Improved aortic pulse wave velocity assessment from multislice two-directional in-plane velocity-encoded magnetic resonance imaging.

PURPOSE

To evaluate the accuracy and reproducibility of aortic pulse wave velocity (PWV) assessment by in-plane velocity-encoded magnetic resonance imaging (MRI).

MATERIALS AND METHODS

In 14 patients selected for cardiac catheterization on suspicion of coronary artery disease and 15 healthy volunteers, PWV was assessed with multislice two-directional in-plane velocity-encoded MRI (PWV(i.p.)) and compared with conventionally assessed PWV from multisite one-directional through-plane velocity-encoded MRI (PWV(t.p.)). In patients, PWV was also obtained from intraarterially acquired pressure-time curves (PWV(pressure)), which is considered the gold standard reference method. In volunteers, PWV(i.p.) and PWV(t.p.) were obtained in duplicate in the same examination to test reproducibility.

RESULTS

In patients, PWV(i.p.) showed stronger correlation and similar variation with PWV(pressure) than PWV(t.p.) (Pearson correlation r = 0.75 vs. r = 0.58, and coefficient of variation [COV] = 10% vs. COV = 12%, respectively). In volunteers, repeated PWV(i.p.) assessment showed stronger correlation and less variation than repeated PWV(t.p.) (proximal aorta: r = 0.97 and COV = 10% vs. r = 0.69 and COV = 17%; distal aorta: r = 0.94 and COV = 12% vs. r = 0.90 and COV = 16%; total aorta: r = 0.97 and COV = 7% vs. r = 0.90 and COV = 13%).

CONCLUSION

PWV(i.p.) is an improvement over conventional PWV(t.p.) by showing higher agreement as compared to the gold standard (PWV(pressure)) and higher reproducibility for repeated MRI assessment.