Coded Excitation in 3D Ultrasound Imaging with a Lensed Row-Column Array

Row-column (RC) arrays in volumetric imaging present a potential alternative to typical matrix arrays due to their fewer electrical connections. However, these probes have a limited field of view (FOV), which is rectangular and equal to the probe’s footprint. Using a diverging lens can expand the FOV, but the lens causes wave attenuation, which decreases the signal-to-noise ratio (SNR) and the penetration depth of the probe. This paper hypothesizes that incorporating a lens and coded excitation (CE) can maintain a larger field of view (FOV) in 3D ultrasound imaging while enhancing the signal-to-noise ratio (SNR) and penetration depth. A chirp signal with a center frequency of 6 MHz, a bandwidth of 4 MHz, and a duration of 5 μs was used to evaluate the proposed method. The SNR measured from a cyst phantom increased by approximately 10 dB when using CE compared to single sinusoid excitation. This improvement is comparable to the 8 dB attenuation introduced by the lens. Consequently, the penetration  depth improved by around 100λ while preserving the increased FOV provided by the lens.