Reliable detection of subendocardial ischemia by high-resolution end-systolic first-pass perfusion imaging in the absence of obstructive coronary disease

Background Among the patients without known disease undergoing invasive angiography, nearly 40% do not have coronary artery disease (CAD) [1]. A possible underlying etiology for such patients is ischemic heart disease associated with coronary microvascular dysfunction (CMD). Despite intense interest and recent advancements, reliable diagnosis of CMD on the basis of first-pass perfusion (FPP) cardiac MRI is an ongoing challenge. We hypothesized that high-resolution systolic FPP imaging can detect diffuse vasodilator-induced subendocardial defects and transmural perfusion gradients (TPGs) consistent with CMD in a swine model of diet-induced diabetes with no obstructive CAD. To this end, we optimized and tested a recently introduced high-resolution FPP method capable of imaging all myocardial slices at the end-systolic phase.