Carotid artery flow as determined by real-time phase-contrast flow MRI and neurovascular ultrasound: A comparative study of healthy subjects. Issue 106 (September 2018)

• Record Type: Journal Article
• Authors: Maier, Ilko L.; Hofer, Sabine; Joseph, Arun A.; Merboldt, K. Dietmar; Tan, Zhengguo; Schregel, Katharina; Knauth, Michael; Bähr, Mathias; Psychogios, Marios-Nikos; Liman, Jan; Frahm, Jens
• Is Part Of: European journal of radiology. Issue 106(2018)
• Page Start: 38
• Page End: 45
• Publication Date: 2018-09
• Subjects: B-mode brightness-mode -- CCA common carotid artery -- ECA external carotid artery -- EDV end-diastolic velocity -- FLASH fast low-angle shot -- ICA internal carotid artery -- nvUS neurovascular ultrasound -- PSV peak-systolic velocity -- RT-PC real-time phase-contrast -- SD standard deviation -- VENC velocity-encoding gradient; Carotid artery -- Doppler sonography -- Duplex sonography -- Neurovascular ultrasound -- Real-time flow MRI -- Velocity profiles; Medical radiology -- Periodicals; Radiology -- Periodicals; Radiologie médicale -- Périodiques; Medical radiology; Periodicals; 616.075705
• DOI: 10.1016/j.ejrad.2018.07.011
• Languages: English
• ISSNs: 0720-048X

Abstract

Highlights: Real-time phase-contrast (RT-PC) flow MRI of the carotids was compared to neurovascular ultrasound (nvUS). RT-PC MRI offers 0.8 mm in-plane resolution at 40 ms temporal resolution. RT-PC MRI yields velocity distributions across the entire vessel lumen. MRI-derived velocities were lower and volumes were higher than by nvUS. RT-PC MRI can add to clinical diagnostics of carotid stenosis. Abstract: Background: The assessment of carotid artery flow by neurovascular ultrasound (nvUS) can be complemented by real-time phase-contrast (RT-PC) flow MRI which apart from quantitative flow parameters offers velocity distributions across the entire vessel lumen. Materials and methods: The feasibility and diagnostic potential of RT-PC flow MRI was evaluated in 20 healthy volunteers in comparison to conventional nvUS. RT-PC flow MRI at 40 ms temporal resolution and 0.8 mm in-plane resolution resulted in velocity maps with low phase noise and high spatiotemporal accuracy by exploiting respective advances of a recent nonlinear inverse model-based reconstruction. Peak-systolic velocities (PSV), end-diastolic velocities (EDV), flow volumes and comprehensive velocity profiles were determined in the common, internal and external carotid artery on both sides. Results: Flow characteristics such as pulsatility and individual abnormalities shown on nvUS could be reproduced and visualized in detail by RT-PC flow MRI. PSV to EDV differences revealed good agreement between both techniques, mean PSV and EDV were significantly lower and flow volumes were higher for MRI. Conclusion: Our findings suggest that RT-PC flow MRI adds to clinical diagnostics, e.g. by alterations of dynamic velocity distributions in patients with carotid stenosis. Lower PSV and EDV values than for nvUS mainly reflect the longer MRI acquisition time which attenuates short peak velocities, while higher flow volumes benefit from a proper assessment of the true vessel lumen.