title: Accuracy of carotid strain estimates from ultrasonic wall tracking: a study based on multiphysics simulations and in vivo data.
abstract: We used a multiphysics model to assess the accuracy of carotid strain estimates derived from a 1-D ultrasonic wall tracking algorithm. The presented tool integrates fluid-structure interaction (FSI) simulations with an ultrasound simulator (Field II), which allows comparison of the ultrasound (US) images with a ground truth. Field II represents tissue as random points on which US waves reflect and whose position can be updated based on the flow field and vessel wall deformation from FSI. We simulated the RF-signal of a patient-specific carotid bifurcation, including the blood pool as well as the vessel wall and surrounding tissue. Distension estimates were obtained from a wall tracking algorithm using tracking points at various depths within the wall, and further processed to assess radial and circumferential strain. The simulated data demonstrated that circumferential strain can be estimated with reasonable accuracy (especially for the common carotid artery and at the lumen-intima and media-adventitia interface), but the technique does not allow to reliably assess intra-arterial radial strain. These findings were supported by in vivo data of 10 healthy adults, showing similar circumferential and radial strain profiles throughout the arterial wall. We concluded that these deviations are present due to the complex 3-D vessel wall deformation, the presence of specular reflections and, to a lesser extent, the spatially varying beam profile, with the error depending on the phase in the cardiac cycle and the scanning location.
authors: Institute of Biomedical Technology, Ghent University, 9000 Ghent, Belgium. abigail.swillens@ugent.be
authors: Abigail
authors: A
authors: Swillens
authors: Gianluca
authors: G
authors: De Santis
authors: Joris
authors: J
authors: Degroote
authors: Lasse
authors: L
authors: Lovstakken
authors: Jan
authors: J
authors: Vierendeels
authors: Patrick
authors: P
authors: Segers
mesh_terms: D000328:Adult; D000465:Algorithms; D001696:Biomechanical Phenomena / Q000502:physiology; D002339:Carotid Arteries / Q000000981:diagnostic imaging* / Q000502:physiology; D003198:Computer Simulation; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D008875:Middle Aged; D019047:Phantoms, Imaging; D014463:Ultrasonography / Q000379:methods*