Comparative performance of gated perfusion SPECT wall thickening, delayed thallium uptake, and F-18 fluorodeoxyglucose SPECT in detecting myocardial viability

To evaluate the comparative abilities of gated single photon emission computed tomography (SPECT) wall thickening, delayed thallium-201 (T1-201) SPECT, and F-18 fluorodeoxyglucose (FDG) SPECT in detecting myocardial viability, 23 patients with previous myocardial infarction and clinically suspected viability were studied. Each patient had at least 1 extensive fixed perfusion defect on rest/stress technetium-99m sestamibi SPECT A total of 41 major vascular territories had fixed defects. The mean (+/-1 SD) left ventricular ejection fraction determined from gated perfusion SPECT was 26% +/- 11%, Wall thickening was assessed in a semiquantitative fashion by the regional increase in myocardial intensity during systole and was considered normal when a greater than or equal to 20% increase was observed, T1-201 SPECT was acquired 4 hours after resting tracer injection was administered. Viability was considered present when regional defect T1-201 count density, determined by quantitative analysis, was >20% greater than that on the resting sestamibi scan. FDG SPECT was performed independently with a 10 mCi F-18 FDG dose after oral glucose loading was performed. A camera equipped with ultrahigh energy collimation was used. Quantitative criteria for viability were the same as for T1-201, In the 23 patients viability within the fixed sestamibi defects was manifest by preserved wall thickening in 8 patients, delayed T1-201 uptake in 10 patients, and FDG uptake in 18 patients. Nine major vascular territories with fixed defects were judged viable by wall thickening, 11 by T1-201 SPECT, and 24 by FDG SPECT (P = .0009), We conclude that FDG SPECT demonstrates more evidence of myocardial viability than either gated sestamibi wall thickening or delayed T1-201 SPECT.