Discordance between invasive coronary flow reserve (CFR) and non-invasive myocardial flow reserve (MFR) in diffuse coronary ectasia (DCE).

Clinical use with evidence base for diagnostic and prognostic value of quantitative positron emission tomography(PET) myocardial perfusion imaging (MPI) in patients with known or suspected coronary artery disease has exponentially increased over the last decade. This case illustrates the very first time that stress myocardial blood flow(MBF) in absolute terms (ml/min/gram) and myocardial flow reserve(MFR) are augmented in three vessel diffuse coronary ectasia by N13-Ammonia PET MPI. Moreover, relative qualitative MPI demonstrated moderate-sized ischemia in right coronary artery territory with chronic total occlusion in middle segment; despite regional myocardial flow reserve remains above ischemic thresholds while regional stress myocardial blood flow is mildly reduced.