Comparison of Computed Tomographic Images of Hepatic VX2 Carcinoma Experimentally Induced in Different Methods: Correlated with Histopathologic Features

To compare characteristics of computed tomographic images of hepatic tumors induced by intra-mesenteric venous and intraparenchymal injection of VX2 carcinoma in rabbits. Thirty two New Zealand White rabbit were divided into two groups; group I for metastatic tumor model (n=8) by injection of 0.1 ml tumor homogenate into mesenteric vein, and group II for solitary tumor model (n=24) by direct intraparenchymal injection of 1 mm tumor cubes. Dual-phase computed tomography (CT) was performed on day 10, 17, and 24 post-tumor implantation. On day of each CT follow-up, 2 or 3 rabbits in both groups were sacrificed for histopathologic examinations which were correlated with CT findings. Tumor creation rates were 100% in Group I, and 87.5% in Group II. In group I, arterial phase showed multiple tiny lesions on day 10, and hypodense lesions with peripheral rim enhancement and central hyperdensity (target appearance) on day 17 and 24 post-implantation. Target appearance of group I was more distinctive on portal phase, and was correlated with the viable tumor tissue core surrounded by cystic spaces in histopathologic findings. In group II, arterial phase revealed illdefined hypodense lesions with peripheral rim enhancement during entire follow-up periods, and rim enhancement was disappeared on portal phase. Viable tumor cells in group II were mainly found in periphery of tumor with apparent central necrosis, and these observations were well correlated with CT findings. This study showed specific characteristics corresponding to each implantation method, and will provide beneficial information for experimental studies using hepatic VX2 carcinoma.