Abstract 898: Can Angiography With Synchrotron Radiation And A High Sensitivity Receiver Make Lower Doses Of Contrast Medium Possible?

Abstract

Introduction: Contrast-induced nephropathy (CIN) is a serious complication associated with angiography and interventional angioplasty. Increased doses of contrast medium are a major risk factor of CIN. It was assumed that the occurrence of CIN could be decreased by reducing the dose of contrast medium. We investigated the effects of a new high resolution and high contrast angiographic system on the application of diluted contrast medium. Method: Contrast medium was diluted to 32% (a stock solution), 24%, 16%, 12%, 8%, and 4%. Angiography of the hindlimb in rats using a synchrotron radiation and HARP receiver were performed with each concentration of contrast medium (n=5, respectively). The characteristics of synchrotron radiation are high photon density (10,000 times that of conventional X-rays) and straightness of the beam, which lead to high resolution (26 micrometer/pixel). A HARP Receiver is a high sensitivity image capturing system, which was developed by NHK Sci & Tech Res Lab (Tokyo, Japan). It is about 100 times more sensitive than conventional CCD cameras. Each angiographic image was evaluated by 256 grayscale intensity using graphic software NIH Image. The availability of each image as angiography was determined by the judgment of 5 independent cardiologists respectively. Results: In 256 grayscale, the minimum visible contrast distance for identifying vessels was 10. The value of each image in different concentrations of contrast medium was as follows: 4%: 14+/−12, 8%: 22+/−10, 12%: 23+/−18, 16%: 25+/−11, 24%: 28+/−11, 32%: 40+/−10. Vessels are identified from 4% to 32%. Availability as angiography was confirmed from 8% to 32% by common assent. Conclusions: The angiographic system using synchrotron radiation and a HARP receiver was able to take angiographic images with as low as 8% contrast medium. This may lead to beneficial effects in patients who cannot undergo sufficient angiography and interventional angioplasty due to renal dysfunction.