Efficacy of Noncontrast Computed Tomography of the Abdomen and Pelvis for Evaluating Nontraumatic Acute Abdominal Pain in the Emergency Department.

BACKGROUND: Computed tomography (CT) clarity has significantly improved since it became widely available in the early 1980s, making the utility and benefit of contrast material for image quality of the abdomen and pelvis uncertain, and so far, minimally studied.

OBJECTIVES: This study sought to assess the efficacy of a noncontrast CT scan of the abdomen and pelvis by evaluating patients presenting to the emergency department (ED) with acute nontraumatic abdominal pain by following them for 7 days and observing for signs and symptoms of clinically significant acute emergent pathology.

METHODS: We enrolled, and for 7 days followed, a prospective observational convenience sample of patients who received a noncontrast CT scan of the abdomen and pelvis in the ED for acute nontraumatic abdominal pain. The primary outcome, and defined as a failure, was abdominal surgery or death as the result of an intraabdominal process not found on the original noncontrast CT scan, or a subsequent contrasted CT scan with a finding that could explain the original complaint of abdominal pain that was also not seen on the initial noncontrast CT, during the 7-day observation.

RESULTS: Seventy-two patients were enrolled in the study. The incidence of failure was 0% (0/72), 46% of patients (33/72) had a negative CT scan, 54% (39/72) had a positive CT scan, 57% (41/72) were admitted, 43% (31/72) discharged, 11% (8/72) had abdominal surgery, and a repeat contrasted CT scan was done on 4% (3/72).

CONCLUSIONS: With certain inclusion and exclusion criteria, noncontrast CT of the abdomen and pelvis is likely a reliable diagnostic modality for the evaluation of acute nontraumatic abdominal pain in the ED.