Aims: Comparing aortic pulse wave transit time (TT) and velocity (aPWV) between magnetic resonance imaging (MR) and the oscillometric method Arteriograph (AG) that has potential for outpatient use.

Methods: MR phase-contrast transverse slices were sequentially taken at aortic arch (pulmonary bifurcation level), and 2 cm above aortic bifurcation in 49 men (age: 53±6 yr). TT was calculated using 10% of the MR flow wave amplitudes as wave-feet. The aortic root to bifurcation (aoLength) was measured in 3D volumes rendered from serial sagittal slices. Supine left-arm AG measurements were made post-MR, estimating aoLength from suprasternal-notch to symphysis-pubis surface length. Results are mean differences (95%CI).

Results: TT_MR and aPWV_MR covered a mean 85% of aoLength partly omitting the proximal ascending aorta. TT_AG (71±10 ms) was 6.6(3.8–9.3) ms (10%) higher than TT_MR (64±10 ms) and correlated (r=0.54, p<0.001). aPWV_AG (7.9±1.4) was 1.3(0.9–1.7) m/s higher than aPWV_MR (6.6±1.3) and correlated (r=0.50, p<0.001). AG’s sternum-pubis length was 70(59–81) mm higher than MR’s aoLength (r=0.55, p<0.001).

A regression model was derived from 29 cases predicting measured aoLength_MR using age and height. When tested in the remaining 20 cases, the predicted aoLength_MR was within 5.3(−22-11) mm of that measured by MR. Compared with original aPWV_AG, recalculated aPWV_AG using TT_AG and the regression-predicted aoLength was less different (0.31(0.01–0.61) m/s – p=0.02), and more closely correlated with aPWV_MR (r=0.62).

Conclusions: TT estimations by AG and MR are close, given omitted proximal lengths by MR. More accurate length estimation can significantly improve AG’s aPWV measurement using MR as a reference.