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Abstract #1329

A Novel Method for the Assessment of Valve Effective Orifice Area Using 4D Flow Shear Layer Detection Method in Patients with Aortic Stenosis

Julio Garcia1, Michael Markl1, 2, Susanne Schnell1, Pegah Entezari1, Riti J. Mahadevia1, Can Wu1, Chris Malaisrie3, Philippe Pibarot4, James C. Carr1, Alex J. Barker1

1Radiology, Northwestern University, Chicago, IL, United States; 2Biomedical Engineering, Northwestern University, Chicago, IL, United States; 3Division of Cardiac Surgery, Northwestern University, Chicago, IL, United States; 4Department of Medicine, Laval University, Quebec, Canada

Valve aortic stenosis (AS) is the most common cause of valvular replacement. The AS severity is mainly evaluated by transthoracic Doppler echocardiography (TTE) by measuring transvalvular velocity gradients and valve effective orifice area (EOA). In particular, valve EOA has high variability when measured by TTE. 3D time-resolved phase contrast MRI with 3-directional velocity encoding may improve EOA estimation by leveraging the advantages of a novel jet shear layer detection (JSLD) method for estimating valve EOA. The objective of this study was to validate 4D flow MRI-based EOA estimation using an in-vitro stenosis phantom and in-vivo measurements of the JSLD-determined EOA.

Keywords

absolute accurately acknowledgment acoustical addition adjusted agreement anatomic annulus aorta aortic ascending assessed assessment barker bicuspid biomedical bland blinded blood cardiac cardiovascular cause challenging circulation column common complex comprehensive computed computing continuity contrast control coverage covering decide derived despite detect detection determined directional directly diseases downstream dynamics effective ejection elderly encoding engineering equation error especially estimation evaluated excellent females field findings flow fluid fraction full good heart improve in vivo incomplete integral inter intra layer limits local maximal measured medicine mild mimicking mitigating model morphology northwestern novel observer observers obstructive often orifice overview panel participants patients peak pipe plot position post potential previous proportion radiology regression relevant repair repetition replacement representation resolution respectively severe severity shah shear source spatial steady strategy streamlines stroke structure subjects subset support surface systole systolic temporal term theoretical theory third traditional undergo upstream useful validate valve valves valvular variability velocities velocity view vitro volume vorticity white years zone