Clinical assessment of aortic valve stenosis: Comparison between 4D flow MRI and transthoracic echocardiography

Background The prevalence of valvular aortic stenosis (AS) increases as the population ages. Echocardiographic measurements of peak jet velocity (Vpeak), mean pressure gradient (Pmean), and aortic valve area (AVA) determine AS severity and play a pivotal role in the stratification towards valvular replacement. A multimodality imaging approach might be needed in cases of uncertainty about the actual severity of the stenosis. Purpose To compare four‐dimensional phase‐contrast magnetic resonance (4D PC‐MR), two‐dimensional (2D) PC‐MR, and transthoracic echocardiography (TTE) for quantification of AS. Study Type Prospective. Population Twenty patients with various degrees of AS (69.3 ± 5.0 years). Field Strength/Sequences 4D PC‐MR and 2D PC‐MR at 3T. Assessment We compared Vpeak, Pmean, and AVA between TTE, 4D PC‐MR, and 2D PC‐MR. Flow eccentricity was quantified by means of normalized flow displacement, and its influence on the accuracy of TTE measurements was investigated. Statistical Tests Pearson's correlation, Bland–Altman analysis, paired t‐test, and intraclass correlation coefficient. Results 4D PC‐MR measured higher Vpeak (r = 0.95, mean difference + 16.4 ± 10.7%, P