Quantitative assessment of cardiac oxidative metabolism under physiological and pharmacological stress using CEST imaging and MRS

Motivation: Assessing changes of the cardiac phosphocreatine (PCr) at rest and stress may be a valuable biomarker to cardiometabolic health. Goal(s): To test the feasibility of quantifying changes of PCr concentrations in vivo. Approach: Evaluating feasibility of the cardiac CEST imaging in a canine study with vasodilation. Applying CMR CEST and 31P MR spectroscopy in human subjects and comparing PCr quantification at rest and during exercise. Results: The results of the dog study indicated that myocardial PCr concentrations were conserved during vasodilation. The rest-exercise-recovery imaging session in human experiments demonstrated reduced PCr concentrations during exercise. Impact: The feasibility of tracking PCr changes in different physiological states is critical for the diagnosis of heart tissue dysfunction. The validation of MRS consolidates the accuracy of the CEST results.