RESUMO
BACKGROUND: Myocardial flow reserve (MFR) assessment with cardiac positron emission computed tomography (PET/CT) is well established, and quantification relies on commercial software packages. However, for reliable use, repeatability and reproducibility are important. The aim of this study was therefore to investigate and compare between scans and software packages the repeatability and reproducibility of 82Rb-PET/CT estimated MFR. METHODS AND RESULTS: Forty healthy volunteers completed two 82Rb-PET/CT rest and adenosine stress scans. syngo.MBF (Siemens), quantitative-gated SPECT (QGS) (Cedars-Sinai), and Corridor4DM (4DM) were used for analyses. Motion correction was available for 4DM. Fifty percent were men and age was 24 ± 4 years (mean ± SD). Repeatability of MFR varied between scans. syngo.MBF: mean difference (95% CI) 0.26 (- 0.03 to 0.54), P = 0.07, limits of agreement (LoA): - 1.43 to 1.95; QGS: 0.19 (- 0.08 to 0.46), P = 0.15, LoA: - 1.38 to 1.76; 4DM: 0.08 (- 0.17 to 0.34), P = 0.50, LoA: - 1.37 to 1.53; and 4DM motion corrected: 0.17 (- 0.17 to 0.51), P = 0.32, LoA: - 1.89 to 2.22. MFR was higher using 4DM +/- motion correction compared with syngo.MBF and QGS (all P < 0.0001). Concordance between syngo.MBF and QGS was high (P = 0.83). CONCLUSIONS: Reproducibility of MFR varied for the different software. The highest concordance between MFRs was found between syngo.MBF and QGS.