Evaluation of mitral inflow velocity profile: Optimal through plane location for mitral inflow assessment with cardiac magnetic resonance

Background: Diastology is usually assessed using transthoracic echocardiography (TTE). Velocity?encoded phase?contrast imaging permits evaluation with cardiac magnetic resonance (CMR). Heterogeneous contour locations have been used to measure mitral (MV) inflow velocities and the optimal contour location is uncertain. We evaluated CMR MV inflow velocities against TTE to identify the optimal location. Methods: Revascularized acute myocardial infarction patients with normal left ventricular (LV) systolic function on TTE were assessed by 1.5T CMR. Early and late peak diastolic mitral inflow velocities were determined at 3 contour locations: (i) MV leaflet orifice, (ii) mid?MV inflow region, (iii) annulus and this was compared to TTE parameters of E/A ratio and deceleration times (DT). Results: Fourty?four patients were analysed. Mean LVEF was 59.8±9.3%. Peak E and A velocities underestimated by CMR, E/A ratio showed moderate correlation with TTE, R ² values of 0.52 and 0.46 for leaflet and inflow contours respectively. Bland?Altman analysis showed the MV leaflet contour to have excellent agreement and the best reproducibility. Conclusion: CMR evaluation of mitral inflow velocities has good correlation with TTE. However, measurements vary significantly. The greatest correlation was with MV leaflet and weakest relationship with annulus contour.