Journal of Biomedical Optics最新文献

{"title":"Optical coherence tomography and elastography for <i>ex vivo</i> visualization of early gastric cancer.","authors":"Alana G Gonzales, Caitlin Ruhland, Graham Spicer, Stephen Mead, Massimiliano Di Pietro, Ashraf Sanduka, Photini F S Rice, Ryan H W Mitstifer, Sarah E Bohndiek, Travis W Sawyer, Jennifer Kehlet Barton","doi":"10.1117/1.JBO.31.2.026501","DOIUrl":"10.1117/1.JBO.31.2.026501","url":null,"abstract":"<p><strong>Significance: </strong>Stomach (gastric) cancer survival depends significantly on the stage in which it is detected, and surveillance with white light endoscopy exhibits poor contrast between gastric cancer and healthy tissue, especially at early stages. Early gastric cancer can exhibit changes in epithelial microstructure, including loss of regular gastric pit structure and collagen alterations which increase tissue stiffness.</p><p><strong>Aim: </strong>To improve contrast between early cancer and normal tissue, we investigate the use of optical coherence tomography (OCT) and elastography (OCE) to visualize changes in tissue structure and stiffness consistent with gastric cancer.</p><p><strong>Approach: </strong>Images of eight samples of <i>ex vivo</i> human stomach tissue from three patients were collected with a benchtop OCT system. OCT was performed for qualitative visualization of tissue structure. OCE was then performed on 17 regions of interest using a simplified optical palpation method to extract relative stiffness measurements. A transparent silicone reference layer was placed on the tissue, and axial compression was applied. The resulting deformation (strain) of the reference layer was measured, and the corresponding stress applied to the sample surface was extracted from the characteristic stress-strain curve of the reference material. Spatially resolved stress measurements were mapped and overlaid on en face OCT images. Tissue classification was confirmed by pathology.</p><p><strong>Results: </strong>OCT image volumes showed more distinct gastric pit and tissue layer structure, as well as less optical attenuation, in normal tissue compared to gastric metaplasia and focal signet ring cell carcinoma (SRCC). Exemplary OCE-derived stress maps showed a trend of increasing measured stress with progression of precancer (metaplasia and dysplasia) and SRCC, suggesting increased tissue stiffness.</p><p><strong>Conclusions: </strong>This proof-of-concept study provides evidence that OCT and OCE may be capable of visualizing differences in tissue structure and stiffness between normal, metaplastic, dysplastic, and early cancerous gastric tissue, potentially providing the basis for improved screening tools with higher sensitivity.</p>","PeriodicalId":15264,"journal":{"name":"Journal of Biomedical Optics","volume":"31 2","pages":"026501"},"PeriodicalIF":2.9,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12904152/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146201871","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Integrated spectral and depth compensation approach for optimizing oxygen saturation and total hemoglobin estimation in photoacoustic tomography for ovarian lesion diagnosis.","authors":"Lukai Wang, Yixiao Lin, Haolin Nie, Jinhua Xu, Sanskar Thakur, Quing Zhu","doi":"10.1117/1.JBO.31.2.026002","DOIUrl":"10.1117/1.JBO.31.2.026002","url":null,"abstract":"<p><strong>Significance: </strong>Photoacoustic tomography (PAT) holds promise for non-invasive functional imaging in ovarian cancer diagnostics. However, accurate estimation of oxygen saturation ( <math> <mrow> <msub><mrow><mo>%</mo> <mi>sO</mi></mrow> <mn>2</mn></msub> </mrow> </math> ) and total hemoglobin concentration (THb) is hindered by wavelength- and depth-dependent fluence variations.</p><p><strong>Aim: </strong>We aim to improve the accuracy and clinical utility of <math> <mrow> <msub><mrow><mo>%</mo> <mi>sO</mi></mrow> <mn>2</mn></msub> </mrow> </math> and THb quantification in transvaginal ultrasound-guided PAT (US-PAT) by developing an integrated spectral and depth compensation (ISDC) method that corrects for both spectral distortion and depth-dependent attenuation.</p><p><strong>Approach: </strong>We introduce a spectral compensation strategy derived from Monte Carlo simulations and integrate it with depth-wise fluence correction to construct the proposed ISDC method. The approach has been validated using phantoms with known optical properties and applied to clinical PAT data from 82 ovarian lesions (67 benign and 15 malignant). Diagnostic performance was evaluated using logistic regression and receiver operating characteristic analysis.</p><p><strong>Results: </strong>In phantom experiments, ISDC improved <math> <mrow> <msub><mrow><mo>%</mo> <mi>sO</mi></mrow> <mn>2</mn></msub> </mrow> </math> estimation accuracy compared with linear unmixing (LU) and enhanced uniformity of THb estimates across depth. In clinical data, ISDC has increased <math> <mrow> <msub><mrow><mo>%</mo> <mi>sO</mi></mrow> <mn>2</mn></msub> </mrow> </math> values by <math><mrow><mo>∼</mo> <mn>5</mn> <mo>%</mo></mrow> </math> in both benign and malignant lesions, enhanced contrast of THb between malignant and benign lesion groups (mean THb ratio <math> <mrow> <msub><mrow><mi>R</mi></mrow> <mrow><mi>THb</mi></mrow> </msub> </mrow> </math> has increased from 1.4 to 1.9), and achieved higher classification performance (AUC = 0.93 versus 0.88 for LU) when combining <math> <mrow> <msub><mrow><mo>%</mo> <mi>sO</mi></mrow> <mn>2</mn></msub> </mrow> </math> and THb features.</p><p><strong>Conclusions: </strong>The ISDC approach significantly enhances the quantitative accuracy and diagnostic performance of PAT by compensating for both spectral and depth fluence variations within biological tissue. These improvements support the integration of ISDC into US-PAT systems for ovarian lesion characterization and future clinical applications.</p>","PeriodicalId":15264,"journal":{"name":"Journal of Biomedical Optics","volume":"31 2","pages":"026002"},"PeriodicalIF":2.9,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12869027/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146125181","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Learning to simulate realistic human diffuse reflectance spectra.","authors":"Marco Hübner, Ahmad Bin Qasim, Alexander Studier-Fischer, Maike Rees, Viet Tran Ba, Jan-Hinrich Nölke, Silvia Seidlitz, Jan Sellner, Janne Heinecke, Jule Brandt, Berkin Özdemir, Kris Dreher, Alexander Seitel, Felix Nickel, Caelan Max Haney, Karl-Friedrich Kowalewski, Leonardo Ayala, Lena Maier-Hein","doi":"10.1117/1.JBO.31.2.026004","DOIUrl":"10.1117/1.JBO.31.2.026004","url":null,"abstract":"<p><strong>Significance: </strong>Hyperspectral imaging is a noninvasive, cost-effective modality with transformative clinical potential. Its adoption is limited by the lack of accurate and efficient methods that relate spectra to tissue parameters, essential for both AI training and validation of imaging methods, as gold standard Monte Carlo (MC) simulations remain prohibitively computationally expensive.</p><p><strong>Aim: </strong>We aim to develop a scalable and accurate method for generating realistic tissue reflectance spectra in support of AI development and validation in biomedical imaging.</p><p><strong>Approach: </strong>We trained a general-purpose neural surrogate model on <math><mrow><mo>></mo> <mn>50</mn></mrow> </math> million MC simulations based on a flexible multilayer tissue model. We validated our model against <math><mrow><mo>></mo> <mn>5000</mn></mrow> </math> open surgery <i>in vivo</i> hyperspectral images, annotated with 23 tissue classes for stratified performance analysis. In addition, we qualitatively evaluated clinical potential by testing whether surrogate-generated spectra enable recovery of organ-specific oxygenation dynamics in a controlled porcine aortic clamping experiment.</p><p><strong>Results: </strong>The surrogate model achieved accuracy matching MC simulations with 5-10 million photons while delivering inference five orders of magnitude faster. Across 140 million human tissue spectra, it improved spectral recall by 13-48 percentage points over existing surrogate models. Scaling analyses revealed a power law relationship between training dataset size and test error, enabling the prediction of training data requirements for target accuracy. Our porcine study suggests that the synthetic data generated with the surrogate model is suitable for recovering organ-specific <math> <mrow><msub><mi>s</mi> <mi>t</mi></msub> <msub><mi>O</mi> <mn>2</mn></msub> </mrow> </math> trajectories.</p><p><strong>Conclusion: </strong>Neural surrogate models can achieve MC-level accuracy and <i>in vivo</i> realism at negligible inference cost, enabling large-scale, compute-efficient data generation for biomedical optics and robust AI development for clinical applications.</p>","PeriodicalId":15264,"journal":{"name":"Journal of Biomedical Optics","volume":"31 2","pages":"026004"},"PeriodicalIF":2.9,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12941064/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147326160","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Digital instrument simulator platform to support the development of noninvasive optical NIR device for placenta monitoring.","authors":"Charly Caredda, Frédéric Lange, Niccole Ranaei-Zamani, Uzair Hakim, Olayinka Kowobari, Dimitrios Siassakos, Sara Hillman, Anna L David, Subhabrata Mitra, Ilias Tachtsidis","doi":"10.1117/1.JBO.31.2.027003","DOIUrl":"https://doi.org/10.1117/1.JBO.31.2.027003","url":null,"abstract":"<p><strong>Significance: </strong>Abnormal placental development is a major cause of adverse pregnancy outcomes, but current methods for placenta monitoring are not suitable for bedside use. Continuous-wave near-infrared spectroscopy (CW-NIRS) is an optical technique that takes advantage of the near-infrared light to provide functional measurements such as tissue oxygenation at the bedside. However, the placenta is an organ located beneath several layers of tissue, making robust measurement of placental oxygenation with a CW-NIRS device a complex task.</p><p><strong>Aim: </strong>We propose a framework based on light propagation simulations to evaluate the sensitivity of CW-NIRS devices for placenta detection, along with tools to support NIRS instrument development for engineers.</p><p><strong>Approach: </strong>The maternal abdomen was modeled as a four-layer structure (i.e., skin, adipose tissue, muscle, and placenta). We used a numerical solution of the diffusion equation using a finite-element method to assess the sensitivity to measure placental function under various conditions (tissue layer thickness, skin tone, tissue oxygen saturation). We used a calibration procedure to evaluate the probability of acquiring a sufficient irradiation with a CW-NIRS device. We collected ultrasound abdomen images from 142 healthy pregnant participants that we segmented and digitized to demonstrate our approach.</p><p><strong>Results: </strong>With a Mini-CYRIL CW-NIRS device, we showed that placenta monitoring is not possible when using short integration time with a subject having a deep placenta ( <math><mrow><mo>≥</mo> <mn>20</mn> <mtext>  </mtext> <mi>mm</mi></mrow> </math> ) and dark skin tones. With an integration time of 10 s and a temporal binning of 10 points, simulations indicated that subjects with very fair skin tone have a placenta-scanning probability of 12% at a placenta depth of 20 mm and 39% at a depth of 10 mm, using a 50 mm source-detector separation. Thick skin and dark skin tones act as a filter on the NIRS signal, blocking backscattered light and leading to greater absorption in deeper tissues. The spatially resolved spectroscopy method can be used to monitor placental oxygenation with a placenta close to the surface and an oxygen saturation in the muscle layer lower than that of the placenta. The simulation of a realistic cohort of 142 maternal abdomens aimed to identify the optimal acquisition conditions for CW-NIRS devices to be used in placental monitoring.</p><p><strong>Conclusions: </strong>We proposed a framework to evaluate and optimize CW-NIRS sensitivity for placenta detection. Further work is needed to improve the reliability of placental tissue oxygenation.</p>","PeriodicalId":15264,"journal":{"name":"Journal of Biomedical Optics","volume":"31 2","pages":"027003"},"PeriodicalIF":2.9,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12923275/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147270948","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Evaluation of analytical models to estimate depth of fluorescence objects in biological media.","authors":"Héctor A García, Hang M Nguyen, Caleb Y Kwon, Samuel S Streeter, Veronica C Torres, Mayna H Nguyen, Ethan P M LaRochelle, Alberto J Ruiz, Eric Henderson, Scott C Davis, Kimberley S Samkoe","doi":"10.1117/1.JBO.31.2.026003","DOIUrl":"https://doi.org/10.1117/1.JBO.31.2.026003","url":null,"abstract":"<p><strong>Significance: </strong>Performing a ratiometric analysis of the fluorescence signals noninvasively measured at two different wavelengths can provide depth estimates of subsurface inner structures in a simple and fast manner, allowing for real-time applications in clinical settings. This can be done using the initially proposed single-excitation-multiple-emission wavelengths approach or by implementing a modified multiple-excitation-single-emission approach; the latter being sometimes preferred due to the larger variation of tissue optical properties at shorter wavelengths. However, previous works validating this method with Monte Carlo (MC) simulations, experiments on tissue-mimicking phantoms, and <i>in vivo</i> measurements on small animal models have reported different degrees of accuracy.</p><p><strong>Aim: </strong>We tested the influence of factors not generally accounted for in the analytical model used for data interpretation (e.g., tissue geometry and boundaries, inclusion size and shape, and spectral characteristics of the excitation source). To address these limitations, we developed an improved theoretical framework that explicitly accounts for these factors during data interpretation.</p><p><strong>Approach: </strong>Model validation was carried out with MC simulations and with phantom experiments using indocyanine green as the fluorescence contrast agent. The aimed tissue optical properties were those characteristic of the prostate in a wide range of wavelengths (from 550 to 900 nm).</p><p><strong>Results: </strong>The aforementioned factors have a strong influence when changing the original single-excitation-multiple-emission approach to a multiple-excitation-single-emission approach. Though this might make the latter a less preferable method, the low variability of the optical properties in the multiple emission approach (as it happens with prostate tissue) negatively impacts the depth reconstruction process.</p><p><strong>Conclusions: </strong>Regardless of the ratiometric strategy employed, accurate depth estimation requires that the theoretical model closely replicate the experimental conditions. Careful matching of model assumptions to the measurement environment is essential to achieve reliable data interpretation.</p>","PeriodicalId":15264,"journal":{"name":"Journal of Biomedical Optics","volume":"31 2","pages":"026003"},"PeriodicalIF":2.9,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12926504/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147283946","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Computational modeling of oxygen dynamics in port-wine stain photodynamic therapy: treatment outcome optimization and pain management.","authors":"Yijia Li, Qin Li, Xiaoming Hu","doi":"10.1117/1.JBO.31.2.028001","DOIUrl":"10.1117/1.JBO.31.2.028001","url":null,"abstract":"<p><strong>Significance: </strong>Port-wine stains (PWSs) are congenital capillary malformations with the incidence of in newborns of <math><mrow><mo>∼</mo> <mn>0.8</mn> <mo>%</mo></mrow> </math> to 2.1%. Hematoporphyrin monomethyl ether-mediated photodynamic therapy (HMME-PDT) has been widely applied in China for PWS. However, there remains substantial room for improvement in both the phototherapeutic selectivity coefficient (PSC) and pain management.</p><p><strong>Aim: </strong>We investigated the feasibility of modulating transcutaneous oxygen delivery during photodynamic therapy of PWS to enhance therapeutic efficacy and reduce pain.</p><p><strong>Approach: </strong>A three-dimensional (3D) computational biophysical model was employed to elucidate the mechanisms through which transcutaneous oxygen modulation enhances the therapeutic efficacy of HMME-PDT and improves pain management. The model was constructed to simulate the light propagation, photosensitizer kinetics, oxygen diffusion, and reactive oxygen species (ROS) generation. A treatment optimization strategy based on epidermal oxygen regulation was proposed and evaluated in computational studies. The spatiotemporal distributions of singlet oxygen under normoxic, hypoxic, and anoxic conditions were evaluated, and their effects on treatment-induced pain and lesion-targeted cytotoxicity were analyzed.</p><p><strong>Results: </strong>Computational analysis showed that compared with normoxic conditions, hypoxia and anoxia significantly enhanced PSC, with improvements of 48% and 61%, respectively. Furthermore, these oxygen-modulated regimens attenuated treatment-associated pain, reducing photochemical pain duration of 17% (hypoxia) and 30% (anoxia). Choosing the right combination of light source irradiance and surface oxygen supply rate amplified therapeutic performance and patient comfort, achieving a 213% increase in PSC and a 57% reduction in photochemical pain duration. These findings establish a mechanistic framework for advancing precision PDT protocols with minimized iatrogenic discomfort.</p><p><strong>Conclusions: </strong>Established in this computational study, strategic epidermal oxygen restriction critically augments PDT PSC while improving patient tolerance. Computational modeling demonstrates that controlled epidermal hypoxia spatially redistributes oxygen gradients, thereby suppressing superficial ROS generation in nontargeted epidermal layers and selectively concentrating ROS within PWS vasculature. This dual mechanism-simultaneously enhancing therapeutic precision and attenuating treatment-induced pain-presents a pioneering strategy centered on an active oxygen control strategy for enhancing HMME-PDT clinical outcomes. Future research will progress from preclinical validation in animal models to clinical studies to evaluate the therapeutic efficacy and translational potential of this strategy.</p>","PeriodicalId":15264,"journal":{"name":"Journal of Biomedical Optics","volume":"31 2","pages":"028001"},"PeriodicalIF":2.9,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12867490/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146119089","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"High-performance Brillouin spectroscopy using VIPA-etalon cascades.","authors":"Sophie Chagnon-Lessard, Julian Nicolai, Joshua Steller, Eng Kuan Moo, Hubert Jean-Ruel","doi":"10.1117/1.JBO.31.2.026001","DOIUrl":"10.1117/1.JBO.31.2.026001","url":null,"abstract":"<p><strong>Significance: </strong>Brillouin spectroscopy noninvasively probes mechanical properties of biological materials and has become a valuable tool in various areas of biomedical research. However, the limited contrast of conventional single stage virtually imaged phased array (VIPA) spectrometers restricts many applications. Current contrast enhancement methods have limitations, including incompatibility with line-scanning collection, which is highly advantageous for fast biomechanical mapping.</p><p><strong>Aim: </strong>The aim is to develop and characterize a high-throughput contrast enhancement technique using a VIPA-etalon cascade, designed for compatibility with both confocal and line-scanning geometries across a wide range of wavelengths.</p><p><strong>Approach: </strong>One or more etalons with approximately matched thicknesses are integrated downstream of the VIPA to suppress its Lorentzian tails. A theoretical model and ray-tracing simulation were developed, complemented by experimental validation in confocal and line-scanning setups at 785 and 532 nm, respectively. Brillouin spectra were measured for reference materials and biological samples, including a porcine crystalline lens.</p><p><strong>Results: </strong>Experimentally, the integration of a single high-finesse cascade yielded contrast enhancements of 27 and <math><mrow><mo>∼</mo> <mn>19</mn> <mtext>  </mtext> <mi>dB</mi></mrow> </math> for the confocal and line-scanning geometries, respectively, with less than 50% reduction in peak transmission in both cases. Simulations demonstrated that substantially higher contrast can be achieved in principle with negligible impact on throughput by serializing multiple low-finesse etalons. High-quality Brillouin spectra were obtained in both collection geometries, demonstrating robust performance across diverse samples.</p><p><strong>Conclusions: </strong>The VIPA-etalon cascade markedly improves the performance of Brillouin spectroscopy, offering a straightforward, cost-effective, and versatile solution for analyzing biological samples. It enables precise, high-resolution biomechanical investigations, advancing applications in biomedical research and clinical diagnostics.</p>","PeriodicalId":15264,"journal":{"name":"Journal of Biomedical Optics","volume":"31 2","pages":"026001"},"PeriodicalIF":2.9,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12867489/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146119092","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Circularly polarized light scattering imaging of a cancerous layer creeping under a healthy layer for the diagnosis of early-stage cervical cancer.","authors":"Nozomi Nishizawa, Mahiro Ishikawa, Mike Raj Maskey, Asato Esumi, Toshihide Matsumoto, Takahiro Kuchimaru","doi":"10.1117/1.JBO.31.2.027002","DOIUrl":"10.1117/1.JBO.31.2.027002","url":null,"abstract":"<p><strong>Significance: </strong>Cervical cancer progresses through cervical intraepithelial neoplasia (CIN), which are precursor lesions of cervical cancer. In low-grade CIN, atypical cells are generated inside the squamous epithelium, which causes the accuracy of cytodiagnosis for cervical cancer not to be very high. The grade of CIN can be estimated by the depth of atypical cell infiltration from the basal layer to the surface, rather than the abnormality of cells. Therefore, a noninvasive method is required to evaluate the depths of abnormal cells hidden at depth.</p><p><strong>Aim: </strong>Cancerous tissues beneath healthy tissues were experimentally identified using circularly polarized light scattering (CiPLS). This method enabled the changes in the size of the cell nuclei within the penetration depth in tissue to be investigated.</p><p><strong>Approach: </strong>Artificial unexposed cancerous tissues were prepared that consisted of healthy/cancerous/healthy layers with various thicknesses of the topmost healthy layer and the cancerous layer. A polarization imaging camera with a quarter-wave plate was used to create distribution images of the circular polarization of the scattered light.</p><p><strong>Results: </strong>CiPLS images indicated that the thickness variation of the top healthy layer (the depth of the cancerous layer) caused significant changes in the degree of circular polarization.</p><p><strong>Conclusions: </strong>The depth of unexposed cancer lying within the optical penetration depth can be evaluated using a circular polarization imaging system based on the CiPLS method. These findings will lead to the development of a noninvasive optical diagnostic method for early-stage cervical cancer, potentially improving early detection and treatment outcomes.</p>","PeriodicalId":15264,"journal":{"name":"Journal of Biomedical Optics","volume":"31 2","pages":"027002"},"PeriodicalIF":2.9,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12880821/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146142432","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Deep-learning-based optical coherence tomography reconstruction for high-speed and contrast morphology and vasculature imaging.","authors":"Yudan Chen, Shuo Chen, Jun Song, Da Ma, Mirza Faisal Beg, Zaid Mammo, Myeong Jin Ju","doi":"10.1117/1.JBO.31.2.025001","DOIUrl":"10.1117/1.JBO.31.2.025001","url":null,"abstract":"<p><strong>Significance: </strong>Spectral-domain optical coherence tomography (SD-OCT) has been widely used in clinical ophthalmic imaging for high spatial resolution and phase stability. The implementation of multiple spectrometers could help resolve the challenges of SD-OCT, including limited imaging speed and sensitivity. However, these two improvements cannot be achieved concurrently.</p><p><strong>Aim: </strong>We propose a deep-learning-based approach to enhance both imaging speed and sensitivity of SD-OCT systems using a modified U-Net architecture.</p><p><strong>Approach: </strong>This network adopts a visual state space model to synthesize the high signal-to-noise ratio (SNR) OCT and OCTA from high-speed acquisitions, which bypasses the hardware restriction. The model performance is evaluated both qualitatively and quantitatively using the multiscale structural similarity index measure (MS-SSIM) and contrast-to-noise ratio (CNR).</p><p><strong>Results: </strong>The results demonstrate effective performance in high-SNR OCT/OCTA reconstruction, providing better contrast between the retinal layers and improved delineation of layer boundaries. Fine structures in both the inner and outer retina, such as microcapillaries and choroid, are successfully restored.</p><p><strong>Conclusions: </strong>We proposed an effective approach to improve the OCT image quality while maintaining the high acquisition speed using the DNN-based architecture, enabling simultaneous benefits of high imaging speed and enhanced sensitivity.</p>","PeriodicalId":15264,"journal":{"name":"Journal of Biomedical Optics","volume":"31 2","pages":"025001"},"PeriodicalIF":2.9,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12867675/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146125211","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Considerations for the use of targeted fluorescence contrast agents to detect circulating cancer cell populations with diffuse <i>in vivo</i> flow cytometry.","authors":"Joshua S Pace, Grace Matheson, Gauri Malankar, Lei Wang, Melissa H Wong, Summer L Gibbs, Mark Niedre","doi":"10.1117/1.JBO.31.2.027001","DOIUrl":"10.1117/1.JBO.31.2.027001","url":null,"abstract":"<p><strong>Significance: </strong>Metastasis is a leading cause of cancer-related deaths. Disseminated circulating tumor cells (CTCs) through the bloodstream seed metastatic tumors at distant sites. Most methods for enumerating CTCs in humans clinically rely on drawing and analyzing small blood samples, but these may yield inaccurate estimates of CTC burden and cannot measure CTC changes over time. Identification and enumeration of CTCs for experimental or clinical purposes largely rely on marker-driven analyses by flow cytometry.</p><p><strong>Aim: </strong>In principle, noninvasive fluorescence enumeration of CTCs directly <i>in vivo</i> could provide a more accurate method for enumerating CTCs. However, this will require a specific contrast agent for CTCs. The goal of this work is to define characteristics of useful CTC contrast agents and perform preliminary testing of candidate contrast agents used for fluorescence-guided surgery (FGS).</p><p><strong>Approach: </strong>We evaluated a clinical small-molecule folate receptor-targeted molecular imaging agent (OTL38, pafolacianine), a fluorogenic pan-cathepsin imaging agent (VGT-309, abenacianine), and a set of custom-designed, small-molecule prostate-specific membrane antigen (PSMA)-targeted fluorophores. We tested these contrast agents using <i>in vitro</i> cell culture models and in <i>in vivo</i> murine models.</p><p><strong>Results: </strong>All tested contrast agents showed not only high uptake and labeling by target cell lines but also small but significant labeling of non-cancer blood cells. Contrast agents that exhibited rapid clearance from circulation and the fluorogenic approach resulted in significantly reduced non-specific interfering background fluorescence signals.</p><p><strong>Conclusions: </strong>Although all of the tested targeted fluorescence contrast agents have properties useful for labeling of CTCs, thus far, none has exhibited the required high specificity. This resulted in some labeling of non-cancer blood cells, which presented false-positive CTC counts. Improved contrast agent design and multiplexed use of more than one contrast agent may improve this specificity.</p>","PeriodicalId":15264,"journal":{"name":"Journal of Biomedical Optics","volume":"31 2","pages":"027001"},"PeriodicalIF":2.9,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12842603/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146092801","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}