Project Summary The primary interventional treatment for ischemic coronary artery disease (CAD) is percutaneous intervention (PCI) involving angioplasty and deployment of a vascular stent. Clinical trials have shown that fractional flow reserve (FFR), which is assessed by taking the ratio of pressure distal to the stenosis divided by pressure proximal to the stenosis, reduces the number of adverse cardiac events compared to the use of angiographic-based anatomical criteria alone. Despite its benefit, invasive measurement of FFR is not widely used due to its high expense and procedural complexity. Magnetic resonance imaging (MRI) combined with computational fluid dynamics (CFD) offers a method for determining FFR non-invasively and without ionizing radiation. MRI can be used for coronary artery imaging, can measure coronary flow, is non-invasive, and does not use ionizing radiation. Therefore, our first objective is to develop, validate, and test a cardiac MRI-based method to determine coronary FFR (FFRMRI). We will team with the Siemens Healthineers MRI collaboration division to develop and test new image acquisition and reconstruction methodology, and team with the Siemens Healthineers Medical Imaging Technology division to develop image processing methods and display technology. The new paradigm will be tested in healthy controls and in models studies, then applied to a group of subjects with stable CAD.