OBJECTIVETo investigate the potential utility of microangiography with synchrotron radiation to detect murine hepatocellular carcinoma (HCC) angiogenesis using an ex vivo model system.

METHODSAn HCC xenograft model was established by implanting HCCLM3 cells into male mice livers (n = 6). Twenty-eight days later, three of the mice were randomly selected for barium sulfate infusion into the liver and tumor via the inferior vena cava followed by ligation of the arteries, veins and common bile duct; the remaining three mice were left untreated and served as controls. All mice were sacrificed to collect livers for analysis using the BL13W beamline X-ray imager (Shanghai Synchrotron Radiation Facility, China). In addition, the tumor vasculature was evaluated by immunostaining of formalin-fixed tissues for CD31, CD34, and F8.

RESULTSHigh resolution images of tumor angiogenesis were acquired and image analysis indicated that the normal blood vessels had been displaced by the fast growing tumors. Abundant and tortuous tumor angiogenesis in the tumor periphery area and sparse angiogenesis inside the tumor were also visualized clearly. These features were similar to the immunohistological results. The smallest tumor vessels visualized were approximately 20 mum in diameter.

CONCLUSIONMicroangiography with synchrotron radiation using barium sulfate as contrast agent is a viable imaging strategy for tumor angiogenesis.