Limitations of routine spiral computerized tomography in the evaluation of blunt renal trauma.

Abstract

We have observed that injury to the renal collecting system may be missed during routine abdominal spiral computerized tomography (CT) for trauma. A definitive protocol for spiral CT has been established to identify all cases of renal collecting system injury. A retrospective review of 35 consecutive cases of blunt renal trauma evaluated with spiral CT between 1994 and 1997 at our Level I trauma center was performed. Each patient received 100 cc intravenous contrast at 2 cc per second. There was a 60-second delay after the start of contrast infusion before scanning was initiated. Of the 35 cases 3 (8.6%) injuries to the renal collecting system were detected on delayed scans obtained after the initial CT failed to demonstrate contrast extravasation. Therefore, at our institution we have modified the protocol for spiral CT for abdominal trauma by repeating scans of the kidneys after the initial scans are completed. Injury to the renal collecting system may be missed during routine spiral CT, thereby incorrectly under staging renal trauma. In all cases of suspected blunt renal trauma evaluated with spiral CT repeat scans of the kidneys should be performed.