Improving plane wave ultrasound imaging through real-time beamformation across multiple arrays

Abstract

Ultrasound imaging is a widely used diagnostic tool but has limitations in the imaging of deep lesions or obese patients where the large depth to aperture size ratio (f-number) reduces image quality. Reducing the f-number can improve image quality, and in this work, we combined three commercial arrays to create a large imaging aperture of 100 mm and 384 elements. To maintain the frame rate given the large number of elements, plane wave imaging was implemented with all three arrays transmitting a coherent wavefront. On wire targets at a depth of 100 mm, the lateral resolution is significantly improved; the lateral resolution was 1.27 mm with one array (1/3 of the aperture) and 0.37 mm with the full aperture. After creating virtual receiving elements to fill the inter-array gaps, an autoregressive filter reduced the grating lobes originating from the inter-array gaps by − 5.2 dB. On a calibrated commercial phantom, the extended field-of-view and improved spatial resolution were verified. The large aperture facilitates aberration correction using a singular value decomposition-based beamformer. Finally, after approval of the Stanford Institutional Review Board, the three-array configuration was applied in imaging the liver of a volunteer, validating the potential for enhanced resolution.

In vivo bistatic dual-aperture ultrasound imaging and elastography of the abdominal aorta

“…Recent developments in ultrafast imaging ( Tanter and Fink, 2014 ) have enabled the use of multiple apertures during one acquisition, by performing interleaved scanning ( Peralta et al, 2019 ; de Hoop et al, 2020 ; Liu et al, 2022a ), or in a configuration that enables the transmission of one coherent wavefront using all apertures at the same time ( Foiret et al, 2022 ). In these studies, multiple linear or curved array transducers were used, typically driven by research ultrasound platforms, to develop the multi-aperture imaging systems.…”

“…However, so far all these studies were conducted in ex vivo experiments. In vivo application of ultrafast multi-aperture ultrasound imaging have been shown in ( Peralta et al, 2020 ; Foiret et al, 2022 ), in which its performance in terms of increased field-of-view (FOV) and improved resolution was shown in the liver of a healthy volunteer.…”

Coherent Bistatic 3-D Ultrasound Imaging Using Two Sparse Matrix Arrays

“…The four received signals are denoted by the different combinations in transmit (T) and receive (R), followed by the respective transducer number. In 2D, coherent apertures consisting of multiple arrays have previously shown its merit in enhancing the image quality after coherent compounding in static phantom studies [26][27][28] and in vivo liver imaging [28]. In dynamic cardiovascular phantoms, also functional imaging improved by utilizing the multi-directional gain in high resolution phase information for correlation-based tracking [29].…”

Implementation of Constrained Swept Synthetic Aperture Using a Mechanical Fixture

“…We have recently demonstrated the value of increasing aperture size to improve lateral resolution and detectability at depth in simulation [ 10 ], ex vivo experiment [ 11 ], and in vivo imaging[ 12 ] even in the presence of image-degrading clutter effects. Multi-transducer experiments have demonstrated improvements in resolution that scale with the effective aperture extent [ 13 - 15 ] and provided enhanced visualization of in vivo liver and kidney structures.…”