Forty-seven patients with 58 hepatic hemangiomas were studied prospectively with a dynamic bolus CT protocol (single-level or incremental scans) that included precontrast scans, rapid-sequence scanning during the IV bolus injection of 150 ml of 60% contrast agent, and delayed scans taken as long as 60 min after contrast. Three CT criteria are believed to be necessary to make a specific diagnosis of hemangioma: lesion with diminished attenuation on precontrast scan; peripheral contrast enhancement during the dynamic bolus phase of scanning; and complete isodense fill-in on delayed scans obtained up to 60 min after contrast. These CT criteria were seen in only 32 (55%) of 58 hemangiomas, making CT a relatively poor imaging technique for diagnosis.