Axial and radial waveforms in common carotid artery: an advanced method for studying arterial elastic properties in...

Our objective was to develop a method for studying the biomechanics of the common carotid artery (CCA) by evaluating both radial and less known axial distension of the arterial wall. We developed software capable of tracking the movements of different arterial wall layers from ultrasound recordings of CCA, and we then calculated several indices of arterial stiffness. The wide spectrum of arterial stiffness indices defined from one measurement is a unique feature of our method. The motion-tracking algorithm is based on 2-D cross-correlation enhanced with luminance optimizations. The repeatability and reproducibility of the motion tracking were evaluated by performing 10-s ultrasound recordings of left CCA twice to 19 healthy volunteers (11 women, 8 men, age 41.3 ± 14.3 y). The method revealed a biphasic axial movement of the CCA and demonstrated that the indices of arterial stiffness defined from radial movement of carotid artery are reproducible (Cronbach's α, 0.59-0.97) as well as the indices from axial movement are reproducible (Cronbach's α, -0.68 to 0.93). The good reproducibility of the motion tracking is evidence that this method of studying arterial elastic properties is adequate for in vivo studies.