A Complementary Global and Local Knowledge Network for Ultrasound Denoising with Fine-grained Refinement

Ultrasound imaging serves as an effective and noninvasive diagnostic tool commonly employed in clinical examinations. However, the presence of speckle noise invariably degrades image quality, impeding the performance of subsequent tasks, such as classification and segmentation. Existing methods for speckle noise reduction frequently induce excessive image smoothing or fail to preserve detailed information adequately. In this paper, we propose a complementary global and local knowledge network for ultrasound denoising with fine-grained refinement. Initially, the proposed architecture employs the L-CSwinTransformer as encoder to capture global information, incorporating CNN as decoder to fuse local features. We expand the resolution of the feature at different stages to extract more global information compared to the original CSwinTransformer. Subsequently, we integrate Fine-grained Refinement Block (FRB) within the skip-connection stage to further augment features. We validate our model on two public datasets, HC18 and BUSI. Experimental results demonstrate that our model can achieve competitive performance in both quantitative metrics and visual performance.

I. Introduction

Ultrasound as a cheap and non-invasive examination method has been widely used in various examinations compared with CT and MR [1]–[3]. Although ultrasound examination has huge advantages, ultrasound images are easily affected by speckle noise, which reduces image quality and affects doctors’ clinical diagnosis [4]. Meanwhile, speckle noise in ultrasound images significantly impacts the effectiveness of downstream tasks, such as classification, segmentation and detection [5]–[8]. Thus, creating an automated and efficient algorithm for ultrasound denoising is crucial.