal fistula were measured and the optimal cut-off of ADC values were calculated. Results 59 patients with 71 anal fistulas and 62 internal openings confirmed by surgical results.ADC values were differenct between PIA and NIA anal fistulas(P = 0.001) and the optimal cut-off of ADC value were 1.214. The sensitivity of high resolution MRI fat suppression T2WI,DWI and T2WI combined with DWI for detecting anal fistula and internal opening were 80.28%(57/71),83.10%(59/71),95.77%(68/71) and 82.26%(51/62), 83.87%(52/62),96.77%(60/62),respectively. Conclusion MRI-DWI is very important for evaluating the activities of anal fistula and thigh resolution MRI fat suppression T2WI combined with DWI has the highest sensitivity for detecting anal fistula and internal opening.