Correlation of Flow Velocity Measurements By Magnetic Resonance Phase Contrast Imaging and Intravascular Doppler Ultrasound

Abstract

The assessment of flow alterations in vitro due to variable stenoses using MR phase contrast flow measurements is very well correlated with the Doppler guidewire. Consequently, these results required in vivo measurements of atherosclerotic lesions to evaluate the clinical impact.

Measurement of cerebral blood flow using phase contrast magnetic resonance imaging and duplex ultrasonography

“…10 In vivo and in vitro studies also reported that measurements of CBF were overestimated with Doppler ultrasonography when compared with PC-MRI, 11,12 despite inconsistent findings from others. 13,14 The discrepancies between PC-MRI and Doppler ultrasonography measurements of CBF are likely caused by the inherent methodological limitations for measuring complex blood flow patterns in the large arteries. [15][16][17] In addition, pulsatile changes of blood vessel diameters may influence volumetric CBF measurements.…”

Evaluation of intracranial stenoses and aneurysms with accelerated 4D flow

“…Phase-contrast MR is the gold standard for measuring cerebral blood flow and has been shown to be more accurate than US measurements [12]. For velocity measurements, US has shown good agreement with phasecontrast MR measurements, and studies in pulsatile models of stenoses have shown good correlation between intravascular US and phase contrast [13,14].…”

Flow Assessment Through Four Heart Valves Simultaneously Using 3-Dimensional 3-Directional Velocity-Encoded Magnetic Resonance Imaging With Retrospective Valve Tracking in Healthy Volunteers and Patients With Valvular Regurgitation

“…1,2,4,9 This technique is however prone to inaccuracies because of technical limitations, modeling assumptions, and its dependency on operator experience. 9 Two-dimensional (2D) 1-directional velocity-encoded (VE) magnetic resonance imaging (MRI) 10 enables quantification of valvular regurgitation and is frequently used in different clinical settings. [11][12][13] However, conventional 2D 1-directional VE MRI may lead to imprecise quantification of regurgitant volume, as the location and angulation of the acquisition plane can not be corrected for movement of valve planes during cardiac contraction and relaxation.…”