The future of intravascular ultrasound in the detection and management of coronary artery disease.

Stenosis severity may be underestimated by angiography because the reference segment used to quantify the lesion is itself narrowed by atherosclerotic plaque. Even assessment of the absolute change in lumen diameter on arteriography cannot consistently reflect changes in plaque burden because of the variable presence of vascular remodelling. Intravascular ultrasound (IVUS) differs radically from angiography by providing cross-sectional images of both the coronary arterial lumen and the wall with high resolution. The diffuse nature of coronary artery disease is readily seen and the majority of angiographically normal reference segments are involved in the atherosclerotic process on IVUS imaging. The precise assessment of plaque burden by IVUS makes it the ideal tool for a clinical trial of progression and regression of atherosclerosis.