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Iftimia N, Ferguson RD, Mujat M, Patel AH, Zhang EZ, Fox W, Rajadhyaksha M. Combined reflectance confocal microscopy/optical coherence tomography imaging for skin burn assessment. BIOMEDICAL OPTICS EXPRESS 2013; 4:680-95. [PMID: 23667785 PMCID: PMC3646596 DOI: 10.1364/boe.4.000680] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/29/2013] [Revised: 03/13/2013] [Accepted: 03/18/2013] [Indexed: 05/18/2023]
Abstract
A combined high-resolution reflectance confocal microscopy (RCM)/optical coherence tomography (OCT) instrument for assessing skin burn gravity has been built and tested. This instruments allows for visualizing skin intracellular details with submicron resolution in the RCM mode and morphological and birefringence modifications to depths on the order of 1.2 mm in the OCT mode. Preliminary testing of the dual modality imaging approach has been performed on the skin of volunteers with some burn scars and on normal and thermally-injured Epiderm FTTM skin constructs. The initial results show that these two optical technologies have complementary capabilities that can offer the clinician a set of clinically comprehensive parameters: OCT helps to visualize deeper burn injuries and possibly quantify collagen destruction by measuring skin birefringence, while RCM provides submicron details of the integrity of the epidermal layer and identifies the presence of the superficial blood flow in the upper dermis. Therefore, the combination of these two technologies within the same instrument may provide a more comprehensive set of parameters that may help clinicians to more objectively and nonivasively assess burn injury gravity by determining tissue structural integrity and viability.
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Affiliation(s)
| | | | | | | | - Ellen Ziyi Zhang
- Wellman Center for Photomedicine, Massachusetts General Hospital, Boston, MA 02144, USA
| | | | - Milind Rajadhyaksha
- Dermatology Service, Memorial Sloan-Kettering Cancer Center, New York, NY 10021, USA
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52
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Yousefi S, Qin J, Zhi Z, Wang RK. Uniform enhancement of optical micro-angiography images using Rayleigh contrast-limited adaptive histogram equalization. Quant Imaging Med Surg 2013; 3:5-17. [PMID: 23482880 DOI: 10.3978/j.issn.2223-4292.2013.01.01] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2012] [Accepted: 01/24/2013] [Indexed: 11/14/2022]
Abstract
Optical microangiography is an imaging technology that is capable of providing detailed functional blood flow maps within microcirculatory tissue beds in vivo. Some practical issues however exist when displaying and quantifying the microcirculation that perfuses the scanned tissue volume. These issues include: (I) Probing light is subject to specular reflection when it shines onto sample. The unevenness of the tissue surface makes the light energy entering the tissue not uniform over the entire scanned tissue volume. (II) The biological tissue is heterogeneous in nature, meaning the scattering and absorption properties of tissue would attenuate the probe beam. These physical limitations can result in local contrast degradation and non-uniform micro-angiogram images. In this paper, we propose a post-processing method that uses Rayleigh contrast-limited adaptive histogram equalization to increase the contrast and improve the overall appearance and uniformity of optical micro-angiograms without saturating the vessel intensity and changing the physical meaning of the micro-angiograms. The qualitative and quantitative performance of the proposed method is compared with those of common histogram equalization and contrast enhancement methods. We demonstrate that the proposed method outperforms other existing approaches. The proposed method is not limited to optical microangiography and can be used in other image modalities such as photo-acoustic tomography and scanning laser confocal microscopy.
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Affiliation(s)
- Siavash Yousefi
- University of Washington, Department of Bioengineering, Seattle, Washington 98195, USA
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53
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Jung Y, Dziennis S, Zhi Z, Reif R, Zheng Y, Wang RK. Tracking dynamic microvascular changes during healing after complete biopsy punch on the mouse pinna using optical microangiography. PLoS One 2013; 8:e57976. [PMID: 23469122 PMCID: PMC3585416 DOI: 10.1371/journal.pone.0057976] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2012] [Accepted: 01/29/2013] [Indexed: 12/29/2022] Open
Abstract
Optical microangiography (OMAG) and Doppler optical microangiography (DOMAG) are two non-invasive techniques capable of determining the tissue microstructural content, microvasculature angiography, and blood flow velocity and direction. These techniques were used to visualize the acute and chronic microvascular and tissue responses upon an injury in vivo. A tissue wound was induced using a 0.5 mm biopsy punch on a mouse pinna. The changes in the microangiography, blood flow velocity and direction were quantified for the acute (<30 min) wound response and the changes in the tissue structure and microangiography were determined for the chronic wound response (30 min–60 days). The initial wound triggered recruitment of peripheral capillaries, as well as redirection of main arterial and venous blood flow within 3 min. The complex vascular networks and new vessel formation were quantified during the chronic response using fractal dimension. The highest rate of wound closure occurred between days 8 and 22. The vessel tortuosity increased during this time suggesting angiogenesis. Taken together, these data signify that OMAG has the capability to track acute and chronic changes in blood flow, microangiography and structure during wound healing. The use of OMAG has great potential to improve our understanding of vascular and tissue responses to injury in order to develop more effective therapeutics.
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Affiliation(s)
- Yeongri Jung
- Department of Bioengineering, University of Washington, Seattle, Washington, United States of America
| | - Suzan Dziennis
- Department of Bioengineering, University of Washington, Seattle, Washington, United States of America
| | - Zhongwei Zhi
- Department of Bioengineering, University of Washington, Seattle, Washington, United States of America
| | - Roberto Reif
- Department of Bioengineering, University of Washington, Seattle, Washington, United States of America
| | - Ying Zheng
- Department of Bioengineering, University of Washington, Seattle, Washington, United States of America
| | - Ruikang K. Wang
- Department of Bioengineering, University of Washington, Seattle, Washington, United States of America
- * E-mail:
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54
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Yousefi S, Qin J, Zhi Z, Wang RK. Uniform enhancement of optical micro-angiography images using Rayleigh contrast-limited adaptive histogram equalization. Quant Imaging Med Surg 2013; 3:5-17. [PMID: 23482880 DOI: 10.3978/2fj.issn.2223-4292.2013.01.01] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2012] [Accepted: 01/24/2013] [Indexed: 05/22/2023]
Abstract
Optical microangiography is an imaging technology that is capable of providing detailed functional blood flow maps within microcirculatory tissue beds in vivo. Some practical issues however exist when displaying and quantifying the microcirculation that perfuses the scanned tissue volume. These issues include: (I) Probing light is subject to specular reflection when it shines onto sample. The unevenness of the tissue surface makes the light energy entering the tissue not uniform over the entire scanned tissue volume. (II) The biological tissue is heterogeneous in nature, meaning the scattering and absorption properties of tissue would attenuate the probe beam. These physical limitations can result in local contrast degradation and non-uniform micro-angiogram images. In this paper, we propose a post-processing method that uses Rayleigh contrast-limited adaptive histogram equalization to increase the contrast and improve the overall appearance and uniformity of optical micro-angiograms without saturating the vessel intensity and changing the physical meaning of the micro-angiograms. The qualitative and quantitative performance of the proposed method is compared with those of common histogram equalization and contrast enhancement methods. We demonstrate that the proposed method outperforms other existing approaches. The proposed method is not limited to optical microangiography and can be used in other image modalities such as photo-acoustic tomography and scanning laser confocal microscopy.
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Affiliation(s)
- Siavash Yousefi
- University of Washington, Department of Bioengineering, Seattle, Washington 98195, USA
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55
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Blatter C, Weingast J, Alex A, Grajciar B, Wieser W, Drexler W, Huber R, Leitgeb RA. In situ structural and microangiographic assessment of human skin lesions with high-speed OCT. BIOMEDICAL OPTICS EXPRESS 2012; 3:2636-46. [PMID: 23082302 PMCID: PMC3469999 DOI: 10.1364/boe.3.002636] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/03/2012] [Revised: 08/30/2012] [Accepted: 09/11/2012] [Indexed: 05/17/2023]
Abstract
We demonstrate noninvasive structural and microvascular contrast imaging of different human skin diseases in vivo using an intensity difference analysis of OCT tomograms. The high-speed swept source OCT system operates at 1310 nm with 220 kHz A-scan rate. It provides an extended focus by employing a Bessel beam. The studied lesions were two cases of dermatitis and two cases of basal cell carcinoma. The lesions show characteristic vascular patterns that are significantly different from healthy skin. In case of inflammation, vessels are dilated and perfusion is increased. In case of basal cell carcinoma, the angiogram shows a denser network of unorganized vessels with large vessels close to the skin surface. Those results indicate that assessing vascular changes yields complementary information with important insight into the metabolic demand.
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Affiliation(s)
- Cedric Blatter
- Center of Medical Physics and Biomedical Engineering, Medical
University Vienna, Waehringer Guertel 18-20, 1090 Vienna, Austria
| | - Jessika Weingast
- Department of Dermatology, Division of General Dermatology,
Medical University Vienna, Waehringer Guertel 18-20, 1090 Vienna,
Austria
| | - Aneesh Alex
- Center of Medical Physics and Biomedical Engineering, Medical
University Vienna, Waehringer Guertel 18-20, 1090 Vienna, Austria
| | - Branislav Grajciar
- Center of Medical Physics and Biomedical Engineering, Medical
University Vienna, Waehringer Guertel 18-20, 1090 Vienna, Austria
| | - Wolfgang Wieser
- Lehrstuhl für BioMolekulare Optik,
Ludwig-Maximilians-Universität München, Oettingenstraße 67, 80538 Munich,
Germany
| | - Wolfgang Drexler
- Center of Medical Physics and Biomedical Engineering, Medical
University Vienna, Waehringer Guertel 18-20, 1090 Vienna, Austria
| | - Robert Huber
- Lehrstuhl für BioMolekulare Optik,
Ludwig-Maximilians-Universität München, Oettingenstraße 67, 80538 Munich,
Germany
| | - Rainer A. Leitgeb
- Center of Medical Physics and Biomedical Engineering, Medical
University Vienna, Waehringer Guertel 18-20, 1090 Vienna, Austria
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56
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Reif R, Wang RK. Label-free imaging of blood vessel morphology with capillary resolution using optical microangiography. Quant Imaging Med Surg 2012; 2:207-12. [PMID: 23256081 PMCID: PMC3496511 DOI: 10.3978/j.issn.2223-4292.2012.08.01] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2012] [Accepted: 08/07/2012] [Indexed: 01/26/2023]
Abstract
Several tissue pathologies are correlated with changes in the blood vessel morphology and microcirculation that supplies the tissue. Optical coherence tomography (OCT) is an imaging technique that enables acquiring non-invasive three-dimensional images of biological structures with micrometer resolution. Optical microangiography (OMAG) is a method of processing OCT data which enables visualizing the three-dimensional blood vessel morphology within biological tissues. OMAG has high spatial resolution which allows visualizing single capillary vessels, and does not require the use of contrast agents. The intrinsic optical signals backscattered by the moving blood cells inside blood vessels are used as the contrast for which OMAG images are based on. In this paper, we discuss a brief review of the OMAG theory, and present some examples of applications for this technique.
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Affiliation(s)
- Roberto Reif
- University of Washington, Department of Bioengineering, Seattle, Washington 98195, USA
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57
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Quantifying optical microangiography images obtained from a spectral domain optical coherence tomography system. Int J Biomed Imaging 2012; 2012:509783. [PMID: 22792084 PMCID: PMC3389716 DOI: 10.1155/2012/509783] [Citation(s) in RCA: 133] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2012] [Accepted: 04/13/2012] [Indexed: 02/07/2023] Open
Abstract
The blood vessel morphology is known to correlate with several diseases, such as cancer, and is important for describing several tissue physiological processes, like angiogenesis. Therefore, a quantitative method for characterizing the angiography obtained from medical images would have several clinical applications. Optical microangiography (OMAG) is a method for obtaining three-dimensional images of blood vessels within a volume of tissue. In this study we propose to quantify OMAG images obtained with a spectral domain optical coherence tomography system. A technique for determining three measureable parameters (the fractal dimension, the vessel length fraction, and the vessel area density) is proposed and validated. Finally, the repeatability for acquiring OMAG images is determined, and a new method for analyzing small areas from these images is proposed.
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58
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Qin J, Reif R, Zhi Z, Dziennis S, Wang R. Hemodynamic and morphological vasculature response to a burn monitored using a combined dual-wavelength laser speckle and optical microangiography imaging system. BIOMEDICAL OPTICS EXPRESS 2012; 3:455-66. [PMID: 22435094 PMCID: PMC3296534 DOI: 10.1364/boe.3.000455] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/10/2011] [Revised: 01/14/2012] [Accepted: 01/16/2012] [Indexed: 05/03/2023]
Abstract
A multi-functional imaging system capable of determining relative changes in blood flow, hemoglobin concentration, and morphological features of the blood vasculature is demonstrated. The system combines two non-invasive imaging techniques, a dual-wavelength laser speckle contrast imaging (2-LSI) and an optical microangiography (OMAG) system. 2-LSI is used to monitor the changes in the dynamic blood flow and the changes in the concentration of oxygenated (HbO), deoxygenated (Hb) and total hemoglobin (HbT). The OMAG system is used to acquire high resolution images of the functional blood vessel network. The vessel area density (VAD) is used to quantify the blood vessel network morphology, specifically the capillary recruitment. The proposed multi-functional system is employed to assess the blood perfusion status from a mouse pinna before and immediately after a burn injury. To our knowledge, this is the first non-invasive, non-contact and multifunctional imaging modality that can simultaneously measure variations of several blood perfusion parameters.
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Affiliation(s)
- Jia Qin
- Department of Bioengineering, University of Washington, 3720 15th Avenue NE, Seattle, Washington 98195, USA
- These authors contributed equally to this work
| | - Roberto Reif
- Department of Bioengineering, University of Washington, 3720 15th Avenue NE, Seattle, Washington 98195, USA
- These authors contributed equally to this work
| | - Zhongwei Zhi
- Department of Bioengineering, University of Washington, 3720 15th Avenue NE, Seattle, Washington 98195, USA
| | - Suzan Dziennis
- Department of Bioengineering, University of Washington, 3720 15th Avenue NE, Seattle, Washington 98195, USA
| | - Ruikang Wang
- Department of Bioengineering, University of Washington, 3720 15th Avenue NE, Seattle, Washington 98195, USA
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