Perfusion imaging with thallium-201 to assess stenosis significance

Abstract

Since the introduction of coronary angiography in the 1960’s, this invasive technique has become the foremost important diagnostic method in the assessment of patients with coronary artery disease. Despite a relatively high interobserver and intraobserver variability, coronary angiography is still considered the gold standard for the assessment of physiological effects of coronary stenosis. In general practice the assumption exists that there is a close correlation between the angiographic diameter of a coronary artery stenosis and the perfusion of the myocardium. This assumption implies that the decision as to whether to revascularize in order to alleviate ischemia is predominantly based on the percent diameter stenosis found during coronary angiography. However, several studies comparing angiographic findings with postmortem findings have shown that coronary angiography underestimates the severity of the lesion [1]. Overestimation of diameter stenosis may also occur due to for instance spasm of the coronary artery or insufficient filling with contrast medium.