Small hepatic hemangiomas: Enhancement patterns of abdominal biphasic spiral computed tomography

The purpose of this study was to evaluate the prevalence of particular contrast enhancement patterns in small hemangiomas during the hepatic arterial phase (HAP) and portal venous phase (PVP) during spiral computed tomograpy. Small hemangiomas exhibit three particular enhancement patterns including low attenuation with tiny dot-like enhancement during HAP and PVP (type I), peripheral dot-like or globular enhancement during HAP and progressive central filling-in during PVP (type II), and diffusely homogenous enhancement during HAP and PVP (type III). 80 patients with 131 small hemangiomas were retrospectively reviewed in this study. Tumor diameters were <10mm (n=38), 11-20mm (n=71) & 21-30mm (n=22). Findings were (1) the most common enhancement pattern among the smallest hemangiomas was type I (n=33, 86.8%), (2) the most common enhancement pattern among the largest hemangiomas was type II (n=16, 72.8%), (3) and of the medium sized hemangiomas, 26 were type I, 26 were type II and 19 were type III. Most (123/131) exhibited high attenuation relative to surrounding liver parenchyma during HAP and PVP. In summary, the various enhancement patterns characteristic of small hemangiomas faciliatate interpretation of small hepatic tumors, thereby avoiding unnecessary angiography, MRI or hepatic biopsies.