Abstract 20148: Noninvasive Quantification of Pressure Difference Across a Coronary Stenosis Using Phase-Contrast (PC)-MRI: Initial Patient study Using Fractional Flow Reserve as Reference

Introduction: In patients suspected of coronary artery disease (CAD) undergoing invasive coronary angiography (ICA), ~50% has nonsignificant stenoses ( 0.80). Recent noninvasive technique, FFRCT (coronary computed tomography angiography, CCTA with computational fluid dynamic simulations), has shown to decrease the number of unnecessary invasive procedures, however, CCTA requires exposure to ionizing radiation and is more prone to artifacts caused by calcification. In this study, we evaluate a noninvasive technique using cross-sectional 2D phase-contrast (PC)-MRI and Navier-Stokes analysis to derive pressure difference (ΔP) across a coronary stenosis, with the ultimate goal of estimating FFR. As FFR requires adenosine, which is technically challenging for PC-MRI due to high heart rates, the proposed technique mimics an instantaneous wave-free ratio (iFR) (ΔP obtained at diastole without adenosine; assuming aortic pressure of 74.2 mmHg), denoted as MR-iF...