Journal of Biomedical Optics最新文献

{"title":"Optical imaging of metabolic dynamics in ALS under methionine regulation.","authors":"Khang Hoang, Sirasit Prayotamornkul, Chan-Yu Kuo, Hongje Jang, Lingyan Shi","doi":"10.1117/1.JBO.30.S2.S23906","DOIUrl":"10.1117/1.JBO.30.S2.S23906","url":null,"abstract":"<p><strong>Significance: </strong>Excessive reactive oxygen species (ROS) in dysfunctional mitochondria, combined with inefficient antioxidant defenses, can drive amyotrophic lateral sclerosis (ALS) progression. L-methionine (Met) can neutralize ROS by modulating metabolism and activating antioxidants; however, its impact on ALS remains unknown.</p><p><strong>Aim: </strong>We aim to investigate the influence of excess Met on cellular metabolism and ROS accumulation and its role in ALS using multimodal optical imaging techniques.</p><p><strong>Approach: </strong>We applied deuterium oxide-probed stimulated Raman scattering imaging to study metabolic changes of lipids, proteins, and cytochrome <math><mrow><mi>c</mi></mrow> </math> and two-photon excitation fluorescence imaging to assess mitochondrial redox state (nicotinamide adenine dinucleotide and flavin adenine dinucleotide ratio) in ALS cellular models under excess Met treatment. With three-dimensional (3D) image reconstruction, we investigated morphological changes of lipid droplets (LDs) and stress granules (SGs) in ALS models.</p><p><strong>Results: </strong>Excess Met not only promoted syntheses of lipids and unsaturated lipid membranes but also reduced protein synthesis, cytochrome <math><mrow><mi>c</mi></mrow> </math> oxidation, and oxidative stress. Moreover, 3D image reconstruction showed that LDs increased in volume and number to promote cellular repair, whereas SGs decreased in volume but increased in number in response to reduced cellular stress.</p><p><strong>Conclusions: </strong>Excess Met offers a protective mechanism against oxidative stress and promotes cellular repair in ALS.</p>","PeriodicalId":15264,"journal":{"name":"Journal of Biomedical Optics","volume":"30 Suppl 2","pages":"S23906"},"PeriodicalIF":3.0,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12102500/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144142262","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":"Acetic acid enabled nuclear contrast enhancement in epi-mode quantitative phase imaging.","authors":"Zhe Guang, Amunet Jacobs, Paloma Casteleiro Costa, Zhenmin Li, Francisco E Robles","doi":"10.1117/1.JBO.30.2.026501","DOIUrl":"10.1117/1.JBO.30.2.026501","url":null,"abstract":"<p><strong>Significance: </strong>The acetowhitening effect of acetic acid (AA) enhances light scattering of cell nuclei, an effect that has been widely leveraged to facilitate tissue inspection for (pre)cancerous lesions. Here, we show that a concomitant effect of acetowhitening-changes in refractive index composition-yields nuclear contrast enhancement in quantitative phase imaging (QPI) of thick tissue samples.</p><p><strong>Aim: </strong>We aim to explore how changes in refractive index composition during acetowhitening can be captured through a novel epi-mode 3D QPI technique called quantitative oblique back-illumination microscopy (qOBM). We also aim to demonstrate the potential of using a machine learning-based approach to convert qOBM images of fresh tissues into virtually AA-stained images.</p><p><strong>Approach: </strong>We implemented qOBM, an imaging technique that allows for epi-mode 3D QPI to observe phase changes induced by AA in thick tissue samples. We focus on detecting nuclear contrast changes caused by AA in mouse brain samples. As a proof of concept, we also applied a Cycle-GAN algorithm to convert the acquired qOBM images into virtually AA-stained images, simulating the effect of AA staining.</p><p><strong>Results: </strong>Our findings demonstrate that AA-induced acetowhitening leads to significant nuclear contrast enhancement in qOBM images of thick tissue samples. In addition, the Cycle-GAN algorithm successfully converted qOBM images into virtually AA-stained images, further facilitating the nuclear enhancement process without any physical stains.</p><p><strong>Conclusions: </strong>We show that the acetowhitening effect of acetic acid induces changes in refractive index composition that significantly enhance nuclear contrast in QPI. The application of qOBM with AA, along with the use of a Cycle-GAN algorithm to virtually stain tissues, highlights the potential of this approach for advancing label-free and slide-free, <i>ex vivo</i>, and <i>in vivo</i> histology.</p>","PeriodicalId":15264,"journal":{"name":"Journal of Biomedical Optics","volume":"30 2","pages":"026501"},"PeriodicalIF":3.0,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11792252/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143189354","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":"Enhanced porphyrin-based hypoxia imaging by temporal oversampling of delayed fluorescence signal.","authors":"Marien I Ochoa, Arthur F Petusseau, Matthew S Reed, Petr Brůža, Brian W Pogue","doi":"10.1117/1.JBO.30.S2.S23903","DOIUrl":"10.1117/1.JBO.30.S2.S23903","url":null,"abstract":"<p><strong>Significance: </strong>Protoporphyrin IX (PpIX) delayed fluorescence (DF) is inversely related to the oxygen present in tissues and has potential as a novel biomarker for surgical guidance and real-time tissue metabolism assessment. Despite the unique promise of this technique, its successful clinical translation is limited by the low intensity emitted.</p><p><strong>Aim: </strong>We developed a systematic study of ways to increase the PpIX DF signal through acquisition sampling changes, allowing optimized imaging at video rates.</p><p><strong>Approach: </strong>To accomplish signal increase, time-gating signal compression was achieved through changes in pulse frequency and power density, using sampling rates that are faster than the decay rate of the signal. The increased signal yield was tested and validated <i>in vitro</i> and then demonstrated <i>in vivo</i>, with comparison to settings that sample the full lifetime emission decay.</p><p><strong>Results: </strong>Results <i>in vitro</i> and <i>in vivo</i> demonstrated that optimized timing could increase the detected intensity by a factor of 7. The images showed results that were superior than when sampling the full DF lifetime decay.</p><p><strong>Conclusions: </strong>The proposed timing optimization enhances PpIX-based DF real-time imaging of tissue hypoxia. By increasing sampling frequency and adjusting the acquisition gate and pulse width, the collected signal intensity improved sevenfold, demonstrated both <i>in vitro</i> and <i>in vivo</i>. The technique was shown to enable better visualization of small and anatomically challenging hypoxic structures. The improved target-to-background ratio and compatibility with pressure-enhanced sensing of tissue oxygen technique were demonstrated.</p>","PeriodicalId":15264,"journal":{"name":"Journal of Biomedical Optics","volume":"30 Suppl 2","pages":"S23903"},"PeriodicalIF":3.0,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11774257/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143065986","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":"Portable multi-parametric microscopy for noninvasive metabolic and vascular imaging of orthotopic tongue cancer models <i>in vivo</i>.","authors":"Pranto Soumik Saha, Jing Yan, Caigang Zhu","doi":"10.1117/1.JBO.30.S2.S23905","DOIUrl":"https://doi.org/10.1117/1.JBO.30.S2.S23905","url":null,"abstract":"<p><strong>Significance: </strong>Precise imaging of tumor metabolism with its vascular microenvironment becomes emerging critical for cancer research because increasing evidence shows that the key attribute that allows a tumor to survive therapies is metabolic and vascular reprogramming. However, there are surprisingly few imaging techniques available to provide a systems-level view of tumor metabolism and vasculature <i>in vivo</i> on small animals for cancer discoveries.</p><p><strong>Aim: </strong>We aim to develop a new multi-parametric microscope that can faithfully recapitulate <i>in vivo</i> metabolic and vascular changes with a wide field of view and microscope-level resolution to advance cancer-related investigations. To maximize the ease and accessibility of obtaining <i>in vivo</i> tissue metabolism and vasculature measurements, we aim to develop our new metabolic imaging tool with minimal cost and size, allowing one to easily quantify tissue metabolic and vascular endpoints together <i>in vivo</i>, advancing many critical biomedical inquiries.</p><p><strong>Approach: </strong>We have combined fluorescence microscopy and dark-field microscopy in a re-emission geometry into one portable microscope to image the key metabolic and vascular endpoints on the same tissue site. The portable microscope was first characterized by tissue-mimicking phantoms. Then the multi-parametric system was demonstrated on small animals to image glucose uptake (using 2-NBDG) and mitochondrial membrane potential (using TMRE) along with vascular parameters (oxygen saturation and hemoglobin contents) of orthotopic tongue tumors <i>in vivo</i>.</p><p><strong>Results: </strong>Our phantom studies demonstrated the capability of the portable microscope for effective measurements of several key vascular and metabolic parameters with a comparable accuracy compared with our former reported benchtop spectroscopy and imaging systems. Our <i>in vivo</i> animal studies revealed increased glucose uptake and mitochondrial membrane potential along with reduced vascular oxygenation in tongue tumors compared with normal tongue tissues. The spatial analysis of metabolic and vascular images showed a more heterogeneous metabolic and oxygenation profile in tongue tumors compared with normal tongue tissues.</p><p><strong>Conclusions: </strong>Our <i>in vivo</i> animal studies demonstrated the capability of our portable multi-parametric microscope for imaging the key metabolic and vascular parameters at the same tissue site with about one hour delay using an orthotopic tongue tumor model <i>in vivo</i>. Our study showed the potential of a portable functional microscope to noninvasively evaluate tumor biology using orthotopic tongue cancer models for future head and neck cancer research.</p>","PeriodicalId":15264,"journal":{"name":"Journal of Biomedical Optics","volume":"30 Suppl 2","pages":"S23905"},"PeriodicalIF":3.0,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12017805/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144016919","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":"Er:YAG laser biofilm removal from zero-gap periodontal/peri-implant model system mimicking clinical attachment loss.","authors":"Marko Volk, Dominik Šavli, Katja Molan, Saša Terlep, Špela Levičnik-Höfferle, Mojca Trost, Boris Gašpirc, Matjaž Lukač, Matija Jezeršek, David Stopar","doi":"10.1117/1.JBO.30.2.025002","DOIUrl":"10.1117/1.JBO.30.2.025002","url":null,"abstract":"<p><strong>Significance: </strong>Here, we present a photoacoustic method to remove biofilms from periodontal and peri-implant-constrained geometries.</p><p><strong>Aim: </strong>We aim to remove biofilms from narrow periodontal and peri-implant model systems with the application of Er:YAG ultrashort laser pulses.</p><p><strong>Approach: </strong>Construction of zero-gap model system from PDMS and titanium, growth of biofilms on titanium surfaces, and removal of biofilms with Er:YAG USP, 20 mJ, 15 Hz, and 10 s were performed.</p><p><strong>Results: </strong>The results suggest that geometry, the vertical position of the laser fiber tip, and the evolution of the primary cavitation bubble significantly affect cleaning effectiveness. Cleaning was higher in the wedge part of the model system. In the zero-gap part of the model system, biofilm cleaning effectiveness was highest at the position of the laser fiber tip and decreased above and below the fiber tip. The dimension of the space in which the cavitation bubble develops determines the size and dynamics of the expanded cavitation bubble and consequently the biofilm cleaning effectiveness.</p><p><strong>Conclusions: </strong>The obtained results suggest a very good biofilm removal effectiveness in difficult-to-reach narrow geometries mimicking clinical attachment loss in the periodontal/peri-implant pocket.</p>","PeriodicalId":15264,"journal":{"name":"Journal of Biomedical Optics","volume":"30 2","pages":"025002"},"PeriodicalIF":3.0,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11853840/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143501464","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":"Basis function model to extract the combined confocal and fall-off function from multiple optical coherence tomography A-scans.","authors":"Daniel J Phan, Martin Were, Jörn-Hendrik Weitkamp, Audrey K Bowden","doi":"10.1117/1.JBO.30.2.025003","DOIUrl":"10.1117/1.JBO.30.2.025003","url":null,"abstract":"<p><strong>Significance: </strong>Many derivatives of optical coherence tomography (OCT) rely on the depth-dependent information of the sample in the image. System depth-dependent effects, such as the confocal effect and the sensitivity fall-off, should be corrected to improve the accuracy of the images and information derived from them.</p><p><strong>Aim: </strong>We developed a new single-shot method to extract the combined confocal and fall-off functions and remove system-generated depth-dependent effects from OCT images.</p><p><strong>Approach: </strong>The combined function is modeled as a linear combination of basis functions whose coefficients are found from two or more A-scans (or B-scans) of a sample that are vertically shifted within the imaging range. No prior knowledge of the OCT system parameters or assumed form for the confocal and fall-off functions is needed.</p><p><strong>Results: </strong>The method was derived and validated with simulations and OCT images of a phantom, a biological sample, and human retina. Improvement over the Ratio Fit method was demonstrated.</p><p><strong>Conclusions: </strong>The improvement in the extraction of the combined confocal and fall-off effects by this method should lead to improved medical diagnosis through more accurate attenuation coefficient calculations. The method enables future applications of OCT where precise removal of all depth-dependent effects on OCT images is critical.</p>","PeriodicalId":15264,"journal":{"name":"Journal of Biomedical Optics","volume":"30 2","pages":"025003"},"PeriodicalIF":3.0,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11868661/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143542098","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":"Tetherless miniaturized point detector device for monitoring cortical surface hemodynamics in mice.","authors":"Anupam Bisht, Govind Peringod, Linhui Yu, Ning Cheng, Grant R Gordon, Kartikeya Murari","doi":"10.1117/1.JBO.30.S2.S23904","DOIUrl":"10.1117/1.JBO.30.S2.S23904","url":null,"abstract":"<p><strong>Significance: </strong>Several miniaturized optical neuroimaging devices for preclinical studies mimicking benchtop instrumentation have been proposed in the past. However, they are generally relatively large, complex, and power-hungry, limiting their usability for long-term measurements in freely moving animals. Further, there is limited research in the development of algorithms to analyze long-term signals.</p><p><strong>Aim: </strong>We aim to develop a cost-effective, easy-to-use miniaturized intrinsic optical monitoring system (TinyIOMS) that can be reliably used to record spontaneous and stimulus-evoked hemodynamic changes and further cluster brain states based on hemodynamic features.</p><p><strong>Approach: </strong>We present the design and fabrication of TinyIOMS ( <math><mrow><mn>8</mn> <mtext>  </mtext> <mi>mm</mi> <mo>×</mo> <mn>13</mn> <mtext>  </mtext> <mi>mm</mi> <mo>×</mo> <mn>9</mn> <mtext>  </mtext> <msup><mrow><mi>mm</mi></mrow> <mrow><mn>3</mn></mrow> </msup> </mrow> </math> , 1.2 g with battery). A standard camera-based widefield system (WFIOS) is used to validate the TinyIOMS signals. Next, TinyIOMS is used to continuously record stimulus-evoked activity and spontaneous activity for 7 h in chronically implanted mice. We further show up to 2 days of intermittent recording from an animal. An unsupervised machine learning algorithm is used to analyze the TinyIOMS signals.</p><p><strong>Results: </strong>We observed that the TinyIOMS data is comparable to the WFIOS data. Stimulus-evoked activity recorded using the TinyIOMS was distinguishable based on stimulus magnitude. Using TinyIOMS, we successfully achieved 7 h of continuous recording and up to 2 days of intermittent recording in its home cage placed in the animal housing facility, i.e., outside a controlled lab environment. Using an unsupervised machine learning algorithm ( <math><mrow><mi>k</mi></mrow> </math> -means clustering), we observed the grouping of data into two clusters representing asleep and awake states with an accuracy of <math><mrow><mo>∼</mo> <mn>91</mn> <mo>%</mo></mrow> </math> . The same algorithm was then applied to the 2-day-long dataset, where similar clusters emerged.</p><p><strong>Conclusions: </strong>TinyIOMS can be used for long-term hemodynamic monitoring applications in mice. Results indicate that the device is suitable for measurements in freely moving mice during behavioral studies synchronized with behavioral video monitoring and external stimuli.</p>","PeriodicalId":15264,"journal":{"name":"Journal of Biomedical Optics","volume":"30 Suppl 2","pages":"S23904"},"PeriodicalIF":3.0,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11922257/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143663591","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":"Validation of subpixel target detection and linear spectral unmixing techniques on short-wave infrared hyperspectral images of collagen phantoms.","authors":"Hsian-Min Chen, Hsin-Che Wang, Chiu-Chin Sung, Yu-Ting Hsu, Yi-Jing Sheen","doi":"10.1117/1.JBO.30.2.023518","DOIUrl":"10.1117/1.JBO.30.2.023518","url":null,"abstract":"<p><strong>Significance: </strong>We used three-dimensionally printed experimental molds and designed lard (lipid)-collagen mixed phantoms to simulate biological tissues to verify the practicality and accuracy of short-wave infrared (SWIR) hyperspectral imaging (HSI; 900 to 1700 nm), subpixel target detection (STD), and linear spectral unmixing (LSU). We provide a foundation for future development, validation, and reproducibility of hyperspectral image-processing techniques.</p><p><strong>Aim: </strong>We aim to verify the use of SWIR HSI in bionic tissue phantoms. Second, we focus on the accuracy of STD and spectral unmixing techniques in hyperspectral image processing. Finally, the penetration ability of the technology and its applications at various depths and concentrations are explored.</p><p><strong>Approach: </strong>All experiments were conducted using an SWIR (900 to 1700 nm) HSI sensor. Collagen phantoms of different thicknesses were created to test the penetration abilities. Lard (lipid) was embedded at different depths in the phantoms for STD, whereas LSU was performed on phantoms with varying collagen concentrations. The methods used included constrained energy minimization to detect the lard target and fully constrained least squares (FCLS) to estimate the abundance of collagen phantoms.</p><p><strong>Results: </strong>SWIR HSI effectively penetrated the collagen phantoms. Specifically, STD techniques can accurately detect the presence of lard (lipids) at depths of 7 to 20 mm in the collagen phantoms. Even at a depth of 68 mm, the detection accuracy was 0.907. Moreover, in the LSU analysis, the FCLS method accurately estimated the abundance of collagen phantoms at different concentrations, with a correlation coefficient of 0.9917, indicating high accuracy across different concentrations.</p><p><strong>Conclusions: </strong>This study demonstrated that SWIR HSI is highly accurate for deep target detection and LSU. This technology has great potential for use in future noninvasive biomedical diagnostic models. Collagen phantoms are valuable tools for validating HSI algorithms and provide a solid foundation for clinical applications.</p>","PeriodicalId":15264,"journal":{"name":"Journal of Biomedical Optics","volume":"30 2","pages":"023518"},"PeriodicalIF":3.0,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11853843/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143501472","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":"Hyperspectral imaging in neurosurgery: a review of systems, computational methods, and clinical applications.","authors":"Alankar Kotwal, Vishwanath Saragadam, Joshua D Bernstock, Alfredo Sandoval, Ashok Veeraraghavan, Pablo A Valdés","doi":"10.1117/1.JBO.30.2.023512","DOIUrl":"10.1117/1.JBO.30.2.023512","url":null,"abstract":"<p><strong>Significance: </strong>Accurate identification between pathologic (e.g., tumors) and healthy brain tissue is a critical need in neurosurgery. However, conventional surgical adjuncts have significant limitations toward achieving this goal (e.g., image guidance based on pre-operative imaging becomes inaccurate up to 3 cm as surgery proceeds). Hyperspectral imaging (HSI) has emerged as a potential powerful surgical adjunct to enable surgeons to accurately distinguish pathologic from normal tissues.</p><p><strong>Aim: </strong>We review HSI techniques in neurosurgery; categorize, explain, and summarize their technical and clinical details; and present some promising directions for future work.</p><p><strong>Approach: </strong>We performed a literature search on HSI methods in neurosurgery focusing on their hardware and implementation details; classification, estimation, and band selection methods; publicly available labeled and unlabeled data; image processing and augmented reality visualization systems; and clinical study conclusions.</p><p><strong>Results: </strong>We present a detailed review of HSI results in neurosurgery with a discussion of over 25 imaging systems, 45 clinical studies, and 60 computational methods. We first provide a short overview of HSI and the main branches of neurosurgery. Then, we describe in detail the imaging systems, computational methods, and clinical results for HSI using reflectance or fluorescence. Clinical implementations of HSI yield promising results in estimating perfusion and mapping brain function, classifying tumors and healthy tissues (e.g., in fluorescence-guided tumor surgery, detecting infiltrating margins not visible with conventional systems), and detecting epileptogenic regions. Finally, we discuss the advantages and disadvantages of HSI approaches and interesting research directions as a means to encourage future development.</p><p><strong>Conclusions: </strong>We describe a number of HSI applications across every major branch of neurosurgery. We believe these results demonstrate the potential of HSI as a powerful neurosurgical adjunct as more work continues to enable rapid acquisition with smaller footprints, greater spectral and spatial resolutions, and improved detection.</p>","PeriodicalId":15264,"journal":{"name":"Journal of Biomedical Optics","volume":"30 2","pages":"023512"},"PeriodicalIF":3.0,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11559659/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142621163","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":"Multi-spectral laser speckle contrast imaging for depth-resolved blood perfusion assessment.","authors":"Liban Hussein, Sajjad Moazeni","doi":"10.1117/1.JBO.30.2.023517","DOIUrl":"10.1117/1.JBO.30.2.023517","url":null,"abstract":"<p><strong>Significance: </strong>Laser speckle contrast imaging (LSCI) is a widely used tool in biomedical imaging that leverages the interactions between coherent laser light and tissue to assess blood perfusion. Although effective for 2D imaging applications such as skin burn assessment and wound healing, conventional LSCI lacks depth-resolved capabilities, limiting its potential for deeper perfusion analysis. Enhancing LSCI for depth profiling would significantly expand its utility in applications such as vascular imaging and burn diagnostics.</p><p><strong>Aim: </strong>We investigate the use of multi-spectral laser speckle contrast imaging (MS-LSCI) for assessing blood perfusion at multiple depths, utilizing multiple laser wavelengths and advanced correlation techniques to improve depth localization.</p><p><strong>Approach: </strong>Two tissue phantom molds were fabricated to simulate blood vessels at varying depths. Laser wavelengths from blue to near-infrared (NIR) were used to perform controlled experiments. The visibility parameter, <math> <mrow><msub><mi>V</mi> <mi>r</mi></msub> </mrow> </math> , was employed to correlate and estimate the depth between the phantoms. In addition, a spectral wavelength mapping technique was implemented to enhance signal quality. Validation was conducted by imaging a human hand using the MS-LSCI setup.</p><p><strong>Results: </strong>MS-LSCI demonstrated improved depth profiling accuracy across varying laser wavelengths. The spectral wavelength mapping technique enhanced signal quality for wavelengths with limited penetration. The visibility parameter, <math> <mrow><msub><mi>V</mi> <mi>r</mi></msub> </mrow> </math> , provided consistent depth correlations across phantom models, with results validated through successful imaging of blood perfusion in a human hand.</p><p><strong>Conclusions: </strong>We highlight the potential of MS-LSCI for depth-resolved blood perfusion imaging using multi-wavelength approaches. The findings emphasize the technique's feasibility for non-invasive biomedical applications, including burn wound assessment and vascular imaging.</p>","PeriodicalId":15264,"journal":{"name":"Journal of Biomedical Optics","volume":"30 2","pages":"023517"},"PeriodicalIF":3.0,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11853228/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143501468","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}