Adaptive scaling Wiener postfilter using generalized coherence factor for coherent plane-wave compounding

Abstract

This paper proposes an adaptive scaling Wiener postfilter (AScW) for coherent plane-wave compounding (CPWC) to improve the image quality. AScW introduces an adaptive scale factor dependent on the signal incoherence to maintain the performance balance between good noise suppression and good robustness. AScW utilizes several plane waves with a small angular difference to calculate generalized coherence factor (GCF) for the estimation of signal incoherence and noise power. And a standard depth parameter is used to further adjust the beamforming performance of AScW and improve speckle quality. The proposed method was tested on datasets acquired from simulation, experimental phantom and in-vivo study provided by the Plane-wave Imaging Challenge in Medical Ultrasound (PICMUS). Results show that AScW applied to CPWC can provide a good speckle quality and lateral resolution, while attaining a satisfying contrast. AScW can achieve maximal improvements of speckle signal-to-noise ratio (sSNR) by 36.4% (simulation) and 44.8% (experiment) compared with GCF, while 14.4% (simulation) and 12.5% (experiment) compared with the scaled Wiener postfilter (ScW). And the maximal lateral full width at half maximum (FWHM) improvements are 51.9% upon GCF and 53.7% upon ScW. Meanwhile, the contrast of AScW is comparable to that of GCF. From the results of in-vivo study, AScW also shows its clinical application potential for the visualization of anatomical structures and hyper echoic structures in ultrasound imaging.

Keywords: Adaptive scaling factor; Coherent plane-wave compounding; Generalized coherence factor; Ultrasound imaging; Wiener postfilter.