Volumetric Ultrasound Imaging Based on 4096-Element Large-Aperture 2D Array.

Large aperture 2D arrays improve ultrasound imaging by increasing lateral resolution at depth, owing to the inverse relationship between beamwidth and aperture size, and by enabling higher contrast resolution through electronic focusing in elevation. We present a 4,096-element (128 × 32) large-aperture 2D ultrasound array with element pitches of 0.65 mm (azimuth) and 0.5 mm (elevation), operating at a 2.4 MHz center frequency with over 80% -6 dB bandwidth. The Active aperture measures 83.2 mm × 16 mm and is integrated with custom multiplexing ASICs, local preamplifiers for sensitivity enhancement, and an FPGA-based control interface, forming a fully reconfigurable imaging platform. Phantom experiments using a commercial CIRS 054GS tissue-mimicking phantom demonstrated penetration beyond 120 mm. The system achieved axial and lateral resolutions of 0.40 mm and 0.46 mm respectively at depths of 51 mm, with a maximum CNR of 2.13 and gCNR of 0.94 for cyst targets. These results validate the effectiveness of the large aperture 2D array for high-resolution volumetric ultrasound imaging and underscore the promise for future clinical translation.