Clutter filter wave imaging (CFWI): A new way to visualize and detect mechanical waves propagation

Abstract

The elastic properties of human tissue can be evaluated through the study of mechanical wave propagation using highframe rate imaging and motion estimation. Methods such as block-matching or phase-based motion estimation are usually used to estimate the motion induced by the mechanical wave. These methods can be time consuming because of the processing involved and the need for specific types of averaging filter to detect the mechanical waves. In this paper, a new method able to detect the mechanical wave propagation without motion estimation techniques are presented. Instead of estimate the motion induced by the mechanical waves propagation, the motion is attenuated or rejected using a clutter filter. By doing so, the mechanical wave propagation will be “visible” as gray/darker band on a B-mode sequence. This technique is tested on the propagation of the pulse wave in a carotid artery and compared to the results obtain with Tissue Doppler Imaging. The results show that Clutter Filter Wave Imaging is able to estimate the pulse wave velocity with a better consistency than Tissue Doppler Imaging, using the same averaging filter for both filter. Moreover, we have shown that the presented method is able to detect the mechanical wave without needing any averaging technics.