Sensitivity and specificity of CT scan and angiogram for ongoing internal bleeding following torso trauma

Occult internal bleeding in the trauma patient which remains undiagnosed and unaddressed has the potential to result in morbidity or mortality. Advancements in CT and angiography have played an integral role in the management of this patient population.

The purpose of the study was to identify the sensitivity and specificity of CT scan and angiography in detecting ongoing internal bleeding.

Consecutive patients who sustained torso trauma and subsequently underwent CT scan and angiography were included in this study. Data reviewed included clinical information, CT scan and angiography readings. Extravasations of contrast from CT scan and/or angiogram were considered positive for ongoing internal bleeding.

From January 2002 through July 2007, 113 adult trauma patients sustaining torso trauma underwent CT scan of chest or abdomen followed by angiography. Sixty-six patients were negative for extravasation from either of the tests. Twenty-four of 35 patients had both positive CT scans and angiograms. Eleven patients with positive CT scans did not have bleeding on angiogram. Similarly, 12 out of 36 patients with positive angiograms did not show any extravasation of contrast on CT scan. Both modalities had a specificity of 100% based on clinical definition. The sensitivities of CT scan and angiogram were 74.5% and 76.6%, respectively. They were not significantly different (p=0.95). The negative predictive values for CT and angiogram were 84.6% and 85.7%. They were not significantly different (p=0.95) either. When CT scan was used alone, 25.5% of bleeding patients were missed.

The sensitivity of CT scan and angiography at detecting ongoing bleeding was around 75% across the torso injury spectrum.