Overview of clinical intravenous coronary angiography both in Japan and at ESRF

The clinical program of intravenous coronary angiography (IVCAG) using synchrotron radiation is moving on at the ESRF and at the KEK. Since the X-ray optics and types of detectors are different depending on the needs of technology, the ESRF adopts dual-energy digital subtraction system and the KEK does single-energy two-dimensional dynamic imaging system. A contrast agent is injected intravenously and the image sequence is started. The former technique enhances the image contrast of the coronary arteries in spite of intravenous injection of a contrast agent; whereas, the latter technique produces excellent temporal resolution for imaging of moving objects such as the coronary arteries and the left ventricle. So, the obtained image, the radiation dose, the examination time, and other details are different between the two facilities. Both systems sufficiently visualize the right coronary artery disease, even after coronary angioplasty or coronary artery bypass grafting. Also, the two-dimensional dynamic IVCAG permits the visualization of the left coronary arteries. The coronary morphology obtained by the IVCAG, was almost completely coincident with the results of selective CAG. Accordingly, the IVCAG is clinically validated and useful for the screening and the follow-up of coronary artery disease. However, as some portions of the left circumflex coronary artery are overlapped by the left ventricle, more contrivance is required and its imaging should be improved in future.