Range ambiguities in real-time ultrasound

The frequent occurrence of low-level artifactual echoes in normally echo-free areas of real-time images is shown to be due to a range-ambiguity effect caused by the fast frame rate of real-time equipment. The experimental data demonstrates the range-ambiguous echoes to be present in linear array and mechanical sector scanner real-time images. Several suggestions are made to reduce the effect of the artifact in real-time images. A set of real-time acceptance tests that utilize this artifact are proposed.