Towards reliable myocardial blood-oxygen-level-dependent (BOLD) CMR using late effects of regadenoson with simultaneous 13n-ammonia pet validation in a whole-body hybrid PET/MR system

Background BOLD CMR is a non-contrast approach for examining myocardial perfusion but despite major technical advancements to date, its reliability remains weak. A key reason for this is the unpredictable cardiac motion during stress, which can lead to pronounced artifacts that confound/ mask the true BOLD signal changes during hyperemia. Recently, regadenoson has become the vasodilator of choice owing to greater patient tolerability and ease of use. We hypothesized that at 10-mins post regadenoson administration (p.r.a), (a) BOLD CMR artifacts at stress are markedly reduced compared to those conventionally acquired at 2-mins p.r.a; and (b) that myocardial perfusion reserve (MPR) remains greater than 2.0 and is highly correlated with the BOLD effects estimated from T2 maps.