Simple quantification of myocardial perfusion by pixel-by-pixel graphical analysis using carbon-11 acetate: comparison of the K-complexes of carbon-11 acetate and nitrogen-13 ammonia.

AIM

The aim of this study was to evaluate the measurement of myocardial blood flow (MBF) and develop a method for producing parametric perfusion images with carbon-11 (11C-)acetate by a simple graphical analysis method.

PATIENTS AND METHODS

A total of 14 patients underwent dynamic PET acquisition using nitrogen-13 (13N-)ammonia and 11C-acetate at rest to measure the influx rate constants of the tracers (Kamm and Kace, respectively). Using the early phase of dynamic data (30-150 s), Kamm and Kace were calculated pixel-by-pixel by the graphical analysis method.

RESULTS

The patients were divided into two groups (groups A and B). The regression equation relating Kamm and Kace was calculated with group A. Kamm and Kace were linearly correlated (r2=0.718, P<0.001). The regression equation was Kace=0.736.Kamm+0.086. By using this equation, K*ace was converted into MBFace. To validate this equation, MBFace and MBF measured with 13N-ammonia (MBFamm) in group B were compared. MBFamm and MBFace exhibited a good linear correlation. The regression line was very close to the line of identity (MBFace=1.01.MBFamm +0.01, r2=0.838, P<0.001). The image quality of MBFace was generally better than that of MBFamm.

CONCLUSION

Using the graphical analysis method, it is convenient and reliable to measure myocardial perfusion and develop parametric images with 11C-acetate under resting conditions.