title: Two-dimensional flow imaging in the carotid bifurcation using a combined speckle tracking and phase-shift estimator: a study based on ultrasound simulations and in vivo analysis.
abstract: A two-dimensional (2-D) blood velocity estimator is presented combining speckle tracking (ST) and phase-shift estimation (PE) to measure lateral (vx) and axial (vz) velocities respectively. Estimator properties were assessed in a carotid bifurcation using ultrasound simulations based on computational fluid dynamics, allowing validation toward a ground truth. Simulation results were supported with in vivo data of a healthy carotid. ST and PE estimates were combined as: (1) vx from 2D-ST and vz from PE, (2) vx from 2D-ST and vz from PE with aliasing correction based on ST and (3) vz from PE and only lateral ST for vx. Regression analysis showed a 35% to 77% decrease in standard deviation for vz for PE compared with ST. Aliasing correction based on ST improved results but also introduced spurious artifacts. A marginal decrease in performance was observed when only tracking laterally. Further work will focus on in vivo trials in patients with carotid plaques.
authors.affiliation: IBiTech-bioMMeda (Ghent University), Gent, Belgium. abigail.swillens@ugent.be
authors.forename: Abigail
authors.initials: A
authors.lastname: Swillens
authors.forename: Patrick
authors.initials: P
authors.lastname: Segers
authors.forename: Lasse
authors.initials: L
authors.lastname: Lovstakken
mesh_terms: D000465:Algorithms; D016477:Artifacts; D001783:Blood Flow Velocity; D002339:Carotid Arteries / Q000033:anatomy & histology / Q000000981:diagnostic imaging*; D003198:Computer Simulation; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D012016:Reference Values; D015203:Reproducibility of Results; D012815:Signal Processing, Computer-Assisted; D018615:Ultrasonography, Doppler, Color / Q000379:methods*