Journal of Biomedical Optics最新文献

{"title":"Choice of numerical implementation of spatial contrast calculation impacts microcirculation quantitation in laser speckle contrast imaging.","authors":"Marc Chammas, Frédéric Pain","doi":"10.1117/1.JBO.30.4.046006","DOIUrl":"https://doi.org/10.1117/1.JBO.30.4.046006","url":null,"abstract":"<p><strong>Significance: </strong>Laser speckle contrast imaging (LSCI) allows noninvasive imaging of microcirculation. Its scope of clinical applications is growing, yet the literature lacks a comparison of the accuracy of methods used to compute the spatial contrast <math> <mrow><msub><mi>K</mi> <mi>s</mi></msub> </mrow> </math> from which the blood flow index is derived.</p><p><strong>Aim: </strong>We aim to evaluate the impact on flow quantitation of different computational approaches used to derive <math> <mrow><msub><mi>K</mi> <mi>s</mi></msub> </mrow> </math> .</p><p><strong>Approach: </strong>We compare numerical calculation of <math> <mrow><msub><mi>K</mi> <mi>s</mi></msub> </mrow> </math> in Python and ImageJ applied to noise-free simulated data and to experimental data acquired <i>in vivo</i> in anesthetized mice. The estimation of the decorrelation time <math> <mrow><msub><mi>τ</mi> <mi>c</mi></msub> </mrow> </math> , inversely proportional to the blood flow index, is carried out following two approaches: LSCI asymptotic estimation and fitting the multiple exposure speckle imaging (MESI) model to <math> <mrow><msub><mi>K</mi> <mi>s</mi></msub> <mo>(</mo> <mi>T</mi> <mo>)</mo></mrow> </math> .</p><p><strong>Results: </strong>For simulation data, we found variations of up to 58% for the blood flow index in the LSCI approach. Nonlinear fitting of the MESI model was less affected with discrepancies of only a few percent. Considering experimental data, the LSCI approximation led to <math> <mrow><msub><mi>K</mi> <mi>s</mi></msub> </mrow> </math> with relative differences (up to 35%) depending on the calculation methods. The noise and limited exposure time strongly limited the accuracy of the LSCI asymptotic estimation. Adjustment of the MESI model to the data led to consistent values of <math> <mrow><msub><mi>τ</mi> <mi>c</mi></msub> </mrow> </math> in the 0.05 to 1 ms range with significant variations depending on the method used to calculate <math> <mrow><msub><mi>K</mi> <mi>s</mi></msub> </mrow> </math> .</p><p><strong>Conclusions: </strong>Numerical methods used to calculate <math> <mrow><msub><mi>K</mi> <mi>s</mi></msub> </mrow> </math> should be precisely acknowledged and validated against direct calculation to ensure accuracy. <i>Uniform</i> filter approach leads to accurate <math> <mrow><msub><mi>K</mi> <mi>s</mi></msub> </mrow> </math> values and is 100 times more computationally efficient than the <math><mrow><mi>D</mi> <mi>i</mi> <mi>r</mi> <mi>e</mi> <mi>c</mi> <mi>t</mi></mrow> </math> calculation. Other investigated methods lead to various levels of errors in flow index estimation using LSCI. Errors are minimized using larger kernels. MESI derivation of <math> <mrow><msub><mi>τ</mi> <mi>c</mi></msub> </mrow> </math> is not immune but less affected by such methodological biases.</p>","PeriodicalId":15264,"journal":{"name":"Journal of Biomedical Optics","volume":"30 4","pages":"046006"},"PeriodicalIF":3.0,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12003051/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143993470","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":"Frequency domain broadband short-wave infrared spectroscopy for measurement of tissue optical properties from 685 to 1300 nm.","authors":"Diana Suciu, Thao Pham, Lina Lin Wei, Shripreetika Guruprasad, Darren Roblyer","doi":"10.1117/1.JBO.30.4.045001","DOIUrl":"https://doi.org/10.1117/1.JBO.30.4.045001","url":null,"abstract":"<p><strong>Significance: </strong>Extending frequency domain diffuse optical spectroscopy (FD-DOS) into the short-wave infrared (SWIR) region has the potential to improve measurements of key biological tissue chromophores such as water and lipids, given their higher absorption in SWIR compared with near-infrared wavelengths. Few studies have explored FD-DOS in the SWIR range.</p><p><strong>Aim: </strong>We present the first demonstration of a frequency domain broadband SWIR spectroscopy (FD-Bb-SWIRS) system to measure optical properties from 685 to 1300 nm.</p><p><strong>Approach: </strong>A custom hybrid system was developed, combining discrete frequency domain measurements from 685 to 980 nm with broadband continuous wave measurements from 900 to 1300 nm. This setup provided absolute absorption ( <math> <mrow><msub><mi>μ</mi> <mi>a</mi></msub> </mrow> </math> ) spectra from 685 to 1300 nm. Validation was performed using mineral oil-based solid phantoms, deuterium oxide ( <math> <mrow><msub><mi>D</mi> <mn>2</mn></msub> <mi>O</mi></mrow> </math> ) liquid phantoms, and desiccating porcine tissue.</p><p><strong>Results: </strong>The FD-Bb-SWIRS system was sensitive to changes in <math> <mrow><msub><mi>μ</mi> <mi>a</mi></msub> </mrow> </math> from varying concentrations of absorbers in solid and liquid phantoms. <i>Ex vivo</i> measurements of <math> <mrow><msub><mi>μ</mi> <mi>a</mi></msub> </mrow> </math> spectra indicated differences in tissue water content across different porcine tissue samples during baseline and desiccation.</p><p><strong>Conclusions: </strong>FD-Bb-SWIRS is highly sensitive to <math> <mrow><msub><mi>μ</mi> <mi>a</mi></msub> </mrow> </math> in the 685 to 1300 nm range and enables precise quantification of water in biological tissues. It represents a significant step forward in advancing SWIR-based optical spectroscopy for clinical applications.</p>","PeriodicalId":15264,"journal":{"name":"Journal of Biomedical Optics","volume":"30 4","pages":"045001"},"PeriodicalIF":3.0,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12022801/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143995012","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":"Optical characteristics of human lung cancer for photodynamic therapy with measured absorption and reduced scattering coefficients.","authors":"Yu Shimojo, Yuri Morizane, Takumi Sonokawa, Jitsuo Usuda, Takahiro Nishimura","doi":"10.1117/1.JBO.30.4.048001","DOIUrl":"10.1117/1.JBO.30.4.048001","url":null,"abstract":"<p><strong>Significance: </strong>The optical characteristics of a human lung, such as the light distribution in the tissue, are crucial for evaluating the light delivery of photodynamic therapy (PDT) for peripheral lung cancer.</p><p><strong>Aim: </strong>The light distribution in the human lung is analyzed with absorption ( <math> <mrow><msub><mi>μ</mi> <mi>a</mi></msub> </mrow> </math> ) and reduced scattering ( <math> <mrow> <msubsup><mrow><mi>μ</mi></mrow> <mrow><mi>s</mi></mrow> <mrow><mo>'</mo></mrow> </msubsup> </mrow> </math> ) coefficients measured <i>ex vivo</i> for normal, carbon-deposited, and tumor tissues.</p><p><strong>Approach: </strong>The <math> <mrow><msub><mi>μ</mi> <mi>a</mi></msub> </mrow> </math> and <math> <mrow> <msubsup><mrow><mi>μ</mi></mrow> <mrow><mi>s</mi></mrow> <mrow><mo>'</mo></mrow> </msubsup> </mrow> </math> spectra were measured using a double-integrating-sphere optical system and inverse Monte Carlo technique. The measured values were used to perform a light distribution analysis using a Monte Carlo light transport simulation.</p><p><strong>Results: </strong>The <math> <mrow><msub><mi>μ</mi> <mi>a</mi></msub> </mrow> </math> values varied between tissue types owing to the influence of carbon deposition, blood volume fraction, and oxygen saturation, whereas the <math> <mrow> <msubsup><mrow><mi>μ</mi></mrow> <mrow><mi>s</mi></mrow> <mrow><mo>'</mo></mrow> </msubsup> </mrow> </math> values showed almost no differences between tissue types. The simulation results showed that carbon deposition in the surrounding tissue and oxygen saturation variability had almost no effect on PDT light delivery to a tumor with a 10-mm-diameter sphere.</p><p><strong>Conclusions: </strong>Our analysis revealed the influence of the optical characteristics of the lung tissue on PDT light delivery. Integration of these results with the photosensitizer dose and the degree of necrosis changes will allow us to provide more clinically relevant insight in determining PDT dosimetry.</p>","PeriodicalId":15264,"journal":{"name":"Journal of Biomedical Optics","volume":"30 4","pages":"048001"},"PeriodicalIF":3.0,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11960791/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143764080","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":"Perspective on the use of optics in bladder cancer detection and diagnosis.","authors":"Marinka J Remmelink, Dylan J Peterson, Jakko A Nieuwenhuijzen, Ton G van Leeuwen, Joseph C Liao, Daniel M de Bruin","doi":"10.1117/1.JBO.30.4.040601","DOIUrl":"10.1117/1.JBO.30.4.040601","url":null,"abstract":"<p><strong>Significance: </strong>Bladder cancer (BC) diagnosis, management, and outcomes depend on the accurate detection of tumors via optical technologies. Accordingly, understanding the benefits and limitations of these technologies permits improvements in patient care and identifies areas for future research.</p><p><strong>Aim: </strong>We outline the current process of BC detection and diagnosis, explore the current role of optical technologies, and discuss the opportunities and challenges they present in this field.</p><p><strong>Approach: </strong>The current diagnostic pathway of BC, the use of optical technologies, and their shortcomings in this process are reviewed. From there, opportunities and challenges of optics in BC detection and diagnosis are discussed.</p><p><strong>Results: </strong>BC management is expensive due to the limitations of white light cystoscopy, the requirement for histopathological confirmation, and the need for long-term surveillance. Alternative non-optical methods lack accuracy, and available optical techniques focus only on cancer detection. Alternatives to histopathology need to provide accurate real-time results to be effective. Optical advancements offer potential benefits; however, challenges include cost-effectiveness, device complexity, required training, and tumor heterogeneity.</p><p><strong>Conclusions: </strong>Optical techniques could accelerate BC diagnosis, reduce costs, and enable alternative treatments. However, overcoming technical and practical challenges is essential for their successful integration.</p>","PeriodicalId":15264,"journal":{"name":"Journal of Biomedical Optics","volume":"30 4","pages":"040601"},"PeriodicalIF":3.0,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11970697/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143795584","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":"LED-based multicolor extended resolution transmission fluorescence microscopy.","authors":"Huaiyuan Zhang, Yiting Hu, Xingwei Pu, Shizheng Zhang, Yi He, Kun Chen, Ziji Liu","doi":"10.1117/1.JBO.30.4.046501","DOIUrl":"10.1117/1.JBO.30.4.046501","url":null,"abstract":"<p><strong>Significance: </strong>The multiplexing capabilities of fluorescence imaging are enhanced by its exceptional molecular specificity with diverse fluorescent probes, making it a powerful tool for studying complex biological structures, organization, and functions. Recent advances in super-resolution fluorescence microscopy have further revolutionized our ability to explore biology and related fields. However, current multicolor super-resolution fluorescence imaging systems often come with high costs and bulky designs.</p><p><strong>Aim: </strong>We present a multicolor extended resolution fluorescence imaging system that uses light-emitting diode to simplify the optical path, make the design more compact, and reduce system costs.</p><p><strong>Approach: </strong>This multicolor extended resolution fluorescence imaging system is based on structured illumination, utilizing a simple diffraction unit positioned between the light source and the sample in a wide-field microscope. Notably, this design could be easily integrated into standard widefield microscopes as a convenient add-on unit, enabling extended resolution imaging.</p><p><strong>Results: </strong>Our system demonstrates concurrent extended resolved imaging of three-color microsphere beads and successfully showcases multicolor extended resolution fluorescence imaging of biological tissue samples, revealing intricate structural details.</p><p><strong>Conclusions: </strong>This system provides a structurally simple, cost-effective alternative to traditional microscopes, offering flexible multicolor extended resolution fluorescence imaging and potential applications in multimodal imaging.</p>","PeriodicalId":15264,"journal":{"name":"Journal of Biomedical Optics","volume":"30 4","pages":"046501"},"PeriodicalIF":3.0,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11977515/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143811545","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":"Automated spectral decomposition and reconstruction of optical properties using a mixed autoencoder approach.","authors":"Dongqin Ni, Marine Amouroux, Walter Blondel, Martin Hohmann","doi":"10.1117/1.JBO.30.4.047001","DOIUrl":"https://doi.org/10.1117/1.JBO.30.4.047001","url":null,"abstract":"<p><strong>Significance: </strong>Investigating optical properties (OPs) is crucial in the field of biophotonics, as it has a broad impact on understanding light-tissue interactions. However, current techniques, such as inverse Monte Carlo simulations (IMCS), have limitations in extracting detailed information about the spectral behavior of microscopic absorbers and scatterers.</p><p><strong>Aim: </strong>We aim to develop a customized autoencoder neural network (ANN) that can automatically identify the spectral behavior of each microscopic absorber and scatterer responsible for generating OP.</p><p><strong>Approach: </strong>The ANN is designed to compute OP from measurements, in which the bottleneck corresponds to the number of absorbers and scatterers. The presented ANN functions asymmetrically and computes the OP using a linear combination of absorbers and scatterers. Validation was conducted using intralipid as a scatterer and ink as an absorber.</p><p><strong>Results: </strong>The employment of the decoder weights facilitated the successful extraction of the spectral shape of every constituent, demonstrating the effectiveness of the ANN in extracting detailed information about the spectral behavior of absorbers and scatterers. At the same time, the OP can be predicted with high precision.</p><p><strong>Conclusions: </strong>The presented ANN is a viable tool for extracting the spectral behavior of absorbers and scatterers without the need for prior knowledge of these components in the test and training data. Potential future applications could include the extraction of relative concentrations of constituents in tissue.</p>","PeriodicalId":15264,"journal":{"name":"Journal of Biomedical Optics","volume":"30 4","pages":"047001"},"PeriodicalIF":3.0,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11981679/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144026159","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":"LED-based optoacoustic tomography of mice.","authors":"Sandeep Kumar Kalva, Xiang Liu, Xosé Luís Deán-Ben, Lin Tang, Daniel Razansky","doi":"10.1117/1.JBO.30.4.040501","DOIUrl":"https://doi.org/10.1117/1.JBO.30.4.040501","url":null,"abstract":"<p><strong>Significance: </strong>Optoacoustic tomography systems commonly employ bulky and expensive solid-state laser sources readily capable of generating dozens of millijoules of optical energy per pulse. Light-emitting diodes (LEDs) may offer a significantly more affordable and compact solution with excellent pulse-to-pulse stability. Yet, the optical design must optimize the energy density delivered to the target, given the relatively low per-pulse energy output of LEDs.</p><p><strong>Aim: </strong>We exploit a full-view LED-based optoacoustic tomography (FLOAT) configuration for <i>in vivo</i> imaging of mice.</p><p><strong>Approach: </strong>The system features panoramic light illumination delivering 0.48 mJ of total per-pulse energy with an array of 160 LEDs stacked into a cylindrically focused circular ultrasound array transducer.</p><p><strong>Results: </strong>We characterize the imaging performance of the FLOAT system in tissue-mimicking phantoms, subsequently demonstrating its ability for <i>in vivo</i> cross-sectional mouse imaging.</p><p><strong>Conclusions: </strong>It is anticipated that the compact, low-cost FLOAT imaging system will open up new venues in resource-limited settings for studying large-scale biodynamics such as pharmacokinetics and biodistribution of molecular agents and drugs on a whole-body level.</p>","PeriodicalId":15264,"journal":{"name":"Journal of Biomedical Optics","volume":"30 4","pages":"040501"},"PeriodicalIF":3.0,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11991858/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144020797","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":"<i>In situ</i> observation of urothelial responses to NaCl-induced osmotic stress using optical coherence tomography.","authors":"Lan Dao, Hui Zhu, Hui Wang","doi":"10.1117/1.JBO.30.4.046009","DOIUrl":"https://doi.org/10.1117/1.JBO.30.4.046009","url":null,"abstract":"<p><strong>Significance: </strong>We provide the first direct evidence of the urothelial response to water transport through the urothelium, traditionally considered impermeable. Using optical coherence tomography (OCT), we observe that the urothelium absorbs and expels water under varying concentrations of NaCl, challenging long-held views about its impermeability. The discovery that osmotic stress can induce urothelial damage has implications for bladder disorders such as interstitial cystitis and overactive bladder, where urothelial integrity is compromised.</p><p><strong>Aim: </strong>Traditionally considered impermeable, the urothelium has recently been implicated in water transport due to the presence of aquaporins. Despite this, direct evidence of the urothelial response to water movement through the urothelium remains elusive. We aim to provide such evidence by examining urothelial responses to NaCl solutions using OCT.</p><p><strong>Approach: </strong>Fresh porcine bladder samples were subjected to OCT imaging to observe urothelial responses under varying osmolarity conditions, using NaCl solutions ranging from 0.31 to <math><mrow><mn>2.07</mn> <mtext>  </mtext> <mi>Osm</mi> <mo>/</mo> <mi>L</mi></mrow> </math> . Urothelial optical pathlength thickness was measured pre-NaCl and post-NaCl application. In addition, histological and scanning electron microscopy (SEM) analyses were conducted to assess cellular integrity and damage.</p><p><strong>Results: </strong>OCT imaging revealed a significant increase in urothelial optical pathlength thickness following deionized water application, indicative of water absorption. Conversely, exposure to higher osmolarity NaCl solutions resulted in urothelial shrinkage, suggesting water efflux. Histological analysis demonstrated intact cellular structures at lower osmolarities ( <math><mrow><mn>0.31</mn> <mtext>  </mtext> <mi>Osm</mi> <mo>/</mo> <mi>L</mi></mrow> </math> ) but significant cellular disruption at higher concentrations ( <math><mrow><mo>≥</mo> <mn>1.03</mn> <mtext>  </mtext> <mi>Osm</mi> <mo>/</mo> <mi>L</mi></mrow> </math> ). SEM analysis corroborated these findings, showing progressive damage to umbrella cells with increasing osmolarity.</p><p><strong>Conclusions: </strong>We provide evidence that the urothelium is a dynamic barrier capable of water transport, influenced by osmotic gradients. The observed osmotic-induced urothelial damage may have important implications for the pathophysiology of conditions such as interstitial cystitis and overactive bladder, offering insights into potential diagnostic and therapeutic strategies. These findings warrant further investigation using human tissue.</p>","PeriodicalId":15264,"journal":{"name":"Journal of Biomedical Optics","volume":"30 4","pages":"046009"},"PeriodicalIF":3.0,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12041670/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143970233","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":"Elucidating the effect of tumor and background region-of-interest selection on the performance metrics used to assess fluorescence imaging.","authors":"Augustino V Scorzo, Caleb Y Kwon, Rendall R Strawbridge, P Jack Hoopes, David W Roberts, Scott C Davis","doi":"10.1117/1.JBO.30.4.046004","DOIUrl":"10.1117/1.JBO.30.4.046004","url":null,"abstract":"<p><strong>Significance: </strong>The development of fluorescent contrast agents for fluorescence-guided surgery is rapidly growing with many agents being designed for tumor visualization. Although efforts have been made to standardize the sensitivity of imaging system detection methods for these contrast agents, guidelines to evaluate tumor contrast agent performance, especially the selection of tumor and background regions of interest (ROIs), differ widely across studies. We examine how systematically changing tumor and background ROIs affects common metrics of contrast agent performance.</p><p><strong>Aim: </strong>We aim to elucidate the influence of changing tumor and background brain regions of interest on fluorescent contrast agent performance.</p><p><strong>Approach: </strong>Mice with orthotopic brain tumors were administered a non-targeted fluorescent contrast agent 40 min prior to sacrifice and then imaging of the specimen using whole-body fluorescence cryotomography. The reconstructed 3D fluorescence volumes were then used to compute contrast and diagnostic performance metrics [tumor-to-background brain ratio (TBR), contrast-to-noise (CNR), and area under the receiver operating characteristic curve (AUC)] while systematically varying tumor and normal brain ROIs.</p><p><strong>Results: </strong>ROI selection had a significant impact on the reported values of metrics used to evaluate fluorescence imaging strategies. The use of contralateral background ROIs, commonly used in the field, produced elevated and favorable performance metric values. These metrics decreased as background ROIs approached regions adjacent to the tumor boundary. TBR changed by a factor of 5, CNR by a factor of 7, and AUC by over 10%, largely depending on the proximity of the background region to the tumor.</p><p><strong>Conclusions: </strong>Background ROI selection has a significant impact on the performance metrics commonly used in the field. Future studies should carefully select ROIs relevant to the application and include clear descriptions of these regions.</p>","PeriodicalId":15264,"journal":{"name":"Journal of Biomedical Optics","volume":"30 4","pages":"046004"},"PeriodicalIF":3.0,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11963147/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143772567","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":"Minimum spectral resolution for continuous-wave hyperspectral near-infrared tissue spectroscopy.","authors":"Ann Ping, Redwan Haque, Natalie C Li, Rasa Eskandari, Mamadou Diop","doi":"10.1117/1.JBO.30.4.047002","DOIUrl":"https://doi.org/10.1117/1.JBO.30.4.047002","url":null,"abstract":"<p><strong>Significance: </strong>Continuous-wave hyperspectral near-infrared spectroscopy (h-NIRS) is a reliable and cost-effective technique for noninvasive monitoring of tissue blood content and oxygenation at the point-of-care; however, most h-NIRS devices are based on expensive custom-built spectrometers. For widespread adoption, low-cost, miniature, off-the-shelf spectrometers are needed. To guide the development of such spectrometers, a standard for spectral resolution must first be defined.</p><p><strong>Aim: </strong>We aim to identify the minimum spectral resolution needed for h-NIRS devices to accurately measure oxy- and deoxy-hemoglobin (HbO and Hb) concentrations in tissue.</p><p><strong>Approach: </strong>h-NIRS measurements were acquired from fully oxygenated and deoxygenated blood-lipid phantoms at 13 spectral resolutions. Data for other oxygenation levels were simulated using NIRFAST. HbO and Hb concentrations were estimated at each resolution and compared with the ground truth hemoglobin concentration.</p><p><strong>Results: </strong>The concentration of Hb was estimated with high accuracy for resolutions up to 10 nm, whereas HbO estimates were more variable. For both chromophores, the accuracy of the estimation gradually decreased with resolutions beyond 10 nm.</p><p><strong>Conclusions: </strong>Spectral resolutions up to 10 nm can be used for h-NIRS without compromising the accuracy of estimating tissue blood content and oxygenation.</p>","PeriodicalId":15264,"journal":{"name":"Journal of Biomedical Optics","volume":"30 4","pages":"047002"},"PeriodicalIF":3.0,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12018911/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143967329","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}