Background blood pool and cardiac 18F-fluoride activity. The mean standardized uptake value (SUVMEAN; g/mL) in each region was compared by 3 observers across 2 scans. A, Box-plot of the median and the interquartile range of coefficients of variation for each region (black line, mean). There was no difference in the coefficients of variation of 18F-fluoride SUVMEAN within intracardiac chambers (red), but there were increased coefficients of variation using systemic venous blood pool measurement (P<0.001) and interventricular septal myocardium (P<0.001) compared with measurement of SUVMEAN
18F-fluoride activity in the left atrium. B, Box-plot of the median and the interquartile range of mean standardized uptake values for brachiocephalic, superior vena cava, right atrium, and interventricular septum (black line, mean). Note the low myocardial and background coronary arterial 18F-fluoride uptake compared with blood pool in the right atrium. BCV indicates brachiocephalic vein; IVS, interventricular septum; LA, left atrium; LV, left ventricle; NS, not-significant; RA, right atrium; RV, right ventricle; and SVC, superior vena cava. *P≤0.05; †P≤0.01; ‡P≤0.001; and §P≤0.0001.