Figures 20, 21. (20) Hypoperfusion complex in an 8-year-old boy after a motor vehicle accident. The patient appeared to be in stable condition on entering the CT scanner but experienced cardiac arrest during scanning (after this image was obtained) and could not be resuscitated. CT scan shows diffuse distended small intestine with diffuse wall thickening, findings consistent with the hypoperfusion complex. The aorta (a) is small in caliber. A large amount of free intraperitoneal fluid (F) and a large liver laceration are present. (21) Hypoperfusion complex in a 4-year-old boy after a motor vehicle accident in which he was unrestrained. In the ensuing fire, the patient suffered full-thickness burns over 90% of his body surface area. CT scan shows marked diffuse wall thickening of the small intestine. The aorta (a) and inferior vena cava (i) are small in caliber. C = air-filled colon (not free air), F = free intraperitoneal fluid. The patient died shortly after the CT study.