Accuracy of flow velocity estimations over regions including great depths: an experimental study

Recent advances in flow imaging have warranted a comprehensive system calibration, from shallow to deep flow regions. When using probes equipped with elevation lenses that focus the acoustic energy over a single (and often shallow) depth, significant differences must be expected from velocity measurements at various depths. This study uses a multi-depth flow phantom to examine how the accuracy and precision of Doppler velocity estimation are impacted by the probe acoustic lenses. The results based on linear array probes experimentally confirm that, in velocity measurements, possible spatial velocity gradients determine performance drops that worsen with the distance from the probe elevation focus.