Cardiac applications of digital radiography.

Digital radiography is a rapidly developing new approach to cardiovascular imaging that converts radiographic and fluoroscopic video images into digital format for subsequent image enhancement, analysis, and storage. Cardiac applications proven clinically useful to date include intravenous and reduced-contrast load direct left ventriculography, aortic root bypass graft visualization, and selective coronary arteriography, which allows quantification of arterial stenoses and flow reserve. Myocardial functional reserve can be assessed using exercise or atrial pacing. Advantages over standard radiography include reduced radiation and contrast medium burden, visualization of very low contrast medium concentrations, and an image format that can be directly analyzed by quantitative techniques. As these cardiac applications are developed and improved archiving is implemented, it is likely that the digital approach will replace standard cardiac angiography.