Validation and reproducibility of aortic pulse wave velocity as assessed with velocity-encoded MRI

To validate magnetic resonance imaging (MRI) assessment of aortic pulse wave velocity (PWV(MRI)) with PWV determined from invasive intra-aortic pressure measurements (PWV(INV)) and to test the reproducibility of the measurement by MRI.

PWV(MRI) was compared with PWV(INV) in 18 nonconsecutive patients scheduled for catheterization for suspected coronary artery disease. Reproducibility of PWV(MRI) was tested in 10 healthy volunteers who underwent repeated measurement of PWV(MRI) at a single occasion. Velocity-encoded MRI was performed on all participants to assess PWV(MRI) in the total aorta (Ao(total)), the proximal aorta (Ao(prox)), and the distal aorta (Ao(dist)).

The results are expressed as mean +/- SD, Pearson correlation coefficient (PCC), and intraclass correlation (ICC). Good agreement between PWV(MRI) and PWV(INV) was found for Ao(total) (6.5 +/- 1.1 m/s vs. 6.1 +/- 0.8 m/s; PCC = 0.53), Ao(prox) (6.5 +/- 1.3 m/s vs. 6.2 +/- 1.1 m/s; PCC = 0.69), and for Ao(dist) (6.9 +/- 1.1 m/s vs. 6.1 +/- 1.0 m/s; PCC = 0.71). Reproducibility of PWV(MRI) was high for Ao(total) (4.3 +/- 0.5 m/s vs. 4.6 +/- 0.7 m/s; ICC = 0.90, P < 0.01), Ao(prox) (4.3 +/- 0.9 m/s vs. 4.7 +/- 1.0 m/s; ICC = 0.87, P < 0.01), and Ao(dist) (4.3 +/- 0.6 m/s vs. 4.4 +/- 0.8 m/s; ICC = 0.92, P < 0.01).

MRI assessment of aortic pulse wave velocity shows good agreement with invasive pressure measurements and can be determined with high reproducibility.