Preliminary experimental verification of synthetic aperture flow imaging using a dual stage beamformer approach

Abstract

A dual stage beamformer method for synthetic aperture flow imaging has been developed. The motivation is to increase the frame rate and still maintain a beamforming quality sufficient for flow estimation that is possible to implement in a commercial scanner. With the new method high resolution images can be obtained continuously, which will highly increase the frame rate. The flow velocity is estimated by using a time-domain cross-correlation technique. The approach is investigated through experiments with the SARUS scanner (Synthetic Aperture Real-time Ultrasound System). A flow rig generates a parabolic laminar flow, and the SARUS scanner is used for acquiring the data from individual channels of the transducer. The experimental results showed that increasing the number of imaging lines used for the estimation form 4 to 24 reduces the standard deviation from 21% to 7.6%. The parameter study showed that the number of cross-correlation functions for averaging and length of the search range influence the performance. © 2011 Springer-Verlag.