[Hepatocellular carcinoma and angiogenesis imaging using synchrotron radiation]

OBJECTIVE

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

METHODS

An 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.

RESULTS

High 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.

CONCLUSION

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

[Detection of microvasculature in rat hind limb using synchrotron radiation]

OBJECTIVE

To detect deep-level microvascular structure in rat hind limb by synchrotron radiation and microangiographic technique.

METHODS

Microangiography in vivo and ex vivo was performed by synchrotron radiation based absorption imaging and phase contrast imaging, with omnipaque and barium sulfate solution as contrast media, respectively, and synchrotron radiation-based micro-computed tomography (SRmCT) was also performed to reveal three-dimensional morphology of the blood vessel in rat hind limb.

RESULTS

Using microangiographic technique in vivo and in vitro (with barium sulfate), blood vessels in the rat limb muscle could be visualized with high resolution, and the fourth branches of iliac artery in rat hind limb could be detected with the minimum visualized blood vessels about 40 µm and 9 µm in diameter, respectively. In addition, the vascular network could be defined and analyzed at the micrometer scale from the 3D renderings of limb vessel as shown by SRmCT.

CONCLUSION

Synchrotron radiation-based microangiography and SRmCT thus provided a practical and effective means to observe the microvasculature of rat hindlimb, which might be useful in assessment of angiogenesis in lower limbs.

[Exploring the three-dimensional structure of dermal tissues of normal skin and scar in rat with synchrotron radiation X-ray imaging technology]

OBJECTIVE

To compare the morphological difference between dermal tissue of normal skin and that of scar in rat, and to explore its structural pattern.

METHODS

The full-thickness skin and the scar tissue formed 3 weeks after wound healing from SD rats were harvested as samples, which were prepared appropriately afterwards. Samples were scanned and imaged with synchrotron radiation technology, micro-CT, and phase-contrast imaging technology. The images were rebuilt with three-dimensional software.

RESULTS

The micro-CT was materialized by using X-ray generated by synchrotron radiation light source. The structure of dermal tissues was clearly shown with the assistance of phase-contrast imaging technology in the process. It was demonstrated that the dermal tissues of normal skin of rat were mainly composed of collagenous fibers, which twined together to form an olive-like structure. These olive-like structures as basic units were arranged randomly in a certain way. The collagenous fibers in dermal tissue of the scar were arranged in a parallel manner, while some fibers were crooked and arranged in a disorderly manner.

CONCLUSIONS

Dermal tissue of normal skin in rat has stable three-dimensional structure, and its basic structure and manner of composition are obviously different from those of scar dermal tissue.