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Histopathology has remained the gold standard for surgical margin assessment for decades. However, routine pathological examination based on formalin-fixed and paraffin-embedded (FFPE) tissues is laborious and time-consuming, failing to guide surgeons intraoperatively. Here, we propose a rapid, label-free, and non-destructive histological imaging method, termed microscopy with ultraviolet single-plane illumination (MUSI). With intrinsic fluorescence from deep ultraviolet excitation, MUSI enables both ex vivo and in vivo imaging of fresh and unprocessed tissues at the subcellular level with an imaging speed of 0.5 mm2/s, generating high-quality optically sectioned surface images from irregular surgical tissues with a long depth-of-field. We demonstrate that MUSI could differentiate between different subtypes of human lung adenocarcinomas (e.g., lepidic, acinar, papillary, and micropapillary), revealing diagnostically important features that are comparable to the gold standard FFPE histology. As an assistive imaging platform, MUSI can provide immediate feedback to surgeons and pathologists for intraoperative decision-making, holding great promise to revolutionize the current clinical practice in surgical pathology. © 2024 Author(s).

Clinical histopathological analyses usually require hematoxylin-and eosin-(H&E) as regular staining to visualize various tissue types and morphological changes, whereas some special stains are also essential to provide auxiliary information on particular components. However, it is infeasible to simultaneously implement diverse histological staining on the same tissue section. In this paper, we propose a multiple histological staining model that enables arbitrary staining image generation from label-free autofluorescence images. We use AdaIN to fuse styles into the image reconstruction process for source image content preservation. Moreover, direct image match loss is proposed to replace image reconstruction loss. Experimental results on mouse kidney tissue demonstrate the efficiency and advantage of our model compared to the baseline frameworks. Furthermore, we also validated the superior performance of the proposed model using mouse liver and heart tissues, which confirms that our method is generally applicable to multiple organs. © 2023 IEEE.

Significance: Photoacoustic microscopy (PAM) is a promising imaging technique to provide structural, functional, and molecular information for preclinical and clinical studies. However, expensive and bulky lasers and motorized stages have limited the broad applications of conventional PAM systems. A recent trend is to use low-cost light sources and miniaturized designs to develop a compact PAM system and expand its applications from benchtop to bedside. Aim: We provide (1) an overview of PAM systems and their limitations, (2) a comprehensive review of PAM systems with low-cost light sources and their applications, (3) a comprehensive review of PAM systems with miniaturized and handheld scanning designs, and (4) perspective applications and a summary of the cost-effective and miniaturized PAM systems. Approach: Papers published before July 2023 in the area of using low-cost light sources and miniaturized designs in PAM were reviewed. They were categorized into two main parts: (1) low-cost light sources and (2) miniaturized or handheld designs. The first part was classified into two subtypes: pulsed laser diode and continuous-wave laser diode. The second part was also classified into two subtypes: galvanometer scanner and micro-electro-mechanical system scanner. Results: Significant progress has been made in the development of PAM systems based on low-cost and compact light sources as well as miniaturized and handheld designs. Conclusions: The review highlights the potential of these advancements to revolutionize PAM technology, making it more accessible and practical for various applications in preclinical studies, clinical practice, and long-term monitoring. © 2023 The Authors.

Surgical margin analysis (SMA), an essential procedure to confirm the complete excision of cancerous tissue in tumor resection surgery, requires intraoperative diagnostic tools to avoid repeated surgeries due to a positive surgical margin. Recently, by taking the advantage of the high intrinsic optical absorption of DNA/ RNA at 266 nm wavelength, ultraviolet photoacoustic microscopy (UV-PAM) has been developed to provide high-resolution histological images without labeling, showing great promise as an intraoperative tool for SMA. To enable the development of UV-PAM for SMA, here, a high-speed and open-top UV-PAM system is presented, which can be operated similarly to conventional optical microscopies. The UV-PAM system provides a high lateral resolution of 1.2 µm, and a high imaging speed of 55 kHz A-line rate with one-axis galvanometer mirror scanning. Moreover, to ensure UV-PAM images can be easily interpreted by pathologists without additional training, the original grayscale UV-PAM images are virtually stained by a deep-learning algorithm to mimic the standard hematoxylin-and eosin-stained images, enabling training-free histological analysis. Mouse brain slice imaging is performed to demonstrate the high performance of the open-top UV-PAM system, illustrating its great potential for SMA applications. © 2022 JoVE Journal of Visualized Experiments.