Gunshot wound to the abdomen with injury to the SMA and active extravasation
Presentation
Gunshot wound
Patient Data
Scout image shows paperclip in right posterior hip and left thigh, indicating entry and exit wounds. Old bullet fragments project over the right lower chest.
Bullet trajectory: right posterior hip through iliac bone, right iliacus with small foci of active extravasation, mesentery with active extravasation, left thigh.
Follow the SMA - it loses flow at the level of the upper iliac bones due to injury. There is flow in the ileocolic branches, and therefore enhancement in the TI and cecum. However, the distal ileal branches are completely out. Following the TI retrograde, you will end up in indistinct, hypoenhancing small bowel in the right lower quadrant.
Hypoenhancement of several segments of ileum in the right lower quadrant, which are difficult to distinguish from the hemoperitoneum.
Probable contusion along the bladder dome.
Large amount of hemoperitoneum.
Cleft in liver and spleen.
Delayed images: accumulation of extravasated contrast in the mesentery.
Case Discussion
Teaching points:
- Use the scout images to identify entry and exit wounds (with paperclips). The pathway of the bullet can be highly variably and unpredictable, but following the course of the bullet will help you to identify all of the key injuries.
- The injury to the SMA with active extravasation is pretty obvious. It is important to identify where the injury is and what branches are affected: the ileocolic artery is intact, and therefore there is flow in the cecum and terminal ileum. However the distal ileal branches are out. Therefore, when you follow the TI retrograde, it ends up in indistinct hypoenhancing ileum in the right lower quadrant. This largely blends in with the hemoperitoneum, and is barely noticeable until you follow the leaves of the mesentery out and look for the ileum. There is a lot of bowel that is not enhancing!
- Clefts in the liver and spleen can mimic lacerations.