Journal of Biomedical Optics最新文献

{"title":"Advancing small-animal molecular imaging through multifaceted innovation.","authors":"Guosong Hong, Chongzhao Ran, Scott C Davis, Kenneth M Tichauer","doi":"10.1117/1.JBO.31.5.054701","DOIUrl":"10.1117/1.JBO.31.5.054701","url":null,"abstract":"<p><p>The editorial highlights articles in a JBO special section, as well as emerging trends in small-animal molecular imaging.</p>","PeriodicalId":15264,"journal":{"name":"Journal of Biomedical Optics","volume":"31 5","pages":"054701"},"PeriodicalIF":3.3,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13133712/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147814842","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":"Noninvasive detection and prediction method for temperature in <i>ex vivo</i> biological tissue based on opto-thermal-acoustic co-coupling.","authors":"Yuelin Han, Han Gong, Yiming Ma, Mingjian Sun","doi":"10.1117/1.JBO.31.5.057001","DOIUrl":"10.1117/1.JBO.31.5.057001","url":null,"abstract":"<p><strong>Significance: </strong>Photothermal therapy is a minimally invasive technique that utilizes near-infrared light to induce localized hyperthermia for the selective ablation of cancer cells. Its therapeutic efficacy is highly dependent on precise temperature regulation. Aiming at the problems of invasiveness, insufficient penetration depth existing in current temperature monitoring technologies, we propose an innovative solution.</p><p><strong>Aim: </strong>We propose a method that can be used to monitor the temperature inside <i>ex vivo</i> biological tissues during laser heating.</p><p><strong>Approach: </strong>By constructing an optothermal-acoustic multiphysics coupling model and combining it with our designed dual-optical path co-coupled photoacoustic-photothermal temperature monitoring system, noninvasive observation of the internal heat source distribution in tissues is achieved. On this basis, theoretical data and real data are fused to realize precision measurement of the temperature in the lesion area and adjacent tissues.</p><p><strong>Result: </strong>The results of <i>ex vivo</i> experiments show that this method achieves heat source intensity estimation with an error of less than 3.5% in <i>ex vivo</i> tissues at the millimeter to centimeter depth range, and the temperature measurement error at multiple different validation sampling points is within 0.25°C.</p><p><strong>Conclusion: </strong>The proposed method and system in this study can calculate the temperature inside <i>ex vivo</i> tissues during laser heating, offering a broader temperature measurement range compared with conventional photoacoustic thermometry. This method possesses certain academic value and is expected to provide technical reference for the research on target temperature sensing during photothermal treatment.</p>","PeriodicalId":15264,"journal":{"name":"Journal of Biomedical Optics","volume":"31 5","pages":"057001"},"PeriodicalIF":3.3,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13218832/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148138112","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":"Corneal dose response from exposure to a <i>Q</i>-switched laser at a central wavelength of 1645 nm using a rabbit model.","authors":"Joseph J Chue-Sang, Xomalin G Peralta, Joseph E Clary, Andrea Smith, Amanda Peterson, Matthew E Macasadia, Amanda J Tijerina, Gary D Noojin, Maximillian V Hart, Charles F Schwarten, Wesley T Kinerk, Lyndsey M Ferris, Emily N Boice","doi":"10.1117/1.JBO.31.5.054703","DOIUrl":"10.1117/1.JBO.31.5.054703","url":null,"abstract":"<p><strong>Significance: </strong>Laser safety studies of the eye are well documented for visible wavelength and continuous wave lasers. There are fewer experimental results for infrared wavelengths and pulsed lasers.</p><p><strong>Aim: </strong>We aim to fill the gap at 1645 nm for single nanosecond pulse duration exposures of rabbit cornea and determine the threshold radiant exposure to generate lesions 50% of the time (estimated dose <math> <mrow><msub><mi>ED</mi> <mn>50</mn></msub> </mrow> </math> ).</p><p><strong>Approach: </strong>Images of the cornea during exposures were acquired using slit lamp microscopy and optical coherence tomography. A histological analysis helped provide dosimetry relationships with morphology and mechanisms of the damage.</p><p><strong>Results: </strong>We measured the energy <math> <mrow><msub><mi>ED</mi> <mn>50</mn></msub> </mrow> </math> value at <math><mrow><mn>3.86</mn> <mo>±</mo> <mn>0.085</mn> <mtext>  </mtext> <mi>mJ</mi></mrow> </math> utilizing the slit lamp biomicroscopy. Incorporating the experimental spot size diameter, this corresponds to a peak radiant exposure of <math><mrow><mn>102</mn> <mtext>  </mtext> <mi>J</mi> <mo>/</mo> <msup><mrow><mi>cm</mi></mrow> <mrow><mn>2</mn></mrow> </msup> </mrow> </math> . By contrast, the average radiant exposure <math> <mrow><msub><mi>ED</mi> <mn>50</mn></msub> </mrow> </math> over a 1-mm diameter limiting aperture as per the ANSI Z.136 convention was <math><mrow><mn>0.49</mn> <mtext>  </mtext> <mi>J</mi> <mo>/</mo> <msup><mrow><mi>cm</mi></mrow> <mrow><mn>2</mn></mrow> </msup> </mrow> </math> . Additional analysis via optical coherence tomography (OCT) and histology examined the severity and degree of damage.</p><p><strong>Conclusion: </strong>This experimental approach performed well to characterize damage and identify damage thresholds to inform the laser safety standard community of the accuracy of current exposure limits.</p>","PeriodicalId":15264,"journal":{"name":"Journal of Biomedical Optics","volume":"31 5","pages":"054703"},"PeriodicalIF":3.3,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12893126/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146179678","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":"Enhancing the efficiency of achieving optical transparency in live animals using absorbing molecules.","authors":"Ting Sun, Jing Su, Yanjie Zhao, Xin Tie","doi":"10.1117/1.JBO.31.5.054702","DOIUrl":"10.1117/1.JBO.31.5.054702","url":null,"abstract":"&lt;p&gt;&lt;strong&gt;Significance: &lt;/strong&gt;&lt;i&gt;In vivo&lt;/i&gt; optical imaging is crucial for studying disease mechanisms but is limited by light scattering and poor penetration in biological tissues. While tissue-clearing reagents (hydrophilic/hydrophobic) and bioluminescent probes improve imaging, achieving effective optical transparency in live tissues remains a challenge. This study builds on recent work using absorbing dyes (tartrazine and 4-aminoantipyrine) to enhance &lt;i&gt;in vivo&lt;/i&gt; tissue clearing, aiming to optimize efficacy and biosafety.&lt;/p&gt;&lt;p&gt;&lt;strong&gt;Aim: &lt;/strong&gt;We aimed to develop a mixed solution of tartrazine and 4-aminoantipyrine (4-AA) that improves optical transparency, accelerates clearing, and reduces toxicity compared to individual dyes, enabling safer and more efficient deep-tissue imaging in live animals.&lt;/p&gt;&lt;p&gt;&lt;strong&gt;Approach: &lt;/strong&gt;The study employed a multi-pronged experimental approach: solution optimization involved testing varying ratios of tartrazine and 4-AA (5:1, 10:1) to characterize their optical properties through UV-Vis-NIR spectroscopy and refractive-index measurements, while simultaneously evaluating &lt;i&gt;ex vivo&lt;/i&gt; skin-clearing efficacy; &lt;i&gt;in vivo&lt;/i&gt; validation was conducted by applying the optimized gels to depilated mouse skin and systematically recording key parameters including transparency-onset time, maximum clearing duration, and light transmittance; concurrent biosafety assessments monitored critical health indicators such as animal survival rates, longitudinal weight changes, and liver/kidney function markers [alanine aminotransferase (ALT), aspartate aminotransferase (AST), and creatinine (CREA)] during the post-treatment period.&lt;/p&gt;&lt;p&gt;&lt;strong&gt;Results: &lt;/strong&gt;The optimized mixed solutions (5:1 and 10:1 tartrazine:4-AA ratios) demonstrated superior clearing efficiency, achieving faster tissue transparency than tartrazine alone while matching the performance of 4-AA but with significantly reduced toxicity. Optical characterization revealed stable refractive indices ( &lt;math&gt;&lt;mrow&gt;&lt;mo&gt;∼&lt;/mo&gt; &lt;mn&gt;1.42&lt;/mn&gt;&lt;/mrow&gt; &lt;/math&gt; ) and strong absorption across visible/NIR wavelengths for all formulations. While 4-AA alone exhibited severe hepatorenal toxicity and 100% mortality (3/3 mice), the 5:1 mixed solution maintained efficacy with no mortality and only mild ALT/AST elevation. Transmittance measurements showed 4-AA gels achieved &lt;math&gt;&lt;mrow&gt;&lt;mo&gt;∼&lt;/mo&gt; &lt;mn&gt;40&lt;/mn&gt; &lt;mo&gt;%&lt;/mo&gt;&lt;/mrow&gt; &lt;/math&gt; light transmission, whereas mixed gels reached &lt;math&gt;&lt;mrow&gt;&lt;mo&gt;∼&lt;/mo&gt; &lt;mn&gt;15&lt;/mn&gt; &lt;mo&gt;%&lt;/mo&gt;&lt;/mrow&gt; &lt;/math&gt; due to tartrazine's residual absorption in the red-NIR spectrum, suggesting an optimal balance between clearing performance and biosafety in the composite formulations.&lt;/p&gt;&lt;p&gt;&lt;strong&gt;Conclusions: &lt;/strong&gt;The 5:1 tartrazine:4-AA cocktail optimally balances speed, clarity, and biosafety, advancing &lt;i&gt;in vivo&lt;/i&gt; tissue-clearing technology. This strategy addresses key limitations of stand-alone dyes and expands potential ap","PeriodicalId":15264,"journal":{"name":"Journal of Biomedical Optics","volume":"31 5","pages":"054702"},"PeriodicalIF":3.3,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12904770/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146201812","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":"Radiometric and spectral characterization of multipanel planar light-emitting devices: a generalizable irradiance mapping approach for dose estimation.","authors":"Emmanuel Gerelli, Georges Wagnières, Jaroslava Joniová","doi":"10.1117/1.JBO.31.5.055001","DOIUrl":"10.1117/1.JBO.31.5.055001","url":null,"abstract":"<p><strong>Significance: </strong>Accurate spectral and radiometric characterization of photobiomodulation (PBM) devices is essential for reliable dosimetry and reproducible therapeutic outcomes. Complex, multilight-emitting diode (LED) systems produce heterogeneous irradiance patterns that complicate dose estimation, underscoring the need for standardized quantitative methods.</p><p><strong>Aim: </strong>To develop and validate a generalizable methodology for the spectral and radiometric characterization of multipanel and multi-LED PBM devices, demonstrated using the ATP38® system.</p><p><strong>Approach: </strong>Spectral properties were measured using an optical fiber-based spectrometer. The radiometric properties were determined by measuring 2D irradiance maps acquired at a 4-cm working distance from a single panel at six wavelengths. A critical element of the method was correcting raw irradiance data for the detector's nonideal angular response, modeled by a <math> <mrow><msup><mi>cos</mi> <mi>m</mi></msup> <mo>(</mo> <mi>θ</mi> <mo>)</mo></mrow> </math> function, with <math><mrow><mi>m</mi></mrow> </math> determined for each wavelength. The corrected maps were fitted using double 2D Gaussian surfaces, enabling the generation of continuous irradiance distributions and their extrapolation to other working distances through homothety. This framework also allowed simulation of irradiance maps for multipanel configurations. To validate the physical characterization, <i>in vitro</i> experiments on normal human epidermal keratinocytes compared the biological effects of three illumination protocols applied at two panel locations. PBM effects were assessed by measuring the endogenously produced protoporphyrin IX fluorescence intensity and by the scratch test assay.</p><p><strong>Results: </strong>Six emission peaks were identified at 454, 525, 594, 627, 729, and 842 nm. The detector angular correction improved the accuracy of the radiometric characterization, and Gaussian modeling of the irradiance enabled its prediction at different working distances. Biological responses correlated with spatial irradiance variations.</p><p><strong>Conclusions: </strong>This framework enables quantitative characterization of the ATP38® device spectral and radiometric properties, supporting accurate light propagation modeling and dosimetry optimization.</p>","PeriodicalId":15264,"journal":{"name":"Journal of Biomedical Optics","volume":"31 5","pages":"055001"},"PeriodicalIF":3.3,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13186584/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147981941","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":"Quantitative second harmonic generation microscopy for characterizing collagen remodeling in papillary thyroid carcinoma.","authors":"Wesley Poon, Lin Wang, Orhun Davarci, Reid Master, Hong Zhao, Jun Liu, Helmi S Khadra, Elizabeth M Jacobi, Raksha Raghunathan, Stephen T C Wong","doi":"10.1117/1.JBO.31.5.056501","DOIUrl":"10.1117/1.JBO.31.5.056501","url":null,"abstract":"&lt;p&gt;&lt;strong&gt;Significance: &lt;/strong&gt;Thyroid cancer is the most common endocrine malignancy. Although fine needle aspiration (FNA) is the gold standard for diagnosis, 10% to 20% of FNAs yield indeterminate cytology, of which 20% to 30% prove malignant. Such diagnostic uncertainty drives repeat FNAs, costly molecular tests, and unnecessary surgeries, leading to increased healthcare costs, reduced quality of life, and emotional distress to patients. Current methods provide limited structural information about the extra-cellular matrix, despite collagen remodeling being a hallmark of malignancy. A rapid, label-free, and architecture-based diagnostic approach has the potential to significantly improve real-time or near-real-time decision-making and reduce unnecessary biopsies and interventions.&lt;/p&gt;&lt;p&gt;&lt;strong&gt;Aim: &lt;/strong&gt;We use a systematic, quantitative framework based on second harmonic generation (SHG) microscopy to differentiate between normal and cancerous (papillary thyroid carcinoma [PTC]) human thyroid tissues through collagen architecture signatures.&lt;/p&gt;&lt;p&gt;&lt;strong&gt;Approach: &lt;/strong&gt;Formalin-fixed paraffin-embedded unstained tissue sections ( &lt;math&gt;&lt;mrow&gt;&lt;mn&gt;5&lt;/mn&gt; &lt;mtext&gt;  &lt;/mtext&gt; &lt;mi&gt;μ&lt;/mi&gt; &lt;mi&gt;m&lt;/mi&gt;&lt;/mrow&gt; &lt;/math&gt; thick) of confirmed PTC and normal thyroid tissue were obtained under an approved IRB and imaged under a multiphoton microscope using an excitation wavelength of 803 nm. An emission filter of &lt;math&gt;&lt;mrow&gt;&lt;mn&gt;400&lt;/mn&gt; &lt;mo&gt;±&lt;/mo&gt; &lt;mn&gt;10&lt;/mn&gt; &lt;mtext&gt;  &lt;/mtext&gt; &lt;mi&gt;nm&lt;/mi&gt;&lt;/mrow&gt; &lt;/math&gt; was used to filter the SHG emission from the sample. Thirty-five metrics capturing intensity, geometric, textural, and frequency-domain collagen features were quantified. A linear mixed-effects model was used for quantitative comparison between cancer and normal groups, accounting for the hierarchical structure of the data and rigorously assessing metric significance despite limited sample size.&lt;/p&gt;&lt;p&gt;&lt;strong&gt;Results: &lt;/strong&gt;Of the 35 metrics evaluated, 19 remained statistically significant after false discovery rate (FDR) adjustment for multiple comparisons. The corresponding effect sizes ranged from moderate to large, indicating substantial separation between normal and cancerous samples. Five of the remaining 16 metrics, although not statistically significant, were consistently either higher or lower in one group compared with the other, suggesting directional consistency. This revealed robust and biologically coherent alterations in collagen organization despite small cohort size. These included consistent increases in spectral power across multiple spatial frequency bands and greater collagen heterogeneity in cancer tissue.&lt;/p&gt;&lt;p&gt;&lt;strong&gt;Conclusions: &lt;/strong&gt;The convergence of significant and directionally consistent metrics underscores the strong diagnostic potential of SHG-derived collagen architecture. Integrating these quantitative features into an automated analysis platform could enable rapid, objective, and reproducible optical biopsi","PeriodicalId":15264,"journal":{"name":"Journal of Biomedical Optics","volume":"31 5","pages":"056501"},"PeriodicalIF":3.3,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13210880/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148042440","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":"Composing drug delivery with light distribution improvement: the use of dissolving microneedles in skin cancer with photodynamic therapy.","authors":"Michelle B Requena, Cynthia E Anderson, Dianeth S Lima Bejar, Vladislav V Yakovlev, Vanderlei S Bagnato","doi":"10.1117/1.JBO.31.5.058001","DOIUrl":"10.1117/1.JBO.31.5.058001","url":null,"abstract":"<p><strong>Significance: </strong>Dissolving microneedles (MN) have emerged as a promising platform for drug delivery, providing a minimally invasive approach to bypass the skin's natural barriers and enhance molecular penetration and diffusion. Their biocompatibility, user-friendly application, and ability to deliver precise therapeutic dosing make them particularly suitable for dermatological use. In addition to pharmacological benefits, dissolving MN possesses a geometric structure that enables optical waveguiding, thereby improving light penetration and distribution.</p><p><strong>Aim: </strong>We address a key limitation of photodynamic therapy (PDT): the limited penetration of light into biological tissues. PDT relies on activating photosensitizing agents with specific wavelengths of light to generate cytotoxic species, selectively targeting abnormal or diseased cells while minimizing effects on surrounding healthy tissue.</p><p><strong>Approach: </strong>Pyramidal dissolving MN arrays were fabricated from a biocompatible polymer and systematically characterized. Their light distribution profile under laser illumination was evaluated using image analysis.</p><p><strong>Results: </strong>Quantitative analysis of light distribution demonstrates that MN can simultaneously facilitate drug delivery and light distribution.</p><p><strong>Conclusions: </strong>This multifunctionality provides a synergistic therapeutic advantage, as localized drug release is complemented by optimized light delivery, thereby enhancing treatment outcomes. The dual-function platform has significant implications for PDT, enabling the design of integrated therapeutic systems that combine chemical and photonic modalities within a single, biodegradable device. Such systems may be particularly advantageous in resource-limited settings or outpatient care, where ease of use and effectiveness are essential. This strategy offers an approach to overcoming the limitations of conventional light-based therapies, supporting the development of more effective and accessible treatments for skin cancer and other dermatological conditions.</p>","PeriodicalId":15264,"journal":{"name":"Journal of Biomedical Optics","volume":"31 5","pages":"058001"},"PeriodicalIF":3.3,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13157203/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147868634","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":"Erratum: Damage integral and other predictive formulas for nonisothermal heating during laser exposure (Erratum).","authors":"Elharith M Ahmed, Gary D Noojin, Michael L Denton","doi":"10.1117/1.JBO.31.5.059801","DOIUrl":"https://doi.org/10.1117/1.JBO.31.5.059801","url":null,"abstract":"<p><p>[This corrects the article DOI: 10.1117/1.JBO.27.3.035001.].</p>","PeriodicalId":15264,"journal":{"name":"Journal of Biomedical Optics","volume":"31 5","pages":"059801"},"PeriodicalIF":2.9,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13221161/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148138109","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 dynamic range shortwave infrared imaging of mice with an InGaAs camera.","authors":"Amish Patel, Xingjian Zhong, Mallory Moffett, Yidan Sun, Allison M Dennis","doi":"10.1117/1.JBO.31.5.054704","DOIUrl":"10.1117/1.JBO.31.5.054704","url":null,"abstract":"<p><strong>Significance: </strong>Although shortwave infrared (SWIR) imaging provides superior tissue penetration and reduced autofluorescence for preclinical applications, quantitative fluorescence analysis is hindered by the limited dynamic range (DR) of InGaAs cameras, forcing a focus on either bright or dim anatomical features.</p><p><strong>Aim: </strong>We develop a high dynamic range (HDR) imaging method specifically adapted for the high-noise characteristics of InGaAs detectors to enable quantitative fluorescence imaging across wide intensity ranges. We demonstrate that one-time camera calibration based on a series of images encompassing the range of radiance intensities enables all subsequent image processing.</p><p><strong>Approach: </strong>We modified classical HDR algorithms with exposure-time-dependent dark current subtraction, preprocessing to exclude saturated and noisy pixels before camera response function recovery, and dynamic weighting range adjustment to account for shrinking intensity ranges at longer exposures. High dynamic range image processing effects on preclinical imaging outcomes were analyzed using indocyanine green and SWIR-emitting PbS/CdS quantum dots in mouse models.</p><p><strong>Results: </strong>High dynamic range imaging achieved a 22-dB improvement in DR over single exposures, enabling simultaneous quantification across more than three orders of magnitude of fluorophore concentration. <i>In vivo</i> studies showed improvements in contrast-to-noise ratios across all anatomical features, with improvements in vascular contrast while maintaining quantitative accuracy. After one-time camera calibrations, this approach enables rapid processing of subsequent datasets.</p><p><strong>Conclusions: </strong>This software-based HDR SWIR imaging approach eliminates exposure parameter optimization and enables comprehensive biodistribution analysis across all anatomical structures from a single acquisition sequence, significantly streamlining preclinical imaging workflows while preserving quantitative accuracy.</p>","PeriodicalId":15264,"journal":{"name":"Journal of Biomedical Optics","volume":"31 5","pages":"054704"},"PeriodicalIF":3.3,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13067109/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147672868","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":"Improved method for optical coherence tomography angiography: from reconstruction to clinical indicator quantification.","authors":"Fuxin Cai, Xianglong Feng, Zhihong Zheng, Yuhong Zhang, Duo Xu, Chuanwei Ma, Yu Fan, Xinjian Chen","doi":"10.1117/1.JBO.31.5.056002","DOIUrl":"10.1117/1.JBO.31.5.056002","url":null,"abstract":"&lt;p&gt;&lt;strong&gt;Significance: &lt;/strong&gt;Optical coherence tomography angiography (OCTA) represents a significant advance in noninvasive ophthalmic vascular imaging, yet existing reconstruction algorithms face challenges such as spectral leakage and motion artifacts, which can compromise image quality and the accuracy of subsequent clinical quantification. Improving OCTA reconstruction and developing robust, automated methods for clinical indicator extraction are crucial for enhancing diagnostic reliability and facilitating precise disease monitoring.&lt;/p&gt;&lt;p&gt;&lt;strong&gt;Aim: &lt;/strong&gt;We aim to propose and validate an improved OCTA reconstruction method based on a smoothed Walsh window function to reduce spectral leakage while preserving axial resolution, coupled with an enhanced blood flow B-scan signal using retinal layer segmentation. Furthermore, we seek to develop and evaluate a fully automated pipeline for calculating key clinical indicators-including foveal avascular zone (FAZ) parameters and vessel density-based on local fractal dimension analysis.&lt;/p&gt;&lt;p&gt;&lt;strong&gt;Approach: &lt;/strong&gt;A spectral-domain OCT system was used to acquire volumetric retinal data from healthy volunteers. The reconstruction method utilized a smoothed Walsh window for full-spectrum splitting to mitigate spectral leakage, combined with a deep learning-based retinal layer segmentation algorithm and Otsu's thresholding to enhance blood flow B-scan signals. For clinical quantification, local fractal dimension analysis was employed to segment vascular networks and FAZ regions automatically, from which perimeter, area, circularity index, and sectoral vessel density were computed.&lt;/p&gt;&lt;p&gt;&lt;strong&gt;Results: &lt;/strong&gt;The proposed reconstruction method demonstrated superior performance compared with traditional OMAG and SSADA algorithms, showing significant improvements in vessel connectivity, contrast (increase up to &lt;math&gt;&lt;mrow&gt;&lt;mo&gt;∼&lt;/mo&gt; &lt;mn&gt;0.74&lt;/mn&gt;&lt;/mrow&gt; &lt;/math&gt; ), and signal-to-noise ratio (SNR increase up to &lt;math&gt;&lt;mrow&gt;&lt;mo&gt;∼&lt;/mo&gt; &lt;mn&gt;1.09&lt;/mn&gt; &lt;mtext&gt;  &lt;/mtext&gt; &lt;mi&gt;dB&lt;/mi&gt;&lt;/mrow&gt; &lt;/math&gt; ). The FAZ segmentation based on local fractal dimension achieved a high similarity index of &lt;math&gt;&lt;mrow&gt;&lt;mn&gt;0.9735&lt;/mn&gt; &lt;mo&gt;±&lt;/mo&gt; &lt;mn&gt;0.0066&lt;/mn&gt;&lt;/mrow&gt; &lt;/math&gt; with manual ground truth, with low false positive ( &lt;math&gt;&lt;mrow&gt;&lt;mn&gt;1.76&lt;/mn&gt; &lt;mo&gt;%&lt;/mo&gt; &lt;mo&gt;±&lt;/mo&gt; &lt;mn&gt;0.75&lt;/mn&gt; &lt;mo&gt;%&lt;/mo&gt;&lt;/mrow&gt; &lt;/math&gt; ) and false negative ( &lt;math&gt;&lt;mrow&gt;&lt;mn&gt;3.48&lt;/mn&gt; &lt;mo&gt;%&lt;/mo&gt; &lt;mo&gt;±&lt;/mo&gt; &lt;mn&gt;0.78&lt;/mn&gt; &lt;mo&gt;%&lt;/mo&gt;&lt;/mrow&gt; &lt;/math&gt; ) rates. Intraclass correlation coefficients for FAZ area, perimeter, and circularity index all exceeded 0.90. Vessel density measurements across retinal sectors were consistent with established normative data.&lt;/p&gt;&lt;p&gt;&lt;strong&gt;Conclusions: &lt;/strong&gt;The integration of a smoothed Walsh window function and retinal layer segmentation significantly enhances OCTA image quality and blood flow signal clarity. The local fractal dimension-based automated analysis pipeline provides accurate, reproducible qu","PeriodicalId":15264,"journal":{"name":"Journal of Biomedical Optics","volume":"31 5","pages":"056002"},"PeriodicalIF":3.3,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13180278/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147972886","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}