Abstract
Measurement of hemodynamic wall shear stress (WSS) is important in investigating the role of WSS in the initiation and progression of atherosclerosis. Echo particle image velocimetry (echo PIV) is a novel ultrasound-based technique for measuring WSS in vivo that has previously been validated in vitro using the standard optical PIV technique. We evaluated the repeatability and reproducibility of echo PIV for measuring WSS in the human common carotid artery. We measured WSS in 28 healthy participants (18 males and 10 females, mean age: 56 ± 12 y). Echo PIV was highly repeatable, with an intra-observer variability of 1.0 ± 0.1 dyn/cm2 for peak systolic (maximum), 0.9 dyn/cm2 for mean and 0.5 dyn/cm2 for end-diastolic (minimum) WSS measurements. Likewise, echo PIV was reproducible, with a low inter-observer variability (max: 2.0 ± 0.2 dyn/cm2, mean: 1.3 ± 0.1 dyn/cm2, end-diastolic: 0.7 dyn/cm2) and more variable inter-scan (test–retest) variability (max: 7.1 ± 2.3 dyn/cm2, mean: 2.9 ± 0.4 dyn/cm2, min: 1.5 ± 0.1 dyn/cm2). We compared echo PIV with the reference method, phase-contrast magnetic resonance imaging (PC-MRI); echo PIV-based WSS measurements agreed qualitatively with PC-MRI measurements (r = 0.89, p < 0.05). Significant differences were observed in some WSS measurements (echo PIV vs. PC-MRI): WSS at peak systole: 21 ± 7.0 dyn/cm2 vs. 15 ± 5.0 dyn/cm2; time-averaged WSS: 8.9 ± 3.0 dyn/cm2 vs. 7.1 ± 3.0 dyn/cm2 (p < 0.05); WSS at end diastole: 3.8 ± 2.8 dyn/cm2 vs. 3.9 ± 2 dyn/cm2 (p > 0.05). For the first time, we report that echo PIV can measure WSS with good repeatability and reproducibility in adult humans with a broad age range. Echo PIV is feasible in humans and offers an easy-to-use, ultrasound-based, quantitative technique for measuring WSS in vivo in humans with good repeatability and reproducibility.
Original language | English (US) |
---|---|
Pages (from-to) | 1618-1627 |
Number of pages | 10 |
Journal | Ultrasound in Medicine and Biology |
Volume | 43 |
Issue number | 8 |
DOIs | |
State | Published - Aug 2017 |
Funding
This work was made possible by grants from the National Institutes of Health (NIH T32-HL072738, K24-081506, ROI-HL114753). This study was supported in part by the National Institute for Health Research (NIHR) Exeter Clinical Research Facility. The views expressed are those of the authors and not necessarily those of the NIH, National Health Service, NIHR or Department of Health. We thank South West Stroke Research Network for their help in recruitment and the staff of the Diabetes and Vascular Medicine Research Centre, University of Exeter Medical School, for their valuable assistance in carrying out this study.
Keywords
- Atherosclerosis
- Echo pulse imaging velocimetry
- Measurement uncertainty
- Phase-contrast magnetic resonance imaging
- Plaque rupture
- Ultrasound imaging velocimetry
ASJC Scopus subject areas
- Radiological and Ultrasound Technology
- Biophysics
- Acoustics and Ultrasonics