Does Curvature Affect Vascular Haemodynamic and Shear-Stress?

Many vascular compartments of interest for diagnostic or therapeutic purpose, such as the coronary arteries, the umbilical vessels, the circle of Willis and the aorta itself are curved and/or coiled, causing the appearance of non axial velocity components (influencing the wall’s shear-stress) and changing the pattern of the axial velocity components (for instance, by raising the turbolence threshold) [1]. Current clinical flowmetry techniques are based on the principle that, upon insonifying the vessels with a US beam, a (Doppler shifted) signal is obtained which is proportional to the haematic velocity. In the simplest cases, i.e.when the blood is moving in the direction of the vessel’s axis, a linear relationship between the Doppler signal and the blood velocity is expected. [...]