Phase-coherence volumetric ultrasonic imaging of full matrix capture data using row-column-addressed array

Row-column-addressed (RCA) arrays enable three-dimensional (3D) volumetric ultrasonic imaging with significantly reduced channel count and system complexity compared with fully addressed planar arrays. However, their imaging performance is limited by steering-angle-dependent acoustic fields and receive sensitivity, which can lead to degraded off-axis resolution, elevated sidelobes, and ghost artifacts. To address these challenges, this study proposes a systematic phase-coherence-based imaging framework for enhancing 3D volumetric imaging quality using full matrix capture data acquired with RCA arrays. A suite of 3D imaging algorithms is developed based on different statistical phase-coherence measures, enabling effective suppression of incoherent contributions in the beamformed signals. Experimental results demonstrate that phase-coherence weighting substantially improves contrast ratio and reduces imaging artifacts compared with conventional delay-and-sum based approaches. Among the evaluated methods, the sign coherence factor achieves a favorable balance between computational efficiency and imaging performance while effectively mitigating near-field effects. Overall, these results demonstrate the feasibility of achieving high-quality 3D volumetric ultrasonic imaging with RCA arrays and highlight the potential of phase-coherence-based strategies to provide robust and interpretable volumetric reconstructions for a broad range of ultrasonic imaging applications.