Doppler color-flow images from a stenosed arterial model: interpretation of flow patterns

The capability of the recently introduced Doppler color-flow mapping devices to accurately detect flow patterns in the region of an arterial stenosis was evaluated by use of an in vitro flow model. Pulsatile flow simulating that in a low-resistance vessel was induced through a straight acrylic tube, which alternatively contained axisymmetric stenoses of 0%, 20%, 40%, 60%, and 80% diameter reduction. Doppler color-flow mapper images were taken in realtime along the tube midplane from 0 to 8 diameters downstream of each stenosis. Comparison of the Doppler color-flow mapping results with similarly recorded flow visualization (hydrogen bubble) images showed a close correspondence of key features of the flow, including detection of a high-velocity, centerline jet and near-wall separated flow zones. Distinctive flow patterns exist with each stenotic case, and these should be of considerable value in diagnosing clinical disease conditions.