Test-retest repeatability of myocardial blood flow and infarct size using ¹¹C-acetate micro-PET imaging in mice.

Purpose: Global and regional responses of absolute myocardial blood flow index (iMBF) are used as surrogate markers to assess response to therapies in coronary artery disease. In this study, we assessed the test-retest repeatability of iMBF imaging, and the accuracy of infarct sizing in mice using (11)C-acetate PET.

Methods: (11)C-Acetate cardiac PET images were acquired in healthy controls, endothelial nitric oxide synthase (eNOS) knockout transgenic mice, and mice after myocardial infarction (MI) to estimate global and regional iMBF, and myocardial infarct size compared to (18)F-FDG PET and ex-vivo histology results.

Results: Global test-retest iMBF values had good coefficients of repeatability (CR) in healthy mice, eNOS knockout mice and normally perfused regions in MI mice (CR = 1.6, 2.0 and 1.5 mL/min/g, respectively). Infarct size measured on (11)C-acetate iMBF images was also repeatable (CR = 17 %) and showed a good correlation with the infarct sizes found on (18)F-FDG PET and histopathology (r (2) > 0.77; p < 0.05).

Conclusion: (11)C-Acetate micro-PET assessment of iMBF and infarct size is repeatable and suitable for serial investigation of coronary artery disease progression and therapy.