Potential of Intravascular Ultrasound Imaging in the Evaluation of Morphology, Elastic Properties and Vasomotor Function of Coronary Arteries

Abstract

With rapidly evolving advances in the use of catheter-based interventional procedures for the management of coronary arterial disease, it has become important to delineate the coronary anatomy with much greater detail than has been possible to date by selective angiography. Besides many well known limitations of coronary angiography, an important problem has been the inability to visualize the arterial wall and the atheroma directly [1,2]. The morphology of a coronary atherosclerotic lesion is a major determinant of the clinical expression of coronary artery disease. In addition, the lesion morphology is a determinant of the primary success or failure of interventional procedures such as balloon angioplasty, mechanical atherectomy or laser ablation of atheromatous lesions. The composition and architecture of the atheroma before and immediately after an intervention also dictate the likelihood of complications such as acute total occlusion of the coronary artery treated. While the development of restenosis after an intervention is reduced by multiple factors, the size of the vessel following catheter-based treatments and the morphologic disruptions caused by those procedures are also important factors in the occurrence of restenosis. Elastic properties of the diseased arterial wall and vasoconstriction also playa role in the evolution of restenosis and its clinical expression. The increasing realization that coronary arterial morphology carries important therapeutic and prognostic implication has fueled the attempts to develop methods that could display the artery in a morphologic and morphometric fashion. Intravascular ultrasound is ideally suited to provide such information [3–10].