Contrast-Enhanced Structured Illumination Ultrasound Imaging (CE-SIU)

Super-resolution ultrasound (SRUS) technology based on contrast agents has shown great potential in in vivo microvascular blood flow imaging and has become a hot topic in the industry in recent years. SRUS represented by ultrasound localization microscopy (ULM) eliminates the point spread function (PSF) caused by diffraction by localizing sparse microbubbles in the image, and then constructs a super-resolution blood flow structure map through long-term image accumulation. It is worth mentioning that almost all current super-resolution strategies, including ULM, adopt postimage processing strategies. In optics, in addition to postimage processing super-resolution techniques, the design of the illumination light field is also a popular super-resolution imaging method. This inspired us to design the acoustic field to achieve a super-resolution blood flow imaging strategy based on structured acoustic field illumination. In this article, we propose a new structured acoustic field illumination design method, which achieves 2-D structured acoustic field design by improving the acoustic field calculation of Gerchberg-Saxton algorithm (GSA) based on Talbot effect. At the same time, we have designed a corresponding structured acoustic field reconstruction strategy that can adaptively reconstruct any structured illumination method, and the reconstructed image frame rate is comparable to that of multiangle plane wave. Combined with image postprocessing methods, we have obtained contrast-enhanced structured illumination ultrasound (CE-SIU), which reduces the full width at half maximum (FWHM) of the microbubble PSF, breaking through the lateral resolution limit of contrast-enhanced imaging. The super-resolution strategy based on acoustic field design proposed in this study provides new insights and perspectives for the development of the overall technical route of SRUS.