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Belcastro L, Jonasson H, Saager RB. Multi-frequency spatial frequency domain imaging: a depth-resolved optical scattering model to isolate scattering contrast in thin layers of skin. JOURNAL OF BIOMEDICAL OPTICS 2024; 29:046003. [PMID: 38650893 PMCID: PMC11033580 DOI: 10.1117/1.jbo.29.4.046003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/29/2023] [Revised: 03/24/2024] [Accepted: 03/28/2024] [Indexed: 04/25/2024]
Abstract
Significance Current methods for wound healing assessment rely on visual inspection, which gives qualitative information. Optical methods allow for quantitative non-invasive measurements of optical properties relevant to wound healing. Aim Spatial frequency domain imaging (SFDI) measures the absorption and reduced scattering coefficients of tissue. Typically, SFDI assumes homogeneous tissue; however, layered structures are present in skin. We evaluate a multi-frequency approach to process SFDI data that estimates depth-specific scattering over differing penetration depths. Approach Multi-layer phantoms were manufactured to mimic wound healing scattering contrast in depth. An SFDI device imaged these phantoms and data were processed according to our multi-frequency approach. The depth sensitive data were then compared with a two-layer scattering model based on light fluence. Results The measured scattering from the phantoms changed with spatial frequency as our two-layer model predicted. The performance of two δ - P 1 models solutions for SFDI was consistently better than the standard diffusion approximation. Conclusions We presented an approach to process SFDI data that returns depth-resolved scattering contrast. This method allows for the implementation of layered optical models that more accurately represent physiologic parameters in thin tissue structures as in wound healing.
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Affiliation(s)
- Luigi Belcastro
- Linköping University, Department of Biomedical Engineering, Linköping, Sweden
| | - Hanna Jonasson
- Linköping University, Department of Biomedical Engineering, Linköping, Sweden
| | - Rolf B. Saager
- Linköping University, Department of Biomedical Engineering, Linköping, Sweden
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2
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Shugar AL, Konger RL, Rohan CA, Travers JB, Kim YL. Mapping cutaneous field carcinogenesis of nonmelanoma skin cancer using mesoscopic imaging of pro-inflammation cues. Exp Dermatol 2024; 33:e15076. [PMID: 38610095 PMCID: PMC11034840 DOI: 10.1111/exd.15076] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2023] [Revised: 03/24/2024] [Accepted: 03/30/2024] [Indexed: 04/14/2024]
Abstract
Nonmelanoma skin cancers remain the most widely diagnosed types of cancers globally. Thus, for optimal patient management, it has become imperative that we focus our efforts on the detection and monitoring of cutaneous field carcinogenesis. The concept of field cancerization (or field carcinogenesis), introduced by Slaughter in 1953 in the context of oral cancer, suggests that invasive cancer may emerge from a molecularly and genetically altered field affecting a substantial area of underlying tissue including the skin. A carcinogenic field alteration, present in precancerous tissue over a relatively large area, is not easily detected by routine visualization. Conventional dermoscopy and microscopy imaging are often limited in assessing the entire carcinogenic landscape. Recent efforts have suggested the use of noninvasive mesoscopic (between microscopic and macroscopic) optical imaging methods that can detect chronic inflammatory features to identify pre-cancerous and cancerous angiogenic changes in tissue microenvironments. This concise review covers major types of mesoscopic optical imaging modalities capable of assessing pro-inflammatory cues by quantifying blood haemoglobin parameters and hemodynamics. Importantly, these imaging modalities demonstrate the ability to detect angiogenesis and inflammation associated with actinically damaged skin. Representative experimental preclinical and human clinical studies using these imaging methods provide biological and clinical relevance to cutaneous field carcinogenesis in altered tissue microenvironments in the apparently normal epidermis and dermis. Overall, mesoscopic optical imaging modalities assessing chronic inflammatory hyperemia can enhance the understanding of cutaneous field carcinogenesis, offer a window of intervention and monitoring for actinic keratoses and nonmelanoma skin cancers and maximise currently available treatment options.
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Affiliation(s)
- Andrea L. Shugar
- Department of Pharmacology & Toxicology, Wright State University Boonshoft School of Medicine, Dayton, Ohio, USA
| | - Raymond L. Konger
- Department of Pathology and Laboratory Medicine, Indiana University School of Medicine, Indianapolis, Indiana, USA
- Department of Dermatology, Indiana University School of Medicine, Indianapolis, Indiana, USA
- Department of Pathology, Richard L. Roudebush Veterans Administration Hospital, Indianapolis, Indiana, USA
| | - Craig A. Rohan
- Department of Pharmacology & Toxicology, Wright State University Boonshoft School of Medicine, Dayton, Ohio, USA
- Department of Dermatology, Wright State University Boonshoft School of Medicine, Dayton, Ohio, USA
- Department of Medicine, Dayton Veterans Affairs Medical Center, Dayton, Ohio, USA
| | - Jeffrey B. Travers
- Department of Pharmacology & Toxicology, Wright State University Boonshoft School of Medicine, Dayton, Ohio, USA
- Department of Dermatology, Wright State University Boonshoft School of Medicine, Dayton, Ohio, USA
- Department of Medicine, Dayton Veterans Affairs Medical Center, Dayton, Ohio, USA
| | - Young L. Kim
- Weldon School of Biomedical Engineering, Purdue University, West Lafayette, Indiana, USA
- Purdue Institute for Cancer Research, Purdue University, West Lafayette, Indiana, USA
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Stier AC, Goth W, Hurley A, Brown T, Feng X, Zhang Y, Lopes FCPS, Sebastian KR, Ren P, Fox MC, Reichenberg JS, Markey MK, Tunnell JW. Imaging sub-diffuse optical properties of cancerous and normal skin tissue using machine learning-aided spatial frequency domain imaging. JOURNAL OF BIOMEDICAL OPTICS 2021; 26:JBO-210048RR. [PMID: 34558235 PMCID: PMC8459901 DOI: 10.1117/1.jbo.26.9.096007] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/17/2021] [Accepted: 08/27/2021] [Indexed: 05/28/2023]
Abstract
SIGNIFICANCE Sub-diffuse optical properties may serve as useful cancer biomarkers, and wide-field heatmaps of these properties could aid physicians in identifying cancerous tissue. Sub-diffuse spatial frequency domain imaging (sd-SFDI) can reveal such wide-field maps, but the current time cost of experimentally validated methods for rendering these heatmaps precludes this technology from potential real-time applications. AIM Our study renders heatmaps of sub-diffuse optical properties from experimental sd-SFDI images in real time and reports these properties for cancerous and normal skin tissue subtypes. APPROACH A phase function sampling method was used to simulate sd-SFDI spectra over a wide range of optical properties. A machine learning model trained on these simulations and tested on tissue phantoms was used to render sub-diffuse optical property heatmaps from sd-SFDI images of cancerous and normal skin tissue. RESULTS The model accurately rendered heatmaps from experimental sd-SFDI images in real time. In addition, heatmaps of a small number of tissue samples are presented to inform hypotheses on sub-diffuse optical property differences across skin tissue subtypes. CONCLUSION These results bring the overall process of sd-SFDI a fundamental step closer to real-time speeds and set a foundation for future real-time medical applications of sd-SFDI such as image guided surgery.
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Affiliation(s)
- Andrew C. Stier
- The University of Texas at Austin, Department of Electrical and Computer Engineering, Austin, Texas, United States
| | - Will Goth
- The University of Texas at Austin, Department of Biomedical Engineering, Austin, Texas, United States
| | - Aislinn Hurley
- The University of Texas at Austin, Department of Biomedical Engineering, Austin, Texas, United States
| | - Treshayla Brown
- The University of Texas at Austin, Department of Biomedical Engineering, Austin, Texas, United States
| | - Xu Feng
- The University of Texas at Austin, Department of Biomedical Engineering, Austin, Texas, United States
| | - Yao Zhang
- The University of Texas at Austin, Department of Biomedical Engineering, Austin, Texas, United States
| | - Fabiana C. P. S. Lopes
- The University of Texas at Austin, Dell Medical School, Department of Internal Medicine, Austin, Texas, United States
| | - Katherine R. Sebastian
- The University of Texas at Austin, Dell Medical School, Department of Internal Medicine, Austin, Texas, United States
| | - Pengyu Ren
- The University of Texas at Austin, Department of Biomedical Engineering, Austin, Texas, United States
| | - Matthew C. Fox
- The University of Texas at Austin, Dell Medical School, Department of Internal Medicine, Austin, Texas, United States
| | - Jason S. Reichenberg
- The University of Texas at Austin, Dell Medical School, Department of Internal Medicine, Austin, Texas, United States
| | - Mia K. Markey
- The University of Texas at Austin, Department of Biomedical Engineering, Austin, Texas, United States
- The University of Texas MD Anderson Cancer Center, Imaging Physics Residency Program, Houston, Texas, United States
| | - James W. Tunnell
- The University of Texas at Austin, Department of Biomedical Engineering, Austin, Texas, United States
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4
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Spatial-Frequency Domain Imaging: An Emerging Depth-Varying and Wide-Field Technique for Optical Property Measurement of Biological Tissues. PHOTONICS 2021. [DOI: 10.3390/photonics8050162] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Measurement of optical properties is critical for understanding light-tissue interaction, properly interpreting measurement data, and gaining better knowledge of tissue physicochemical properties. However, conventional optical measuring techniques are limited in point measurement, which partly hinders the applications on characterizing spatial distribution and inhomogeneity of optical properties of biological tissues. Spatial-frequency domain imaging (SFDI), as an emerging non-contact, depth-varying and wide-field optical imaging technique, is capable of measuring the optical properties in a wide field-of-view on a pixel-by-pixel basis. This review first describes the typical SFDI system and the principle for estimating optical properties using the SFDI technique. Then, the applications of SFDI in the fields of biomedicine, as well as food and agriculture, are reviewed, including burn assessment, skin tissue evaluation, tumor tissue detection, brain tissue monitoring, and quality evaluation of agro-products. Finally, a discussion on the challenges and future perspectives of SFDI for optical property estimation is presented.
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Applegate MB, Spink SS, Roblyer D. Dual-DMD hyperspectral spatial frequency domain imaging (SFDI) using dispersed broadband illumination with a demonstration of blood stain spectral monitoring. BIOMEDICAL OPTICS EXPRESS 2021; 12:676-688. [PMID: 33520393 PMCID: PMC7818964 DOI: 10.1364/boe.411976] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/09/2020] [Revised: 12/17/2020] [Accepted: 12/17/2020] [Indexed: 06/12/2023]
Abstract
Spatial frequency domain imaging (SFDI) is a widefield diffuse optical measurement technique capable of generating 2D maps of sub-surface absorption and scattering in biological tissue. We developed a new hyperspectral SFDI instrument capable of collecting images at wavelengths from the visible to the near infrared. The system utilizes a custom-built monochromator with a digital micromirror device (DMD) that can dynamically select illumination wavelength bands from a broadband quartz tungsten halogen lamp, and a second DMD to provide spatially modulated sample illumination. The system is capable of imaging 10 wavelength bands in approximately 25 seconds. The spectral resolution can be varied from 12 to 30 nm by tuning the input slit width and the output DMD column width. We compared the optical property extraction accuracy between the new device and a commercial SFDI system and found an average error of 23% in absorption and 6% in scattering. The system was highly stable, with less than 5% variation in absorption and less than 0.2% variation in scattering across all wavelengths over two hours. The system was used to monitor hyperspectral changes in the optical absorption and reduced scattering spectra of blood exposed to air over 24 hours. This served as a general demonstration of the utility of this system, and points to a potential application for blood stain age estimation. We noted significant changes in both absorption and reduced scattering spectra over multiple discrete stages of aging. To our knowledge, these are the first measurement of changes in scattering of blood stains. This hyperspectral SFDI system holds promise for a multitude of applications in quantitative tissue and diffuse sample imaging.
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Affiliation(s)
- Matthew B. Applegate
- Boston University, Dept. of Biomedical Engineering, Boston, MA 02215, USA
- Authors contributed equally to this work
| | - Samuel S. Spink
- Boston University, Dept. of Biomedical Engineering, Boston, MA 02215, USA
- Authors contributed equally to this work
| | - Darren Roblyer
- Boston University, Dept. of Biomedical Engineering, Boston, MA 02215, USA
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6
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Schmeusser B, Borchers C, Travers JB, Borchers S, Trevino J, Rubin M, Donnelly H, Kellawan K, Carpenter L, Bahl S, Rohan C, Muennich E, Guenthner S, Hahn H, Rkein A, Darst M, Mousdicas N, Cates E, Sunar U, Bihl T. Inter- and Intra-physician variation in quantifying actinic keratosis skin photodamage. JOURNAL OF CLINICAL AND INVESTIGATIVE DERMATOLOGY 2020; 8:4. [PMID: 33088904 PMCID: PMC7575200] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
We investigated the variations in physician evaluation of skin photodamage based on a published photodamage scale. Of interest is the utility of a 10-level scale ranging from none and mild photodamage to actinic keratosis (AK). The dorsal forearms of 55 adult subjects with various amounts of photodamage were considered. Each forearm was independently evaluated by 15 board-certified dermatologists according to the Global Assessment Severity Scale ranging from 0 (less severe) to 9 (the most progressed stage of skin damage). Dermatologists rated the levels of photodamage based upon the photographs in blinded fashion. Results show substantial disagreement amongst the dermatologists on the severity of photodamage. Our results indicate that ratings could be more consistent if using a scale of less levels (5-levels or 3-levels). Ultimately, clinicians can use this knowledge to provide better interpretation of inter-rater evaluations and provide more reliable assessment and frequent monitoring of high-risk populations.
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Affiliation(s)
- Benjamin Schmeusser
- Department of Pharmacology & Toxicology, Boonshoft School of Medicine, Wright State University, Dayton, OH, 45435, USA
| | - Christina Borchers
- Department of Pharmacology & Toxicology, Boonshoft School of Medicine, Wright State University, Dayton, OH, 45435, USA
| | - Jeffrey B. Travers
- Department of Pharmacology & Toxicology, Boonshoft School of Medicine, Wright State University, Dayton, OH, 45435, USA
- Department of Dermatology, Boonshoft School of Medicine, Wright State University, Dayton, OH, 45435, USA
- Dayton Veterans Administration Medical Center, Dayton, OH, 45428, USA
| | - Samia Borchers
- Department of Dermatology, Boonshoft School of Medicine, Wright State University, Dayton, OH, 45435, USA
| | - Julian Trevino
- Department of Dermatology, Boonshoft School of Medicine, Wright State University, Dayton, OH, 45435, USA
| | - Max Rubin
- Department of Dermatology, Boonshoft School of Medicine, Wright State University, Dayton, OH, 45435, USA
| | - Heidi Donnelly
- Department of Dermatology, Boonshoft School of Medicine, Wright State University, Dayton, OH, 45435, USA
| | - Karl Kellawan
- Department of Dermatology, Boonshoft School of Medicine, Wright State University, Dayton, OH, 45435, USA
| | - Lydia Carpenter
- Department of Dermatology, Boonshoft School of Medicine, Wright State University, Dayton, OH, 45435, USA
| | - Shalini Bahl
- Department of Dermatology, Boonshoft School of Medicine, Wright State University, Dayton, OH, 45435, USA
| | - Craig Rohan
- Department of Dermatology, Boonshoft School of Medicine, Wright State University, Dayton, OH, 45435, USA
| | - Elizabeth Muennich
- Department of Dermatology, Boonshoft School of Medicine, Wright State University, Dayton, OH, 45435, USA
| | | | - Holly Hahn
- Department of Dermatology, Boonshoft School of Medicine, Wright State University, Dayton, OH, 45435, USA
| | - Ali Rkein
- Department of Dermatology, Boonshoft School of Medicine, Wright State University, Dayton, OH, 45435, USA
| | - Marc Darst
- Charlotte Dermatology, Charlotte, NC 28277, USA
| | - Nico Mousdicas
- Richard L. Roudebush VA Medical Center, Indianapolis, IN, 46202, USA
| | - Elizabeth Cates
- Department of Pharmacology & Toxicology, Boonshoft School of Medicine, Wright State University, Dayton, OH, 45435, USA
| | - Ulas Sunar
- Department of Biomedical, Industrial & Human Factors Engineering, Wright State University, Dayton, OH, 45435, USA
| | - Trevor Bihl
- Department of Pharmacology & Toxicology, Boonshoft School of Medicine, Wright State University, Dayton, OH, 45435, USA
- Department of Biomedical, Industrial & Human Factors Engineering, Wright State University, Dayton, OH, 45435, USA
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7
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Applegate MB, Karrobi K, Angelo Jr. JP, Austin W, Tabassum SM, Aguénounon E, Tilbury K, Saager RB, Gioux S, Roblyer D. OpenSFDI: an open-source guide for constructing a spatial frequency domain imaging system. JOURNAL OF BIOMEDICAL OPTICS 2020; 25:1-13. [PMID: 31925946 PMCID: PMC7008504 DOI: 10.1117/1.jbo.25.1.016002] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/18/2019] [Accepted: 12/12/2019] [Indexed: 05/09/2023]
Abstract
Significance: Spatial frequency domain imaging (SFDI) is a diffuse optical measurement technique that can quantify tissue optical absorption (μa) and reduced scattering (<inline-formula>μs'</inline-formula>) on a pixel-by-pixel basis. Measurements of μa at different wavelengths enable the extraction of molar concentrations of tissue chromophores over a wide field, providing a noncontact and label-free means to assess tissue viability, oxygenation, microarchitecture, and molecular content. We present here openSFDI: an open-source guide for building a low-cost, small-footprint, three-wavelength SFDI system capable of quantifying μa and <inline-formula>μs'</inline-formula> as well as oxyhemoglobin and deoxyhemoglobin concentrations in biological tissue. The companion website provides a complete parts list along with detailed instructions for assembling the openSFDI system.<p> Aim: We describe the design of openSFDI and report on the accuracy and precision of optical property extractions for three different systems fabricated according to the instructions on the openSFDI website.</p> <p> Approach: Accuracy was assessed by measuring nine tissue-simulating optical phantoms with a physiologically relevant range of μa and <inline-formula>μs'</inline-formula> with the openSFDI systems and a commercial SFDI device. Precision was assessed by repeatedly measuring the same phantom over 1 h.</p> <p> Results: The openSFDI systems had an error of 0 ± 6 % in μa and -2 ± 3 % in <inline-formula>μs'</inline-formula>, compared to a commercial SFDI system. Bland-Altman analysis revealed the limits of agreement between the two systems to be ± 0.004 mm - 1 for μa and -0.06 to 0.1 mm - 1 for <inline-formula>μs'</inline-formula>. The openSFDI system had low drift with an average standard deviation of 0.0007 mm - 1 and 0.05 mm - 1 in μa and <inline-formula>μs'</inline-formula>, respectively.</p>,<p> Conclusion: The openSFDI provides a customizable hardware platform for research groups seeking to utilize SFDI for quantitative diffuse optical imaging.</p>
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Affiliation(s)
- Matthew B. Applegate
- Boston University, Department of Biomedical Engineering, Boston, Massachusetts, United States
| | - Kavon Karrobi
- Boston University, Department of Biomedical Engineering, Boston, Massachusetts, United States
| | | | - Wyatt Austin
- University of Maine, Department of Chemical and Biomedical Engineering, Orono, Maine, United States
| | - Syeda M. Tabassum
- Boston University, Department of Electrical and Computer Engineering, Boston, Massachusetts, United States
| | | | - Karissa Tilbury
- University of Maine, Department of Chemical and Biomedical Engineering, Orono, Maine, United States
| | - Rolf B. Saager
- Linköping University, Department of Biomedical Engineering, Linköping Sweden
| | - Sylvain Gioux
- University of Strasbourg, ICube Laboratory, Strasbourg, France
| | - Darren Roblyer
- Boston University, Department of Biomedical Engineering, Boston, Massachusetts, United States
- Address all correspondence to Darren Roblyer, E-mail:
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8
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Travers JB, Poon C, Bihl T, Rinehart B, Borchers C, Rohrbach DJ, Borchers S, Trevino J, Rubin M, Donnelly H, Kellawan K, Carpenter L, Bahl S, Rohan C, Muennich E, Guenthner S, Hahn H, Rkein A, Darst M, Mousdicas N, Cates E, Sunar U. Quantifying skin photodamage with spatial frequency domain imaging: statistical results. BIOMEDICAL OPTICS EXPRESS 2019; 10:4676-4683. [PMID: 31565518 PMCID: PMC6757479 DOI: 10.1364/boe.10.004676] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/07/2019] [Accepted: 08/08/2019] [Indexed: 06/10/2023]
Abstract
We investigated the change in optical properties and vascular parameters to characterize skin tissue from mild photodamage to actinic keratosis (AK) with comparison to a published photodamage scale. Multi-wavelength spatial frequency domain imaging (SFDI) measurements were performed on the dorsal forearms of 55 adult subjects with various amounts of photodamage. Dermatologists rated the levels of photodamage based upon the photographs in blinded fashion to allow comparison with SFDI data. For characterization of statistical data, we used artificial neural networks. Our results indicate that optical and vascular parameters can be used to quantify photodamage and can discriminate between the stages as low, medium, and high grades, with the best performance of ∼70%, ∼76% and 80% for characterization of low- medium- and high-grade lesions, respectively. Ultimately, clinicians can use this noninvasive approach for risk assessment and frequent monitoring of high-risk populations.
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Affiliation(s)
- Jeffrey B. Travers
- Department of Pharmacology & Toxicology, Boonshoft School of Medicine, Wright State University, Dayton, OH 45435, USA
- Department of Dermatology, Boonshoft School of Medicine, Wright State University, Dayton, OH 45435, USA
- Dayton Veterans Administration Medical Center, Dayton, OH 45428, USA
| | - Chien Poon
- Department of Biomedical, Industrial & Human Factors Engineering, Wright State University, Dayton, OH 45435, USA
| | - Trevor Bihl
- Department of Pharmacology & Toxicology, Boonshoft School of Medicine, Wright State University, Dayton, OH 45435, USA
- Department of Biomedical, Industrial & Human Factors Engineering, Wright State University, Dayton, OH 45435, USA
| | - Benjamin Rinehart
- Department of Biomedical, Industrial & Human Factors Engineering, Wright State University, Dayton, OH 45435, USA
| | - Christina Borchers
- Department of Pharmacology & Toxicology, Boonshoft School of Medicine, Wright State University, Dayton, OH 45435, USA
| | - Daniel J. Rohrbach
- Department of Biomedical, Industrial & Human Factors Engineering, Wright State University, Dayton, OH 45435, USA
| | - Samia Borchers
- Department of Dermatology, Boonshoft School of Medicine, Wright State University, Dayton, OH 45435, USA
| | - Julian Trevino
- Department of Dermatology, Boonshoft School of Medicine, Wright State University, Dayton, OH 45435, USA
| | - Max Rubin
- Department of Dermatology, Boonshoft School of Medicine, Wright State University, Dayton, OH 45435, USA
| | - Heidi Donnelly
- Department of Dermatology, Boonshoft School of Medicine, Wright State University, Dayton, OH 45435, USA
| | - Karl Kellawan
- Department of Dermatology, Boonshoft School of Medicine, Wright State University, Dayton, OH 45435, USA
| | - Lydia Carpenter
- Department of Dermatology, Boonshoft School of Medicine, Wright State University, Dayton, OH 45435, USA
| | - Shalini Bahl
- Department of Dermatology, Boonshoft School of Medicine, Wright State University, Dayton, OH 45435, USA
| | - Craig Rohan
- Department of Dermatology, Boonshoft School of Medicine, Wright State University, Dayton, OH 45435, USA
| | - Elizabeth Muennich
- Department of Dermatology, Boonshoft School of Medicine, Wright State University, Dayton, OH 45435, USA
| | | | - Holly Hahn
- Department of Dermatology, Boonshoft School of Medicine, Wright State University, Dayton, OH 45435, USA
| | - Ali Rkein
- Department of Dermatology, Boonshoft School of Medicine, Wright State University, Dayton, OH 45435, USA
| | - Marc Darst
- Charlotte Dermatology, Charlotte, NC 28277, USA
| | - Nico Mousdicas
- Richard L. Roudebush VA Medical Center, Indianapolis, IN 46202, USA
| | - Elizabeth Cates
- Department of Pharmacology & Toxicology, Boonshoft School of Medicine, Wright State University, Dayton, OH 45435, USA
| | - Ulas Sunar
- Department of Biomedical, Industrial & Human Factors Engineering, Wright State University, Dayton, OH 45435, USA
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9
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Hayakawa CK, Karrobi K, Pera V, Roblyer D, Venugopalan V. Optical sampling depth in the spatial frequency domain. JOURNAL OF BIOMEDICAL OPTICS 2019; 24:JBO-180100R. [PMID: 30218504 PMCID: PMC6675966 DOI: 10.1117/1.jbo.24.7.071603] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/16/2018] [Accepted: 07/10/2018] [Indexed: 05/11/2023]
Abstract
We present a Monte Carlo (MC) method to determine depth-dependent probability distributions of photon visitation and detection for optical reflectance measurements performed in the spatial frequency domain (SFD). These distributions are formed using an MC simulation for radiative transport that utilizes a photon packet weighting procedure consistent with the two-dimensional spatial Fourier transform of the radiative transport equation. This method enables the development of quantitative metrics for SFD optical sampling depth in layered tissue and its dependence on both tissue optical properties and spatial frequency. We validate the computed depth-dependent probability distributions using SFD measurements in a layered phantom system with a highly scattering top layer of variable thickness supported by a highly absorbing base layer. We utilize our method to establish the spatial frequency-dependent optical sampling depth for a number of tissue types and also provide a general tool to determine such depths for tissues of arbitrary optical properties.
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Affiliation(s)
- Carole K. Hayakawa
- University of California at Irvine, Department of Chemical Engineering and Materials Science, Irvine, California, United States
- University of California at Irvine, Beckman Laser Institute, Laser Microbeam and Medical Program, Irvine, California, United States
| | - Kavon Karrobi
- Boston University, Department of Biomedical Engineering, Boston, Massachusetts, United States
| | - Vivian Pera
- Boston University, Department of Biomedical Engineering, Boston, Massachusetts, United States
| | - Darren Roblyer
- Boston University, Department of Biomedical Engineering, Boston, Massachusetts, United States
| | - Vasan Venugopalan
- University of California at Irvine, Department of Chemical Engineering and Materials Science, Irvine, California, United States
- University of California at Irvine, Beckman Laser Institute, Laser Microbeam and Medical Program, Irvine, California, United States
- Address all correspondence to: Vasan Venugopalan, E-mail:
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10
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Abstract
Despite our understanding that the microvasculature plays a multifaceted role in the development and progression of various conditions, we know little about the extent of this involvement. A need exists for non-invasive, clinically meaningful imaging modalities capable of elucidating microvascular information to aid in our understanding of disease, and to aid in the diagnosis/monitoring of disease for more patient-specific care. In this review article, a number of imaging techniques are summarized that have been utilized to investigate the microvasculature of skin, along with their advantages, disadvantages and future perspectives in preclinical and clinical settings. These techniques include dermoscopy, capillaroscopy, Doppler sonography, laser Doppler flowmetry (LDF) and perfusion imaging, laser speckle contrast imaging (LSCI), optical coherence tomography (OCT), including its Doppler and dynamic variant and the more recently developed OCT angiography (OCTA), photoacoustic imaging, and spatial frequency domain imaging (SFDI). Attention is largely, but not exclusively, placed on optical imaging modalities that use intrinsic optical signals to contrast the microvasculature. We conclude that whilst each imaging modality has been successful in filling a particular niche, there is no one, all-encompassing modality without inherent flaws. Therefore, the future of cutaneous microvascular imaging may lie in utilizing a multi-modal approach that will counter the disadvantages of individual systems to synergistically augment our imaging capabilities.
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Affiliation(s)
- Anthony J Deegan
- Department of Bioengineering, University of Washington, 3720 15th Ave. NE., Seattle, WA 98195, United States of America
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11
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Angelo JP, Chen SJ, Ochoa M, Sunar U, Gioux S, Intes X. Review of structured light in diffuse optical imaging. JOURNAL OF BIOMEDICAL OPTICS 2018; 24:1-20. [PMID: 30218503 PMCID: PMC6676045 DOI: 10.1117/1.jbo.24.7.071602] [Citation(s) in RCA: 47] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/06/2018] [Accepted: 05/31/2018] [Indexed: 05/11/2023]
Abstract
Diffuse optical imaging probes deep living tissue enabling structural, functional, metabolic, and molecular imaging. Recently, due to the availability of spatial light modulators, wide-field quantitative diffuse optical techniques have been implemented, which benefit greatly from structured light methodologies. Such implementations facilitate the quantification and characterization of depth-resolved optical and physiological properties of thick and deep tissue at fast acquisition speeds. We summarize the current state of work and applications in the three main techniques leveraging structured light: spatial frequency-domain imaging, optical tomography, and single-pixel imaging. The theory, measurement, and analysis of spatial frequency-domain imaging are described. Then, advanced theories, processing, and imaging systems are summarized. Preclinical and clinical applications on physiological measurements for guidance and diagnosis are summarized. General theory and method development of tomographic approaches as well as applications including fluorescence molecular tomography are introduced. Lastly, recent developments of single-pixel imaging methodologies and applications are reviewed.
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Affiliation(s)
- Joseph P. Angelo
- National Institute of Standards and Technology, Sensor Science Division, Gaithersburg, Maryland, United States
- Address all correspondence to: Joseph P. Angelo, E-mail: ; Sez-Jade Chen, E-mail:
| | - Sez-Jade Chen
- Rensselaer Polytechnic Institute, Department of Biomedical Engineering, Troy, New York, United States
- Address all correspondence to: Joseph P. Angelo, E-mail: ; Sez-Jade Chen, E-mail:
| | - Marien Ochoa
- Rensselaer Polytechnic Institute, Department of Biomedical Engineering, Troy, New York, United States
| | - Ulas Sunar
- Wright State University, Department of Biomedical Industrial and Human Factor Engineering, Dayton, Ohio, United States
| | - Sylvain Gioux
- University of Strasbourg, ICube Laboratory, Strasbourg, France
| | - Xavier Intes
- Rensselaer Polytechnic Institute, Department of Biomedical Engineering, Troy, New York, United States
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12
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Monte AFG, Reis AF, Cruz Junior LB, Antunes A. Preparation and quantitative characterization of polydimethylsiloxane optical phantoms with zinc-phthalocyanine dye absorbers. APPLIED OPTICS 2018; 57:5865-5871. [PMID: 30118059 DOI: 10.1364/ao.57.005865] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/19/2018] [Accepted: 05/07/2018] [Indexed: 06/08/2023]
Abstract
We described a method for the preparation of polydimethylsiloxane (PDMS) phantoms to mimic the optical properties of biologic tissues at distinct wavelengths ranging from the visible to the near-infrared spectra. The present method for fabricating solid optical tissue phantoms using zinc-phthalocyanine chromophores has demonstrated high photostability with optical absorption coefficients up to 1.0 mm-1, making this phantom proper with absorption bands ranging from 600 to 850 nm. It also happens that the chromophore absorption coefficient is linear as a function of its concentration inside the previous optical window. The optical scattering properties were quantitatively selected by adding TiO2 particle concentrations to the PDMS phantom. Thus, the quantitative optical properties of absorption and scattering for a large-batch fabrication were demonstrated, making the zinc-phthalocyanine phantoms suitable for use as a reference standard.
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13
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Poon C, Sunar U, Rohrbach DJ, Krishnamurthy S, Olsen T, Kent M, Weir NM, Simman R, Travers JB. Early assessment of burn severity in human tissue ex vivo with multi-wavelength spatial frequency domain imaging. Toxicol In Vitro 2018; 52:251-254. [PMID: 29859991 DOI: 10.1016/j.tiv.2018.05.015] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2018] [Accepted: 05/28/2018] [Indexed: 12/20/2022]
Abstract
Early knowledge about burn severity and depth can lead to improved outcome for patients. In this study, we investigated the change in optical properties in ex vivo human skin following thermal burn injuries. Human skin removed during body contouring procedures was subjected to thermal burn injury for either 10 or 60 s. Multi-wavelength spatial frequency domain imaging (SFDI) measurements were performed on each sample and the optical properties (absorption and scattering parameters) were obtained at each wavelength. Multi-wavelength fitting was used to quantify absorption and scattering parameters, and these parameters were compared to histologic assessments of burn depth related to burn severity. Our results indicated substantial changes in optical scattering parameters and these changes correlated well with the burn severity and depth, and fit closely with previously reported studies using porcine in vivo models. This study provides the characterization of thermal burn injury on human skin ex vivo by using the optical method of SFDI with high sensitivity and specificity. This preclinical human model system without live animals could have uses in testing the imaging parameters of other skin injuries, including from caustic agents.
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Affiliation(s)
- Chien Poon
- Department of Biomedical, Industrial & Human Factors Engineering, Wright State University, Dayton, OH 45435, USA
| | - Ulas Sunar
- Department of Biomedical, Industrial & Human Factors Engineering, Wright State University, Dayton, OH 45435, USA
| | - Daniel J Rohrbach
- Department of Biomedical, Industrial & Human Factors Engineering, Wright State University, Dayton, OH 45435, USA
| | - Smita Krishnamurthy
- Department of Dermatology, Boonshoft School of Medicine, Wright State University, Dayton, OH 45435, USA; Dayton Veterans Administration Medical Center, Dayton, OH 45428, USA; Department of Pathology & Laboratory Medicine, Boonshoft School of Medicine, Wright State University, Dayton, OH 45435, USA
| | - Thomas Olsen
- Department of Dermatology, Boonshoft School of Medicine, Wright State University, Dayton, OH 45435, USA; Dermpathology Laboratory of Central States, Dayton, OH 45459, USA
| | - Michael Kent
- Department of Dermatology, Boonshoft School of Medicine, Wright State University, Dayton, OH 45435, USA; Dermpathology Laboratory of Central States, Dayton, OH 45459, USA
| | - Nathan M Weir
- Department of Dermatology, Boonshoft School of Medicine, Wright State University, Dayton, OH 45435, USA
| | - Richard Simman
- Department of Dermatology, Boonshoft School of Medicine, Wright State University, Dayton, OH 45435, USA; Department of Pharmacology & Toxicology, Boonshoft School of Medicine, Wright State University, Dayton, OH 45435, USA
| | - Jeffrey B Travers
- Department of Dermatology, Boonshoft School of Medicine, Wright State University, Dayton, OH 45435, USA; Department of Pharmacology & Toxicology, Boonshoft School of Medicine, Wright State University, Dayton, OH 45435, USA; Dayton Veterans Administration Medical Center, Dayton, OH 45428, USA.
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Pera V, Karrobi K, Tabassum S, Teng F, Roblyer D. Optical property uncertainty estimates for spatial frequency domain imaging. BIOMEDICAL OPTICS EXPRESS 2018; 9:661-678. [PMID: 29552403 PMCID: PMC5854069 DOI: 10.1364/boe.9.000661] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/13/2017] [Revised: 12/21/2017] [Accepted: 01/08/2018] [Indexed: 05/02/2023]
Abstract
Spatial frequency domain imaging (SFDI) is a wide-field diffuse optical imaging modality that has attracted considerable interest in recent years. Typically, diffuse reflectance measurements of spatially modulated light are used to quantify the optical absorption and reduced scattering coefficients of tissue, and with these, chromophore concentrations are extracted. However, uncertainties in estimated absorption and reduced scattering coefficients are rarely reported, and we know of no method capable of providing these when look-up table (LUT) algorithms are used to recover the optical properties. We present a method to generate optical property uncertainty estimates from knowledge of diffuse reflectance measurement errors. By employing the Cramér-Rao bound, we can quickly and efficiently explore theoretical SFDI performance as a function of spatial frequencies and sample optical properties, allowing us to optimize spatial frequency selection for a given application. In practice, we can also obtain useful uncertainty estimates for optical properties recovered with a two-frequency LUT algorithm, as we demonstrate with tissue-simulating phantom and in vivo experiments. Finally, we illustrate how absorption coefficient uncertainties can be propagated forward to yield uncertainties for chromophore concentrations, which could significantly impact the interpretation of experimental results.
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Affiliation(s)
- Vivian Pera
- Department of Biomedical Engineering, Boston University, 44 Cummington Mall, Boston, MA 02215,
USA
| | - Kavon Karrobi
- Department of Biomedical Engineering, Boston University, 44 Cummington Mall, Boston, MA 02215,
USA
| | - Syeda Tabassum
- Department of Electrical and Computer Engineering, Boston University, 8 Saint Mary’s Street, Boston, MA 02215,
USA
| | - Fei Teng
- Department of Electrical and Computer Engineering, Boston University, 8 Saint Mary’s Street, Boston, MA 02215,
USA
| | - Darren Roblyer
- Department of Biomedical Engineering, Boston University, 44 Cummington Mall, Boston, MA 02215,
USA
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15
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Chen X, Lin W, Wang C, Chen S, Sheng J, Zeng B, Xu M. In vivo real-time imaging of cutaneous hemoglobin concentration, oxygen saturation, scattering properties, melanin content, and epidermal thickness with visible spatially modulated light. BIOMEDICAL OPTICS EXPRESS 2017; 8:5468-5482. [PMID: 29296481 PMCID: PMC5745096 DOI: 10.1364/boe.8.005468] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/24/2017] [Revised: 10/20/2017] [Accepted: 10/24/2017] [Indexed: 05/04/2023]
Abstract
We present the real-time single snapshot multiple frequency demodulation - spatial frequency domain imaging (SSMD-SFDI) platform implemented with a visible digital mirror device that is capable of imaging and monitoring dynamic turbid medium and processes over a large field of view. One challenge in quantitative imaging of biological tissue such as the skin is the complex structure rendering techniques based on homogeneous medium models to fail. To address this difficulty we have also developed a novel method that maps the layered structure to a homogeneous medium for spatial frequency domain imaging. The varying penetration depth of spatially modulated light on its wavelength and modulation frequency is used to resolve the layered structure. The efficacy of the real-time SSMD-SFDI platform and this two-layer model is demonstrated by imaging forearms of 6 healthy subjects under the reactive hyperemia protocol. The results show that our approach not only successfully decouples light absorption by melanin from that by hemoglobin and yields accurate determination of cutaneous hemoglobin concentration and oxygen saturation, but also provides reliable estimation of the scattering properties, the melanin content and the epidermal thickness in real time. Potential applications of our system in imaging skin physiological and functional states, cancer screening, and microcirculation monitoring are discussed at the end.
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Affiliation(s)
- Xinlin Chen
- Institute of Lasers and Biomedical Photonics, Biomedical Engineering College, Wenzhou Medical University, Wenzhou, Zhejiang, 325035, China
| | - Weihao Lin
- Institute of Lasers and Biomedical Photonics, Biomedical Engineering College, Wenzhou Medical University, Wenzhou, Zhejiang, 325035, China
| | - Chenge Wang
- Institute of Lasers and Biomedical Photonics, Biomedical Engineering College, Wenzhou Medical University, Wenzhou, Zhejiang, 325035, China
| | - Shaoheng Chen
- Institute of Lasers and Biomedical Photonics, Biomedical Engineering College, Wenzhou Medical University, Wenzhou, Zhejiang, 325035, China
| | - Jing Sheng
- Institute of Lasers and Biomedical Photonics, Biomedical Engineering College, Wenzhou Medical University, Wenzhou, Zhejiang, 325035, China
| | - Bixin Zeng
- Institute of Lasers and Biomedical Photonics, Biomedical Engineering College, Wenzhou Medical University, Wenzhou, Zhejiang, 325035, China
| | - M. Xu
- Institute of Lasers and Biomedical Photonics, Biomedical Engineering College, Wenzhou Medical University, Wenzhou, Zhejiang, 325035, China
- Dept. of Physics, Fairfield University, 1073 North Road, Fairfield, CT 06824, USA
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16
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Meitav O, Shaul O, Abookasis D. Determination of the complex refractive index segments of turbid sample with multispectral spatially modulated structured light and models approximation. JOURNAL OF BIOMEDICAL OPTICS 2017; 22:1-10. [PMID: 28959825 DOI: 10.1117/1.jbo.22.9.097004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/03/2017] [Accepted: 09/12/2017] [Indexed: 06/07/2023]
Abstract
Spectral data enabling the derivation of a biological tissue sample's complex refractive index (CRI) can provide a range of valuable information in the clinical and research contexts. Specifically, changes in the CRI reflect alterations in tissue morphology and chemical composition, enabling its use as an optical marker during diagnosis and treatment. In the present work, we report a method for estimating the real and imaginary parts of the CRI of a biological sample using Kramers-Kronig (KK) relations in the spatial frequency domain. In this method, phase-shifted sinusoidal patterns at single high spatial frequency are serially projected onto the sample surface at different near-infrared wavelengths while a camera mounted normal to the sample surface acquires the reflected diffuse light. In the offline analysis pipeline, recorded images at each wavelength are converted to spatial phase maps using KK analysis and are then calibrated against phase-models derived from diffusion approximation. The amplitude of the reflected light, together with phase data, is then introduced into Fresnel equations to resolve both real and imaginary segments of the CRI at each wavelength. The technique was validated in tissue-mimicking phantoms with known optical parameters and in mouse models of ischemic injury and heat stress. Experimental data obtained indicate variations in the CRI among brain tissue suffering from injury. CRI fluctuations correlated with alterations in the scattering and absorption coefficients of the injured tissue are demonstrated. This technique for deriving dynamic changes in the CRI of tissue may be further developed as a clinical diagnostic tool and for biomedical research applications. To the best of our knowledge, this is the first report of the estimation of the spectral CRI of a mouse head following injury obtained in the spatial frequency domain.
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Affiliation(s)
- Omri Meitav
- Ariel University, Department of Electrical and Electronics Engineering, Ariel 40700, Israel
| | - Oren Shaul
- Ariel University, Department of Electrical and Electronics Engineering, Ariel 40700, Israel
| | - David Abookasis
- Ariel University, Department of Electrical and Electronics Engineering, Ariel 40700, Israel
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17
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Chen W, Zhao H, Li T, Yan P, Zhao K, Qi C, Gao F. Reference-free determination of tissue absorption coefficient by modulation transfer function characterization in spatial frequency domain. Biomed Eng Online 2017; 16:100. [PMID: 28789661 PMCID: PMC5549354 DOI: 10.1186/s12938-017-0394-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2017] [Accepted: 08/04/2017] [Indexed: 11/24/2022] Open
Abstract
Background Spatial frequency domain (SFD) measurement allows rapid and non-contact wide-field imaging of the tissue optical properties, thus has become a potential tool for assessing physiological parameters and therapeutic responses during photodynamic therapy of skin diseases. The conventional SFD measurement requires a reference measurement within the same experimental scenario as that for a test one to calibrate mismatch between the real measurements and the model predictions. Due to the individual physical and geometrical differences among different tissues, organs and patients, an ideal reference measurement might be unavailable in clinical trials. To address this problem, we present a reference-free SFD determination of absorption coefficient that is based on the modulation transfer function (MTF) characterization. Methods Instead of the absolute amplitude that is used in the conventional SFD approaches, we herein employ the MTF to characterize the propagation of the modulated lights in tissues. With such a dimensionless relative quantity, the measurements can be naturally corresponded to the model predictions without calibrating the illumination intensity. By constructing a three-dimensional database that portrays the MTF as a function of the optical properties (both the absorption coefficient μa and the reduced scattering coefficient \documentclass[12pt]{minimal}
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\begin{document}$$\mu^{\prime}_{s}$$\end{document}μs′) and the spatial frequency, a look-up table approach or a least-square curve-fitting method is readily applied to recover the absorption coefficient from a single frequency or multiple frequencies, respectively. Results Simulation studies have verified the feasibility of the proposed reference-free method and evaluated its accuracy in the absorption recovery. Experimental validations have been performed on homogeneous tissue-mimicking phantoms with μa ranging from 0.01 to 0.07 mm−1 and \documentclass[12pt]{minimal}
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\begin{document}$$\mu^{\prime}_{s}$$\end{document}μs′ = 2.0 mm−1, respectively. We have also presented quantitative ex vivo imaging of human lung cancer in a subcutaneous xenograft mouse model for further validation, and observed high absorption contrast in the tumor region. Conclusions The proposed method can be applied to the rapid and accurate determination of the absorption coefficient, and better yet, in a reference-free way. We believe this reference-free strategy will facilitate the clinical translation of the SFD measurement to achieve enhanced intraoperative hemodynamic monitoring and personalized treatment planning in photodynamic therapy.
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Affiliation(s)
- Weiting Chen
- College of Precision Instrument and Optoelectronics Engineering, Tianjin University, Tianjin, 300072, China
| | - Huijuan Zhao
- College of Precision Instrument and Optoelectronics Engineering, Tianjin University, Tianjin, 300072, China. .,Tianjin Key Laboratory of Biomedical Detecting Techniques and Instruments, Tianjin, 300072, China.
| | - Tongxin Li
- College of Precision Instrument and Optoelectronics Engineering, Tianjin University, Tianjin, 300072, China
| | - Panpan Yan
- College of Precision Instrument and Optoelectronics Engineering, Tianjin University, Tianjin, 300072, China
| | - Kuanxin Zhao
- College of Precision Instrument and Optoelectronics Engineering, Tianjin University, Tianjin, 300072, China
| | - Caixia Qi
- College of Precision Instrument and Optoelectronics Engineering, Tianjin University, Tianjin, 300072, China
| | - Feng Gao
- College of Precision Instrument and Optoelectronics Engineering, Tianjin University, Tianjin, 300072, China. .,Tianjin Key Laboratory of Biomedical Detecting Techniques and Instruments, Tianjin, 300072, China.
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18
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Travers JB, Poon C, Rohrbach DJ, Weir NM, Cates E, Hager F, Sunar U. Noninvasive mesoscopic imaging of actinic skin damage using spatial frequency domain imaging. BIOMEDICAL OPTICS EXPRESS 2017; 8:3045-3052. [PMID: 28663925 PMCID: PMC5480448 DOI: 10.1364/boe.8.003045] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/29/2017] [Revised: 05/08/2017] [Accepted: 05/09/2017] [Indexed: 05/17/2023]
Abstract
For prevention and accurate intervention planning, it is crucial to predict if lesions will progress towards cancer. In this study, we investigated the change in optical properties and vascular parameters to characterize skin tissue from mild photodamage to actinic keratosis (AK). Multi-wavelength spatial frequency domain imaging (SFDI) measurements were performed on three patients with clinically normal skin, as well as pre-cancerous actinic keratosis lesions. Our results indicate that there exist significant differences in both optical and vascular parameters between these patients, and that these parameters can be early biomarkers of neoplasia. Ultimately, clinicians can use this noninvasive approach for frequent monitoring of high-risk population.
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Affiliation(s)
- Jeffrey B. Travers
- Department of Pharmacology & Toxicology, Boonshoft School of Medicine, Wright State University, Dayton, OH 45435, USA
- Department of Dermatology, Boonshoft School of Medicine, Wright State University, Dayton, OH 45435, USA
- Dayton Veterans Administration Medical Center, Dayton, OH 45428, USA
- These authors contributed equally to this manuscript
| | - Chien Poon
- Department of Biomedical, Industrial & Human Factors Engineering, Wright State University, Dayton, OH 45435, USA
- These authors contributed equally to this manuscript
| | - Daniel J. Rohrbach
- Department of Biomedical, Industrial & Human Factors Engineering, Wright State University, Dayton, OH 45435, USA
| | - Nathan M. Weir
- Department of Dermatology, Boonshoft School of Medicine, Wright State University, Dayton, OH 45435, USA
| | - Elizabeth Cates
- Department of Pharmacology & Toxicology, Boonshoft School of Medicine, Wright State University, Dayton, OH 45435, USA
| | - Faye Hager
- Department of Pharmacology & Toxicology, Boonshoft School of Medicine, Wright State University, Dayton, OH 45435, USA
| | - Ulas Sunar
- Department of Biomedical, Industrial & Human Factors Engineering, Wright State University, Dayton, OH 45435, USA
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19
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Baruch D, Abookasis D. Multimodal optical setup based on spectrometer and cameras combination for biological tissue characterization with spatially modulated illumination. JOURNAL OF BIOMEDICAL OPTICS 2017; 22:46007. [PMID: 28425559 DOI: 10.1117/1.jbo.22.4.046007] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/17/2016] [Accepted: 03/29/2017] [Indexed: 06/07/2023]
Abstract
The application of optical techniques as tools for biomedical research has generated substantial interest for the ability of such methodologies to simultaneously measure biochemical and morphological parameters of tissue. Ongoing optimization of optical techniques may introduce such tools as alternative or complementary to conventional methodologies. The common approach shared by current optical techniques lies in the independent acquisition of tissue’s optical properties (i.e., absorption and reduced scattering coefficients) from reflected or transmitted light. Such optical parameters, in turn, provide detailed information regarding both the concentrations of clinically relevant chromophores and macroscopic structural variations in tissue. We couple a noncontact optical setup with a simple analysis algorithm to obtain absorption and scattering coefficients of biological samples under test. Technically, a portable picoprojector projects serial sinusoidal patterns at low and high spatial frequencies, while a spectrometer and two independent CCD cameras simultaneously acquire the reflected diffuse light through a single spectrometer and two separate CCD cameras having different bandpass filters at nonisosbestic and isosbestic wavelengths in front of each. This configuration fills the gaps in each other’s capabilities for acquiring optical properties of tissue at high spectral and spatial resolution. Experiments were performed on both tissue-mimicking phantoms as well as hands of healthy human volunteers to quantify their optical properties as proof of concept for the present technique. In a separate experiment, we derived the optical properties of the hand skin from the measured diffuse reflectance, based on a recently developed camera model. Additionally, oxygen saturation levels of tissue measured by the system were found to agree well with reference values. Taken together, the present results demonstrate the potential of this integrated setup for diagnostic and research applications.
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Affiliation(s)
- Daniel Baruch
- Ariel University, Department of Electrical and Electronics Engineering, Ariel, IsraelbAriel University, Department of Physics, Ariel, Israel
| | - David Abookasis
- Ariel University, Department of Electrical and Electronics Engineering, Ariel, Israel
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20
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Saager RB, Sharif A, Kelly KM, Durkin AJ. In vivo isolation of the effects of melanin from underlying hemodynamics across skin types using spatial frequency domain spectroscopy. JOURNAL OF BIOMEDICAL OPTICS 2016; 21:57001. [PMID: 27143641 PMCID: PMC4890358 DOI: 10.1117/1.jbo.21.5.057001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/23/2015] [Accepted: 04/13/2016] [Indexed: 05/03/2023]
Abstract
Skin is a highly structured tissue, raising concerns as to whether skin pigmentation due to epidermal melanin may confound accurate measurements of underlying hemodynamics. Using both venous and arterial cuff occlusions as a means of inducing differential hemodynamic perturbations, we present analyses of spectra limited to the visible or near-infrared regime, in addition to a layered model approach. The influence of melanin, spanning Fitzpatrick skin types I to V, on underlying estimations of hemodynamics in skin as interpreted by these spectral regions are assessed. The layered model provides minimal cross-talk between melanin and hemodynamics and enables removal of problematic correlations between measured tissue oxygenation estimates and skin phototype.
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Affiliation(s)
- Rolf B. Saager
- University of California, Irvine, Beckman Laser Institute and Medical Clinic, 1002 Health Sciences Road East, Irvine, California 92612, United States
- Address all correspondence to: Rolf B. Saager, E-mail:
| | - Ata Sharif
- University of California, Irvine, Beckman Laser Institute and Medical Clinic, 1002 Health Sciences Road East, Irvine, California 92612, United States
| | - Kristen M. Kelly
- University of California, Irvine, Beckman Laser Institute and Medical Clinic, 1002 Health Sciences Road East, Irvine, California 92612, United States
- University of California, Irvine, Department of Dermatology, 118 Medical Surge 1, Irvine, California 92697, United States
| | - Anthony J. Durkin
- University of California, Irvine, Beckman Laser Institute and Medical Clinic, 1002 Health Sciences Road East, Irvine, California 92612, United States
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21
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Yang B, Lesicko J, Moy A, Reichenberg J, Sacks M, Tunnell JW. Color structured light imaging of skin. JOURNAL OF BIOMEDICAL OPTICS 2016; 21:50503. [PMID: 27207112 PMCID: PMC4890357 DOI: 10.1117/1.jbo.21.5.050503] [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: 02/22/2016] [Accepted: 04/27/2016] [Indexed: 05/17/2023]
Abstract
We illustrate wide-field imaging of skin using a structured light (SL) approach that highlights the contrast from superficial tissue scattering. Setting the spatial frequency of the SL in a regime that limits the penetration depth effectively gates the image for photons that originate from the skin surface. Further, rendering the SL images in a color format provides an intuitive format for viewing skin pathologies. We demonstrate this approach in skin pathologies using a custom-built handheld SL imaging system.
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Affiliation(s)
- Bin Yang
- University of Texas at Austin, Biophotonics Laboratory, Department of Biomedical Engineering, 107 West Dean Keeton Street Stop C0800, Austin, Texas 78712, United States
| | - John Lesicko
- University of Texas at Austin, Biomechanics Experimental Lab, Department of Biomedical Engineering, 107 West Dean Keeton Street Stop C0800, Austin, Texas 78712, United States
| | - Austin Moy
- University of Texas at Austin, Biophotonics Laboratory, Department of Biomedical Engineering, 107 West Dean Keeton Street Stop C0800, Austin, Texas 78712, United States
| | - Jason Reichenberg
- University of Texas at Austin, Dell Medical School, 1912 Speedway, Austin, Texas 78712, United States
| | - Michael Sacks
- University of Texas at Austin, Biomechanics Experimental Lab, Department of Biomedical Engineering, 107 West Dean Keeton Street Stop C0800, Austin, Texas 78712, United States
| | - James W. Tunnell
- University of Texas at Austin, Biophotonics Laboratory, Department of Biomedical Engineering, 107 West Dean Keeton Street Stop C0800, Austin, Texas 78712, United States
- Address all correspondence to: James W. Tunnell, E-mail:
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22
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Abookasis D, Volkov B, Shochat A, Kofman I. Noninvasive assessment of hemodynamic and brain metabolism parameters following closed head injury in a mouse model by comparative diffuse optical reflectance approaches. NEUROPHOTONICS 2016; 3:025003. [PMID: 27175372 PMCID: PMC4860005 DOI: 10.1117/1.nph.3.2.025003] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/23/2016] [Accepted: 04/12/2016] [Indexed: 05/03/2023]
Abstract
Optical techniques have gained substantial interest over the past four decades for biomedical imaging due to their unique advantages, which may suggest their use as alternatives to conventional methodologies. Several optical techniques have been successfully adapted to clinical practice and biomedical research to monitor tissue structure and function in both humans and animal models. This paper reviews the analysis of the optical properties of brain tissue in the wavelength range between 500 and 1000 nm by three different diffuse optical reflectance methods: spatially modulated illumination, orthogonal diffuse light spectroscopy, and dual-wavelength laser speckle imaging, to monitor changes in brain tissue morphology, chromophore content, and metabolism following head injury. After induction of closed head injury upon anesthetized mice by weight-drop method, significant changes in hemoglobin oxygen saturation, blood flow, and metabolism were readily detectible by all three optical setups, up to 1 h post-trauma. Furthermore, the experimental results clearly demonstrate the feasibility and reliability of the three methodologies, and the differences between the system performances and capabilities are also discussed. The long-term goal of this line of study is to combine these optical systems to study brain pathophysiology in high spatiotemporal resolution using additional models of brain trauma. Such combined use of complementary algorithms should fill the gaps in each system's capabilities, toward the development of a noninvasive, quantitative tool to expand our knowledge of the principles underlying brain function following trauma, and to monitor the efficacy of therapeutic interventions in the clinic.
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Affiliation(s)
- David Abookasis
- Ariel University, Department of Electrical and Electronics Engineering, Ariel 40700, Israel
- Address all correspondence to: David Abookasis, E-mail:
| | - Boris Volkov
- Ariel University, Department of Electrical and Electronics Engineering, Ariel 40700, Israel
| | - Ariel Shochat
- Ariel University, Department of Electrical and Electronics Engineering, Ariel 40700, Israel
| | - Itamar Kofman
- Ariel University, Department of Electrical and Electronics Engineering, Ariel 40700, Israel
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