Detection of microvasculature in rat hind limb using synchrotron radiation.

Background New X-ray microangiography and third-generation synchrotron radiation-based micro-computed tomography have opened new perspectives for microvascular imaging of extremity. Here we aimed to visualize deep-level microvascular structure in rat hind limb by microangiographic technique, and compare images with those by conventional method. Materials and Methods A total of 10 Sprague Dawley rats were used for in vivo and ex vivo study (five rats / group). Microangiography in vivo and ex vivo was performed and images were compared with those by conventional method. Synchrotron radiation-based micro-computed tomography (SRμCT) was also performed to reveal three-dimensional (3D) morphology of the blood vessel in rat hind limb. Results By microangiographic technique, blood vessels in the rat limb could be clearly depicted with the minimum visualized blood vessel about 9 μm in diameter, and higher angiographic scores were achieved than those by conventional X-ray. In addition, the vascular network could be defined and analyzed at the micrometer scale from the 3D renderings of limb vessel as shown by SRμCT. Conclusions Synchrotron radiation-based microangiography and SRμCT thus provided a practical and effective means to observe the microvasculature of limbs, which might be useful in assessment of angiogenesis in lower limbs.