Presentation
High speed motor vehicle collision. Seatbelt sign.
Patient Data
Multiple locules of free gas. Low-density (10 HU) free fluid within the pelvis and both paracolic gutters. Fat stranding surrounds colon at the junction of descending/sigmoid in the left lower quadrant. Ileal loops in the right lower quadrant have hyperenhancing walls. Extensive subcutaneous fat stranding/hematoma of the anterior lateral pelvis and right flank.
Comminuted and displaced fracture of the left ilium, with a fracture line extending to the left sacro-iliac joint. Associated gluteal and iliac muscle hematoma. Small bone fragment anterior to the left sacro-iliac joint is equivocal for fracture (differential is degenerative change).
- orange arrows = subcutaneous bruising (seatbelt sign)
- red arrow = free fluid in the right paracolic gutter
- blue arrow = focal sigmoid colonic wall thickening with pericolonic inflammatory change
Case Discussion
The patient proceeded to laparotomy. Operative findings:
- perforation in the terminal ileum
- sigmoid serosal tears
Bowel injuries on CT are often occult and difficult to appreciate. The presence of free gas, in addition to pelvic free fluid and thickened bowel loops increases suspicions substantially.