Iodine-Filter Imaging System for Subtraction Angiography and Its Improvement by Fluorescent-Screen Harpicon Detector

Our initial studies in animal experiments using K-edge energy subtraction transvenous coronary angiography at the Photon Factory were undertaken using an iodine filter for energy switching combined with an X-ray image intensifier. In vivo subtracted images of coronary arteries in dogs were obtained in the form of motion pictures. However, the image quality was not good for medical examinations because the contrast material was highly diluted. A new image detector with a fluorescent-screen lens-coupling approach has been developed to take high quality images. By using the new detector in place of the X-ray image intensifier, image quality has markedly increased in coronary angiography.