Fig. 4
From: Magnetic resonance imaging in the workup of patients with perianal fistulas
A 66-year-old male patient who presented with right perianal discharge. MRI examination after local injection of US gel through the fistulous tract revealed through axial T2 images (A–C): A External cutaneous opening of the fistulous tract (white arrow). B A non-branching simple tract at the right intersphincteric space (red arrow). C Internal mucosal opening connected to the anal canal at six o’clock (yellow arrow). Coronal T2 images showed: D the course of the linear intersphincteric tract (green arrow). E A coronal STIR image showed hyper-intense signal of the right intersphincteric tract (blue arrow). The final diagnosis was a right, grade I, intersphincteric fistula