Experimental study on the association among flow profile shape, systemic and local hemodynamics, wave reflections, based on Vector Doppler imaging

Blood flow velocity profile in large arteries, although commonly assumed parabolic, quite often shows more complex patterns. The aim of this study was to investigate possible correlations between the different flow patterns and their potential determinants like systemic hemodynamic factors as well as local vessel geometry, distensibility and wave reflections. The study focuses on carotid (common, CCA, and internal, ICA) and femoral (common, CFA) arteries in normal subjects. The velocity profiles were obtained through the Multi Line Vector Doppler (MLVD) approach implemented in the ULA-OP 256 scanner, and their shape was quantified through the Bluntness Index (BI), i.e. the ratio between peak and cross-section averaged velocity. Possible correlations among BI and the other systemic and local parameters were investigated. We found that in healthy subjects, plaque free, the profile shape in the CCA is almost parabolic, but it is not in ICA and CFA. Moreover, the profile shape in the carotid is mainly affected by systemic hemodynamic factors, while local factors are more relevant for the profile in CFA.