Assessing Myocardial Microvascular Reactivity with a Novel MRI Blood-Pool Imaging Approach

Coronary microvascular dysfunction is driven by vascular inflammation and can go undetected for years. Current imaging diagnostics lack the ability to quantify microvascular vasomodulation, a potential biomarker for cardiac diseases dominated by microvascular disease. We propose a novel MRI approach that utilizes elevated carbon dioxide and a blood-pool contrast agent to quantify changes in microvascular blood volume. Our results confirmed hypercapnia caused strong vasodilation within female myocardium but no response in males. Transitioning from hypercapnia to room air elicited strong vasoconstriction in both sexes. This technology will be valuable for early detection of microvascular dysfunction in various diseases.