The results of this study suggest that the introduction of vector Doppler methods in commercial machines may finally be considered mature and capable of overcoming the angle-dependent overestimation typical of the standard spectral Doppler approach.Īngle independent Blood velocity estimation Carotid artery hemodynamics Real-time velocity measurement Spectral Doppler Vector Doppler.Ĭopyright © 2015 World Federation for Ultrasound in Medicine & Biology. Inter- and intra-operator repeatability measurements performed in a group of 8 healthy volunteers provided equivalent results for all of the methods (coefficients of variability in the range 2.7%-6.9%), even though the sonographers were not familiar with the VD methods. Analysis of the results obtained from 15 internal carotid arteries led to similar conclusions, indicating significant overestimation of peak systolic velocity with the spectral Doppler method. Application of Bland-Altman analysis to comparison of either VD technique with the spectral Doppler method provided a 21%-25% average difference with ± 13%-15% limits of agreement. The peak systolic velocities measured in 22 healthy common carotid arteries by the two VD techniques were very close (according to Bland-Altman analysis, the average difference was 3.2%, with limits of agreement of ± 8.6%). Although the two VD techniques were completely different (using the transmission of focused beams and plane waves, respectively), the measurement results indicate that these techniques are nearly equivalent. In this study, blood peak systolic velocities in the common and internal carotid arteries of both healthy volunteers and patients with internal carotid artery stenosis were measured by two vector Doppler (VD) methods and compared with measurements obtained with the conventional spectral Doppler approach. All rights reserved.Although severely affected by the angle dependency, carotid artery peak systolic velocity measurements are widely used for assessment of stenosis. Internal carotid artery stenosis continuous-wave Doppler pulse-wave Doppler ultrasonography.Ĭopyright © 2016 National Stroke Association. CW Doppler appears to have better inter-rater reproducibility than PW Doppler in assessing high PSV. Inter-rater reliability was similar between PW Doppler with angle correction and CW Doppler without angle correction in evaluating PSV in patients with ICAS. Measuring PSV with CW Doppler using a sector probe was feasible. When limited to patients with a PSV greater than 200 cm/s with both PW Doppler examinations (25 ICAS sites), inter-rater reliability was relatively higher for CW PSV (Spearman's ρ =. 810) was similar to that of PW PSV (Spearman's ρ =. 1C) ICA/CCA ratio: 4. 15, 16 The pulse amplitude of flow velocity was the difference between PSV and EDV. CCA velocity: 110 cm/s, normal ICA systolic velocity/end-diastolic velocity: 522/115 cm/s, 80 to 99 diameter stenosis (Fig. Inter-rater reproducibility of CW PSV (Spearman's ρ =. The maxima of peak systolic velocity (PSV) and the minima end-diastolic velocity (EDV) of the left and right flow velocities were measured by pulse-wave Doppler in the CCA and ICA for at least 3 cardiac cycles for blood flow velocity measurements. Measuring PSV using a sector probe insonating nearly parallel to the flow was feasible in all cases. The inter-rater reliabilities of PW PSV and CW PSV were analyzed by Spearman's rank correlation test.Ī total of 37 ICAS sites (median 67 % stenosis) were enrolled. PSV was measured with PW Doppler with angle correction (PW PSV) and CW Doppler without angle correction (CW PSV) by 2 examiners.
This hypothesis was tested using a sector probe and continuous-wave (CW) Doppler without angle correction.Ĭonsecutive patients with more than 50% ICAS were enrolled from a prospective database. A complete carotid duplex examination should include: the peak systolic and end diastolic velocities of common, internal, and external carotid arteries, right and left subclavian arteries, and vertebral arteries the internal carotid to common carotid artery peak systolic velocities ratio flow direction of the vertebral artery (antegrade, retro. We hypothesized that measuring PSV without angle correction would lead to better inter-rater reliability. However, the correlation between conventional angiography and PSV shows considerable scattering. Peak systolic velocity (PSV) is measured with pulse-wave (PW) Doppler with angle correction in patients with internal carotid artery stenosis (ICAS).
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