Estimation of arterial wall motion using ultrafast imaging and transverse oscillations: in vivo study

Early detection of cardiovascular diseases can be done by assessing the dynamic properties of arteries. In this study, two phenomena related to the carotid wall motion are presented. The 2D motion estimation method employs (i) ultrafast imaging which became a world-wide use modality, (ii) transverse oscillations technics which allow improving the motion estimation in transverse direction i.e. perpendicular to the beam, and (iii) a 2D phase shift estimator. First, using only the radial acceleration wall, the Wall Spatial Periodic Ripples (WSPR) is studied under a cold pressor test. The results show that the WSPR mean maximum amplitude decreased of 22.9% at the systolic wave and 33.2% at the dicrotic notch. So, the WSPR is a possible artery wall rigidity marker. Then, using a very high frame rate imaging, the longitudinal carotid wall motion of one healthy subject is studied. This second experimentation permits to estimate the propagation of a longitudinal motion on an in vivo carotid. Its mean velocity was evaluated at 16.1 m.s-1, which given a ratio of 3 between with the estimated PWV.