4d Flow Mri Pressure Mapping In Patients With Bicuspid Aortic Valve: Feasibility Study With Comparison To Pressure Gradient Quantification

Introduction: Aortic valve disease is typically evaluated by trans-valvular velocities and Pressure Gradients (PG). 4D Flow MRI allows for Pressure Mapping (PM), a novel and alternate hemodynamic marker of severity. Hypothesis: To demonstrate feasibility of PM in patients with Bicuspid Aortic Valve (BAV) and compare to PG quantification. Methods: Patients with BAV and healthy volunteers were enrolled. Imaging was performed at 3T inclusive of cine imaging and 4D flow. 4D flow data was processed using commercial software at nine pre-defined aortic locations from left ventricular outflow tract (LVOT) to distal descending aorta (DDA) (Fig. 1). Net flow, Peak Velocity (PV), peak PG, and maximum Pressure Drop (PD) were calculated at each plane, PD representing cumulative drop in pressure from a pre-valvular reference (LVOT). Results: Twenty-four patients with BAV (49±14 years, 8 women) and 11 healthy volunteers (52±10 years, 2 women) were studied. All subjects had an LVEF u003e55%. The maximum PG in BAV and volunte...