Rat Coronary Microangiography System for Preclinical Imaging using Synchrotron Radiation

A rat microangiography system using a synchrotron radiation source was developed at SPring-8 to enable in vivo visualization of coronary arteries for vascular-based functional imaging. Angiographic images of beating hearts were obtained with spatial resolution in the micrometer range and temporal resolution in the millisecond range using a new rotating-disk X-ray shutter and an X-ray direct-conversion type detector. Quantitative evaluations of the imaging system were extracted from measurements of the smallest-detectable vessel size and detection of the vessel function Small blood vessels of around 50 mu m diameter were visualized clearly at heart rates of 350-400 per minute. Apparent vasodilation compared to baseline vessel diameters was observed by infusion of vasoactive agents. The microangiography system enables direct investigation of the mechanisms of vascular dysfunction.