Fig. 8

A 40-year-old diabetic male patient complaining of recurrent perianal fistula after surgery. MRI examination in the form of multiple pulse sequences after IV contrast injection revealed in pre-contrast axial Fat Sat T1 images: A a faint horseshoe fistulous tract at the intersphincteric space (orange arrow). Post-contrast axial Fat Sat T1 images (B–E) showed: B external cutaneous opening of the branched fistulous tract in the left perianal region (white arrow). C An enhanced fistulous tract seen in the intersphincteric space with secondary branches (red arrow). D One branch seen connected with the anal canal at six o’clock (yellow arrow). E The enhanced fistulous tract forming a horseshoe extension (blue arrow) connected with the anal canal at 11 o’clock (green arrow). The final diagnosis was a left, grade II, intersphincteric fistula