Journal of Biomedical Optics最新文献

{"title":"<i>In vivo</i> tumor imaging of pre-clinical models via reflection-mode measurements of circular degree of polarization.","authors":"Michael D Singh, Héctor A Contreras-Sánchez, Alex Vitkin","doi":"10.1117/1.JBO.30.S3.S34105","DOIUrl":"10.1117/1.JBO.30.S3.S34105","url":null,"abstract":"<p><strong>Significance: </strong>Tumor tissues exhibit contrast with healthy tissue in circular degree of polarization (DOP) images via higher magnitude circular DOP values and increased helicity-flipping. This phenomenon may enable polarimetric tumor detection and surgical/procedural guidance applications.</p><p><strong>Aim: </strong>Depolarization metrics have been shown to exhibit differential responses to healthy and cancer tissue, whereby tumor tissues tend to induce less depolarization; however, the understanding of this depolarization-based contrast remains limited. Therefore, we investigate depolarization signals from tumor tissue and non-tumor tissue.</p><p><strong>Approach: </strong>Mice ( <math><mrow><mi>n</mi> <mo>=</mo> <mn>3</mn></mrow> </math> ) with human pancreatic ductal adenocarcinoma (PDAC) xenografts enable polarimetric comparison between tumor tissue and non-tumor tissues. Modified signed-value DOP equations aid in the interpretation of DOP images, which encode helicity-flipping and co-linearity as negative values, but still yield the same magnitudes as conventional DOP calculations.</p><p><strong>Results: </strong>Linear DOP is greater in magnitude than circular DOP across both tissue types; however, circular DOP yields greater contrast between tumor and non-tumor tissues. Circular DOP values are higher in magnitude and more negative (i.e., more helicity-flipping) in tumors, whereas linear DOP values exhibit similar behavior; however, they are only slightly higher in magnitude and slightly more negative (i.e., more co-linearity) in tumors.</p><p><strong>Conclusions: </strong>Circular DOP images yield useful contrast between human PDAC xenografts and surrounding healthy skin in live mice. Each tumor region exhibited higher magnitude circular DOP (and total DOP) values, as previously observed. We noted three indications of Rayleigh scattering in the tumor tissue: (1) linear DOP > circular DOP, (2) helicity-flipping > helicity-preservation, and (3) co-linear intensity > cross-linear intensity. Rayleigh scatterers have been found to be highly polarization preserving; thus, we posit that higher DOP in tumor tissues may arise from an increased presence of Rayleigh scatterers. Furthermore, circular DOP may yield greater contrast between tumor and non-tumor via its well-observed sensitivity to scatterer size. Further investigation is warranted to test these hypotheses.</p>","PeriodicalId":15264,"journal":{"name":"Journal of Biomedical Optics","volume":"30 Suppl 3","pages":"S34105"},"PeriodicalIF":2.9,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12411644/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145015445","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":"Experimental method to assess depth sensing limits of inelastic scattering measurements using spatial-offset Raman spectroscopy imaging.","authors":"Hugo Tavera, Guillaume Sheehy, Patrick Orsini, Jacques Bismuth, Marie-Maude de Denus-Baillargeon, Maroun Massabki, Jean-François Masson, Frederic Leblond","doi":"10.1117/1.JBO.30.S3.S34108","DOIUrl":"10.1117/1.JBO.30.S3.S34108","url":null,"abstract":"<p><strong>Significance: </strong>The relationship between spatial offset and tissue sensing depth is not well understood in spatial offset Raman spectroscopy (SORS). Detection of the subsurface biochemical composition could improve clinical translation of SORS-based methods, including for lumpectomy margin characterization in breast cancer surgery.</p><p><strong>Aim: </strong>We aimed at developing an experimental method to establish a relationship between spatial offset in SORS and sampling depth. The technique was developed using a custom hyperspectral line-scanning imaging system optimized for Raman spectroscopy detection.</p><p><strong>Approach: </strong>Bilayer phantoms were produced with top and bottom layers made of material with different Raman spectroscopy signatures, i.e., poly(dimethylsiloxane) polymer (PDMS) and Nylon. The top layer of PDMS had different values of absorption and reduced elastic scattering coefficients, as well as a thickness up to <math><mrow><mo>∼</mo> <mn>3</mn> <mtext>  </mtext> <mi>mm</mi></mrow> </math> . A metric was used, called spectral angle mapper, that allowed for comparing SORS measurements with reference spectra of pure PDMS and Nylon. That metric was used to develop a technique predicting sensing depth for different values of spatial offset. A proof-of-concept study was performed to assess the performance of the method in biological tissue, demonstrating detectability of protein-rich tissue across layers of Intralipid and porcine fat to simulate the optical properties of human adipose tissue.</p><p><strong>Results: </strong>A total of 60 optical phantoms with varying optical properties and top layer thicknesses were imaged and processed to estimate sampling depth as a function of spatial offset. The study demonstrated the detectability of the underlying Nylon layer across a PDMS layer up to 3 mm in thickness. Similarly, the detectability of protein-rich tissue was demonstrated across layers of Intralipid up to 3 mm thick and <math><mrow><mo><</mo> <mn>2</mn> <mtext>  </mtext> <mi>mm</mi></mrow> </math> for porcine fat.</p><p><strong>Conclusions: </strong>We showed the feasibility of using bilayer solid optical phantoms to create correlation curves between the optimal spatial offset for a desired probed depth given the optical properties of the top layer. The technique could facilitate the clinical translation of SORS measurements for tumor detection and margins assessment.</p>","PeriodicalId":15264,"journal":{"name":"Journal of Biomedical Optics","volume":"30 Suppl 3","pages":"S34108"},"PeriodicalIF":2.9,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12447185/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145113185","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":"ALA-based photodynamic priming in murine skin increases blood flow and oxygenation.","authors":"Aleksandra Ilina, Marien Iliza Ochoa Mendoza, Xu Cao, Tayyaba Hasan, Brian W Pogue","doi":"10.1117/1.JBO.30.S3.S34106","DOIUrl":"10.1117/1.JBO.30.S3.S34106","url":null,"abstract":"<p><strong>Significance: </strong>Topical photodynamic therapy (PDT) with protoporphyrin IX (PpIX) converted from 5-aminolevulinic acid (ALA) is a well-established noninvasive method of treating skin conditions and lesions. During PDT, there can be response dynamics within the tissue that are affected by the light delivery, seen with fractionated delivery and in subcurative priming delivery. Fractionated light doses can considerably increase efficacy of 5-ALA PDT response.</p><p><strong>Aim: </strong>We aim to examine the changes in physiological blood flow, tissue oxygenation, and PpIX concentration during and after light delivery in topical ALA-PDT in nude mouse skin.</p><p><strong>Approach: </strong>We compared three schemes of light delivery for topical ALA-PDT in nude mice, including (1) full light delivery without fractionation, (2) two equal fractions (50% and 50%) of light separated by 2 h, and (3) a 5% light dose fractionation by 2 h prior to the main 95% light dose. Tissue oxygen imaging was assessed with the hypoxia signal from delayed fluorescence of PpIX itself within the tissue, as well as by confirmation with Oxyphor phosphorescence lifetime quenching imaging.</p><p><strong>Results: </strong>The results of blood flow imaging and hypoxia imaging from PpIX and oxygen imaging with Oxyphor each showed evidence of increased capillary flow and tissue oxygenation after the initial 5% light dose, increased at the side of irradiation. This increased capillary flow and tissue oxygenation are presumably from vasodilation and local capillary flow increase. PpIX replenishment occurs during the intervening dark period after the initial light delivery.</p><p><strong>Conclusion: </strong>These observations suggest that increasing oxygen and capillary flow combined with increased PpIX production together yield increased PDT efficiency, amplified by this initial light dose from a photodynamic optical priming event occurring 2 h prior to full PDT light delivery.</p>","PeriodicalId":15264,"journal":{"name":"Journal of Biomedical Optics","volume":"30 Suppl 3","pages":"S34106"},"PeriodicalIF":2.9,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12433272/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145064708","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":"Reverberant optical coherence elastography using 3D-printed randomly distributed scatterers: elasticity mapping of hydrogels in culture dishes.","authors":"Hao Xu, FanLei Yang, Ting Liang, Wen Zhang, JianQiang Mo, ZongPing Luo","doi":"10.1117/1.JBO.30.12.124507","DOIUrl":"10.1117/1.JBO.30.12.124507","url":null,"abstract":"<p><strong>Significance: </strong>Accurate estimation of hydrogel phantom elasticity in 3D cell culture systems provides valuable insights into cellular responses to various mechanical stimuli. Although reverberant wave elastography has been applied to measure hydrogel elasticity in 3D cell cultures using multi-point loading, achieving a high-quality reverberant displacement field remains critical for accurate reverberant wave elastography.</p><p><strong>Aim: </strong>We develop an innovative approach using 3D-printed randomly distributed scatterers to improve displacement field quality in reverberant wave elastography, inspired by scattering-coded architectured boundaries in object localization.</p><p><strong>Approach: </strong>Numerical simulations were performed to analyze the reverberant displacement fields under various loading conditions. The results were compared to determine the optimal loading configuration to enhance the reverberation level of the displacement field. Subsequently, both numerical and experimental reverberant wave elastography were carried out to validate the elasticity measurement with 3D-printed randomly distributed scatterers.</p><p><strong>Results: </strong>The comparison of reverberant displacement patterns under various loading conditions revealed that the displacement pattern under circular loading with 64 scatterers most closely approximated a diffuse wave field, exhibiting both spatial uniformity and directional isotropy. Numerical reverberant wave elastography was subsequently performed, successfully demonstrating its capability for elasticity measurements. Furthermore, the shear wave speeds obtained through optical coherence elastography showed good agreement with shear rheometry measurements.</p><p><strong>Conclusions: </strong>The developed 3D-printed randomly distributed scatterers successfully enhanced the quality of the reverberant displacement field for reverberant wave elastography. Our approach presents a novel and promising tool for quantifying tissue elasticity in reverberant wave elastography applications.</p>","PeriodicalId":15264,"journal":{"name":"Journal of Biomedical Optics","volume":"30 12","pages":"124507"},"PeriodicalIF":2.9,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12503060/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145251275","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":"Development and characterization of a combined fluorescence and spatial frequency domain imaging system for real-time dosimetry of photodynamic therapy.","authors":"Alec B Walter, E Duco Jansen","doi":"10.1117/1.JBO.30.S3.S34103","DOIUrl":"10.1117/1.JBO.30.S3.S34103","url":null,"abstract":"<p><strong>Significance: </strong>Current methods of measuring dosimetry for photodynamic therapy (PDT) have proven to be inadequate in their inability to provide accurate, real-time, and spatially resolved monitoring without interrupting the PDT treatment.</p><p><strong>Aim: </strong>Our goal was to develop and validate a combined treatment and dosimetry system capable of monitoring implicit and explicit dosimetry in real time during non-contact PDT.</p><p><strong>Approach: </strong>By employing both fluorescence imaging and spatial frequency domain imaging (SFDI), designed with low-cost, off-the-shelf components, the combined imaging system would be able to provide information on the spatial distributions of photosensitizer concentrations, tissue oxygenation, and delivered light dose, all while monitoring the photobleaching dynamics of the photosensitizer. Although the concept behind the combined system is not specific to any one photosensitizer, we focused on designing the system for the endogenous PDT of Gram-positive bacteria which utilizes coproporphyrin III as the photosensitizer.</p><p><strong>Results: </strong>The overall performance of the system was assessed, with the accuracy, precision, and resolution of the SFDI-derived optical property maps being determined to fall within comparable ranges to other systems, despite the <math><mrow><mn>1.0</mn> <mtext> </mtext> <msup><mrow><mi>mm</mi></mrow> <mrow><mo>-</mo> <mn>1</mn></mrow> </msup> </mrow> </math> spatial frequency utilized for the shorter wavelengths. After validating the ability of the system to correct for tissue-like optical properties, and thus produce accurate quantitative fluorescence images, a preliminary assessment of antimicrobial PDT photobleaching dosimetry was performed, and high correlations were found between the fluorescence and PDT outcomes.</p><p><strong>Conclusions: </strong>Overall, the developed imaging system showcases the potential to enable a more thorough analysis of PDT dosimetry and the impact of different variables on treatment outcomes.</p>","PeriodicalId":15264,"journal":{"name":"Journal of Biomedical Optics","volume":"30 Suppl 3","pages":"S34103"},"PeriodicalIF":2.9,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12118877/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144181697","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":"Integrating optical coherence tomography and bioluminescence with predictive modeling for quantitative assessment of methicillin-resistant <i>S. aureus</i> biofilms.","authors":"Valentin V Demidov, Olivia P Jackson, Natalia Demidova, Jason R Gunn, I Leah Gitajn, Jonathan Thomas Elliott","doi":"10.1117/1.JBO.30.S3.S34111","DOIUrl":"10.1117/1.JBO.30.S3.S34111","url":null,"abstract":"<p><strong>Significance: </strong>Methicillin-resistant <i>Staphylococcus aureus</i> (MRSA) biofilm infections present a critical challenge in orthopedic trauma surgery and are notoriously resistant to systemic antibiotic therapy. Noninvasive, quantitative imaging methods are urgently needed to assess biofilm burden and therapeutic efficacy, especially for emerging photodynamic therapy (PDT) strategies.</p><p><strong>Aim: </strong>We aim to establish a quantitative framework using a combined bioluminescence and optical coherence tomography (OCT) imaging approach to correlate bioluminescent signal with viable MRSA burden in both planktonic and biofilm states and to determine how biofilm density and structure influence this relationship.</p><p><strong>Approach: </strong>Bioluminescent MRSA (SAP231-luxCDABE) was cultured in planktonic and biofilm forms using <i>in vitro</i> growth models in 24-well plates and custom macrofluidic devices, respectively. Bacteria bioluminescence intensity (BLI), counted colony-forming units (CFU), and OCT-based biofilm thickness measurements were collected to construct linear regression models to evaluate how well BLI alone, or combined with biofilm density (CFU/volume), predicts bacterial counts across culture conditions.</p><p><strong>Results: </strong>Bioluminescence strongly correlated with CFU in planktonic cultures ( <math> <mrow><msup><mi>R</mi> <mn>2</mn></msup> <mo>=</mo> <mn>0.98</mn></mrow> </math> ). In biofilms, BLI per CFU decreased with density, indicating metabolic downregulation, and BLI alone was less reliable ( <math> <mrow><msup><mi>R</mi> <mn>2</mn></msup> <mo>=</mo> <mn>0.59</mn></mrow> </math> ). Incorporating biofilm density (CFU/volume) improved prediction ( <math> <mrow><msup><mi>R</mi> <mn>2</mn></msup> <mo>=</mo> <mn>0.84</mn></mrow> </math> ). A joint model for both states showed excellent fit ( <math> <mrow><msup><mi>R</mi> <mn>2</mn></msup> <mo>=</mo> <mn>0.985</mn></mrow> </math> ), but the biofilm versus planktonic group remained a significant factor ( <math><mrow><mi>p</mi> <mo>=</mo> <mn>0.002</mn></mrow> </math> ), revealing systematic differences. This highlights the need for a mixed-model approach that segments subvolumes by morphological features to improve accurate, generalizable CFU estimation across both growth states.</p><p><strong>Conclusions: </strong>Bioluminescence alone underestimates bacterial burden in dense, metabolically suppressed MRSA biofilms. The combination of BLI with OCT-derived structural metrics enables accurate, nondestructive quantification of viable bacterial load. This approach provides a robust toolset for preclinical evaluation of antimicrobial therapies, particularly for optimizing PDT dosimetry and assessing biofilm response in translational infection models.</p>","PeriodicalId":15264,"journal":{"name":"Journal of Biomedical Optics","volume":"30 Suppl 3","pages":"S34111"},"PeriodicalIF":2.9,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12456866/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145137511","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":"Asynchronous optical coherence elastography and directional phase gradient analysis.","authors":"Ginger Schmidt, Ryan McAuley, Brett E Bouma, Néstor Uribe-Patarroyo","doi":"10.1117/1.JBO.30.12.124506","DOIUrl":"10.1117/1.JBO.30.12.124506","url":null,"abstract":"<p><strong>Significance: </strong>The stiffness and compliance of biological tissues are key properties that often change in the presence of pathology, yet current shear wave elastography approaches using optical coherence tomography (OCT) face limitations due to slow image acquisition, sensitivity to motion artifacts, and reliance on advanced hardware, hindering clinical translation.</p><p><strong>Aim: </strong>The aim is to develop and validate a practical, high-speed method for three-dimensional shear wave imaging compatible with standard OCT systems and wave propagation variability.</p><p><strong>Approach: </strong>We introduce a technique for the rapid, asynchronous acquisition of three-dimensional shear wave fields. Our technique operates at conventional acquisition rates and utilizes pairs of B-scans, similar to angiography scanning protocols. This approach significantly reduces motion sensitivity and enhances acquisition speed, even with much denser lateral sampling. In addition, we present a technique for estimating the shear wave number, termed directional phase gradient analysis. This method computes the phase gradient of the autocorrelation of the directionally-filtered, complex-valued shear wave and is robust across unidirectional, partially diffuse, and fully diffuse shear wave conditions.</p><p><strong>Results: </strong>We validated the accuracy of our techniques through direct comparison with phase-locked, synchronous-mode imaging in benchtop experiments using tissue-mimicking phantoms. Furthermore, we demonstrated their robustness to variations in wave orientation, excitation amplitude, and diffusivity, as confirmed by repeated measurements on the same sample under diverse conditions.</p><p><strong>Conclusions: </strong>Together, these methods may offer a more practical approach for shear wave imaging without requiring modifications to existing clinical phase-stable OCT systems.</p>","PeriodicalId":15264,"journal":{"name":"Journal of Biomedical Optics","volume":"30 12","pages":"124506"},"PeriodicalIF":2.9,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12447186/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145113180","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":"Development of breast-mimicking phantoms for use in optical coherence elastography.","authors":"Farzan Navaeipour, Rowan W Sanderson, Jiayue Li, Scarlett Rawlins, Matt S Hepburn, Brendan F Kennedy","doi":"10.1117/1.JBO.30.12.124504","DOIUrl":"10.1117/1.JBO.30.12.124504","url":null,"abstract":"<p><strong>Significance: </strong>Optical coherence elastography (OCE) is an emerging technique for mapping tissue mechanical properties into an image, known as an elastogram, with microscale resolution. Although system characterization phantoms are widely used in OCE development, there is a critical need for tissue-mimicking phantoms that can more accurately replicate the complex structural and mechanical properties of tissues, particularly for validating clinical applications, such as in breast cancer.</p><p><strong>Aim: </strong>We aim to investigate the effects of tissue-like structures on elastogram formation in a controlled environment by developing and characterizing two types of breast tissue-mimicking phantoms, replicating invasive ductal carcinoma (IDC) morphology and the other mimicking breast ductal networks.</p><p><strong>Approach: </strong>We present a comprehensive methodology for fabricating breast-mimicking phantoms using optical coherence tomography and ductography images to provide information on tissue structure. The method employs 3D-printed molds, casting different silicone materials for IDC-mimicking phantoms and implementing a dissolving mold technique to create duct-mimicking phantoms, which can be tested in both empty and fluid-filled states.</p><p><strong>Results: </strong>The IDC-mimicking phantom successfully replicates structural features as small as <math><mrow><mn>100</mn> <mtext>  </mtext> <mi>μ</mi> <mi>m</mi></mrow> </math> , revealing complex mechanical behaviors at tissue interfaces, including strain concentrations where tissues of different stiffness interact. The duct-mimicking phantom demonstrates distinct mechanical responses between configurations, with hollow ducts creating sharp discontinuities at boundaries, whereas fluid-filled ducts exhibit more gradual transitions in mechanical properties.</p><p><strong>Conclusions: </strong>Our methodology demonstrates the capability to fabricate breast tissue-mimicking phantoms that reproduce both the structural and mechanical properties of breast tissue, providing a controlled environment for investigating OCE performance and understanding how tissue architecture influences elastogram formation, particularly at interfaces among different tissue types.</p>","PeriodicalId":15264,"journal":{"name":"Journal of Biomedical Optics","volume":"30 12","pages":"124504"},"PeriodicalIF":2.9,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12404407/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144992774","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":"Reconstruction of tensile and shear elastic moduli in anisotropic nearly incompressible media using Rayleigh wave phase and group velocities.","authors":"Gabriel Regnault, Ruikang K Wang, Matthew O'Donnell, Ivan Pelivanov","doi":"10.1117/1.JBO.30.12.124503","DOIUrl":"10.1117/1.JBO.30.12.124503","url":null,"abstract":"<p><strong>Significance: </strong>Dynamic optical coherence elastography can excite and detect propagating mechanical waves in soft tissue without physical contact and in near real time. However, most soft tissue is anisotropic, characterized by at least three independent elastic moduli. As a result, reconstructing these moduli from mechanical wave fields requires a complex procedure.</p><p><strong>Aim: </strong>We consider a nearly incompressible transverse isotropic (NITI) material, which has been shown to locally define the symmetry of many soft tissues such as muscle, tendon, skin, cornea, heart, and brain. Reconstruction of elastic moduli in the NITI medium using Rayleigh waves is addressed here. A method to accurately compute the angular dependence of Rayleigh wave phase velocity for the most common geometries (point-like and line sources) of mechanical wave excitation is described.</p><p><strong>Approach: </strong>When a line source is used to launch plane mechanical waves over the medium surface, the phase velocity of Rayleigh waves in the direction of propagation is directly accessible. For a point-like source, propagation of the energy flux is tracked (i.e., its group velocity), which cannot be directly used for moduli inversion. In this case, angular spectrum decomposition is used to access the phase velocity. Both numerical simulations in OnScale and experiments in a stretched PVA phantom were performed.</p><p><strong>Results: </strong>We show that both methods (line source wave excitation and angular decomposition from a point-like source) produce similar results and accurately estimate the angular anisotropy of the Rayleigh wave phase velocity. We also explicitly show that a commonly used group velocity approach leads to inadequate moduli inversion and should not be used for reconstruction.</p><p><strong>Conclusions: </strong>We suggest that the line source is best when a surface area must be scanned, whereas the point-like source with the proposed phase velocity reconstruction is best for single-point moduli estimation or when tissue motion is a concern.</p>","PeriodicalId":15264,"journal":{"name":"Journal of Biomedical Optics","volume":"30 12","pages":"124503"},"PeriodicalIF":2.9,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12334138/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144816691","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":"3D photogrammetry quantifies the size of basal cell carcinoma lesions with submillimeter accuracy: high correlation with lesion response to photodynamic therapy.","authors":"Edward V Maytin, Nathalie C Zeitouni, Abigail Updyke, Jeffrey T Negrey, Alan S Shen, Lauren E Heusinkveld, Sanjay Anand, Christine B Warren, Tayyaba Hasan, Brian W Pogue","doi":"10.1117/1.JBO.30.S3.S34107","DOIUrl":"10.1117/1.JBO.30.S3.S34107","url":null,"abstract":"<p><strong>Significance: </strong>Noninvasive imaging to accurately measure subtle changes in tumor size is underutilized when assessing therapeutic responses in the skin. During photodynamic therapy (PDT) for basal cell carcinoma (BCC), a better definition of the tumor size threshold for PDT responsiveness is needed.</p><p><strong>Aim: </strong>We aim to quantitatively demonstrate the first clinical evidence of tumor shrinkage after multiple rounds of PDT using a robust measurement and analysis approach.</p><p><strong>Approach: </strong>Tumors were monitored experimentally using a 3D camera and software system (stereo photogrammetry). A total of 122 BCC tumors in 35 patients were treated with PDT (5-ALA and blue light) in three sessions. Calculated volumes and heights were used to plot changes in tumor size.</p><p><strong>Results: </strong>In total, 70% of BCC cleared completely. Measured heights correlated with histological tumor depth; average heights were <math><mrow><mo>∼</mo> <mn>10</mn> <mo>%</mo></mrow> </math> to 20% of actual tumor depth. From photogrammetry at baseline, an average height of <math><mrow><mo><</mo> <mn>0.15</mn> <mtext>  </mtext> <mi>mm</mi></mrow> </math> was found to predict a complete therapeutic response. Thus, our 3D morphometric technique provides a surrogate measure of BCC tumor depth that predicts PDT response and is accurate to well below the millimeter level.</p><p><strong>Conclusions: </strong>3D photogrammetry can inform the selection of BCC tumors for PDT with exceptionally high spatial accuracy, dramatically better than can be quantified by a clinician.</p>","PeriodicalId":15264,"journal":{"name":"Journal of Biomedical Optics","volume":"30 Suppl 3","pages":"S34107"},"PeriodicalIF":2.9,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12463384/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145185958","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}