Fig. 2
From: Role of transperineal ultrasound in evaluation of patients with perianal inflammatory disorders
A 50-year-old male patient presenting with recurrent high perianal fistula. TPUS with saline injection through the skin opening shows the external opening at the scrotal skin (a), sagittal plane shows the fistula joining the anal canal at the anterior aspect of the ano-rectal junction (b), leading to the internal opening at 12 o’clock (c). In oblique axial MRI T2WI (d, e), the internal opening is seen breaching the proximal part of the deep external anal sphincter to reach the anal canal (d) without breaching the puborectalis muscle (e). In sagittal T2 MR image (f), the tract is seen breaching the anal canal anteriorly. A small side branch is seen emerging from the under surface of the tract can be seen which was not detected by TPUS (star)