RT Journal Article SR Electronic T1 Myocardial Viability Assessment by PET: 82Rb Defect Washout Does Not Predict the Results of Metabolic–Perfusion Mismatch JF Journal of Nuclear Medicine JO J Nucl Med FD Society of Nuclear Medicine SP 1602 OP 1609 VO 46 IS 10 A1 Stankewicz, Mark A. A1 Mansour, Craig S. A1 Eisner, Robert L. A1 Churchwell, Keith B. A1 Williams, Byron R. A1 Sigman, Steven R. A1 Streeter, James A1 Patterson, Randolph E. YR 2005 UL http://jnm.snmjournals.org/content/46/10/1602.abstract AB PET is a sensitive technique for the identification of viable myocardial tissue in patients with coronary disease. Metabolic assessment with 18F-FDG is considered the gold standard for assessment of viability before surgical revascularization. Prior research has suggested that viability may be assessed with washout of 82Rb between early and late resting images. Our objective was to determine whether assessment of myocardial viability with 82Rb washout is reliable when compared with PET using 18F-FDG. Methods: We performed PET for 194 patients referred for PET 18F-FDG/82Rb to assess viability for clinical indications. We included 151 patients with resting defects >10% of the left ventricle (LV) (n = 159 defects). Patients with smaller resting 82Rb defects (<10% LV) were excluded for the purpose of this study. PET images acquired with 82Rb and 18F-FDG defined viability by the mismatch between metabolism and perfusion (18F-FDG >125% of 82Rb uptake in the 82Rb defect). Evidence of viability with 82Rb was assessed by the presence of (i) severity: 82Rb counts in the defect >50% of 82Rb in the normal zone of the resting PET images; (ii) washout: decrease of 82Rb counts in the defect from early to late resting 82Rb images <17% between the first 90-s image and the final 300-s image; or (iii) combined severity and washout criteria, which required positive criteria for (i) and (ii) to indicate viability. Results: Prevalence of viability by 18F-FDG/82Rb criteria was 50% (n = 79). Severity criteria yielded a sensitivity of 76% and a specificity of 17%, washout criteria yielded a sensitivity of 81% and a specificity of 23%, and both criteria had a sensitivity of 63% and a specificity of 32%. Positive and negative predictive values were poor for all criteria. No correlation existed between 82Rb washout and 18F-FDG–82Rb mismatch (r2 = 0.00). Multiple receiver-operating-characteristic plots showed very poor discrimination despite varying criteria for viability by 82Rb (severity from 50% to 60% of normal zone, washout from 12% to 17%). Conclusion: 82Rb washout from early to late resting images, combined with quantitative severity of the resting 82Rb defect, did not yield results equivalent to PET 18F-FDG–82Rb mismatch and may not accurately assess myocardial viability.