Enhancement of Displacement Estimation of Breast Tissue in Ultrasound Elastography

Breast tissue displacements estimation in static ultrasound elastography, is a medical imaging technique which provides information on the local rigidity of tissues. Despite the fact that this technique has a major interest in clinical diagnosis, it suffers from increased deterioration due to the presence of speckle noise, artifacts and poor detail accuracy which appeared during the B-mode image acquisition process. Therefore, the application of Block Matching (BM) technique will greatly amplify the speckle noise and deteriorate the image quality. In this perspective, the implementation of an optimal technique is crucial for optimizing the quality of mammary displacements tissue. In this paper, we propose a new method based on the BM model that is to improve the old BM (OBM) technique. In this respect, an improvement of pre-processing step is satisfactory, in order to establish accurate tissue displacement estimation. The research was validated on a database of 20 patients with breast malignant tumor. Biophysical parameters has been adapted and used to eliminate artifacts and speckle noise, once the images are filtered; the BM model is implemented after to estimate tissue displacements. Based on the clinical results, quantitative analysis verifies that the tissue displacements estimated by our proposed strategy are more efficient than the OBM and Bilinear Deformable Block Matching (BDBM) techniques, our proposed approach gives better values in term of standard deviation (SD), higher contrast to noise ratio (CNR), greater peak signal-to-noise ratio (PSNR) and excellent structural similarity (SSIM) than OBM and BDBM techniques. The results of the proposed model are encouraging, allowing excellent estimates. The proposed model provides a new and appropriate solution for improving estimation of mammary tissue displacements. The proposed new strategy could be a powerful diagnostic tool to be used in clinical evaluation dedicated to breast ultrasound elastography.