Right ventricular diastolic filling: evaluation with velocity-encoded cine MRI

Abnormal flow velocity curves across the tricuspid valve (TV) and in the superior vena cava have been described in patients with abnormal right ventricular (RV) relaxation or restriction and with pericardial diseases by means of Doppler echocardiography. In this study, various imaging planes and strategies of velocity-encoded cine (VEC) MR for measurement of peak E and peak A velocities and the E/A ratio across the TV were evaluated and compared to Doppler measurements in 10 normal volunteers. In addition, VEC-MR velocity measurements were performed in the superior vena cava. Peak E and peak A velocities derived from three-dimensional VEC-MR phase images were slightly higher than velocities derived from two-dimensional VEC images. Higher velocities were measured by VEC-MR in the vertical long-axis plane compared with the horizontal long-axis plane. Excellent correlations (r > 0.89) were found between E/A ratios derived by VEC-MR and Doppler echocardiography. The interobserver variability for VEC-MR measurements was in the range of 2%. The VEC-MR depicted normal superior vena cava velocity curves in every volunteer. These results indicate that VEC-MR may offer a highly reproducible means of assessing abnormal filling properties of the RV.