Huabei Jiang’s research while affiliated with Chongqing University of Posts and Telecommunications and other places

Prenatal alcohol exposure (PAE) is a major contributor to fetal alcohol spectrum disorder (FASD), resulting in neurodevelopmental abnormalities. This study utilizes photoacoustic tomography (PAT) to investigate the effects of PAE on fetal brain vasculature in mice. PAT imaging was conducted from embryonic Day 10 (E10) to Day 20 (E20), aimed to compare two alcohol‐exposed groups with a control group. Key vascular parameters, including blood vessel diameter and density, and oxygen saturation (sO 2 ), were analyzed. Results show significant reductions in vessel size and density, as well as reduced sO 2 levels, in alcohol‐exposed groups, especially from E14 onward, compared to controls. These findings underscore the vulnerability of the fetal brain to alcohol exposure during early development and highlight the potential of PAT as a valuable tool for investigating FASD‐related vascular changes.

In photoacoustic imaging (PAI), a delay-and-sum (DAS) beamforming reconstruction algorithm is widely used due to its ease of implementation and fast execution. However, it is plagued by issues such as high sidelobe artifacts and low contrast, that significantly hinder the ability to differentiate various structures in the reconstructed images. In this study, we propose an adaptive weighting factor called spatial coherence mean-to-standard deviation factor (scMSF) in DAS, which is extended into the spatial frequency domain. By combining scMSF with a minimum variance (MV) algorithm, the clutter level is reduced, thereby enhancing the image contrast. Quantitative results obtained from the phantom experiment demonstrate that our proposed method improves contrast ratio (CR) by 30.15 dB and signal-to-noise ratio (SNR) by 8.62 dB compared to DAS while also improving full-width at half maxima (FWHM) by 56%. From the in-vivo experiments, the scMSF-based reconstruction image exhibits a higher generalized contrast-to-noise ratio (gCNR), indicating improved target detectability with a 25.6% enhancement over DAS and a 22.5% improvement over MV.

In the rapidly evolving landscape of medical imaging, endoscopy emerged as a revolutionary technique, facilitating non-invasive visualization of internal body structures, and playing a crucial role in the diagnosis, treatment, and monitoring of diverse medical conditions. Photoacoustic endoscopy (PAE) is an advanced endoscopic imaging technique that evolved from photoacoustic imaging and traditional endoscopy. PAE’s high-resolution images, which reveal both functional and molecular information, are made possible through the combination of laser light with sound waves. Recent advancements in PAE include miniaturized probes and high-speed imaging capability. These are propelling its clinical translation for early disease detection, accurate diagnosis, and image-guided interventions. PAE’s potential applications are vast, and its integration with artificial intelligence and other imaging modalities holds promise for personalized medicine and comprehensive medical imaging in the future. This chapter offers an overview of PAE, encompassing its historical development and recent applications in the medical field. The fundamental principle of PAE is explored, alongside key technological advancements that have propelled its clinical utility. Additionally, the chapter delves into the applications of a typical PAE device in cutting-edge research, showcasing its potential in various medical disciplines. In conclusion, this chapter discusses current challenges in the development of PAE and its potential to reshape the medical landscape through transformative diagnostic and therapeutic possibilities.

Puncture biopsy is an important clinical technique to obtain diseased tissue for pathological diagnosis, where imaging guidance is critical. In this paper, we describe a metal reflector-enhanced microwave-induced thermoacoustic imaging (TAI) approach capable of guiding puncture biopsy for detection of breast cancer and joint diseases. Numerical experimentations simulating puncture guidance in breast cancer and knee gout models were first conducted using (CST STUDIO SUITE) (CST) software, and then ex-vivo experiments were performed followed by qualitative observations and semi-quantitative analysis. The results of both the simulations and ex-vivo experiments showed that our reflector-enhanced TAI could image the puncture needle in high resolution with a large depth of >12cm.

Traditional diagnostic techniques including visual examination, ultrasound (US), and magnetic resonance imaging (MRI) have limitations of in-depth information for the detection of nail disorders, resolution, and practicality. This pilot study, for the first time, evaluates a dual-modality imaging system that combines photoacoustic tomography (PAT) with the US for the multiparametric quantitative assessment of human nail. The study involved a small cohort of five healthy volunteers who underwent PAT/US imaging for acquiring the nail unit data. The PAT/US dual-modality imaging successfully revealed the fine anatomical structures and microvascular distribution within the nail and nail bed. Moreover, this system utilized multispectral PAT to analyze functional tissue parameters, including oxygenated hemoglobin, deoxyhemoglobin, oxygen saturation, and collagen under tourniquet and cold stimulus tests to evaluate changes in the microcirculation of the nail bed. The quantitative analysis of multispectral PAT reconstructed images demonstrated heightened sensitivity in detecting alterations in blood oxygenation levels and collagen content within the nail bed, under simulated different physiological conditions. This pilot study highlights the potential of PAT/US dual-modality imaging as a real-time, noninvasive diagnostic modality for evaluating human nail health and for early detection of nail bed pathologies.

INTRODUCTION Delirium is associated with mortality and new onset dementia, yet the underlying pathophysiology remains poorly understood. Development of imaging biomarkers has been difficult given the challenging nature of imaging delirious patients. Diffuse optical tomography (DOT) offers a promising approach for investigating delirium given its portability and three‐dimensional capabilities. METHODS Twenty‐five delirious and matched non‐delirious patients (n = 50) were examined using DOT, comparing cerebral oxygenation and functional connectivity in the prefrontal cortex during and after an episode of delirium. RESULTS Total hemoglobin values were significantly decreased in the delirium group, even after delirium resolution. Functional connectivity between the dorsolateral prefrontal cortex and dorsomedial prefrontal cortex was strengthened post‐resolution compared to during an episode; however, this relationship was still significantly weaker compared to controls. DISCUSSION These findings highlight DOT's potential as an imaging biomarker to measure impaired cerebral oxygenation and functional dysconnectivity during and after delirium. Future studies should focus on the role of cerebral oxygenation in delirium pathogenesis and exploring the etiological link between delirium and dementias. Highlights We developed a portable diffuse optical tomography (DOT) system for bedside three‐dimensional functional neuroimaging to study delirium in the hospital. We implemented a novel DOT task‐focused seed‐based correlation analysis. DOT revealed decreased cerebral oxygenation and functional connectivity strength in the delirium group, even after resolution of delirium.

Visualization and analysis of microstructure of materials or tissue play a pivotal role in industrial manufacturing and pathological diagnosis. Microwave-induced thermoacoustic microscopy (TAM) enables imaging at the microscopic level. TAM, however, is currently qualitative and cannot quantitatively measure intrinsic electromagnetic parameters of materials/tissue, such as conductivity. Here, we propose a quantitative microwave-induced thermoacoustic microscopy (qTAM) approach capable of quantitatively recovering conductivity using a finite element-based iterative inversion strategy coupled with thermoacoustic measurements. We validate the qTAM approach using tissue-mimicking phantoms, and demonstrate its applications to imaging flexible circuits, ex vivo rabbit bone, and rat brain tissues. The results obtained suggest that qTAM may have the potential to become a quantitative tool for microscopic imaging of materials and tissues.