COVID-19 vaccines, hesitancy and mental health

Abstract

In this study, we compared the accuracy of the rate of myocardial glucose use (rMGU) measured using PET and 1-¹¹C-glucose with the rate measured using PET and the more conventional tracer ¹⁸F-FDG. <b>Methods:</b> PET measurements of myocardial tracer uptake (K, in mL/g/min) and rMGU (in nmol/g/min) were obtained with 1-¹¹C-glucose and ¹⁸F-FDG in 21 dogs using kinetic modeling and the Patlak graphical method, respectively. Eighteen dogs were studied during hyperinsulinemic-euglycemic clamp performed either at rest or combined with phenylephrine, dobutamine, intralipid infusion, or intralipid infusion and dobutamine. Three dogs were studied during intralipid infusion alone under resting conditions. Arterial-coronary sinus sampling was performed to measure the K of both tracers (<i>n</i> = 14) and rMGU by the Fick method (<i>n</i> = 21). <b>Results:</b> PET-derived values for K from either 1-¹¹C-glucose or ¹⁸F-FDG correlated closely with directly measured tracer K values (glucose: y = 0.98x + 0.01, <i>r</i> = 0.79, <i>P</i> &lt; 0.001; ¹⁸F-FDG: y = 0.74x + 0.03, <i>r</i> = 0.77, <i>P</i> &lt; 0.001). In contrast, correlation with K values of unlabeled glucose measured directly was better for 1-¹¹C-glucose (y = 0.92x + 0.02, <i>r</i> = 0.96, <i>P</i> &lt; 0.0001) than for ¹⁸F-FDG (y = 0.66x + 0.05, <i>r</i> = 0.72, <i>P</i> &lt; 0.01) (<i>P</i> &lt; 0.001 for comparison of correlation coefficients). As a consequence, PET-derived values for rMGU correlated more closely with Fick-derived measurements of unlabeled glucose using 1-¹¹C-glucose (y = 0.82x + 168, <i>r</i> = 0.97, <i>P</i> &lt; 0.0001) than with ¹⁸F-FDG (y = 0.81x + 278, <i>r</i> = 0.79, <i>P</i> &lt; 0.001) (<i>P</i> &lt; 0.001 for comparison of correlation coefficients). <b>Conclusion:</b> Over a wide range of conditions, PET-derived measurements of rMGU are obtained more accurately with 1-¹¹C-glucose than with ¹⁸F-FDG.

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