Optimal synthetic aperture duplex imaging

Current medical ultrasound scanners operate in a sequential fashion. The image is assembled by acquiring data in one direction at a time - this makes the acquisition process cumbersome and slow.  

This is a problem especially for blood flow imaging, where several emissions have to be made in the same direction to find the shift in position of the scatterers between emissions. Therefore, the accuracy of the velocity estimates is directly linked to the number of observation and there is, thus, a trade-off between accuracy and resulting frame rate. 

Scanners are either optimized to see fast flow, and the low velocity components are not visible, or they can visualize slower flow, but then the high velocity part is aliased.

The purpose of this project is to implement a duplex, B-mode and flow, imaging sequence based on the synthetic aperture approach. Optimizing the imaging sequence and stationary echo cancelling filters for different clinical examples. Overcoming the actual limitation of low dynamic range in flow measurements, yielding a high range of applications such as cardiac imaging as an example for fast flow and flow in kidneys and cancer tumors for low velocity flow.

As the vasculature can be an indication of the function, the project will focus on attempts to measure this flow without contrast agents and quantify its value.

Project co-funded by the Danish Advanced Technology Foundation and BK Medical