Radionmclide Detection of Myocardial Ischemia and Myocardial Viability: Is the Glass Half Empty or Half Full?*

Noninvasive cardiac imaging, either at rest or during stress, has been for many years an integral part of evahrating and managing patients with suspected or known coronary artery disease. In the present era, when appropriate use of resources is under heavy scrutiny, the use of noninvasive imaging modalities can be expected to increase, further serving as effective gatekeepers for triaging and directing patients toward appropriate management strategies (1). In this value-driven environment, radiiuciide myocardird perfusiin imaging will play an important role for two reasons: the ability to assess the fmmtionai significance of anatomic coronary artery disease and the ability to quantify such variables. In recent years the methodology of interpreting myocardial perfusion images has changed accordiig to the clinical questions posed. Stress testing in patients with corouary artery disc= aims to reproduce a patient’s symptoms and to elicit unequivocal objedve evidence of myocardird is&et&. This is entirely dependent on the ability of a stress modality to achieve metabolic demand-supply imbahmce and thus myocardiai ischemia. There are multiple clinical reasons wby this may not ahvays be successfuk tack of patient motivation, inability to exercim and inability to achieve appropriate work load.