PURPOSE: To evaluate contrast enhancement patterns of hemangioma according to size, as seen during thearterial and portal venous phase of spiral CT. MATERIAL AND METHODS: During a recent six month-period, 52patients with hemangiomas underwent two-phase spiral CT examination with 10mm collimation at 10mm/sec table speed,and with 100mL of contrast material(37g iodine) injected at a rate of 2.5 mL/sec. CT images of the hepaticarterial and portal venous phase were obtained with 30-second and 65-second delay, respectively. In 52 patients,82 hemangiomas were seen. The diameter of the tumors were as follows ; < or =10 mm(n=31), 11-20 mm(n=19), and> or =21mm(n=32). The enhancement patterns of tumors compared with attenuation of surrounding liver parenchyma weredivided into four types : peripheral high, uniform high, iso, and low. RESULTS: Overall, the most commonenhancement pattern was peripheral high(44/82, 53.7%), during the arterial and portal venous phase. The second andthird most common patterns were uniform high(11/82, 13.4%) and peripheral high-uniform high(9/82, 11.0%), alsoduring the arterial and portal venous phase. Sixty-one(74.4%) showed peripheral high attenuation andeleven(13.4%), uniform high attenuation, during the arterial and/or portal venous phase. In tumors smaller than20mm, low-low attenuation was seen in eight(9.8%), and iso-low attenuation in two(2.4%), during the arterial andportal venous phase, respectively. CONCLUSION: On two-phase spiral CT, the most common enhancement pattern ofhemangioma was peripheral high, seen during the arterial and portal venous phase. However, a small hemangioma lessthan 2 cm may show atypical patterns, including low and iso attenuation.