High resolution 3D color flow mapping: applied to the assessment of breast vasculature

In order to develop a three dimensional (3D) color flow map of low velocity flow through small vessels, we explore the use of a high resolution velocity estimation technique and a new technique for the differentiation of regions of flow and stationary tissue. Following the transmission of a wideband signal, a signal processing strategy that tracks the motion of small regions of blood is used to estimate velocity. We find that the use of wideband transmission, with coherent estimation over a long pulse train, provides the opportunity to map very low velocity flow, and to detect flow at beam-vessel angles near 90 degrees. The use of 3D continuity processing to differentiate flow and stationary tissue is shown to improve noise immunity. In-vitro and in-vivo velocity maps are presented. The 3D velocity profile is then constructed.