HSD: Hough-Based Structure-Aware Detection of B-Lines in Lung Ultrasound

B-lines are artifacts produced by the interaction of the ultrasound with the small air-liquid interface, which often serve as crucial biomarkers for evaluating lung pathology, such as the presence of liquid. However, due to the reverberation phenomenon, B-lines manifest as blurred, strip-like comet tails perpendicularly originating from the pleural line, making their automatic identification in speckle-noisy ultrasound images particularly challenging. This study proposes a Hough-based structure-aware detection framework, dubbed HSD, which leverages structural priors and the intrinsic relationship between the pleural line and B-lines to enhance B-line detection in ultrasound images. First, the proposed method adopts the shared encoder and two collaborative decoders to improve B-lines identification with the auxiliary pleural line detection, ensuring effective representation learning of linear structural features under inherent prior constraints. Specifically, one decoder incorporates Hough-based regression to reinforce the modeling of the global linear nature for B-line detection, alleviating the appearance influences of the fuzzy comet-tail. Simultaneously, another pathway enhances the exploration of the slender, curved morphology by integrating semantic context learning with linear heatmap regression, thereby facilitating the detection of the pleural line for calibration of B-lines. Second, we introduce a position-aware rectification module to ensure the consistency of the pleural line and its perpendicular alignment with B-lines. This post-processing module reduces the influence of ambiguous pixels, improving the robustness of B-line detection. Extensive experimental results on an in-house ultrasound dataset demonstrate the superiority of the proposed approach, which achieves a precision of 0.743, a recall of 0.953, and an F-measure of 0.837, substantially ahead of other methods, suggesting its potential for detecting pathological indicators in lung ultrasound.