PREDICTION OF MYOCARDIAL VIABILITY TL-201 VERSUS SESTAMIBI VERSUS TEBOROXIME COMPARED WITH FDG UPTAKE

Several radionuclide imaging agents have been used for assessing the p resence of myocardial viability. These include Tl-201 chloride, Tc-99m sestamibi, and Tc-99m teboroxime. Currently, the most reliable indica tor is F-18 FDG, which accumulates in severely hypoperfused myocardium , indicating preserved metabolic activity. The presence of chronically ischemic myocardium that has preserved metabolic activity is referred to as ''hibernating'' myocardium. In this series, the ability of Tl-2 01, sestamibi, and teboroxime to establish the existence of viable myo cardium was compared with that of F-18 FDG. Seventy-seven patients wit h ischemic cardiomyopathy were referred for determination of myocardia l viability. FDG images were compared with representative resting bloo d-flow images obtained from either: 1) 24 hour Tl-201 reinjection-redi stribution images, 2) resting sestamibi blood-flow images, or 3) early images from resting teboroxime washout analysis. Tl-201 was found to underestimate myocardial viability in 41% of patients, Tc-99m sestamib i underestimated viability in 38% of patients, and Tc-99m teboroxime u nderestimated viability in 26% of patients. There was no significant d ifference in the prediction of viable myocardium among the three radio pharmaceuticals, as all three underestimated myocardial viability.