Accelerated Phase-Contrast MR Imaging: Comparison of k-t BLAST With SENSE and Doppler Ultrasound for Velocity and Flow Measurements in the Aorta

Purpose: To evaluate differences in velocity and flow measurements in the aorta between accelerated phase-contrast (PC) magnetic resonance imaging (MRI) using SENSE and k-t BLAST and In peal, velocity to Doppler ultrasound. Materials and Methods: Two-dimensional PC-MRI perpendicular to the ascending and descending aorta was performed in I I volunteers using SENSE (R 2) and k-t BLAST (2-, 4-, 6-, and 8-fold). Peak velocity, mean velocity, and stroke Volume of the accelerated PC-MRI experiments were correlated. Peak velocities were compared to Doppler ultrasound. Results: All acceleration techniques showed significant correlations for peak velocity with Doppler ultrasound. However, k-t BLAST 6 and 8 showed a significant underestimation. Strong correlations between SENSE and k-t BLAST were found for all three parameters. Significant differences in peak velocity were found between SENSE and all k-t BLAST experiments, but not for 2-fold k-t. BLAST in the ascending aorta, and 2- and 4-fold k-t BLAST in the descending aorta. For mean velocity no significant differences were found. Stroke volume showed significant differences for all k-t BLAST experiments in the ascending and for 6- and 8-fold k-t BLAST in the descending aorta. Conclusion: Peak velocity of accelerated PC-MRI correlated with CW Doppler measurements, but high k-t BLAST acceleration factors lead to a significant underestimation, SENSE with R = 2 and 2-fold k-t BLAST are most highly correlated in phase-contrast flow measurements.