Fig. 3

a T2-weighted MR image reveals soft-tissue intensity with enhancement anterior to S1–S3 (white arrowheads). b Lateral radiograph during Gastrografin enema shows extravasation of contrast material from the top of the pouch to the S1–S2 presacral space (white arrow), indicating the existence of residual abscess. There is no communication between the abscess and epidural space