Contribution
A Simulation-Based Comparison of Beamforming Strategies for Local Speed of Sound Estimation using Annular Arrays
* Presenting author
Abstract:
Hyperthermia and thermal ablation are widely used techniques in cancer treatment. To protect surrounding tissues from damage and to accurately monitor thermal doses, ultrasound thermometry can be used, which is based on the measurement of the local speed of sound (SoS) within the tissue. Annular arrays are particularly well suited for such SoS measurements because of their ability to achieve high resolution in all spatial directions with low technical complexity. The ultrasound signal data is acquired using the Full Matrix Capture mode. Beamforming is applied and the SoS is estimated by maximizing or minimizing a figure of merit such as the signal energy in a given beamforming window.In this study, we compare two beamforming strategies, i.e., conventional beamforming and feature-based beamforming, using simulated data to mimic real tissue. Conventional beamforming, typically used in medical applications with linear arrays, focuses on predefined grid points within the measurement region. In contrast, feature-based beamforming identifies significant amplitude maxima in the received signals and performs beamforming at these features. We compare the two approaches for different types of media and reflectors, such as interfaces or uniformly distributed scatterers. The optimal choice and combination of these beamforming strategies improves the local SoS estimation.