Proposal and comparison of quality measures in Crawling Waves Sonoelastography

Ultrasound shear-wave elastography has emerged as a promising non-invasive technique for assessing tissue stiffness and elasticity, enabling the detection and monitoring of pathological changes for disease diagnosis, treatment and monitoring. Crawling Waves Sonoelastography (CWS) is an elastography approach that generates mechanical waves to measure Shear Wave Speed (SWS). However, current estimation techniques for CWS present important limitations such as the presence of artifacts leading to potential diagnostic inaccuracies. The paper proposes two quality parameters for CWS, the coefficient of variation and the normalized spectral deviation, which can be evaluated and used to discard regions where SWS measurements are inaccurate. The proposed quality parameters are tested on gelatin homogeneous and heterogeneous phantoms. Evaluation is carried out across frequencies ranging from 200 Hz to 500 Hz. Results show that both methods can help reduce the variation in SWS and increase the CNR by up to 6dB while reducing the bias by up to 20%.