Flow Velocity Measurement in the Carotid Bifurcation Using 4D Flow-Sensitive MRI and Doppler Ultrasound

Andreas Harloff¹, Timo Zech¹, Felix Wegent¹, Simon Bauer¹, Martin Schumacher¹, Michael Markl¹

Flow-sensitive 4D MRI was used to assess absolute blood flow velocities within the carotid bifurcation in healthy volunteers and patients with high-grade internal carotid artery (ICA) stenosis before and after carotid endarterectomy. MRI data were compared with Doppler ultrasound as the reference method. Reliability and reproducibility of MRI based measurements were tested. Velocity measurement was feasible at any desired site of the carotid bifurcation. Compared to Doppler ultrasound, however, MRI underestimated systolic blood flow velocity by approximately 30%.