Abstract: Objective Using Micro-computed tomography (Micro-CT) imaging to quantify the three-dimensional (3D) structural characteristics of vascular in orthotopic transplanted tumor model of liver cancer in nude mice.Methods Twenty male Babl/c nude mice were randomly divided into the hepatocellular carcinoma (HCC) group (n=10) and the normal control group (n=10). Human liver cancer cell line MHCC97H was applied for constructing orthotopic transplantation tumor models in the HCC group. The same volume of saline was injected internally in the normal control group. After 21 days of modeling, the vascular casting and Micro-CT scan of the target vessel were used to reconstruct the blood vessel image. The characteristics of vascular density and morphological were analyzed quantitatively in liver cancer and normal liver tissues.Results The blood vessels of normal liver distributed regularly and ran orderly, while the vessels of HCC did not. Quantitative analysis showed that compared with normal liver, the vessel ratio [(5.57 ± 1.16) % vs (14.29 ± 2.89) %, P<0.001], the vascular branch density (3.86 ± 1.15 vs 7.25 ± 3.30, P=0.007) and the average radius (0.17 ± 0.03 mm vs 0.22 ± 0.04 mm, P=0.004) in HCC were significantly reduced; the average distance factor (1.20 ± 0.01 vs 1.16 ± 0.00, P<0.001) and the average sum of angles metric (4.56 ± 0.10 rad/mm vs 4.33 ± 0.20 rad/mm, P=0.004) were increased; the average vascular branch length was slightly shorter with no statistical significance (P>0.05).Conclusion This study showed the 3D structure of blood vessels in hepatic orthotopic transplanted tumor based on Micro-CT imaging, and indicated the potential ways for reducing tumor blood supply by quantitatively analyzing the characteristics of blood vessels in HCC and healthy liver tissues.

Key words: Liver cancer, Orthotopic transplantation tumor, Micro-computed tomography, Quantitative analysis