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Updated: Mar 2, 2026
Pulse Wave Velocity Testing in the Baltimore Longitudinal Study of Aging
Published on: February 7, 2014
Effects of inaccuracies in arterial path length measurement on differences in MRI and tonometry measured pulse wave
Jonathan R Weir-McCall1, Faisel Khan2, Deirdre B Cassidy1
1Division of Molecular and Clinical Medicine, Medical Research Institute, University of Dundee, Dundee, DD1 9SY, UK.
Background:
Carotid-femoral pulse wave velocity (cf-PWV) and aortic PWV measured using MRI (MRI-PWV) show good correlation, but with a significant and consistent bias across studies. The aim of the current study was to evaluate whether the differences between cf.-PWV and MRI-PWV can be accounted for by inaccuracies of currently used distance measurements.
Methods:
One hundred fourteen study participants were recruited into one of 4 groups: Type 2 diabetes melltus (T2DM) with cardiovascular disease (CVD) (n = 23), T2DM without CVD (n = 41), CVD without T2DM (n = 25) and a control group (n = 25). All participants underwent cf.-PWV, cardiac MRI and whole body MR angiography(WB-MRA). 90 study participants also underwent aortic PWV using MRI. cf.-PWVEXT was performed using a SphygmoCor device (Atcor Medical, West Ryde, Australia). The true intra-arterial pathlength was measured using the WB-MRA and then used to recalculate the cf.-PWVEXT to give a cf.-PWVMRA.
Results:
Distance measurements were significantly lower on WB-MRA than on external tape measure (mean diff = -85.4 ± 54.0 mm,p < 0.001). MRI-PWV was significantly lower than cf.-PWVEXT (MRI-PWV = 8.1 ± 2.9 vs. cf.-PWVEXT = 10.9 ± 2.7 ms-1,p < 0.001). When cf.-PWV was recalculated using the inter-arterial distance from WB-MRA, this difference was significantly reduced but not lost (MRI-PWV = 8.1 ± 2.9 ms-1 vs. cf.-PWVMRA 9.1 ± 2.1 ms-1, mean diff = -0.96 ± 2.52 ms-1,p = 0.001). Recalculation of the PWV increased correlation with age and pulse pressure.
Conclusion:
Differences in cf.-PWV and MRI PWV can be predominantly but not entirely explained by inaccuracies introduced by the use of simple surface measurements to represent the convoluted arterial path between the carotid and femoral arteries.
Insights
Differences in carotid-femoral pulse wave velocity (cf-PWV) and MRI-PWV are mainly due to inaccurate distance measurements. Recalculating cf-PWV with MRI-derived distances significantly reduces this bias, improving accuracy.
Area of Science:
- Cardiovascular Physiology
- Medical Imaging
- Biomedical Engineering
Background:
- Carotid-femoral pulse wave velocity (cf-PWV) and MRI-measured aortic PWV (MRI-PWV) correlate but show bias.
- The source of this bias in PWV measurements is under investigation.
Purpose of the Study:
- To determine if distance measurement inaccuracies explain the bias between cf-PWV and MRI-PWV.
- To assess the impact of using MRI-derived arterial pathlength on PWV calculations.
Main Methods:
- 114 participants (Type 2 diabetes, CVD, controls) underwent cf-PWV and cardiac MRI.
- Whole-body MR angiography (WB-MRA) provided accurate arterial pathlength for cf-PWV recalculation.
- cf-PWV was measured externally (cf-PWV_EXT) and recalculated using MRA distance (cf-PWV_MRA).
Main Results:
- WB-MRA showed significantly shorter distances than external tape measurements.
- MRI-PWV was significantly lower than cf-PWV_EXT.
- Recalculating cf-PWV using MRA distances (cf-PWV_MRA) reduced the difference with MRI-PWV, but bias remained.
- Recalculation improved PWV correlation with age and pulse pressure.
Conclusions:
- Inaccuracies in external distance measurements predominantly explain the bias between cf-PWV and MRI-PWV.
- While improved, a residual bias suggests other factors may also contribute to PWV measurement differences.
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