Intravascular ultrasound

Introduction

At early stages of the formation of the coronary atheroma, the remodeling of the vessel wall usually prevent plaque from encroaching the lumen, thereby masking the presence of atheroma on angiography. In contrast, greyscale intravascular ultrasound (IVUS) can fully assess the extension of the disease axially and longitudinally. This intravascular imaging technique has played a vital role in advancing our understanding of the pathophysiology of coronary artery disease, and in the development of novel cardiovascular drugs and device therapies. This intravascular imaging technology and its clinical and research applications are discussed in detail in the different sections of this chapter.

Rationale for intravascular imaging

Coronary angiography depicts arteries as a planar silhouette of the contrast-filled lumen. Importantly, angiography does not provide visualisation of the vessel wall and is not suitable for assessment of atherosclerosis. Angiographic disease assessment is based on the comparison of the stenotic segment with the adjacent, “normal appearing” coronary, which is often an incorrect assumption due to the diffuse nature of atherosclerosis as shown by pathological and IVUS studies (Figure 1) 1, 2