A Centralized Displacement Operation with Application to Artifact Reduction in Ultrasonic Elastography

Because stiff tissue deforms less than soft tissue under the same external compression, elastography can provide relative stiffness information of biological tissue. However, elastography suffers from artifact noise which may come from two dominant sources: decorrelation error and amplitude modulation error. In order to reduce artifacts and improve the quality of ultrasonic elastography, this paper proposes a centralized displacement operation based on an adaptive anisotropic diffusion filtering. We have applied the median and the mean of displacement axial gradient to differentiate edges from artifacts and categorize the whole displacement image into two different patterns; followed by the adjustable anisotropic diffusion filtering. The proposed algorithm can reduce artifact noise and, at the same time, maintain the tissue structure. Phantom testing shows that the proposed method can improve the quality of ultrasonic elastography in terms of tissue SNRe and CNRe values.