A new time delay estimation method for displacement estimation in Ultrasound Elastography

Ultrasound Elastography (UE) is a non-invasive technique to image the elasticity distribution of the soft tissues. In UE two ultrasound RF signals obtained before and after applying a compressing load on the tissue are processed for local time delay estimation (TDE) between them. To increase the accuracy of the TDE, it is necessary to use a sub-sample TDE method. In this paper a new TDE method based on the SSD-spline TDE is presented which not only directly produces continuous time delay estimates from the sampled data but also provides a higher rate of accuracy in final elastograms by compensating for the decorrelation of the post-compression RF signals due to the applied compression. Moreover, a two-stage procedure is proposed to reduce the processing time. The experimental results show the proposed algorithm outperforms the golden TDE method of ldquoSSD with cubic spline fitting sub-sample TDErdquo technique in terms of the SNRe and CNRe.