The key to extremely accelerated model-based quantitative first-pass perfusion cardiac MRI

First-pass perfusion cardiac MR (FP-CMR) is one of the methods of choice for evaluating myocardial ischemia. Moreover, quantitative FP-CMR methods that provide pixel-wise quantitative myocardial perfusion maps are increasingly being applied as an alternative to visual inspection. Recently, a DIRect QuanTitative (DIREQT) FP-CMR model-based reconstruction has been proposed to directly estimate myocardial perfusion maps and highly accelerate FP-CMR scans. Here, DIREQT is combined with the idea of view-sharing and KEYhole imaging (DIREQT-KEY) to improve DIREQT reconstructions, particularly from extremely accelerated FP-CMR acquisitions. DIREQT-KEY directly generates high-quality quantitative myocardial perfusion maps from less than 4 radial spokes per time frame.