High-Frame-Rate Ultrasound Velocimetry in the Healthy Femoral Bifurcation: A Comparative Study Against 4-D Flow Magnetic Resonance
Majorie van Helvert 1, Janna Ruisch 2, Joosje M K de Bakker 3, Anne E C M Saris 3, Chris L de Korte 4, Michel Versluis 5, Erik Groot Jebbink 6, Michel M P J Reijnen 6
Abstract
Objective: Local flow dynamics impact atherosclerosis yet are difficult to quantify with conventional ultrasound techniques. This study investigates the performance of ultrasound vector flow imaging (US-VFI) with and without ultrasound contrast agents in the healthy femoral bifurcation.
Methods: High-frame-rate ultrasound data with incremental acoustic outputs were acquired in the femoral bifurcations of 20 healthy subjects before (50V) and after contrast injection (2V, 5V and 10V). 2-D blood-velocity profiles were obtained through native blood speckle tracking (BST) and contrast tracking (echo particle image velocimetry [echoPIV]). As a reference, 4-D flow magnetic resonance imaging (4-D flow MRI) was acquired. Contrast-to-background ratio and vector correlation were used to assess the quality of the US-VFI acquisitions. Spatiotemporal velocity profiles were extracted, from which peak velocities (PSV) were compared between the modalities. Furthermore, root-mean-square error analysis was performed.
Results: US-VFI was successful in 99% of the cases and optimal VFI quality was established with the 10V echoPIV and BST settings. A good correspondence between 10V echoPIV and BST was found, with a mean PSV difference of -0.5 cm/s (limits of agreement: -14.1-13.2). Both US-VFI techniques compared well with 4-D flow MRI, with a mean PSV difference of 1.4 cm/s (-18.7-21.6) between 10V echoPIV and MRI, and 0.3 cm/s (-23.8-24.4) between BST and MRI. Similar complex flow patterns among all modalities were observed.
Conclusion: 2-D blood-flow quantification of femoral bifurcation is feasible with echoPIV and BST. Both modalities showed good agreement compared to 4-D flow MRI. For the femoral tract the administration of contrast was not needed to increase the echogenicity of the blood for optimal image quality.
Keywords: 4-D flow MRI; Blood speckle tracking; Blood-flow imaging; Echo particle image velocimetry; Femoral artery; High-frame-rate ultrasound; Ultrasound vector flow imaging.
Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.
Conflict of interest statement
Conflict of interest This work was supported in part by the Dutch Research Council VORTECS program (17219) and in part by Rijnstate Vriendenfonds (VF19-a10).