laceration or contusion. Pancreatic injuries, most commonly caused by bicycle accidents (especially by impact with the handlebars) in children and vehicular accidents in adults, usually occur in isolation in children and accompanied by other injuries in adults. Indications that the pancreas is injured include enlargement and the presence of fluid around the pancreas. Kidneys The kidneys may also be injured; they are somewhat but not completely protected by the ribs. Kidney lacerations and contusions may also occur. Kidney injury, a common finding in children with blunt abdominal trauma, may be associated with bloody urine. Kidney lacerations may be associated with urinoma or leakage of urine into the abdomen. A shattered kidney is one with multiple lacerations and an associated fragmentation of the kidney tissue. Bowel The small intestine takes up a large part of the abdomen and is likely to be damaged in penetrating injury. The bowel may be perforated. Gas within the abdominal cavity seen on CT is understood to be a diagnostic sign of bowel perforation; however intra-abdominal air can also be caused by pneumothorax (air in the pleural cavity outside the lungs that has escaped from the respiratory system) or pneumomediastinum (air in the mediastinum, the center of the chest cavity). The injury may not be detected on CT. Bowel injury may be associated with complications such as infection, abscess, bowel obstruction, and the formation of a fistula. Bowel perforation requires surgery. Diagnosis Ten percent of people with polytrauma who had no signs of abdominal injury did have evidence of such injuries using radiological imaging. Diagnostic techniques used include CT scanning, ultrasound, and X-ray. X-ray can help determine the path of a penetrating object and locate any foreign matter left in the wound, but may not be helpful in blunt trauma. Diagnostic laparoscopy or exploratory laparotomy may also be performed if other diagnostic methods do not yield conclusive results. Ultrasound Ultrasound can detect fluid such as blood or gastrointestinal contents in the abdominal cavity, and it is a noninvasive procedure and relatively safe. CT scanning is the preferred technique for people who are not at immediate risk of shock, but since ultrasound can be performed right in an emergency room, the latter is recommended for people who are not stable enough to move to CT scanning. A normal ultrasound does not rule out all injuries. CT People with abdominal trauma frequently need CT scans for other trauma