Sonographic diagnosis of a small fistulous communication between a subphrenic abscess and a perforated duodenal ulcer.

We report a case of a fistula between a subphrenic abscess and a perforated duodenal ulcer diagnosed by sonography and confirmed by CT. The sonographic findings included a subphrenic fluid collection connected to the anterior aspect of the superior duodenum by a nonpulsatile, anechoic tubular lesion. Manual compression of the upper epigastrium resulted in movement of echogenic debris from the antrum and superior duodenum through the fistulous tract into the abscess.