Acute Biliary Disease: Initial CT and Follow-up US versus Initial US and Follow-up CT

PURPOSE: To evaluate the utility of ultrasonography (US) versus that of computed tomography (CT) for assessment of acute biliary disease. MATERIALS AND METHODS: Radiologic reports and clinical charts were reviewed in all patients who underwent US and CT within 48 hours of each other for evaluation of acute right upper quadrant pain. Radiologic findings and clinical outcome were correlated. RESULTS: CT was the initial imaging study in 57 patients, and CT findings resulted in underdiagnosis or misdiagnosis of acute biliary disease in eight of 11 patients. Follow-up US results were suggestive of the correct diagnosis and provided additional clinical information in seven of these eight patients. US findings resulted in altered clinical treatment in six of 11 patients with acute biliary disease. US was the initial study in 66 patients, and US findings were suggestive of biliary disease or the correct diagnosis in seven of seven patients with acute biliary disease. Follow-up CT did not result in changes in clinical treatment in any patient with acute biliary disease. CONCLUSION: Initial US is better than initial CT in patients suspected of having acute biliary disease. Follow-up CT provides no additional information regarding the biliary system, and its use should be limited to those patients with a wider differential diagnosis or with confusing clinical symptoms and signs.