Measurement of myocardial blood flow with PET using 1-C-11-acetate

C-11-acetate has been used extensively for the noninvasive assessment of my ocardial oxygen consumption and viability with PET. The use of early uptake of acetate by the heart to measure myocardial perfusion has been proposed. This study evaluated the application of C-11-acetate for absolute measurem ent of myocardial blood flow using a simple compartmental model that does n ot require blood sampling. Methods: Eight healthy volunteers and 13 subject s with concentric left ventricular hypertrophy were studied under resting c onditions with both C-11-acetate and O-15-water. Myocardial blood flow with C-11-acetate was obtained by fitting the first 3 min of the brood and tiss ue tracer activity curves to a two-compartment model. Flows obtained were c ompared with a validated approach using O-15-water. Results: In healthy vol unteers, regional myocardial perfusion at rest estimated with C-11-acetate was comparable with values obtained with O-15-water (1.06 +/- 0.25 and 0.96 +/- 0.12 mL/g/min, respectively). Perfusion in subjects with left ventricu lar hypertrophy was also comparable if the recovery coefficient (F-MM) used was corrected for ventricular mass. If a fixed FMM was used, flow was grea tly overestimated. FMM could be estimated from left ventricular mass (F-MM = 0.46 + 0.002 X mass, r = 0.86, P < 0.0001). Conclusion: The results of th is study suggest that C-11-acetate can be applied to quantitatively estimat e myocardial perfusion under resting conditions using a two-compartment mod el without the need for blood sampling, provided that an appropriate FMM is chosen. This approach should increase the usefulness of this tracer and ob viate administration of a separate tracer to independently measure perfusio n.