Designing a system for forward-viewing 3D intravascular ultrasound imaging of blood flow velocity: assessing the effect of the catheter on velocity estimation in stenoses

Wall shear stress (WSS) has been associated with development of high-risk plaque, which increases the likelihood for major adverse cardiac events. Recently, we have used a catheter-based, 3D intravascular forward-viewing ultrasound (FV US) transducer to directly estimate velocity fields in the femoral artery of a pig. Because inserting a catheter will affect the blood flow dynamics in the artery, in this work, the effects of a catheter on flow dynamics are experimentally quantified in both femoral and coronary stenotic vessels in phantoms to determine conditions in which velocity can be accurately estimated. An external linear array transducer was used to estimate velocity in the lumen at 5000 fps via a particle imaging velocimetry approach. The current study indicates that a hollow, catheter-based FV US could be used to quantify the flow dynamics surrounding stenoses with minimal flow disturbance, and thus could potentially assess elevated WSS and risk of plaque rupture.