IMAGING IN THE CATHETERIZATION LABORATORY

In the past decade, there has been dramatic growth in the number of catheterization procedures, with over 1.3 million performed in 1990. In the past year, several large studies have documented the clinical safety of nonionic contrast agents for performing angiography. These agents are much more expensive than conventional high-osmolarity ionic agents, and thus their widespread use continues to be controversial. Digital recording of angiographic images is now routinely available. Although useful for rapid review of images, digital processing for analysis of stenoses, ventriculography, and coronary flow has not been widely accepted. Several recent studies compared quantitative techniques with subjective analysis and found little advantage. Similarly, although flow can be determined, no practical clinical method has emerged. Over the past year, intracoronary ultrasound and angioscopy have made important advances. These adjunctive imaging techniques allow careful investigation of atheroma morphology and lumen geometry not available with routine angiography. Use of these imaging modalities will contribute greatly to the study of vascular disease in the catheterization laboratory.