Quantitative Blood Flow Measurements in the Common Carotid Artery: A Comparative Study of High-Frame-Rate Ultrasound Vector Flow Imaging, Pulsed Wave Doppler, and Phase Contrast Magnetic Resonance Imaging.

Yigang Du,Alfred C H Yu,Lei Zhu,Linsong Deng,Haiyan Ding,Le He,Billy Y S Yiu

doi:10.3390/diagnostics12030690

Abstract

V Flow is commercially developed by high-frame-rate ultrasound vector flow imaging. Compared to conventional color Doppler, V Flow is angle-independent and is capable of measuring both the magnitude and the direction of blood flow velocities. This paper aims to investigate the differences between V Flow and pulsed wave Doppler (PW) relative to phase contrast magnetic resonance imaging (PC-MRI), for the quantitative measurements of blood flow in common carotid arteries (CCA) and, consequently, to evaluate the accuracy of the new technique, V Flow. Sixty-four CCAs were measured using V Flow, PW, and PC-MRI. The maximum velocities, time-averaged mean (TAMEAN) velocities, and volume flow were measured using different imaging technologies. The mean error with standard deviation (Std), the median of absolute errors, and the r-values between V Flow and PC-MRI results for the maximum velocity, the TAMEAN velocity, and the volume flow measurements are {9.40% ± 14.91%; 11.84%; 0.84}, {21.52% ± 14.46%; 19.28%; 0.86}, and {−2.80% ± 14.01%; 10.38%; 0.7}, respectively, and are {53.44% ± 29.68%; 49.79%; 0.74}, {27.83% ± 31.60%; 23.83; 0.71}, and {21.01% ± 29.64%; 25.48%; 0.34}, respectively, for those between PW and PC-MRI. The boxplot, linear regression and Bland–Altman plots were performed for each comparison, which illustrated that the results measured via V Flow rather than via PW agreed more closely with those measured via PC-MRI.

Highlights

Doppler ultrasound is one of the most commonly used medical imaging techniques for the routine examination of vascular disease
To improve the performance of the diagnosis methods further, the use of Doppler US was proposed. This technique can facilitate the diagnosis of internal carotid artery (ICA) stenosis, using pulsed wave Doppler (PW) to measure the peak systolic and end-diastolic velocities of ICA, as well as the peak systolic velocity ratios between the ICA and the common carotid artery (CCA); these velocities are used to classify ICA stenosis [4,5]
This study aims to evaluate the accuracy of velocity and volume flow measurements for the high-frame-rate V Flow function

Summary

Introduction

Doppler ultrasound is one of the most commonly used medical imaging techniques for the routine examination of vascular disease. The degree of stenosis for carotid arteries can be detected and quantified by measuring the narrowest diameter of the remaining stenotic lumen directly and by comparing it to the distal normal lumen (NASCET [1]) or the estimated original lumen at its narrowest point (ESCT [2]). This could be performed based on the carotid angiography, which is an invasive imaging technique that still has several deficiencies in assessing stenosis, in combination with the above methods (NASCET and ESCT). This technique can facilitate the diagnosis of internal carotid artery (ICA) stenosis, using PW to measure the peak systolic and end-diastolic velocities of ICA, as well as the peak systolic velocity ratios between the ICA and the common carotid artery (CCA); these velocities are used to classify ICA stenosis [4,5]

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Conclusion