A Novel High Frame Rate and High Contrast Coherent Plane Wave Compounding Approach Utilizing Euclidean Distance Transform

To address the challenge of reduced image quality in plane-wave imaging (PWI), coherent plane-wave compounding (CPWC) has been introduced. CPWC combines plane wave images from various directions (i.e., with different angles) to enhance image quality. However, the number of angles required to achieve satisfactory image quality directly impacts the maximum attainable frame rate in CPWC. Consequently, there exists a tradeoff between image quality, particularly contrast, and frame rate. In this study, our goal is to mitigate this compromise by enhancing image contrast while simultaneously improving the frame rate of CPWC imaging. Our proposed technique includes skeleton-based spatial filtering of each beamformed radio frequency (RF) image at each angle before coherent compounding. For this purpose, we introduce a novel filtering technique based on the Euclidean distance transform (EDT). EDT assigns the minimum distance from each foreground pixel to the background. Given that lower contrast in CPWC imaging stems from information leakage (i.e., higher sidelobe levels), we propose using the EDT to reduce this effect, thereby improving contrast. We implemented our proposed technique using the Plane Wave Imaging Challenge in Medical Ultrasound (PICMUS) datasets.