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Kim Y, Choi WJ, Oh J, Lee K, Kim JK. Smartphone-Based Rigid Endoscopy Device with Hemodynamic Response Imaging and Laser Speckle Contrast Imaging. BIOSENSORS 2023; 13:816. [PMID: 37622902 PMCID: PMC10452712 DOI: 10.3390/bios13080816] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/11/2023] [Revised: 08/11/2023] [Accepted: 08/13/2023] [Indexed: 08/26/2023]
Abstract
Modern smartphones have been employed as key elements in point-of-care (POC) devices due to remarkable advances in their form factor, computing, and display performances. Recently, we reported a combination of the smartphone with a handheld endoscope using laser speckle contrast imaging (LSCI), suggesting potential for functional POC endoscopy. Here, we extended our work to develop a smartphone-combined multifunctional handheld endoscope using dual-wavelength LSCI. Dual-wavelength LSCI is used to monitor the changes in dynamic blood flow as well as changes in the concentration of oxygenated (HbO2), deoxygenated (Hbr), and total hemoglobin (HbT). The smartphone in the device performs fast acquisition and computation of the raw LSCI data to map the blood perfusion parameters. The flow imaging performance of the proposed device was tested with a tissue-like flow phantom, exhibiting a speckle flow index map representing the blood perfusion. Furthermore, the device was employed to assess the blood perfusion status from an exteriorized intestine model of rat in vivo during and after local ischemia, showing that blood flow and HbO2 gradually decreased in the ischemic region whereas hyperemia and excess increases in HbO2 were observed in the same region right after reperfusion. The results indicate that the combination of LSCI with smartphone endoscopy delivers a valuable platform for better understanding of the functional hemodynamic changes in the vasculatures of the internal organs, which may benefit POC testing for diagnosis and treatment of vascular diseases.
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Affiliation(s)
- Youngkyu Kim
- Biomedical Engineering Research Center, Asan Medical Center, Seoul 05505, Republic of Korea;
| | - Woo June Choi
- School of Electrical and Electronics Engineering, Chung-Ang University, Seoul 06974, Republic of Korea;
| | - Jeongmin Oh
- Department of Biomedical Engineering, College of Medicine, University of Ulsan, Seoul 05505, Republic of Korea; (J.O.); (K.L.)
| | - Kwanhee Lee
- Department of Biomedical Engineering, College of Medicine, University of Ulsan, Seoul 05505, Republic of Korea; (J.O.); (K.L.)
| | - Jun Ki Kim
- Biomedical Engineering Research Center, Asan Medical Center, Seoul 05505, Republic of Korea;
- Department of Biomedical Engineering, College of Medicine, University of Ulsan, Seoul 05505, Republic of Korea; (J.O.); (K.L.)
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Wang HL, Chen JW, Yang SH, Lo YC, Pan HC, Liang YW, Wang CF, Yang Y, Kuo YT, Lin YC, Chou CY, Lin SH, Chen YY. Multimodal Optical Imaging to Investigate Spatiotemporal Changes in Cerebrovascular Function in AUDA Treatment of Acute Ischemic Stroke. Front Cell Neurosci 2021; 15:655305. [PMID: 34149359 PMCID: PMC8209306 DOI: 10.3389/fncel.2021.655305] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2021] [Accepted: 05/10/2021] [Indexed: 01/03/2023] Open
Abstract
Administration of 12-(3-adamantan-1-yl-ureido)-dodecanoic acid (AUDA) has been demonstrated to alleviate infarction following ischemic stroke. Reportedly, the main effect of AUDA is exerting anti-inflammation and neovascularization via the inhibition of soluble epoxide hydrolase. However, the major contribution of this anti-inflammation and neovascularization effect in the acute phase of stroke is not completely elucidated. To investigate the neuroprotective effects of AUDA in acute ischemic stroke, we combined laser speckle contrast imaging and optical intrinsic signal imaging techniques with the implantation of a lab-designed cranial window. Forepaw stimulation was applied to assess the functional changes via measuring cerebral metabolic rate of oxygen (CMRO2) that accompany neural activity. The rats that received AUDA in the acute phase of photothrombotic ischemia stroke showed a 30.5 ± 8.1% reduction in the ischemic core, 42.3 ± 15.1% reduction in the ischemic penumbra (p < 0.05), and 42.1 ± 4.6% increase of CMRO2 in response to forepaw stimulation at post-stroke day 1 (p < 0.05) compared with the control group (N = 10 for each group). Moreover, at post-stroke day 3, increased functional vascular density was observed in AUDA-treated rats (35.9 ± 1.9% higher than that in the control group, p < 0.05). At post-stroke day 7, a 105.4% ± 16.4% increase of astrocytes (p < 0.01), 30.0 ± 10.9% increase of neurons (p < 0.01), and 65.5 ± 15.0% decrease of microglia (p < 0.01) were observed in the penumbra region in AUDA-treated rats (N = 5 for each group). These results suggested that AUDA affects the anti-inflammation at the beginning of ischemic injury and restores neuronal metabolic rate of O2 and tissue viability. The neovascularization triggered by AUDA restored CBF and may contribute to ischemic infarction reduction at post-stroke day 3. Moreover, for long-term neuroprotection, astrocytes in the penumbra region may play an important role in protecting neurons from apoptotic injury.
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Affiliation(s)
- Han-Lin Wang
- Department of Biomedical Engineering, National Yang Ming Chiao Tung University, Taipei, Taiwan
| | - Jia-Wei Chen
- Department of Biomedical Engineering, National Yang Ming Chiao Tung University, Taipei, Taiwan
| | - Shih-Hung Yang
- Department of Mechanical Engineering, National Cheng Kung University, Tainan, Taiwan
| | - Yu-Chun Lo
- The Ph.D. Program for Neural Regenerative Medicine, College of Medical Science and Technology, Taipei Medical University, Taipei, Taiwan
| | - Han-Chi Pan
- National Laboratory Animal Center, Taipei, Taiwan
| | - Yao-Wen Liang
- Department of Biomedical Engineering, National Yang Ming Chiao Tung University, Taipei, Taiwan
| | - Ching-Fu Wang
- Department of Biomedical Engineering, National Yang Ming Chiao Tung University, Taipei, Taiwan
| | - Yi Yang
- Department of Biomedical Engineering, National Yang Ming Chiao Tung University, Taipei, Taiwan
| | - Yun-Ting Kuo
- Department of Biomedical Engineering, National Yang Ming Chiao Tung University, Taipei, Taiwan
| | - Yi-Chen Lin
- Department of Biomedical Engineering, National Yang Ming Chiao Tung University, Taipei, Taiwan
| | - Chin-Yu Chou
- Department of Biomedical Engineering, National Yang Ming Chiao Tung University, Taipei, Taiwan
| | - Sheng-Huang Lin
- Department of Neurology, Hualien Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, Hualien, Taiwan.,Department of Neurology, School of Medicine, Tzu Chi University, Hualien, Taiwan
| | - You-Yin Chen
- Department of Biomedical Engineering, National Yang Ming Chiao Tung University, Taipei, Taiwan.,The Ph.D. Program for Neural Regenerative Medicine, College of Medical Science and Technology, Taipei Medical University, Taipei, Taiwan
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Heeman W, Steenbergen W, van Dam GM, Boerma EC. Clinical applications of laser speckle contrast imaging: a review. JOURNAL OF BIOMEDICAL OPTICS 2019; 24:1-11. [PMID: 31385481 PMCID: PMC6983474 DOI: 10.1117/1.jbo.24.8.080901] [Citation(s) in RCA: 124] [Impact Index Per Article: 24.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/15/2019] [Accepted: 07/02/2019] [Indexed: 05/02/2023]
Abstract
When a biological tissue is illuminated with coherent light, an interference pattern will be formed at the detector, the so-called speckle pattern. Laser speckle contrast imaging (LSCI) is a technique based on the dynamic change in this backscattered light as a result of interaction with red blood cells. It can be used to visualize perfusion in various tissues and, even though this technique has been extensively described in the literature, the actual clinical implementation lags behind. We provide an overview of LSCI as a tool to image tissue perfusion. We present a brief introduction to the theory, review clinical studies from various medical fields, and discuss current limitations impeding clinical acceptance.
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Affiliation(s)
- Wido Heeman
- University of Groningen, Faculty Campus Fryslân, Leeuwarden, The Netherlands
- University Medical Centre Groningen, Department of Surgery, Optical Molecular Imaging Groningen, Groningen, The Netherlands
- LIMIS Development BV, Leeuwarden, The Netherlands
| | - Wiendelt Steenbergen
- University of Twente, Techmed Center, Faculty of Science and Technology, Biomedical Photonic Imaging Group, Enschede, The Netherlands
| | - Gooitzen M. van Dam
- University Medical Centre Groningen, Department of Surgery, Optical Molecular Imaging Groningen, Groningen, The Netherlands
| | - E. Christiaan Boerma
- Medical Centre Leeuwarden, Department of Intensive Care, Leeuwarden, The Netherlands
- Address all correspondence to E. Christiaan Boerma, E-mail:
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Liu Q, Chen S, Soetikno B, Liu W, Tong S, Zhang HF. Monitoring Acute Stroke in Mouse Model Using Laser Speckle Imaging-Guided Visible-Light Optical Coherence Tomography. IEEE Trans Biomed Eng 2017; 65:2136-2142. [PMID: 28541195 DOI: 10.1109/tbme.2017.2706976] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
OBJECTIVE Monitoring hemodynamic and vascular changes in the acute stages of mouse stroke models is invaluable in studying ischemic stroke pathophysiology. However, there lacks a tool to simultaneously and dynamically investigate these changes. METHODS We integrated laser speckle imaging (LSI) and visible-light optical coherence tomography (Vis-OCT) to reveal dynamic vascular responses in acute stages in the distal middle cerebral artery occlusion (dMCAO) model in rodents. LSI provides full-field, real-time imaging to guide Vis-OCT imaging and monitor the dynamic cerebral blood flow (CBF). Vis-OCT offers depth-resolved angiography and oxygen saturation (sO2) measurements. RESULTS Our results showed detailed CBF and vasculature changes before, during, and after dMCAO. After dMCAO, we observed insignificant sO2 variation in arteries and arterioles and location-dependent sO2 drop in veins and venules. We observed that higher branch-order veins had larger drops in sO2 at the reperfusion stage after dMCAO. CONCLUSION This work suggests that integrated LSI and Vis-OCT is a promising tool for investigating ischemic stroke in mouse models. SIGNIFICANCE For the first time, LSI and Vis-OCT are integrated to investigate ischemic strokes in rodent models.
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Chen CL, Wang RK. Optical coherence tomography based angiography [Invited]. BIOMEDICAL OPTICS EXPRESS 2017; 8:1056-1082. [PMID: 28271003 PMCID: PMC5330554 DOI: 10.1364/boe.8.001056] [Citation(s) in RCA: 269] [Impact Index Per Article: 38.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/01/2016] [Accepted: 01/16/2017] [Indexed: 05/18/2023]
Abstract
Optical coherence tomography (OCT)-based angiography (OCTA) provides in vivo, three-dimensional vascular information by the use of flowing red blood cells as intrinsic contrast agents, enabling the visualization of functional vessel networks within microcirculatory tissue beds non-invasively, without a need of dye injection. Because of these attributes, OCTA has been rapidly translated to clinical ophthalmology within a short period of time in the development. Various OCTA algorithms have been developed to detect the functional micro-vasculatures in vivo by utilizing different components of OCT signals, including phase-signal-based OCTA, intensity-signal-based OCTA and complex-signal-based OCTA. All these algorithms have shown, in one way or another, their clinical values in revealing micro-vasculatures in biological tissues in vivo, identifying abnormal vascular networks or vessel impairment zones in retinal and skin pathologies, detecting vessel patterns and angiogenesis in eyes with age-related macular degeneration and in skin and brain with tumors, and monitoring responses to hypoxia in the brain tissue. The purpose of this paper is to provide a technical oriented overview of the OCTA developments and their potential pre-clinical and clinical applications, and to shed some lights on its future perspectives. Because of its clinical translation to ophthalmology, this review intentionally places a slightly more weight on ophthalmic OCT angiography.
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Affiliation(s)
- Chieh-Li Chen
- Department of Bioengineering, University of Washington, 3720 15th Ave NE, Seattle, WA 98195, USA
- Department of Ophthalmology, University of Washington, 325 9th Ave, Seattle, WA 98104, USA
| | - Ruikang K. Wang
- Department of Bioengineering, University of Washington, 3720 15th Ave NE, Seattle, WA 98195, USA
- Department of Ophthalmology, University of Washington, 325 9th Ave, Seattle, WA 98104, USA
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6
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Liao R, Wang M, Han D, Huang Z, Zeng Y. High-temporal-resolution, full-field optical angiography based on short-time modulation depth for vascular occlusion tests. JOURNAL OF BIOMEDICAL OPTICS 2016; 21:86002. [PMID: 27490222 DOI: 10.1117/1.jbo.21.8.086002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/25/2016] [Accepted: 07/19/2016] [Indexed: 06/06/2023]
Abstract
We developed high-temporal-resolution, full-field optical angiography for use in vascular occlusion tests (VOTs). In the proposed method, undersampled signals are acquired by a high-speed digital camera that separates the dynamic and static speckle signals. The two types of speckle signal are used to calculate the short-time modulation depth (STMD) of each of the camera pixels. STMD is then used to realize high-temporal-resolution, full-field optical angiography. Phantom and biological experiments conducted and demonstrated the feasibility of using our proposed method to perform VOTs and to study the reaction kinetics in microfluidic systems.
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Affiliation(s)
- Riwei Liao
- Foshan University, Department of Photoelectric Technology, Foshan 528000, ChinabSouth China Normal University, School of Physics and Telecommunication, Guangzhou 510006, China
| | - Mingyi Wang
- Foshan University, Department of Photoelectric Technology, Foshan 528000, China
| | - Dingan Han
- Foshan University, Department of Photoelectric Technology, Foshan 528000, China
| | - Zuohua Huang
- South China Normal University, School of Physics and Telecommunication, Guangzhou 510006, China
| | - Yaguang Zeng
- Foshan University, Department of Photoelectric Technology, Foshan 528000, China
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External Compression Versus Intravascular Injection: A Mechanistic Animal Model of Filler-Induced Tissue Ischemia. Ophthalmic Plast Reconstr Surg 2016; 32:261-6. [DOI: 10.1097/iop.0000000000000484] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Liu J, Ma Y, Dou S, Wang Y, La D, Liu J, Ma Z. Hemodynamic changes in a rat parietal cortex after endothelin-1-induced middle cerebral artery occlusion monitored by optical coherence tomography. JOURNAL OF BIOMEDICAL OPTICS 2016; 21:75014. [PMID: 27469083 DOI: 10.1117/1.jbo.21.7.075014] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/09/2016] [Accepted: 07/11/2016] [Indexed: 05/14/2023]
Abstract
A blockage of the middle cerebral artery (MCA) on the cortical branch will seriously affect the blood supply of the cerebral cortex. Real-time monitoring of MCA hemodynamic parameters is critical for therapy and rehabilitation. Optical coherence tomography (OCT) is a powerful imaging modality that can produce not only structural images but also functional information on the tissue. We use OCT to detect hemodynamic changes after MCA branch occlusion. We injected a selected dose of endothelin-1 (ET-1) at a depth of 1 mm near the MCA and let the blood vessels follow a process first of occlusion and then of slow reperfusion as realistically as possible to simulate local cerebral ischemia. During this period, we used optical microangiography and Doppler OCT to obtain multiple hemodynamic MCA parameters. The change trend of these parameters from before to after ET-1 injection clearly reflects the dynamic regularity of the MCA. These results show the mechanism of the cerebral ischemia-reperfusion process after a transient middle cerebral artery occlusion and confirm that OCT can be used to monitor hemodynamic parameters.
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Affiliation(s)
- Jian Liu
- Northeastern University, School of Information Science and Engineering, No. 11 Lane Three Culture Road, Heping Area, Shenyang 110819, China
| | - Yushu Ma
- Northeastern University, School of Information Science and Engineering, No. 11 Lane Three Culture Road, Heping Area, Shenyang 110819, China
| | - Shidan Dou
- Northeastern University, School of Information Science and Engineering, No. 11 Lane Three Culture Road, Heping Area, Shenyang 110819, China
| | - Yi Wang
- Northeastern University, School of Information Science and Engineering, No. 11 Lane Three Culture Road, Heping Area, Shenyang 110819, China
| | - Dongsheng La
- Northeastern University, School of Information Science and Engineering, No. 11 Lane Three Culture Road, Heping Area, Shenyang 110819, China
| | - Jianghong Liu
- Capital Medical University, Department of Neurology, Xuan Wu Hospital, No. 45 Changchun Street, Xicheng District, Beijing 100053, China
| | - Zhenhe Ma
- Northeastern University, School of Information Science and Engineering, No. 11 Lane Three Culture Road, Heping Area, Shenyang 110819, China
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9
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Sakamoto M, Morimoto N, Ogino S, Jinno C, Kawaguchi A, Kawai K, Suzuki S. Preparation of Partial-Thickness Burn Wounds in Rodents Using a New Experimental Burning Device. Ann Plast Surg 2016; 76:652-8. [DOI: 10.1097/sap.0000000000000655] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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10
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Shi R, Chen M, Tuchin VV, Zhu D. Accessing to arteriovenous blood flow dynamics response using combined laser speckle contrast imaging and skin optical clearing. BIOMEDICAL OPTICS EXPRESS 2015; 6:1977-89. [PMID: 26114023 PMCID: PMC4473738 DOI: 10.1364/boe.6.001977] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/25/2015] [Revised: 04/24/2015] [Accepted: 04/28/2015] [Indexed: 05/18/2023]
Abstract
Laser speckle contrast imaging (LSCI) shows a great potential for monitoring blood flow, but the spatial resolution suffers from the scattering of tissue. Here, we demonstrate the capability of a combination method of LSCI and skin optical clearing to describe in detail the dynamic response of cutaneous vasculature to vasoactive noradrenaline injection. Moreover, the superior resolution, contrast and sensitivity make it possible to rebuild arteries-veins separation and quantitatively assess the blood flow dynamical changes in terms of flow velocity and vascular diameter at single artery or vein level.
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Affiliation(s)
- Rui Shi
- Britton Chance Center for Biomedical Photonics, Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan 430074, China
- MoE Key Laboratory of Biomedical Photonics, Department of Biomedical Engineering, Huazhong University of Science and Technology, Wuhan 430074, China
- These authors contributed equally to this work
| | - Min Chen
- Affiliated Hospital, Huazhong University of Science and Technology, Wuhan 430074, China
- These authors contributed equally to this work
| | - Valery V. Tuchin
- Research-Educational Institute of Optics and Biophotonics, Saratov State University, Saratov 410012, Russia
- Institute of Precise Mechanics and Control RAS, Saratov 410028, Russia
| | - Dan Zhu
- Britton Chance Center for Biomedical Photonics, Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan 430074, China
- MoE Key Laboratory of Biomedical Photonics, Department of Biomedical Engineering, Huazhong University of Science and Technology, Wuhan 430074, China
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Dziennis S, Qin J, Shi L, Wang RK. Macro-to-micro cortical vascular imaging underlies regional differences in ischemic brain. Sci Rep 2015; 5:10051. [PMID: 25941797 PMCID: PMC4419594 DOI: 10.1038/srep10051] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2014] [Accepted: 03/19/2015] [Indexed: 01/05/2023] Open
Abstract
The ability to non-invasively monitor and quantify hemodynamic responses down to the capillary level is important for improved diagnosis, treatment and management of neurovascular disorders, including stroke. We developed an integrated multi-functional imaging system, in which synchronized dual wavelength laser speckle contrast imaging (DWLS) was used as a guiding tool for optical microangiography (OMAG) to test whether detailed vascular responses to experimental stroke in male mice can be evaluated with wide range sensitivity from arteries and veins down to the capillary level. DWLS enabled rapid identification of cerebral blood flow (CBF), prediction of infarct area and hemoglobin oxygenation over the whole mouse brain and was used to guide the OMAG system to hone in on depth information regarding blood volume, blood flow velocity and direction, vascular architecture, vessel diameter and capillary density pertaining to defined regions of CBF in response to ischemia. OMAG-DWLS is a novel imaging platform technology to simultaneously evaluate multiple vascular responses to ischemic injury, which can be useful in improving our understanding of vascular responses under pathologic and physiological conditions, and ultimately facilitating clinical diagnosis, monitoring and therapeutic interventions of neurovascular diseases.
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Affiliation(s)
- Suzan Dziennis
- Department of Bioengineering, University of Washington, Seattle, Washington 98195, USA
| | - Jia Qin
- Department of Bioengineering, University of Washington, Seattle, Washington 98195, USA
| | - Lei Shi
- Department of Bioengineering, University of Washington, Seattle, Washington 98195, USA
| | - Ruikang K Wang
- Department of Bioengineering, University of Washington, Seattle, Washington 98195, USA
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Poole KM, McCormack DR, Patil CA, Duvall CL, Skala MC. Quantifying the vascular response to ischemia with speckle variance optical coherence tomography. BIOMEDICAL OPTICS EXPRESS 2014; 5:4118-30. [PMID: 25574425 PMCID: PMC4285592 DOI: 10.1364/boe.5.004118] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/15/2014] [Revised: 10/16/2014] [Accepted: 10/29/2014] [Indexed: 05/18/2023]
Abstract
Longitudinal monitoring techniques for preclinical models of vascular remodeling are critical to the development of new therapies for pathological conditions such as ischemia and cancer. In models of skeletal muscle ischemia in particular, there is a lack of quantitative, non-invasive and long term assessment of vessel morphology. Here, we have applied speckle variance optical coherence tomography (OCT) methods to quantitatively assess vascular remodeling and growth in a mouse model of peripheral arterial disease. This approach was validated on two different mouse strains known to have disparate rates and abilities of recovering following induction of hind limb ischemia. These results establish the potential for speckle variance OCT as a tool for quantitative, preclinical screening of pro- and anti-angiogenic therapies.
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Reif R, Baran U, Wang RK. Motion artifact and background noise suppression on optical microangiography frames using a naïve Bayes mask. APPLIED OPTICS 2014; 53:4164-71. [PMID: 25089975 PMCID: PMC4303031 DOI: 10.1364/ao.53.004164] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
Optical coherence tomography (OCT) is a technique that allows for the three-dimensional (3D) imaging of small volumes of tissue (a few millimeters) with high resolution (∼10 μm). Optical microangiography (OMAG) is a method of processing OCT data, which allows for the extraction of the tissue vasculature with capillary resolution from the OCT images. Cross-sectional B-frame OMAG images present the location of the patent blood vessels; however, the signal-to-noise-ratio of these images can be affected by several factors such as the quality of the OCT system and the tissue motion artifact. This background noise can appear in the en face projection view image. In this work we propose to develop a binary mask that can be applied on the cross-sectional B-frame OMAG images, which will reduce the background noise while leaving the signal from the blood vessels intact. The mask is created by using a naïve Bayes (NB) classification algorithm trained with a gold standard image which is manually segmented by an expert. The masked OMAG images present better contrast for binarizing the image and quantifying the result without the influence of noise. The results are compared with a previously developed frequency rejection filter (FRF) method which is applied on the en face projection view image. It is demonstrated that both the NB and FRF methods provide similar vessel length fractions. The advantage of the NB method is that the results are applicable in 3D and that its use is not limited to periodic motion artifacts.
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Affiliation(s)
- Roberto Reif
- Department of Bioengineering, University of Washington, 3720 15 Ave. NE, Seattle WA 98195, USA
| | - Utku Baran
- Department of Electrical Engineering, University of Washington, 185 Stevens Way, Seattle WA 98195, USA
| | - Ruikang K. Wang
- Department of Bioengineering, University of Washington, 3720 15 Ave. NE, Seattle WA 98195, USA
- Corresponding author:
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14
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Choi WJ, Wang H, Wang RK. Optical coherence tomography microangiography for monitoring the response of vascular perfusion to external pressure on human skin tissue. JOURNAL OF BIOMEDICAL OPTICS 2014; 19:056003. [PMID: 24810259 PMCID: PMC4160975 DOI: 10.1117/1.jbo.19.5.056003] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/08/2014] [Accepted: 04/16/2014] [Indexed: 05/04/2023]
Abstract
Characterization of the relationship between external pressure and blood flow is important in the examination of pressure-induced disturbance in tissue microcirculation. Optical coherence tomography (OCT)-based microangiography is a promising imaging technique, capable of providing the noninvasive extraction of functional vessels within the skin tissue with capillary-scale resolution. Here, we present a feasibility study of OCT microangiography (OMAG) to evaluate changes in blood perfusion in response to externally applied pressure on human skin tissue in vivo. External force is loaded normal to the tissue surface at the nailfold region of a healthy human volunteer. An incremental force is applied step by step and then followed by an immediate release. Skin perfusion events including baseline are continuously imaged by OMAG, allowing for visualization and quantification of the capillary perfusion in the nailfold tissue. The tissue strain maps are simultaneously evaluated through the available OCT structural images to assess the relationship of the microcirculation response to the applied pressure. The results indicate that the perfusion progressively decreases with the constant increase of pressure. Reactive hyperemia occurs right after the removal of the pressure. The perfusion returns to the baseline level after a few minutes. These findings suggest that OMAG may have great potential for quantitatively assessing tissue microcirculation in the locally pressed tissue in vivo.
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Affiliation(s)
- Woo June Choi
- University of Washington, Department of Bioengineering, Seattle, Washington 98195
| | - Hequn Wang
- University of Washington, Department of Bioengineering, Seattle, Washington 98195
| | - Ruikang K. Wang
- University of Washington, Department of Bioengineering, Seattle, Washington 98195
- Address all correspondence to: Ruikang K. Wang, E-mail:
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15
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Reif R, Yousefi S, Choi WJ, Wang RK. Analysis of cross-sectional image filters for evaluating nonaveraged optical microangiography images. APPLIED OPTICS 2014; 53:806-15. [PMID: 24663258 PMCID: PMC3978384 DOI: 10.1364/ao.53.000806] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/07/2013] [Accepted: 12/20/2013] [Indexed: 05/07/2023]
Abstract
Optical microangiography (OMAG) is a method that enables the noninvasive extraction of blood vessels within biological tissues. OMAG B-frames are prone to noise; therefore, techniques such as B-frame averaging have been applied to reduce these effects. A drawback of this method is that the total acquisition time and amount of data collected are increased; hence, the data are susceptible to motion artifacts and decorrelation. In this paper we propose using an image filter on a nonaveraged OMAG B-frame to reduce its noise. Consequently, B-frames comparable to the averaged OMAG B-frame are obtained, while reducing the total acquisition and processing time. The method is tested with two different systems, a high-resolution spectral domain and a relatively low-resolution swept-source optical coherence tomography system. It is demonstrated that the weighted average filter produces the lowest B-frame error; however, all filters produce comparable results when quantifying the en face projection view image.
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Affiliation(s)
- Roberto Reif
- Department of Bioengineering, University of Washington, 3720 15 Ave. NE, Seattle WA 98195, USA
| | - Siavash Yousefi
- Department of Bioengineering, University of Washington, 3720 15 Ave. NE, Seattle WA 98195, USA
| | - Woo June Choi
- Department of Bioengineering, University of Washington, 3720 15 Ave. NE, Seattle WA 98195, USA
| | - Ruikang K. Wang
- Department of Bioengineering, University of Washington, 3720 15 Ave. NE, Seattle WA 98195, USA
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Reif R, Qin J, Shi L, Dziennis S, Zhi Z, Nuttall AL, Wang RK. Monitoring hypoxia induced changes in cochlear blood flow and hemoglobin concentration using a combined dual-wavelength laser speckle contrast imaging and Doppler optical microangiography system. PLoS One 2012; 7:e52041. [PMID: 23272205 PMCID: PMC3525546 DOI: 10.1371/journal.pone.0052041] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2012] [Accepted: 11/08/2012] [Indexed: 01/08/2023] Open
Abstract
A synchronized dual-wavelength laser speckle contrast imaging (DWLSCI) system and a Doppler optical microangiography (DOMAG) system was developed to determine several ischemic parameters in the cochlea due to a systemic hypoxic challenge. DWLSCI can obtain two-dimensional data, and was used to determine the relative changes in cochlear blood flow, and change in the concentrations of oxyhemoglobin (HbO), deoxyhemoglobin (Hb) and total hemoglobin (HbT) in mice. DOMAG can obtain three-dimensional data, and was used to determine the changes in cochlear blood flow with single vessel resolution. It was demonstrated that during a hypoxic challenge there was an increase in the concentrations of Hb, a decrease in the concentrations of HbO and cochlear blood flow, and a slight decrease in the concentration of HbT. Also, the rate of change in the concentrations of Hb and HbO was quantified during and after the hypoxic challenge. The ability to simultaneously measure these ischemic parameters with high spatio-temporal resolution will allow the detailed quantitative analysis of several hearing disorders, and will be useful for diagnosing and developing treatments.
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Affiliation(s)
- Roberto Reif
- Department of Bioengineering, University of Washington, Seattle, Washington, United States of America
| | - Jia Qin
- Department of Bioengineering, University of Washington, Seattle, Washington, United States of America
| | - Lei Shi
- 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
| | - Alfred L. Nuttall
- Oregon Hearing Research Center, School of Medicine, Oregon Health and Science University, Portland, Oregon, United States of America
| | - Ruikang K. Wang
- Department of Bioengineering, University of Washington, Seattle, Washington, United States of America
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Qin J, Shi L, Dziennis S, Reif R, Wang RK. Fast synchronized dual-wavelength laser speckle imaging system for monitoring hemodynamic changes in a stroke mouse model. OPTICS LETTERS 2012; 37:4005-7. [PMID: 23027260 PMCID: PMC3980730 DOI: 10.1364/ol.37.004005] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
In this Letter, we describe a newly developed synchronized dual-wavelength laser speckle contrast imaging system, which contains two cameras that are synchronously triggered to acquire data. The system can acquire data at a high spatiotemporal resolution (up to 500 Hz for ~1000×1000 pixels). A mouse model of stroke is used to demonstrate the capability for imaging the fast changes (within tens of milliseconds) in oxygenated and deoxygenated hemoglobin concentration, and the relative changes in blood flow in the mouse brain, through an intact cranium. This novel imaging technology will enable the study of fast hemodynamics and metabolic changes in vascular diseases.
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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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