1
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Hannan MN, Sharma AK, Baran TM. Preliminary measurements of optical properties in human abscess cavities prior to methylene blue photodynamic therapy. PROCEEDINGS OF SPIE--THE INTERNATIONAL SOCIETY FOR OPTICAL ENGINEERING 2023; 12359:123590A. [PMID: 37860151 PMCID: PMC10585982 DOI: 10.1117/12.2648453] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/21/2023]
Abstract
As part of our ongoing Phase 1 clinical trial to establish the safety and feasibility of methylene blue photodynamic therapy (MB-PDT) for human deep tissue abscess cavities, we have shown that determination of abscess wall optical properties is vital for the design of personalized treatment plans aiming to optimize light dose. To that end, we have developed and validated an optical spectroscopy system for the assessment of optical properties at the cavity wall, including a compact fiber-optic probe that can be inserted through the catheter used for the standard of care abscess drainage. Here we report preliminary findings from the first three human subjects to receive these optical spectroscopy measurements. We observed wide variability in concentrations of oxy- and deoxy-hemoglobin prior to MB administration, ranging from 7.3-213 μM and 0.1-47.2 μM, respectively. Reduced scattering coefficients also showed inter-patient variability, but recovered values were more similar between subjects (5.5-10.9 cm-1 at 665 nm). Further, methylene blue uptake was found to vary between subjects, and was associated with a reduction in oxygen saturation. These measured optical properties, along with pre-procedure computed tomography (CT) images, will be used with our previously developed Monte Carlo simulation framework to generate personalized treatment plans for individual patients, which could significantly improve the efficacy of MB-PDT while ensuring safety.
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Affiliation(s)
- Md Nafiz Hannan
- Department of Physics and Astronomy, University of Rochester, 601 Elmwood Ave., Rochester, NY 14642
| | - Ashwani K. Sharma
- Department of Imaging Sciences, University of Rochester, 601 Elmwood Ave., Rochester, NY 14642
| | - Timothy M. Baran
- Department of Imaging Sciences, University of Rochester, 601 Elmwood Ave., Rochester, NY 14642
- Department of Biomedical Engineering, University of Rochester, 601 Elmwood Ave., Rochester, NY 14642
- The Institute of Optics, University of Rochester, 601 Elmwood Ave., Rochester, NY 14642
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2
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Sourvanos D, Hall Morales RD, Dimofte A, Fiorellini JP, Zhu TC. Validating Homogeneity for a Novel 3-Dimensional Tissue Phantom Modeling System of the Human Maxilla. PROCEEDINGS OF SPIE--THE INTERNATIONAL SOCIETY FOR OPTICAL ENGINEERING 2023; 12362:1236204. [PMID: 37206702 PMCID: PMC10193594 DOI: 10.1117/12.2654593] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Silicon phantom models have been utilized to calculate light fluence in patients being treated with Photodynamic Therapy (PDT). This application can be utilized for other non-ionizing wavelength therapies such as Photobiomodulation (PBM). We have developed a novel protocol to validate homogeneity for 3-dimensional silicon phantom models of the human maxilla. Accurately quantifying the light profiles of human tissue can accommodate for varying optical properties that occur between subjects. More importantly, this can help optimize light fluence dosimetry calculations to achieve intended results. Silicon models of identical composition were fabricated into two different shapes: 1 flat-planar cylindrical shaped model, 2) non-flat planar (3-dimensional) mold of the human maxilla. Fabricating homogenous silicon phantom models continues to be a challenge as micro-bubbles can contaminate the compound during the curing process. Integrating both proprietary CBCT and handheld surface acquisition imaging devices confirmed our results to be within 0.5mm of accuracy. This protocol was specifically used to cross-reference and validate homogeneity at various depths of penetration. These results present the first known successful validation of identical silicon tissue phantoms with a flat-planar surface vs. a non-flat 3D planar surface. This proof-of-concept phantom validation protocol is sensitive to the specific variations of 3-dimensional surfaces and can be applied to a workflow used to capture accurate light fluence calculations in the clinical setting.
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Affiliation(s)
- Dennis Sourvanos
- Department of Periodontics, School of Dental Medicine, University of Pennsylvania, PA, USA
- Center for Innovation and Precision Dentistry (CiPD), School of Dental Medicine, School of Engineering, University of Pennsylvania, PA, USA
- Institute for Translational Medicine and Therapeutics (ITMAT), Perelman School of Medicine, University of Pennsylvania, PA, USA
| | - Ryan D Hall Morales
- Department of Radiation Oncology, Perelman Center for Advanced Medicine, University of Pennsylvania, PA, USA
| | - Andreea Dimofte
- Department of Radiation Oncology, Perelman Center for Advanced Medicine, University of Pennsylvania, PA, USA
| | - Joseph P Fiorellini
- Department of Periodontics, School of Dental Medicine, University of Pennsylvania, PA, USA
- Center for Innovation and Precision Dentistry (CiPD), School of Dental Medicine, School of Engineering, University of Pennsylvania, PA, USA
| | - Timothy C Zhu
- Center for Innovation and Precision Dentistry (CiPD), School of Dental Medicine, School of Engineering, University of Pennsylvania, PA, USA
- Department of Radiation Oncology, Perelman Center for Advanced Medicine, University of Pennsylvania, PA, USA
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3
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Chang S, Bowden AK. Review of methods and applications of attenuation coefficient measurements with optical coherence tomography. JOURNAL OF BIOMEDICAL OPTICS 2019; 24:1-17. [PMID: 31520468 PMCID: PMC6997582 DOI: 10.1117/1.jbo.24.9.090901] [Citation(s) in RCA: 45] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/16/2019] [Accepted: 08/16/2019] [Indexed: 05/03/2023]
Abstract
The optical attenuation coefficient (AC), an important tissue parameter that measures how quickly incident light is attenuated when passing through a medium, has been shown to enable quantitative analysis of tissue properties from optical coherence tomography (OCT) signals. Successful extraction of this parameter would facilitate tissue differentiation and enhance the diagnostic value of OCT. In this review, we discuss the physical and mathematical basis of AC extraction from OCT data, including current approaches used in modeling light scattering in tissue and in AC estimation. We also report on demonstrated clinical applications of the AC, such as for atherosclerotic tissue characterization, malignant lesion detection, and brain injury visualization. With current studies showing AC analysis as a promising technique, further efforts in the development of methods to accurately extract the AC and to explore its potential use for more extensive clinical applications are desired.
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Affiliation(s)
- Shuang Chang
- Vanderbilt University, Vanderbilt Biophotonics Center, Department of Biomedical Engineering, Nashville, Tennessee, United States
| | - Audrey K. Bowden
- Vanderbilt University, Vanderbilt Biophotonics Center, Department of Biomedical Engineering, Nashville, Tennessee, United States
- Address all correspondence to Audrey K. Bowden, E-mail:
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4
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Ong YH, Li AQ, Zhu TC. Monte Carlo investigation of the effect of skin tissue optical properties on detected Cherenkov emission. PROCEEDINGS OF SPIE--THE INTERNATIONAL SOCIETY FOR OPTICAL ENGINEERING 2019; 10862. [PMID: 31057198 DOI: 10.1117/12.2509854] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
In this study, we use Monte Carlo modelling to investigate the effect of tissue optical properties on Cherenkov emission detected from tissue surface. MC simulations are performed for wavelength between 400-1000nm and the values of absorption coefficient at each wavelength are determined based on the molar extinction coefficients of oxy- and deoxy-hemoglobin, with varying total haemoglobin concentration and tissue oxygen saturation of 70%. Tissue reduced scattering coefficient is approximated using μs'(λ) = Aλ-0.838. A range of clinically relevant tissue optical properties was investigated, with absorption coefficient between 0.1 and 1 cm-1 and reduced scattering coefficient between 5 and 40 cm-1 at 665nm. The angular distribution, depth of origins and the effect of tissue optical properties on Cherenkov emission on tissue surface are evaluated.
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Affiliation(s)
- Yi Hong Ong
- Department of Radiation Oncology, University of Pennsylvania, Philadelphia, PA 19104.,Department of Physics and Astronomy, University of Pennsylvania, Philadelphia, PA 19104
| | - Andrew Q Li
- Department of Radiation Oncology, University of Pennsylvania, Philadelphia, PA 19104
| | - Timothy C Zhu
- Department of Radiation Oncology, University of Pennsylvania, Philadelphia, PA 19104
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Bashkatov AN, Berezin KV, Dvoretskiy KN, Chernavina ML, Genina EA, Genin VD, Kochubey VI, Lazareva EN, Pravdin AB, Shvachkina ME, Timoshina PA, Tuchina DK, Yakovlev DD, Yakovlev DA, Yanina IY, Zhernovaya OS, Tuchin VV. Measurement of tissue optical properties in the context of tissue optical clearing. JOURNAL OF BIOMEDICAL OPTICS 2018; 23:1-31. [PMID: 30141286 DOI: 10.1117/1.jbo.23.9.091416] [Citation(s) in RCA: 50] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/12/2018] [Accepted: 07/30/2018] [Indexed: 05/05/2023]
Abstract
Nowadays, dynamically developing optical (photonic) technologies play an ever-increasing role in medicine. Their adequate and effective implementation in diagnostics, surgery, and therapy needs reliable data on optical properties of human tissues, including skin. This paper presents an overview of recent results on the measurements and control of tissue optical properties. The issues reported comprise a brief review of optical properties of biological tissues and efficacy of optical clearing (OC) method in application to monitoring of diabetic complications and visualization of blood vessels and microcirculation using a number of optical imaging technologies, including spectroscopic, optical coherence tomography, and polarization- and speckle-based ones. Molecular modeling of immersion OC of skin and specific technique of OC of adipose tissue by its heating and photodynamic treatment are also discussed.
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Affiliation(s)
- Alexey N Bashkatov
- Saratov State University, Research-Educational Institute of Optics and Biophotonics, Saratov, Russia
- Tomsk State University, Interdisciplinary Laboratory of Biophotonics, Tomsk, Russia
| | - Kirill V Berezin
- Saratov State University, Research-Educational Institute of Optics and Biophotonics, Saratov, Russia
| | - Konstantin N Dvoretskiy
- Saratov State Medical University, Subdivision of Medical and Biological Physics, Saratov, Russia
| | - Maria L Chernavina
- Saratov State University, Research-Educational Institute of Optics and Biophotonics, Saratov, Russia
| | - Elina A Genina
- Saratov State University, Research-Educational Institute of Optics and Biophotonics, Saratov, Russia
- Tomsk State University, Interdisciplinary Laboratory of Biophotonics, Tomsk, Russia
| | - Vadim D Genin
- Saratov State University, Research-Educational Institute of Optics and Biophotonics, Saratov, Russia
| | - Vyacheslav I Kochubey
- Saratov State University, Research-Educational Institute of Optics and Biophotonics, Saratov, Russia
- Tomsk State University, Interdisciplinary Laboratory of Biophotonics, Tomsk, Russia
| | - Ekaterina N Lazareva
- Saratov State University, Research-Educational Institute of Optics and Biophotonics, Saratov, Russia
- Tomsk State University, Interdisciplinary Laboratory of Biophotonics, Tomsk, Russia
- Immanuel Kant Baltic Federal University, Center for Functionalized Magnetic Materials, Kaliningrad, Russia
| | - Alexander B Pravdin
- Saratov State University, Research-Educational Institute of Optics and Biophotonics, Saratov, Russia
| | - Marina E Shvachkina
- Saratov State University, Research-Educational Institute of Optics and Biophotonics, Saratov, Russia
| | - Polina A Timoshina
- Saratov State University, Research-Educational Institute of Optics and Biophotonics, Saratov, Russia
- Tomsk State University, Interdisciplinary Laboratory of Biophotonics, Tomsk, Russia
| | - Daria K Tuchina
- Saratov State University, Research-Educational Institute of Optics and Biophotonics, Saratov, Russia
- Tomsk State University, Interdisciplinary Laboratory of Biophotonics, Tomsk, Russia
- Prokhorov General Physics Institute of the Russian Academy of Sciences, Moscow, Russia
| | - Dmitry D Yakovlev
- Saratov State University, Research-Educational Institute of Optics and Biophotonics, Saratov, Russia
| | - Dmitry A Yakovlev
- Saratov State University, Research-Educational Institute of Optics and Biophotonics, Saratov, Russia
| | - Irina Yu Yanina
- Saratov State University, Research-Educational Institute of Optics and Biophotonics, Saratov, Russia
- Tomsk State University, Interdisciplinary Laboratory of Biophotonics, Tomsk, Russia
| | - Olga S Zhernovaya
- Saratov State University, Research-Educational Institute of Optics and Biophotonics, Saratov, Russia
| | - Valery V Tuchin
- Saratov State University, Research-Educational Institute of Optics and Biophotonics, Saratov, Russia
- Tomsk State University, Interdisciplinary Laboratory of Biophotonics, Tomsk, Russia
- Institute of Precision Mechanics and Control of the Russian Academy of Sciences, Saratov, Russia
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6
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Greening G, Mundo A, Rajaram N, Muldoon TJ. Sampling depth of a diffuse reflectance spectroscopy probe for in-vivo physiological quantification of murine subcutaneous tumor allografts. JOURNAL OF BIOMEDICAL OPTICS 2018; 23:1-14. [PMID: 30152204 PMCID: PMC8357195 DOI: 10.1117/1.jbo.23.8.085006] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/21/2018] [Accepted: 07/23/2018] [Indexed: 05/04/2023]
Abstract
Diffuse reflectance spectroscopy (DRS) is a probe-based spectral biopsy technique used in cancer studies to quantify tissue reduced scattering (μs') and absorption (μa) coefficients and vary in source-detector separation (SDS) to fine-tune sampling depth. In subcutaneous murine tumor allografts or xenografts, a key design requirement is ensuring that the source light interrogates past the skin layer into the tumor without significantly sacrificing signal-to-noise ratio (target of ≥15 dB). To resolve this requirement, a DRS probe was designed with four SDSs (0.75, 2.00, 3.00, and 4.00 mm) to interrogate increasing tissue volumes between 450 and 900 nm. The goal was to quantify percent errors in extracting μa and μs', and to quantify sampling depth into subcutaneous Balb/c-CT26 colon tumor allografts. Using an optical phantom-based experimental method, lookup-tables were constructed relating μa,μs', diffuse reflectance, and sampling depth. Percent errors were <10 % and 5% for extracting μa and μs', respectively, for all SDSs. Sampling depth reached up to 1.6 mm at the first Q-band of hemoglobin at 542 nm, the key spectral region for quantifying tissue oxyhemoglobin concentration. This work shows that the DRS probe can accurately extract optical properties and the resultant physiological parameters such as total hemoglobin concentration and tissue oxygen saturation, from sufficient depth within subcutaneous Balb/c-CT26 colon tumor allografts. Methods described here can be generalized for other murine tumor models. Future work will explore the feasibility of the DRS in quantifying volumetric tumor perfusion in response to anticancer therapies.
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Affiliation(s)
- Gage Greening
- University of Arkansas, Department of Biomedical Engineering, Fayetteville, Arkansas, United States
| | - Ariel Mundo
- University of Arkansas, Department of Biomedical Engineering, Fayetteville, Arkansas, United States
| | - Narasimhan Rajaram
- University of Arkansas, Department of Biomedical Engineering, Fayetteville, Arkansas, United States
| | - Timothy J. Muldoon
- University of Arkansas, Department of Biomedical Engineering, Fayetteville, Arkansas, United States
- Address all correspondence to: Timothy J. Muldoon, E-mail:
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7
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Ong YH, Finlay JC, Zhu TC. Monte Carlo modelling of fluorescence in semi-infinite turbid media. PROCEEDINGS OF SPIE--THE INTERNATIONAL SOCIETY FOR OPTICAL ENGINEERING 2018; 10492. [PMID: 29853731 DOI: 10.1117/12.2290137] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
The incident field size and the interplay of absorption and scattering can influence the in-vivo light fluence rate distribution and complicate the absolute quantification of fluorophore concentration in-vivo. In this study, we use Monte Carlo simulations to evaluate the effect of incident beam radius and optical properties to the fluorescence signal collected by isotropic detector placed on the tissue surface. The optical properties at the excitation and emission wavelengths are assumed to be identical. We compute correction factors to correct the fluorescence intensity for variations due to incident field size and optical properties. The correction factors are fitted to a 4-parameters empirical correction function and the changes in each parameter are compared for various beam radius over a range of physiologically relevant tissue optical properties (μa = 0.1 - 1 cm-1, μs'= 5 - 40 cm-1).
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Affiliation(s)
- Yi Hong Ong
- Department of Radiation Oncology, University of Pennsylvania, Philadelphia, PA 19104.,Department of Physics and Astronomy, University of Pennsylvania, Philadelphia, PA 19104
| | - Jarod C Finlay
- Department of Radiation Oncology, University of Pennsylvania, Philadelphia, PA 19104
| | - Timothy C Zhu
- Department of Radiation Oncology, University of Pennsylvania, Philadelphia, PA 19104
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Lefebvre J, Castonguay A, Pouliot P, Descoteaux M, Lesage F. Whole mouse brain imaging using optical coherence tomography: reconstruction, normalization, segmentation, and comparison with diffusion MRI. NEUROPHOTONICS 2017; 4:041501. [PMID: 28721357 PMCID: PMC5506292 DOI: 10.1117/1.nph.4.4.041501] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/30/2017] [Accepted: 06/19/2017] [Indexed: 05/10/2023]
Abstract
An automated massive histology setup combined with an optical coherence tomography (OCT) microscope was used to image a total of [Formula: see text] whole mouse brains. Each acquisition generated a dataset of thousands of OCT volumetric tiles at a sampling resolution of [Formula: see text]. This paper describes techniques for reconstruction and segmentation of the sliced brains. In addition to the measured OCT optical reflectivity, a single scattering photon model was used to compute the attenuation coefficients within each tissue slice. Average mouse brain templates were generated for both the OCT reflectivity and attenuation contrasts and were used with an [Formula: see text]-tissue segmentation algorithm. To better understand the brain tissue OCT contrast origin, one of the mouse brains was acquired using dMRI and coregistered to its corresponding assembled brain. Our results indicate that the optical reflectivity in a fiber bundle varies with its orientation, its fiber density, and the number of fiber orientations it contains. The OCT mouse brain template generation and coregistration to dMRI data demonstrate the potential of this massive histology technique to pursue cross-sectional, multimodal, and multisubject investigations of small animal brains.
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Affiliation(s)
- Joël Lefebvre
- École Polytechnique de Montréal, Montréal, Québec, Canada
- Address all correspondence to: Joël Lefebvre, E-mail:
| | | | - Philippe Pouliot
- École Polytechnique de Montréal, Montréal, Québec, Canada
- Institut de Cardiologie de Montréal, Montréal, Québec, Canada
| | - Maxime Descoteaux
- Université de Sherbrooke, Sherbrooke Connectivity Imaging Laboratory, Sherbrooke, Québec, Canada
| | - Frédéric Lesage
- École Polytechnique de Montréal, Montréal, Québec, Canada
- Institut de Cardiologie de Montréal, Montréal, Québec, Canada
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Zhang H, Salo D, Kim DM, Komarov S, Tai YC, Berezin MY. Penetration depth of photons in biological tissues from hyperspectral imaging in shortwave infrared in transmission and reflection geometries. JOURNAL OF BIOMEDICAL OPTICS 2016; 21:126006. [PMID: 27930773 PMCID: PMC5147011 DOI: 10.1117/1.jbo.21.12.126006] [Citation(s) in RCA: 71] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/03/2016] [Accepted: 11/11/2016] [Indexed: 05/20/2023]
Abstract
Measurement of photon penetration in biological tissues is a central theme in optical imaging. A great number of endogenous tissue factors such as absorption, scattering, and anisotropy affect the path of photons in tissue, making it difficult to predict the penetration depth at different wavelengths. Traditional studies evaluating photon penetration at different wavelengths are focused on tissue spectroscopy that does not take into account the heterogeneity within the sample. This is especially critical in shortwave infrared where the individual vibration-based absorption properties of the tissue molecules are affected by nearby tissue components. We have explored the depth penetration in biological tissues from 900 to 1650 nm using Monte–Carlo simulation and a hyperspectral imaging system with Michelson spatial contrast as a metric of light penetration. Chromatic aberration-free hyperspectral images in transmission and reflection geometries were collected with a spectral resolution of 5.27 nm and a total acquisition time of 3 min. Relatively short recording time minimized artifacts from sample drying. Results from both transmission and reflection geometries consistently revealed that the highest spatial contrast in the wavelength range for deep tissue lies within 1300 to 1375 nm; however, in heavily pigmented tissue such as the liver, the range 1550 to 1600 nm is also prominent.
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Affiliation(s)
- Hairong Zhang
- Washington University School of Medicine, Department of Radiology, St. Louis, Missouri, United States
| | - Daniel Salo
- Washington University School of Medicine, Department of Radiology, St. Louis, Missouri, United States
| | - David M. Kim
- Washington University School of Medicine, Department of Radiology, St. Louis, Missouri, United States
| | - Sergey Komarov
- Washington University School of Medicine, Department of Radiology, St. Louis, Missouri, United States
| | - Yuan-Chuan Tai
- Washington University School of Medicine, Department of Radiology, St. Louis, Missouri, United States
| | - Mikhail Y. Berezin
- Washington University School of Medicine, Department of Radiology, St. Louis, Missouri, United States
- Address all correspondence to: Mikhail Y. Berezin, E-mail:
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10
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Martin C, Ben-Yakar A. Determination of scattering properties and damage thresholds in tissue using ultrafast laser ablation. JOURNAL OF BIOMEDICAL OPTICS 2016; 21:115004. [PMID: 27901549 PMCID: PMC5127827 DOI: 10.1117/1.jbo.21.11.115004] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/23/2016] [Accepted: 11/04/2016] [Indexed: 05/27/2023]
Abstract
Ultrafast laser surgery of tissue requires precise knowledge of the tissue’s optical properties to control the extent of subsurface ablation. Here, we present a method to determine the scattering lengths, ?s, and fluence thresholds, Fth, in multilayered and turbid tissue by finding the input energies required to initiate ablation at various depths in each tissue layer. We validated the method using tissue-mimicking phantoms and applied it to porcine vocal folds, which consist of an epithelial (ep) layer and a superficial lamina propia (SLP) layer. Across five vocal fold samples, we found ?s,ep=51.0±3.9???m, Fth,ep=1.78±0.08??J/cm2, ?s,SLP=26.5±1.6???m, and Fth,SLP=1.14±0.12??J/cm2. Our method can enable personalized determination of tissue optical properties in a clinical setting, leading to less patient-to-patient variability and more favorable outcomes in operations, such as femto-LASIK surgery.
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Affiliation(s)
- Chris Martin
- University of Texas at Austin, Department of Biomedical Engineering, 107 West Dean Keeton Street, Stop C0800, Austin, Texas 78712, United States
| | - Adela Ben-Yakar
- University of Texas at Austin, Department of Biomedical Engineering, 107 West Dean Keeton Street, Stop C0800, Austin, Texas 78712, United States
- University of Texas at Austin, Department of Mechanical Engineering, 204 East Dean Keeton Street, Stop C2200, Austin, Texas 78712, United States
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Zhu TC, Lu A, Ong YH. An improved analytic function for predicting light fluence rate in circular fields on a semi-infinite geometry. PROCEEDINGS OF SPIE--THE INTERNATIONAL SOCIETY FOR OPTICAL ENGINEERING 2016; 9706:97061D. [PMID: 27053827 DOI: 10.1117/12.2213052] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Accurate determination of in-vivo light fluence rate is critical for preclinical and clinical studies involving photodynamic therapy (PDT). This study compares the longitudinal light fluence distribution inside biological tissue in the central axis of a 1 cm diameter circular uniform light field for a range of in-vivo tissue optical properties (absorption coefficients (μa) between 0.01 and 1 cm-1 and reduced scattering coefficients (μs') between 2 and 40 cm-1). This was done using Monte-Carlo simulations for a semi-infinite turbid medium in an air-tissue interface. The end goal is to develop an analytical expression that would fit the results from the Monte Carlo simulation for both the 1 cm diameter circular beam and the broad beam. Each of these parameters is expressed as a function of tissue optical properties. These results can then be compared against the existing expressions in the literature for broad beam for analysis in both accuracy and applicable range. Using the 6-parameter model, the range and accuracy for light transport through biological tissue is improved and may be used in the future as a guide in PDT for light fluence distribution for known tissue optical properties.
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Affiliation(s)
- Timothy C Zhu
- Department of Radiation Oncology, University of Pennsylvania, Philadelphia, PA, USA
| | - Amy Lu
- The Warton School, University of Pennsylvania, Philadelphia, PA, USA
| | - Yi-Hong Ong
- Department of Radiation Oncology, University of Pennsylvania, Philadelphia, PA, USA
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12
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Espigares J, Sadr A, Hamba H, Shimada Y, Otsuki M, Tagami J, Sumi Y. Assessment of natural enamel lesions with optical coherence tomography in comparison with microfocus x-ray computed tomography. J Med Imaging (Bellingham) 2015; 2:014001. [PMID: 26158079 DOI: 10.1117/1.jmi.2.1.014001] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2014] [Accepted: 01/12/2015] [Indexed: 11/14/2022] Open
Abstract
A technology to characterize early enamel lesions is needed in dentistry. Optical coherence tomography (OCT) is a noninvasive method that provides high-resolution cross-sectional images. The aim of this study is to compare OCT with microfocus x-ray computed tomography ([Formula: see text]) for assessment of natural enamel lesions in vitro. Ten human teeth with visible white spot-like changes on the enamel smooth surface and no cavitation (ICDAS code 2) were subjected to imaging by μCT (SMX-100CT, Shimadzu) and 1300-nm swept-source OCT (Dental SS-OCT, Panasonic Health Care). In [Formula: see text], the lesions appeared as radiolucent dark areas, while in SS-OCT, they appeared as areas of increased signal intensity beneath the surface. An SS-OCT attenuation coefficient based on Beer-Lambert law could discriminate lesions from sound enamel. Lesion depth ranged from 175 to [Formula: see text] in SS-OCT. A correlation between [Formula: see text] and SS-OCT was found regarding lesion depth ([Formula: see text], [Formula: see text]) and also surface layer thickness ([Formula: see text], [Formula: see text]). The images obtained clinically in real time using the dental SS-OCT system are suitable for the assessment of natural subsurface lesions and their surface layer, providing comparable images to a laboratory high-resolution [Formula: see text] without the use of x-ray.
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Affiliation(s)
- Jorge Espigares
- Tokyo Medical and Dental University , Department of Restorative Sciences, Cariology and Operative Dentistry, 1-5-45 Yushima, Bunkyo-ku, Tokyo 113-8549, Japan
| | - Alireza Sadr
- University of Washington School of Dentistry , 1959 NE Pacific Street, Seattle, Washington 98195, United States ; Tokyo Medical and Dental University , International Exchange Center, 1-5-45 Yushima, Bunkyo-ku, Tokyo 113-8549, Japan
| | - Hidenori Hamba
- Tokyo Medical and Dental University , Department of Restorative Sciences, Cariology and Operative Dentistry, 1-5-45 Yushima, Bunkyo-ku, Tokyo 113-8549, Japan
| | - Yasushi Shimada
- Tokyo Medical and Dental University , Department of Restorative Sciences, Cariology and Operative Dentistry, 1-5-45 Yushima, Bunkyo-ku, Tokyo 113-8549, Japan
| | - Masayuki Otsuki
- Tokyo Medical and Dental University , Department of Restorative Sciences, Cariology and Operative Dentistry, 1-5-45 Yushima, Bunkyo-ku, Tokyo 113-8549, Japan
| | - Junji Tagami
- Tokyo Medical and Dental University , Department of Restorative Sciences, Cariology and Operative Dentistry, 1-5-45 Yushima, Bunkyo-ku, Tokyo 113-8549, Japan
| | - Yasunori Sumi
- National Center for Geriatrics and Gerontology , National Hospital for Geriatric Medicine, Department of Advanced Medicine, Division of Oral and Dental Surgery, 36-3, Gengo, Morioka, Obu, Aichi 474-8511, Japan
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Greening GJ, Istfan R, Higgins LM, Balachandran K, Roblyer D, Pierce MC, Muldoon TJ. Characterization of thin poly(dimethylsiloxane)-based tissue-simulating phantoms with tunable reduced scattering and absorption coefficients at visible and near-infrared wavelengths. JOURNAL OF BIOMEDICAL OPTICS 2014; 19:115002. [PMID: 25387084 PMCID: PMC4227531 DOI: 10.1117/1.jbo.19.11.115002] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/11/2014] [Revised: 09/17/2014] [Accepted: 09/26/2014] [Indexed: 05/21/2023]
Abstract
Optical phantoms are used in the development of various imaging systems. For certain applications, the development of thin phantoms that simulate the physical size and optical properties of tissue is important. Here, we demonstrate a method for producing thin phantom layers with tunable optical properties using poly(dimethylsiloxane) (PDMS) as a substrate material. The thickness of each layer (between 115 and 880 μm) was controlled using a spin coater. The reduced scattering and absorption coefficients were controlled using titanium dioxide and alcohol-soluble nigrosin, respectively. These optical coefficients were quantified at six discrete wavelengths (591, 631, 659, 691, 731, and 851 nm) at varying concentrations of titanium dioxide and nigrosin using spatial frequency domain imaging. From the presented data, we provide lookup tables to determine the appropriate concentrations of scattering and absorbing agents to be used in the design of PDMS-based phantoms with specific optical coefficients. In addition, heterogeneous phantoms mimicking the layered features of certain tissue types may be fabricated from multiple stacked layers, each with custom optical properties. These thin, tunable PDMS optical phantoms can simulate many tissue types and have broad imaging calibration applications in endoscopy, diffuse optical spectroscopic imaging, and optical coherence tomography, etc.
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Affiliation(s)
- Gage J. Greening
- University of Arkansas, Department of Biomedical Engineering, Fayetteville, Arkansas 72701, United States
| | - Raeef Istfan
- Boston University, Department of Biomedical Engineering, Boston, Massachusetts 02215, United States
| | - Laura M. Higgins
- Rutgers, State University of New Jersey, Department of Biomedical Engineering, Piscataway, New Jersey 08854, United States
| | - Kartik Balachandran
- University of Arkansas, Department of Biomedical Engineering, Fayetteville, Arkansas 72701, United States
| | - Darren Roblyer
- Boston University, Department of Biomedical Engineering, Boston, Massachusetts 02215, United States
| | - Mark C. Pierce
- Rutgers, State University of New Jersey, Department of Biomedical Engineering, Piscataway, New Jersey 08854, United States
| | - Timothy J. Muldoon
- University of Arkansas, Department of Biomedical Engineering, Fayetteville, Arkansas 72701, United States
- Address all correspondence to: Timothy J. Muldoon, E-mail:
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Flynn BP, DSouza AV, Kanick SC, Davis SC, Pogue BW. White light-informed optical properties improve ultrasound-guided fluorescence tomography of photoactive protoporphyrin IX. JOURNAL OF BIOMEDICAL OPTICS 2013; 18:046008. [PMID: 23584445 PMCID: PMC3639786 DOI: 10.1117/1.jbo.18.4.046008] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
Subsurface fluorescence imaging is desirable for medical applications, including protoporphyrin-IX (PpIX)-based skin tumor diagnosis, surgical guidance, and dosimetry in photodynamic therapy. While tissue optical properties and heterogeneities make true subsurface fluorescence mapping an ill-posed problem, ultrasound-guided fluorescence-tomography (USFT) provides regional fluorescence mapping. Here USFT is implemented with spectroscopic decoupling of fluorescence signals (auto-fluorescence, PpIX, photoproducts), and white light spectroscopy-determined bulk optical properties. Segmented US images provide a priori spatial information for fluorescence reconstruction using region-based, diffuse FT. The method was tested in simulations, tissue homogeneous and inclusion phantoms, and an injected-inclusion animal model. Reconstructed fluorescence yield was linear with PpIX concentration, including the lowest concentration used, 0.025 μg/ml. White light spectroscopy informed optical properties, which improved fluorescence reconstruction accuracy compared to the use of fixed, literature-based optical properties, reduced reconstruction error and reconstructed fluorescence standard deviation by factors of 8.9 and 2.0, respectively. Recovered contrast-to-background error was 25% and 74% for inclusion phantoms without and with a 2-mm skin-like layer, respectively. Preliminary mouse-model imaging demonstrated system feasibility for subsurface fluorescence measurement in vivo. These data suggest that this implementation of USFT is capable of regional PpIX mapping in human skin tumors during photodynamic therapy, to be used in dosimetric evaluations.
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Affiliation(s)
- Brendan P. Flynn
- Thayer School of Engineering, Dartmouth College, Hanover, New Hampshire 03755
| | - Alisha V. DSouza
- Thayer School of Engineering, Dartmouth College, Hanover, New Hampshire 03755
| | - Stephen C. Kanick
- Thayer School of Engineering, Dartmouth College, Hanover, New Hampshire 03755
| | - Scott C. Davis
- Thayer School of Engineering, Dartmouth College, Hanover, New Hampshire 03755
| | - Brian W. Pogue
- Thayer School of Engineering, Dartmouth College, Hanover, New Hampshire 03755
- Address all correspondence to: Brian W. Pogue, Thayer School of Engineering, Dartmouth College, Hanover, New Hampshire 03755. Tel: (603) 646-3861; E-mail:
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Prasad A, Pospíšil P. Ultraweak photon emission induced by visible light and ultraviolet A radiation via photoactivated skin chromophores: in vivo charge coupled device imaging. JOURNAL OF BIOMEDICAL OPTICS 2012; 17:085004. [PMID: 23224187 DOI: 10.1117/1.jbo.17.8.085004] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Solar radiation that reaches Earth's surface can have severe negative consequences for organisms. Both visible light and ultraviolet A (UVA) radiation are known to initiate the formation of reactive oxygen species (ROS) in human skin by photosensitization reactions (types I and II). In the present study, we investigated the role of visible light and UVA radiation in the generation of ROS on the dorsal and the palmar side of a hand. The ROS are known to oxidize biomolecules such as lipids, proteins, and nucleic acids to form electronically excited species, finally leading to ultraweak photon emission. We have employed a highly sensitive charge coupled device camera and a low-noise photomultiplier tube for detection of two-dimensional and one-dimensional ultraweak photon emission, respectively. Our experimental results show that oxidative stress is generated by the exposure of human skin to visible light and UVA radiation. The oxidative stress generated by UVA radiation is claimed to be significantly higher than that by visible light. Two-dimensional photon imaging can serve as a potential tool for monitoring the oxidative stress in the human skin induced by various stress factors irrespective of its physical or chemical nature.
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Affiliation(s)
- Ankush Prasad
- Palacký University, Faculty of Science, Department of Biophysics, Centre of the Region Haná for Biotechnological and Agricultural Research, Šlechtitelů 11, 783 71 Olomouc, Czech Republic
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Choi WJ, Pi LQ, Min G, Lee WS, Lee BH. Qualitative investigation of fresh human scalp hair with full-field optical coherence tomography. JOURNAL OF BIOMEDICAL OPTICS 2012; 17:036010. [PMID: 22502568 DOI: 10.1117/1.jbo.17.3.036010] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
We have investigated depth-resolved cellular structures of unmodified fresh human scalp hairs with ultrahigh-resolution full-field optical coherence tomography (FF-OCT). The Linnik-type white light interference microscope has been home-implemented to observe the micro-internal layers of human hairs in their natural environment. In hair shafts, FF-OCT has qualitatively revealed the cellular hair compartments of cuticle and cortex layers involved in keratin filaments and melanin granules. No significant difference between black and white hair shafts was observed except for absence of only the melanin granules in the white hair, reflecting that the density of the melanin granules directly affects the hair color. Anatomical description of plucked hair bulbs was also obtained with the FF-OCT in three-dimensions. We expect this approach will be useful for evaluating cellular alteration of natural hairs on cosmetic assessment or diagnosis of hair diseases.
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Affiliation(s)
- Woo June Choi
- School of Information and Communications, Gwangju Institute of Science and Technology (GIST), 261 Cheomdan-gwagiro, Buk-gu, Gwangju, 500-712, Republic of Korea
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