Review Myocardial Viability and Perfusion Scintigraphy

Accurate assessment of myocardial viability in patients with coronary artery disease and left ventricular dysfunction is of clinical importance because a substantial subset of the patients will show striking improvement in ventricular function after successful revascularization. There are a number of invasive and noninvasive techniques for the assessment of myocardial viability. Among these, two modalities, myocardial perfusion imaging (MPI) and two-dimensional (2-D) echocardiography, have met with wide acceptance. Although positron emission tomography (PET) is a very effective tool in detecting myocardial viability, its high costs and limited availability reduce its clinical use significantly. Thallium-201 MPI, which is cheaper and widely available, have had great acceptance, especially after recent modifications on imaging and interpretation methodologies, in viability assessment. The most commonly used technetium- labelled MPI radiopharmaceutical, Tc- 99m methoxyisobutyl isonitrile (MIBI), seems to be a promising viability agent. In this review, the role of MPI with thallium-201 or MIBI in the assessment of myocardial viability was discussed.