Journal of Biomedical Optics最新文献

{"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":"Combined dual-channel fluorescence depth sensing of indocyanine green and protoporphyrin IX kinetics in subcutaneous murine tumors.","authors":"Madhusudan B Kulkarni, Matthew S Reed, Xu Cao, Héctor A García, Marien I Ochoa, Shudong Jiang, Tayyaba Hasan, Marvin M Doyley, Brian W Pogue","doi":"10.1117/1.JBO.30.S1.S13709","DOIUrl":"https://doi.org/10.1117/1.JBO.30.S1.S13709","url":null,"abstract":"<p><strong>Significance: </strong>Fluorescence sensing within tissue is an effective tool for tissue characterization; however, the modality and geometry of the image acquisition can alter the observed signal.</p><p><strong>Aim: </strong>We introduce a novel optical fiber-based system capable of measuring two fluorescent contrast agents through 2 cm of tissue with simple passive electronic switching between the excitation light, simultaneously acquiring fluorescence and excitation data. The goal was to quantify indocyanine green (ICG) and protoporphyrin IX (PpIX) within tissue, and the sampling method was compared with wide-field surface imaging to contrast the value of deep sensing versus surface imaging.</p><p><strong>Approach: </strong>This was achieved by choosing filters for specific wavelengths that were mutually exclusive between ICG and PpIX and coupling these filters to two separate detectors, which allows for direct swapping of the excitation and emission channels by switching the on-time of each excitation laser between 780- and 633-nm wavelengths.</p><p><strong>Results: </strong>This system was compared with two non-contact surface imaging systems for both ICG and PpIX, which revealed that the fluorescence depth sensing system was superior in its ability to resolve kinetics differences in deeper tissues that would normally be dominated by strong signals from skin and other surface tissues. Specifically, the system was tested using pancreatic adenocarcinoma tumors injected into murine models, which were imaged at several time points throughout tumor growth to its <math><mrow><mo>∼</mo> <mn>6</mn> <mtext>-</mtext> <mi>mm</mi></mrow> </math> diameter. This demonstrated the system's capability to track longitudinal changes in ICG and PpIX kinetics that result from tumor growth and development, with larger tumors showing sluggish uptake and clearance of ICG, which was not observable with surface imaging. Similarly, PpIX was quantified, which showed slower kinetics over different time points, and was further compared with the wide-filed imager. These results were further validated through depth measurements in tissue phantoms and model-based interpretation.</p><p><strong>Conclusion: </strong>This fluorescence depth sensing system can be used to sample the interior blood flow characteristics by ICG sensing of tissue as deep as 20 mm into the tissue with sensitivity to kinetics that are superior to surface imaging and may be combined with other imaging modalities such as ultrasound to provide guided deep fluorescence measurements.</p>","PeriodicalId":15264,"journal":{"name":"Journal of Biomedical Optics","volume":"30 Suppl 1","pages":"S13709"},"PeriodicalIF":3.0,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11571966/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142668150","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":"Systematic comparison of fluorescence imaging in the near-infrared and shortwave-infrared spectral range using clinical tumor samples containing cetuximab-IRDye800CW.","authors":"Bas Keizers, Thomas S Nijboer, Christa A M van der Fels, Marius C van den Heuvel, Gooitzen M van Dam, Schelto Kruijff, Igle Jan de Jong, Max J H Witjes, Floris J Voskuil, Dimitris Gorpas, Wesley R Browne, Pieter J van der Zaag","doi":"10.1117/1.JBO.30.S1.S13708","DOIUrl":"10.1117/1.JBO.30.S1.S13708","url":null,"abstract":"<p><strong>Significance: </strong>Shortwave-infrared (SWIR) imaging is reported to yield better contrast in fluorescence-guided surgery than near-infrared (NIR) imaging, due to a reduction in scattering. This benefit of SWIR was shown in animal studies, however not yet in clinical studies with patient samples.</p><p><strong>Aim: </strong>We investigate the potential benefit of SWIR to NIR imaging in clinical samples containing cetuximab-IRDye800CW in fluorescence-guided surgery.</p><p><strong>Approach: </strong>The potential of the epidermal growth factor-targeted NIR dye cetuximab-IRDye800CW in the shortwave range was examined by recording the absorption and emission spectrum. An <i>ex vivo</i> comparison of NIR and SWIR images using clinical tumor samples of patients with penile squamous cell carcinoma (PSCC) and head and neck squamous cell carcinoma (HNSCC) containing cetuximab-IRDye800CW was performed. The comparison was based on the tumor-to-background ratio and an adapted contrast-to-noise ratio (aCNR) using the standard of care pathology tissue assessment as the golden standard.</p><p><strong>Results: </strong>Based on the emission spectrum, cetuximab-IRDye800CW can be detected in the SWIR range. In clinical PSCC samples, overall SWIR imaging was found to perform similarly to NIR imaging (NIR imaging is better than SWIR in the 2/7 criteria examined, and SWIR is better than NIR in the 3/7 criteria). However, when inspecting HNSCC data, NIR is better than SWIR in nearly all (5/7) examined criteria. This difference seems to originate from background autofluorescence overwhelming the off-peak SWIR fluorescence signal in HNSCC tissue.</p><p><strong>Conclusion: </strong>SWIR imaging using the targeted tracer cetuximab-IRDye800CW currently does not provide additional benefit over NIR imaging in <i>ex vivo</i> clinical samples. Background fluorescence in the SWIR region, resulting in a higher background signal, limits SWIR imaging in HNSCC samples. However, SWIR shows potential in increasing the contrast of tumor borders in PSCC samples, as shown by a higher aCNR over a line.</p>","PeriodicalId":15264,"journal":{"name":"Journal of Biomedical Optics","volume":"30 Suppl 1","pages":"S13708"},"PeriodicalIF":3.0,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11566260/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142648323","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 a protocol for whole-lung <i>in vivo</i> lung perfusion-assisted photodynamic therapy using a porcine model.","authors":"Khaled Ramadan, Tina Saeidi, Edson Brambate, Vanderlei Bagnato, Marcelo Cypel, Lothar Lilge","doi":"10.1117/1.JBO.29.11.118001","DOIUrl":"10.1117/1.JBO.29.11.118001","url":null,"abstract":"<p><strong>Significance: </strong>Standard treatments for isolated lung metastases remain a clinical challenge. <i>In vivo</i> lung perfusion technique provides flexibility to overcome the limitations of photodynamic therapy (PDT) by replacing the blood with acellular perfusate, allowing greater light penetration.</p><p><strong>Aim: </strong>Using Monte Carlo-based simulations, we will evaluate the abilities of a light delivery system to irradiate the lung homogenously. Afterward, we aim to demonstrate the feasibility and safety profile of a whole-lung perfusion-assisted PDT protocol using 5-ALA and Chlorin e6.</p><p><strong>Approach: </strong>A porcine model of a simplified lung perfusion procedure was used. PDT was performed at 630 or 660 nm with 5-ALA or Chlorin e6, respectively. Light fluence rate measurements and computed tomography (CT) scan segmentations were used to create <i>in silico</i> models of light propagation. Physiologic, gross, CT, and histological assessment of lung toxicity was performed 72 h post-PDT.</p><p><strong>Results: </strong>Dose-volume histograms showed homogeneity of light intensity throughout the lung. Predicted and measured fluence rates showed strong reliability. The photodynamic threshold of 5-ALA was <math><mrow><mn>2.10</mn> <mo>×</mo> <msup><mrow><mn>10</mn></mrow> <mrow><mn>17</mn></mrow> </msup> <mo>±</mo> <mn>8.24</mn> <mo>×</mo> <msup><mrow><mn>10</mn></mrow> <mrow><mn>16</mn></mrow> </msup> <mtext>  </mtext> <mi>h</mi> <mi>ν</mi> <mo>/</mo> <msup><mrow><mi>cm</mi></mrow> <mrow><mn>3</mn></mrow> </msup> </mrow> </math> , whereas Chlorin e6 showed negligible uptake in lung tissue.</p><p><strong>Conclusions: </strong>We lay the groundwork for personalized preoperative <i>in silico</i> dosimetry planning to achieve desired treatment volumes within the therapeutic range. Chlorin e6 demonstrated the greatest therapeutic potential, with a minimal uptake in healthy lung tissues.</p>","PeriodicalId":15264,"journal":{"name":"Journal of Biomedical Optics","volume":"29 11","pages":"118001"},"PeriodicalIF":3.0,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11563932/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142648325","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":"Detection of breast cancer using machine learning on time-series diffuse optical transillumination data.","authors":"Nils Harnischmacher, Erik Rodner, Christoph H Schmitz","doi":"10.1117/1.JBO.29.11.115001","DOIUrl":"https://doi.org/10.1117/1.JBO.29.11.115001","url":null,"abstract":"<p><strong>Significance: </strong>Optical mammography as a promising tool for cancer diagnosis has largely fallen behind expectations. Modern machine learning (ML) methods offer ways to improve cancer detection in diffuse optical transmission data.</p><p><strong>Aim: </strong>We aim to quantitatively evaluate the classification of cancer-positive versus cancer-negative patients using ML methods on raw transmission time series data from bilateral breast scans during subjects' rest.</p><p><strong>Approach: </strong>We use a support vector machine (SVM) with hyperparameter optimization and cross-validation to systematically explore a range of data preprocessing and feature-generation strategies. We also apply an automated ML (AutoML) framework to validate our findings. We use receiver operating characteristics and the corresponding area under the curve (AUC) to quantify classification performance.</p><p><strong>Results: </strong>For the sample group available ( <math><mrow><mi>N</mi> <mo>=</mo> <mn>63</mn></mrow> </math> , 18 cancer patients), we demonstrate an AUC score of up to 93.3% for SVM classification and up to 95.0% for the AutoML classifier.</p><p><strong>Conclusions: </strong>ML offers a viable strategy for clinically relevant breast cancer diagnosis using diffuse-optical transmission measurements. The diagnostic performance of ML on raw data can outperform traditional statistical biomarkers derived from reconstructed image time series. To achieve clinically relevant performance, our ML approach requires simultaneous bilateral scanning of the breasts with spatially dense channel coverage.</p>","PeriodicalId":15264,"journal":{"name":"Journal of Biomedical Optics","volume":"29 11","pages":"115001"},"PeriodicalIF":3.0,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11552526/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142621238","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":"Effects of phantom microstructure on their optical properties.","authors":"Jošt Stergar, Rok Hren, Matija Milanič","doi":"10.1117/1.JBO.29.9.093502","DOIUrl":"10.1117/1.JBO.29.9.093502","url":null,"abstract":"<p><strong>Significance: </strong>Developing stable, robust, and affordable tissue-mimicking phantoms is a prerequisite for any new clinical application within biomedical optics. To this end, a thorough understanding of the phantom structure and optical properties is paramount.</p><p><strong>Aim: </strong>We characterized the structural and optical properties of PlatSil SiliGlass phantoms using experimental and numerical approaches to examine the effects of phantom microstructure on their overall optical properties.</p><p><strong>Approach: </strong>We employed scanning electron microscope (SEM), hyperspectral imaging (HSI), and spectroscopy in combination with Mie theory modeling and inverse Monte Carlo to investigate the relationship between phantom constituent and overall phantom optical properties.</p><p><strong>Results: </strong>SEM revealed that microspheres had a broad range of sizes with average <math><mrow><mo>(</mo><mn>13.47</mn><mo>±</mo><mn>5.98</mn><mo>)</mo><mtext>  </mtext><mi>μ</mi><mi>m</mi></mrow></math> and were also aggregated, which may affect overall optical properties and warrants careful preparation to minimize these effects. Spectroscopy was used to measure pigment and SiliGlass absorption coefficient in the VIS-NIR range. Size distribution was used to calculate scattering coefficients and observe the impact of phantom microstructure on scattering properties. The results were surmised in an inverse problem solution that enabled absolute determination of component volume fractions that agree with values obtained during preparation and explained experimentally observed spectral features. HSI microscopy revealed pronounced single-scattering effects that agree with single-scattering events.</p><p><strong>Conclusions: </strong>We show that knowledge of phantom microstructure enables absolute measurements of phantom constitution without prior calibration. Further, we show a connection across different length scales where knowledge of precise phantom component constitution can help understand macroscopically observable optical properties.</p>","PeriodicalId":15264,"journal":{"name":"Journal of Biomedical Optics","volume":"29 9","pages":"093502"},"PeriodicalIF":3.5,"publicationDate":"2024-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11070965/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140876461","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":"Distribution-informed and wavelength-flexible data-driven photoacoustic oximetry.","authors":"Janek Gröhl, Kylie Yeung, Kevin Gu, Thomas R Else, Monika Golinska, Ellie V Bunce, Lina Hacker, Sarah E Bohndiek","doi":"10.1117/1.JBO.29.S3.S33303","DOIUrl":"10.1117/1.JBO.29.S3.S33303","url":null,"abstract":"<p><strong>Significance: </strong>Photoacoustic imaging (PAI) promises to measure spatially resolved blood oxygen saturation but suffers from a lack of accurate and robust spectral unmixing methods to deliver on this promise. Accurate blood oxygenation estimation could have important clinical applications from cancer detection to quantifying inflammation.</p><p><strong>Aim: </strong>We address the inflexibility of existing data-driven methods for estimating blood oxygenation in PAI by introducing a recurrent neural network architecture.</p><p><strong>Approach: </strong>We created 25 simulated training dataset variations to assess neural network performance. We used a long short-term memory network to implement a wavelength-flexible network architecture and proposed the Jensen-Shannon divergence to predict the most suitable training dataset.</p><p><strong>Results: </strong>The network architecture can flexibly handle the input wavelengths and outperforms linear unmixing and the previously proposed learned spectral decoloring method. Small changes in the training data significantly affect the accuracy of our method, but we find that the Jensen-Shannon divergence correlates with the estimation error and is thus suitable for predicting the most appropriate training datasets for any given application.</p><p><strong>Conclusions: </strong>A flexible data-driven network architecture combined with the Jensen-Shannon divergence to predict the best training data set provides a promising direction that might enable robust data-driven photoacoustic oximetry for clinical use cases.</p>","PeriodicalId":15264,"journal":{"name":"Journal of Biomedical Optics","volume":"29 Suppl 3","pages":"S33303"},"PeriodicalIF":3.5,"publicationDate":"2024-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11151660/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141260266","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":"Generalized 3D registration algorithm for enhancing retinal optical coherence tomography images.","authors":"Tiffany Tse, Yudan Chen, Mahsa Siadati, Yusi Miao, Jun Song, Da Ma, Zaid Mammo, Myeong Jin Ju","doi":"10.1117/1.JBO.29.6.066002","DOIUrl":"10.1117/1.JBO.29.6.066002","url":null,"abstract":"<p><strong>Significance: </strong>Optical coherence tomography (OCT) has emerged as the standard of care for diagnosing and monitoring the treatment of various ocular disorders due to its noninvasive nature and <i>in vivo</i> volumetric acquisition capability. Despite its widespread applications in ophthalmology, motion artifacts remain a challenge in OCT imaging, adversely impacting image quality. While several multivolume registration algorithms have been developed to address this issue, they are often designed to cater to one specific OCT system or acquisition protocol.</p><p><strong>Aim: </strong>We aim to generate an OCT volume free of motion artifacts using a system-agnostic registration algorithm that is independent of system specifications or protocol.</p><p><strong>Approach: </strong>We developed a B-scan registration algorithm that removes motion and corrects for both translational eye movements and rotational angle differences between volumes. Tests were carried out on various datasets obtained from two different types of custom-built OCT systems and one commercially available system to determine the reliability of the proposed algorithm. Additionally, different system specifications were used, with variations in axial resolution, lateral resolution, signal-to-noise ratio, and real-time motion tracking. The accuracy of this method has further been evaluated through mean squared error (MSE) and multiscale structural similarity index measure (MS-SSIM).</p><p><strong>Results: </strong>The results demonstrate improvements in the overall contrast of the images, facilitating detailed visualization of retinal vasculatures in both superficial and deep vasculature plexus. Finer features of the inner and outer retina, such as photoreceptors and other pathology-specific features, are discernible after multivolume registration and averaging. Quantitative analyses affirm that increasing the number of averaged registered volumes will decrease MSE and increase MS-SSIM as compared to the reference volume.</p><p><strong>Conclusions: </strong>The multivolume registered data obtained from this algorithm offers significantly improved visualization of the retinal microvascular network as well as retinal morphological features. Furthermore, we have validated that the versatility of our methodology extends beyond specific OCT modalities, thereby enhancing the clinical utility of OCT for the diagnosis and monitoring of ocular pathologies.</p>","PeriodicalId":15264,"journal":{"name":"Journal of Biomedical Optics","volume":"29 6","pages":"066002"},"PeriodicalIF":3.0,"publicationDate":"2024-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11091473/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140922369","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":"Functional hemodynamic imaging markers for the prediction of pathological outcomes in breast cancer patients treated with neoadjuvant chemotherapy.","authors":"Bin Deng, Ailis Muldoon, Jayne Cormier, Nathaniel D Mercaldo, Elizabeth Niehoff, Natalie Moffett, Mansi A Saksena, Steven J Isakoff, Stefan A Carp","doi":"10.1117/1.JBO.29.6.066001","DOIUrl":"10.1117/1.JBO.29.6.066001","url":null,"abstract":"<p><strong>Significance: </strong>Achieving pathologic complete response (pCR) after neoadjuvant chemotherapy (NACT) is a significant predictor of increased likelihood of survival in breast cancer patients. Early prediction of pCR is of high clinical value as it could allow personalized adjustment of treatment regimens in non-responding patients for improved outcomes.</p><p><strong>Aim: </strong>We aim to assess the association between hemoglobin-based functional imaging biomarkers derived from diffuse optical tomography (DOT) and the pathological outcome represented by pCR at different timepoints along the course of NACT.</p><p><strong>Approach: </strong>Twenty-two breast cancer patients undergoing NACT were enrolled in a multimodal DOT and X-ray digital breast tomosynthesis (DBT) imaging study in which their breasts were imaged at different compression levels. Logistic regressions were used to study the associations between DOT-derived imaging markers evaluated after the first and second cycles of chemotherapy, respectively, with pCR status determined after the conclusion of NACT at the time of surgery. Receiver operating characteristic curve analysis was also used to explore the predictive performance of selected DOT-derived markers.</p><p><strong>Results: </strong>Normalized tumor HbT under half compression was significantly lower in the pCR group compared to the non-pCR group after two chemotherapy cycles (<math><mrow><mi>p</mi><mo>=</mo><mn>0.042</mn></mrow></math>). In addition, the change in normalized tumor <math><mrow><msub><mi>StO</mi><mn>2</mn></msub></mrow></math> upon reducing compression from full to half mammographic force was identified as another potential indicator of pCR at an earlier time point, i.e., after the first chemo cycle (<math><mrow><mi>p</mi><mo>=</mo><mn>0.038</mn></mrow></math>). Exploratory predictive assessments showed that AUCs using DOT-derived functional imaging markers as predictors reach as high as 0.75 and 0.71, respectively, after the first and second chemo cycle, compared to AUCs of 0.50 and 0.53 using changes in tumor size measured on DBT and MRI.</p><p><strong>Conclusions: </strong>These findings suggest that breast DOT could be used to assist response assessment in women undergoing NACT, a critical but unmet clinical need, and potentially enable personalized adjustments of treatment regimens.</p>","PeriodicalId":15264,"journal":{"name":"Journal of Biomedical Optics","volume":"29 6","pages":"066001"},"PeriodicalIF":3.0,"publicationDate":"2024-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11088438/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140911842","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":"Assessing changes in regional cerebral hemodynamics in adults with a high-density full-head coverage time-resolved near-infrared spectroscopy device.","authors":"Farah Kamar, Leena N Shoemaker, Rasa Eskandari, Daniel Milej, Darren Drosdowech, John M Murkin, Keith St Lawrence, Jason Chui, Mamadou Diop","doi":"10.1117/1.JBO.29.S3.S33302","DOIUrl":"https://doi.org/10.1117/1.JBO.29.S3.S33302","url":null,"abstract":"<p><strong>Significance: </strong>Cerebral oximeters have the potential to detect abnormal cerebral blood oxygenation to allow for early intervention. However, current commercial systems have two major limitations: (1) spatial coverage of only the frontal region, assuming that surgery-related hemodynamic effects are global and (2) susceptibility to extracerebral signal contamination inherent to continuous-wave near-infrared spectroscopy (NIRS).</p><p><strong>Aim: </strong>This work aimed to assess the feasibility of a high-density, time-resolved (tr) NIRS device (Kernel Flow) to monitor regional oxygenation changes across the cerebral cortex during surgery.</p><p><strong>Approach: </strong>The Flow system was assessed using two protocols. First, digital carotid compression was applied to healthy volunteers to cause a rapid oxygenation decrease across the ipsilateral hemisphere without affecting the contralateral side. Next, the system was used on patients undergoing shoulder surgery to provide continuous monitoring of cerebral oxygenation. In both protocols, the improved depth sensitivity of trNIRS was investigated by applying moment analysis. A dynamic wavelet filtering approach was also developed to remove observed temperature-induced signal drifts.</p><p><strong>Results: </strong>In the first protocol (<math><mrow><mn>28</mn><mo>±</mo><mn>5</mn></mrow></math> years; five females, five males), hair significantly impacted regional sensitivity; however, the enhanced depth sensitivity of trNIRS was able to separate brain and scalp responses in the frontal region. Regional sensitivity was improved in the clinical study given the age-related reduction in hair density of the patients (<math><mrow><mn>65</mn><mo>±</mo><mn>15</mn></mrow></math> years; 14 females, 13 males). In five patients who received phenylephrine to treat hypotension, different scalp and brain oxygenation responses were apparent, although no regional differences were observed.</p><p><strong>Conclusions: </strong>The Kernel Flow has promise as an intraoperative neuromonitoring device. Although regional sensitivity was affected by hair color and density, enhanced depth sensitivity of trNIRS was able to resolve differences in scalp and brain oxygenation responses in both protocols.</p>","PeriodicalId":15264,"journal":{"name":"Journal of Biomedical Optics","volume":"29 Suppl 3","pages":"S33302"},"PeriodicalIF":3.5,"publicationDate":"2024-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11068267/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140849033","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}