A Comparison of Thallium-201 Spect and F-18 Deoxyglucose Positron Emission Tomography in Assessing Myocardial Viability

Assessment of myocardial viability 1>rior to revascularization procedures is an important clinical consideration for improved functional recovery of regional left ventricular dysfunction. In chronic coronary artery disease, impaired left ventricular function , at least in part, is due to ischemic or hibernating myocardium rather than just myocardial fibrosis. Functional recovery of the left ventricular dysfunction is dependent on a timely revascularization of the ischemic and/or hibernating myocardium. The assessment of myocardial viability by regional ventricular function measurements by various other modalities is imprecise. Myocardial viability in chronic ischemia, hibernating, or stunned myocardium can be assessed by Thallium-201 single photon emission tomography (SPECT) in a ma,jority of the cases. The positron emission tomography (PET) F18 Deoxyglucose (FDG) imaging is considered to be an accurate marker for differentiating hibernating, but viable, myocardium from infarction in a subset of patients not resolved with thallium-201 imaging. In our experience, overall sensitivity for Thallium-201 SPECT imaging for viability was 60% with a negative predictive value of 69.9% and accuracy greater than 79%.