The physical examination in children has been shown to be unreliable in determining the severity of injury in up to 45% of pediatric trauma patients. Indications for CT include: suspicious mechanism of injury, tenderness on exam, seatbelt sign, distention, vomiting, or more than 50 red blood cells per high-power field on urinalysis for blunt trauma. Identification of a pelvic fracture, particularly an anterior ring fracture, should prompt investigation for associated urethral or bladder injury (Fig. 157-1). The role of ultrasound for pediatric abdominal trauma, especially in stable patients, is not well established.