Jinxuan Ma

the application of medical ultrasound imaging instruments, microvessel detection is the basis for accurate measurement of vessel parameters and hemodynamic parameters, which directly affects the instrument's ability to diagnose diseases early and evaluate treatment effects. Ultrasound localization microscopy enables superresolution imaging and detecting of deep microvessels via microbubble (MB) localization and tracking, but with low temporal resolution. To balance spatial and temporal resolution, higher-order statistics improves spatial resolution and enables the reconstruction of a microvessel image with shorter acquisitions. However, in plane wave imaging, the point spread function (PSF) broadens and changes with depth, limiting spatial resolution gains. To overcome this and further improve spatiotemporal resolution, a nonlocalized dynamic microvessel imaging method called MB gradient convergence and accumulation reconstruction (GCAR) was proposed. The GCAR method is implemented via spatial and temporal transformations of data at high MB concentrations; the spatial transformation anisotropically shrinks and separates MBs toward the center by using the symmetry of the MB gradient, and the temporal transformation reconstructs microvessels by measuring the statistical independence of the MB signals through high-order cross accumulation. The simulation results revealed that GCAR decreased the full width at half maximum of the MBs by 80%, and was able to separate parallel vessels with spacings of 0.25λ (4 MHz) and 0.125λ (10 MHz). The in vivo results revealed that GCAR could quickly reconstruct the microvasculature with a spatial resolution of 18.19 μm (12 MHz) for the rat brain and 76.28 μm (4 MHz) for the rabbit kidney. GCAR dynamically displays blood flow with a temporal resolution of 50 ms. The GCAR approach improves the spatiotemporal resolution of medical ultrasound imaging instruments, detects smaller and more microvessels with shorter acquisition times, which may provide a useful tool for hemodynamic measurement and examination of microvascular diseases.

Cerebral microvasculature imaging is crucial in the diagnosis of various cerebrovascular diseases. Ultrasound localization microscopy (ULM) enables microvascular imaging at microscopic resolution through the localization of injected microbubbles. However, the strong attenuation of transcranial ultrasound limits the sensitivity of vascular detection, and phase aberration caused by mismatched speed of sound in different tissues reduces the resolution of transcranial ULM (TULM). In this study, a chirp-coded excitation signal was transmitted, and an adaptive attenuation mismatched filter (AMF) was constructed based on the attenuation of each frequency component to improve the signal-to-noise ratio (SNR) and resolution of the compressed signal. Moreover, a multilayer correlation phase correction method was proposed for precision TULM, independently correcting phase aberration in different fields of view. The simulation results confirm that the chirp-coded excitation and AMF increase the SNR by 11.31 dB and the axial resolution by 0.08λ compared with those of the single-pulse excitation under strong attenuation conditions. For phase aberration, the multilayer correlation phase correction improves the lateral and axial resolutions to 0.77λ and 0.19λ, respectively. Additionally, the advanced phase correction method enhances the refocusing ability, improving the contrast by 2.46 dB. For in vivo TULM, the proposed method was more robust, that can reconstruct richer microvascular structures than the conventional method, with a 15.68% increase in saturation. Moreover, the resolution of the microvasculature improved by 7.19 μm (27.24%). These results validate the advantages of the proposed method in achieving rich microvascular reconstruction with higher resolution than conventional methods under transcranial imaging conditions. Thus, the proposed method has application potential in ultrasound imaging of small vessels in the brain.

Researchers in LIS have been working on projects related to health and wellness in various environments, whether related to medical libraries, public libraries, health information behavior, or health information-related community interventions. At the same time, researchers have explored new methods to educate students on both research and on health and wellness as it relates to LIS. It is our goal to bring together the two and create a collaborative panel in which both the panelists and audience participate in a dialog that highlights our research and our engagement with our students over the past couple of years examining health information and practices in our libraries, communities, and classrooms. This non-traditional panel focuses on health and wellness research and its impact on student education and engagement in research activities. The session aims to provide an opportunity for both the organizers and the audience to share their research and/or research agendas and engage in conversations and feedback that can contribute to a cohesive understanding as to what researchers are doing in the area of health and wellness. Our objective is also to discuss current pedagogical practices or student engagement opportunities related to these topical areas. Some examples will be physical and mental health programs and services in public libraries, health literacy courses taught by LIS students in public libraries, health insurance education, using the OCLC Call to Action Opioid toolkit with public libraries, public library staff as health information facilitators, and much more. The session will begin with the Health SIG members presenting their research through five-minute lightning talks. While the panelists describe their research, they will begin creating a visualization on Google Jamboard that represents the research being discussed. After these first presentations, the audience will be invited to share their own research, which will also be added to the collaborative board. Throughout this process, participants will be invited to offer constructive feedback on each contributor’s ideas. Through this process, we hope to create an exciting, interactive session in which the SIG members and the audience will have the opportunity to share research and teaching strategies and potentially find new collaborators.