Reliable phase-contrast flow volume magnetic resonance measurements are feasible without adjustment of the velocity encoding parameter
Artikel i vetenskaplig tidskrift, 2020

Purpose: To show that adjustment of velocity encoding (VENC) for phase-contrast (PC) flow volume measurements is not necessary in modern MR scanners with effective background velocity offset corrections. Approach: The independence on VENC was demonstrated theoretically, but also experimentally on dedicated phantoms and on patients with chronic aortic regurgitation (n = 17) and one healthy volunteer. All PC measurements were performed using a modern MR scanner, where the pre-emphasis circuit but also a subsequent post-processing filter were used for effective correction of background velocity offset errors. Results: The VENC level strongly affected the velocity noise level in the PC images and, hence, the estimated peak flow velocity. However, neither the regurgitant blood flow volume nor the mean flow velocity displayed any clinically relevant dependency on the VENC level. Also, the background velocity offset was shown to be close to zero (<0.6 cm/s) for a VENC range of 150 to 500 cm/s, adding no significant errors to the PC flow volume measurement. Conclusions: Our study shows that reliable PC flow volume measurements are feasible without adjustment of the VENC parameter. Without the need for VENC adjustments, the scan time can be reduced for the benefit of the patient. (C) 2020 Society of Photo-Optical Instrumentation Engineers (SPIE).

velocity encoding

phase contrast

background velocity offset


magnetic resonance imaging


Kerstin M. Lagerstrand

Göteborgs universitet

Frida Svensson

Göteborgs universitet

Christian L. Polte

Göteborgs universitet

Odd Bech-Hanssen

Göteborgs universitet

Goran Starck

Göteborgs universitet

Artur Chodorowski

Chalmers, Elektroteknik, Signalbehandling och medicinsk teknik

Ase A. Johnsson

Göteborgs universitet

Journal of Medical Imaging

23294302 (ISSN) 23294310 (eISSN)

Vol. 7 6 063502


Medicinsk laboratorie- och mätteknik

Strömningsmekanik och akustik

Medicinsk bildbehandling





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