PET/CT quantitation of the effect of patient-related factors on cardiac ¹⁸F-FDG uptake

The effect of multiple patient-related factors on the degree of cardiac ¹⁸F-FDG uptake was assessed. Methods: Five hundred four consecutive patients undergoing routine ¹⁸F-FDG PET/CT studies completed a clinical questionnaire. ¹⁸F-FDG uptake was measured as the mean standardized uptake value within the heart delineated on the CT component of the study. Univariate and multivariate analyses assessed the influence of 51 clinical factors on cardiac ¹⁸F-FDG uptake. Results: On both multivariate and univariate analyses, cardiac ¹⁸F-FDG uptake was significantly lower in diabetics and in patients receiving bezafibrate or levothyroxine. Cardiac ¹⁸F-FDG uptake was significantly higher in men, patients younger than 30 y old, fasting duration of <5 h, patients with heart failure, and those receiving benzodiazepines. Conclusion: Cardiac ¹⁸F-FDG uptake was lower in patients receiving bezafibrate and levothyroxine and higher in patients receiving benzodiazepines. If further confirmed by prospectively designed studies, manipulation of these drugs may represent tools for optimized PET/CT imaging.