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Li J, Montarello NJ, Hoogendoorn A, Verjans JW, Bursill CA, Peter K, Nicholls SJ, McLaughlin RA, Psaltis PJ. Multimodality Intravascular Imaging of High-Risk Coronary Plaque. JACC Cardiovasc Imaging 2021; 15:145-159. [PMID: 34023267 DOI: 10.1016/j.jcmg.2021.03.028] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/18/2020] [Revised: 03/01/2021] [Accepted: 03/22/2021] [Indexed: 01/13/2023]
Abstract
The majority of coronary atherothrombotic events presenting as myocardial infarction (MI) occur as a result of plaque rupture or erosion. Understanding the evolution from a stable plaque into a life-threatening, high-risk plaque is required for advancing clinical approaches to predict atherothrombotic events, and better treat coronary atherosclerosis. Unfortunately, none of the coronary imaging approaches used in clinical practice can reliably predict which plaques will cause an MI. Currently used imaging techniques mostly identify morphological features of plaques, but are not capable of detecting essential molecular characteristics known to be important drivers of future risk. To address this challenge, engineers, scientists, and clinicians have been working hand-in-hand to advance a variety of multimodality intravascular imaging techniques, whereby 2 or more complementary modalities are integrated into the same imaging catheter. Some of these have already been tested in early clinical studies, with other next-generation techniques also in development. This review examines these emerging hybrid intracoronary imaging techniques and discusses their strengths, limitations, and potential for clinical translation from both an engineering and clinical perspective.
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Affiliation(s)
- Jiawen Li
- Adelaide Medical School, University of Adelaide, Adelaide, Australia; Australian Research Council Centre of Excellence for Nanoscale BioPhotonics, Adelaide, Australia; Institute for Photonics and Advanced Sensing, The University of Adelaide, Adelaide, Australia
| | - Nicholas J Montarello
- Department of Cardiology, Central Adelaide Local Health Network, Adelaide, Australia
| | - Ayla Hoogendoorn
- Australian Research Council Centre of Excellence for Nanoscale BioPhotonics, Adelaide, Australia; Institute for Photonics and Advanced Sensing, The University of Adelaide, Adelaide, Australia; Vascular Research Centre, Heart and Vascular Program, Lifelong Health Theme, South Australian Health and Medical Research Institute, Adelaide, Australia
| | - Johan W Verjans
- Adelaide Medical School, University of Adelaide, Adelaide, Australia; Australian Research Council Centre of Excellence for Nanoscale BioPhotonics, Adelaide, Australia; Department of Cardiology, Central Adelaide Local Health Network, Adelaide, Australia; Vascular Research Centre, Heart and Vascular Program, Lifelong Health Theme, South Australian Health and Medical Research Institute, Adelaide, Australia
| | - Christina A Bursill
- Adelaide Medical School, University of Adelaide, Adelaide, Australia; Australian Research Council Centre of Excellence for Nanoscale BioPhotonics, Adelaide, Australia; Institute for Photonics and Advanced Sensing, The University of Adelaide, Adelaide, Australia; Vascular Research Centre, Heart and Vascular Program, Lifelong Health Theme, South Australian Health and Medical Research Institute, Adelaide, Australia
| | | | - Stephen J Nicholls
- Monash Cardiovascular Research Centre, Victorian Heart Institute, Monash University, Melbourne, Australia
| | - Robert A McLaughlin
- Adelaide Medical School, University of Adelaide, Adelaide, Australia; Australian Research Council Centre of Excellence for Nanoscale BioPhotonics, Adelaide, Australia; Institute for Photonics and Advanced Sensing, The University of Adelaide, Adelaide, Australia
| | - Peter J Psaltis
- Adelaide Medical School, University of Adelaide, Adelaide, Australia; Department of Cardiology, Central Adelaide Local Health Network, Adelaide, Australia; Vascular Research Centre, Heart and Vascular Program, Lifelong Health Theme, South Australian Health and Medical Research Institute, Adelaide, Australia.
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Zhang R, Xu Z, Hao J, Yu J, Liu Z, Liu S, Chen W, Zhou J, Li H, Lin Z, Zheng W. Label-free identification of human coronary atherosclerotic plaque based on a three-dimensional quantitative assessment of multiphoton microscopy images. BIOMEDICAL OPTICS EXPRESS 2021; 12:2979-2995. [PMID: 34168910 PMCID: PMC8194630 DOI: 10.1364/boe.422525] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/16/2021] [Revised: 04/12/2021] [Accepted: 04/15/2021] [Indexed: 06/13/2023]
Abstract
The rupture of coronary atherosclerotic plaque (CAP) and the resulting intracoronary thrombosis account for most acute coronary syndromes. Thus, the early identification and risk assessment of CAP is crucial for timely medical intervention. In this study, we propose a quantitative and label-free method for human CAP identification using multiphoton microscopy (MPM) and three-dimensional (3D) image analysis techniques. By detecting the intrinsic MPM signals, the microstructures of collagen and elastin fibers within normal and CAP-lesioned human coronary artery walls were imaged. Using a 3D gray level co-occurrence matrix method and 3D weighted vector summation algorithm, quantitative indicators that characterize the spatial texture and orientation features of the fibers were extracted. We demonstrate that these indicators show superior accuracy and repeatability over 2D texture features in CAP discrimination. Furthermore, by combining the 3D microstructural indicators, a support vector machine model that classifies CAP from the normal arterial wall with an accuracy of >97% was established. In conjunction with advances in multiphoton endoscopy, the proposed method shows great potential in providing a quantitative, label-free, and real-time tool for the early identification and risk assessment of CAP in the future.
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Affiliation(s)
- Rongli Zhang
- Guangdong Provincial Geriatrics Institute, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangzhou, Guangdong 510080, China
- Department of Cardiology, Guangdong Provincial Cardiovascular Institute, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangzhou, Guangdong 510080, China
- Research Center for Biomedical Optics and Molecular Imaging, Shenzhen Key Laboratory for Molecular Imaging, Guangdong Provincial Key Laboratory of Biomedical Optical Imaging Technology, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen 518055, China
- CAS Key Laboratory of Health Informatics, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen 518055, China
| | - Zhongbiao Xu
- Department of Radiotherapy, Cancer Center, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangzhou, Guangdong 510080, China
| | - Junhai Hao
- Department of Intensive Care Unit of Cardiovascular Surgery, Guangdong Cardiovascular Institute, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangzhou, Guangdong 510080, China
| | - Jia Yu
- Research Center for Biomedical Optics and Molecular Imaging, Shenzhen Key Laboratory for Molecular Imaging, Guangdong Provincial Key Laboratory of Biomedical Optical Imaging Technology, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen 518055, China
- CAS Key Laboratory of Health Informatics, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen 518055, China
| | - Zhiyi Liu
- State Key Laboratory of Modern Optical Instrumentation, College of Optical Science and Engineering, International Research Center for Advanced Photonics, Zhejiang University, Hangzhou, Zhejiang 310058, China
| | - Shun Liu
- Research Center for Biomedical Optics and Molecular Imaging, Shenzhen Key Laboratory for Molecular Imaging, Guangdong Provincial Key Laboratory of Biomedical Optical Imaging Technology, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen 518055, China
- CAS Key Laboratory of Health Informatics, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen 518055, China
- School of Optoelectronic Engineering, Xi'an Technological University, Xi'an 710021, China
| | - Wanwen Chen
- Department of Cardiology, Guangdong Provincial Cardiovascular Institute, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangzhou, Guangdong 510080, China
| | - Jiahui Zhou
- Department of Cardiology, Guangdong Provincial Cardiovascular Institute, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangzhou, Guangdong 510080, China
| | - Hui Li
- Research Center for Biomedical Optics and Molecular Imaging, Shenzhen Key Laboratory for Molecular Imaging, Guangdong Provincial Key Laboratory of Biomedical Optical Imaging Technology, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen 518055, China
- CAS Key Laboratory of Health Informatics, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen 518055, China
| | - Zhanyi Lin
- Guangdong Provincial Geriatrics Institute, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangzhou, Guangdong 510080, China
- Department of Cardiology, Guangdong Provincial Cardiovascular Institute, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangzhou, Guangdong 510080, China
| | - Wei Zheng
- Research Center for Biomedical Optics and Molecular Imaging, Shenzhen Key Laboratory for Molecular Imaging, Guangdong Provincial Key Laboratory of Biomedical Optical Imaging Technology, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen 518055, China
- CAS Key Laboratory of Health Informatics, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen 518055, China
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Label-Free Visualization and Quantification of Biochemical Markers of Atherosclerotic Plaque Progression Using Intravascular Fluorescence Lifetime. JACC Cardiovasc Imaging 2020; 14:1832-1842. [PMID: 33221238 DOI: 10.1016/j.jcmg.2020.10.004] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/15/2020] [Revised: 10/06/2020] [Accepted: 10/14/2020] [Indexed: 12/25/2022]
Abstract
OBJECTIVES This study aimed to systematically investigate whether plaque autofluorescence properties assessed with intravascular fluorescence lifetime imaging (FLIm) can provide qualitative and quantitative information about intimal composition and improve the characterization of atherosclerosis lesions. BACKGROUND Despite advances in cardiovascular diagnostics, the analytic tools and imaging technologies currently available have limited capabilities for evaluating in situ biochemical changes associated with luminal surface features. Earlier studies of small number of samples have shown differences among the autofluorescence lifetime signature of well-defined lesions, but a systematic pixel-level evaluation of fluorescence signatures associated with various histological features is lacking and needed to better understand the origins of fluorescence contrast. METHODS Human coronary artery segments (n = 32) were analyzed with a bimodal catheter system combining multispectral FLIm with intravascular ultrasonography compatible with in vivo coronary imaging. Various histological components present along the luminal surface (200-μm depth) were systematically tabulated (12 sectors) from each serial histological section (n = 204). Morphological information provided by ultrasonography allowed for the accurate registration of imaging data with histology data. The relationships between histological findings and FLIm parameters obtained from 3 spectral channels at each measurement location (n = 33,980) were characterized. RESULTS Our findings indicate that fluorescence lifetime from different spectral bands can be used to quantitatively predict the superficial presence of macrophage foam cells (mFCs) (area under the receiver-operator characteristic curve: 0.94) and extracellular lipid content in advanced lesions (lifetime increase in 540-nm band), detect superficial calcium (lifetime decrease in 450-nm band area under the receiver-operator characteristic curve: 0.90), and possibly detect lesions consistent with active plaque formation such as pathological intimal thickening and healed thrombus regions (lifetime increase in 390-nm band). CONCLUSIONS Our findings indicate that autofluorescence lifetime provides valuable information for characterizing atherosclerotic lesions in coronary arteries. Specifically, FLIm can be used to identify key phenomena linked with plaque progression (e.g., peroxidized-lipid-rich mFC accumulation and recent plaque formation).
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Chen X, Kim W, Serafino M, Tan Z, Jo J, Applegate B. Dual-modality optical coherence tomography and frequency-domain fluorescence lifetime imaging microscope system for intravascular imaging. JOURNAL OF BIOMEDICAL OPTICS 2020; 25:JBO-200151R. [PMID: 33000570 PMCID: PMC7525154 DOI: 10.1117/1.jbo.25.9.096010] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/29/2020] [Accepted: 09/16/2020] [Indexed: 05/03/2023]
Abstract
SIGNIFICANCE Detailed biochemical and morphological imaging of the plaque burdened coronary arteries holds the promise of improved understanding of atherosclerosis plaque development, ultimately leading to better diagnostics and therapies. AIM Development of a dual-modality intravascular catheter supporting swept-source optical coherence tomography (OCT) and frequency-domain fluorescence lifetime imaging (FD-FLIM) of endogenous fluorophores with UV excitation. APPROACH We instituted a refined approach to endoscope development that combines simulation in a commercial ray tracing program, fabrication, and a measurement method for optimizing ball-lens performance. With this approach, we designed and developed a dual-modality catheter endoscope based on a double-clad fiber supporting OCT through the core and fluorescence collection through the first cladding. We varied the relative percent of UV excitation launched into the core and first cladding to explore the potential resolution improvement for FD-FLIM. The developed catheter endoscope was optically characterized, including measurement of spatial resolution and fluorescent lifetimes of standard fluorophores. Finally, the system was demonstrated on fresh ex vivo human coronary arteries. RESULTS The developed endoscope was shown to have optical performance similar to predictions derived from the simulation approach. The FLIM resolution can be improved by over a factor of 4 by primarily illuminating through the core rather than the first cladding. However, time-dependent solarization losses need to be considered when choosing the relative percentage. We ultimately chose to illuminate with 7% of the power transmitting through the core. The resulting catheter endoscope had 40-μm lateral resolution for OCT and <100 μm lateral resolution for FD-FLIM. Images of ex vivo coronary arteries are consistent with expectations based on histopathology. CONCLUSIONS The results demonstrate that our approach for endoscope simulation produces reliable predictions of endoscope performance. Simulation results guided our development of a multimodal OCT/FD-FLIM catheter imaging system for investigating atherosclerosis in coronary arteries.
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Affiliation(s)
- Xi Chen
- Texas A&M Univ., United States
| | - Wihan Kim
- The Univ. of Southern California, United States
| | | | | | - Javier Jo
- The Univ. of Oklahoma, United States
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Serafino MJ, Applegate BE, Jo JA. Direct frequency domain fluorescence lifetime imaging using field programmable gate arrays for real time processing. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2020; 91:033708. [PMID: 32260007 PMCID: PMC7269681 DOI: 10.1063/1.5127297] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
Frequency domain (FD) fluorescence lifetime imaging (FLIM) involves the excitation of the sample of interest with a modulated light source and digitization of the fluorescence emission for further analysis. Traditional FD-FLIM systems use heterodyne or homodyne detection, where the excitation light source and detector are modulated at specific frequency(s). More recently, FD-FLIM systems that use reflection of the light source as a trigger or phase reference for lifetime calculations have been developed. These detection schemes, however, require extra components that increase the cost and complexity of the FD-FLIM system. Here, we report a novel FD-FLIM detection scheme whereby the light source modulation and emission digitization are implemented using Field Programmable Gate Arrays (FPGAs), and fixed gain avalanche photodiodes are used for fluorescence detection. The reported FD-FLIM system was designed for probing nanosecond lifetime fluorophores (2-10 ns) at three emission bands simultaneously. The system utilizes a 375 nm diode laser for excitation at multiple simultaneous modulation frequencies (between 1 MHz and 83 MHz, bandwidth limited intentionally by using a lowpass filter) and three fixed gain avalanche photodiodes for simultaneous detection of three emission bands: 405/20 nm, 440/40 nm, and 525/50 nm (center/FWHM). Real-time computation of the modulation and phase lifetimes is simply performed by direct application of the discrete Fourier transform (max. of 10 frequencies) to the digitized fluorescence emission signals. The accuracy and sensitivity of this novel FD-FLIM detection scheme was demonstrated by imaging standard fluorophores and ex vivo unfixed human coronary artery tissue samples.
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Affiliation(s)
| | | | - Javier A. Jo
- Author to whom correspondence should be addressed:
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6
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Buja LM, Ottaviani G, Mitchell RN. Pathobiology of cardiovascular diseases: an update. Cardiovasc Pathol 2019; 42:44-53. [PMID: 31255975 DOI: 10.1016/j.carpath.2019.06.002] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/30/2019] [Accepted: 06/07/2019] [Indexed: 01/10/2023] Open
Abstract
This article introduces the Second Special Issue of Cardiovascular Pathology (CVP), the official journal of the Society for Cardiovascular Pathology (SCVP). This CVP Special Issue showcases a series of commemorative review articles in celebration of the 25th anniversary of CVP originally published in 2016 and now compiled into a virtual collection with online access for the cardiovascular pathology community. This overview also provides updates on the major categories of cardiovascular diseases from the perspective of cardiovascular pathologists, highlighting publications from CVP, as well as additional important review articles and clinicopathologic references.
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Affiliation(s)
- L Maximilian Buja
- Department of Pathology and Laboratory Medicine, McGovern Medical School, The University of Texas Health Science Center at Houston (UTHealth), Houston, TX, USA; Cardiovascular Pathology Research Laboratory, Texas Heart Institute, CHI St. Luke's Hospital, Houston, TX, USA.
| | - Giulia Ottaviani
- Department of Pathology and Laboratory Medicine, McGovern Medical School, The University of Texas Health Science Center at Houston (UTHealth), Houston, TX, USA; "Lino Rossi" Research Center for the study and prevention of unexpected perinatal death and sudden infant death syndrome, Department of Biomedical, Surgical and Dental Sciences, University of Milan, Milan, Italy
| | - Richard N Mitchell
- Department of Pathology, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA
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7
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Automated detection of superficial macrophages in atherosclerotic plaques using autofluorescence lifetime imaging. Atherosclerosis 2019; 285:120-127. [PMID: 31051415 DOI: 10.1016/j.atherosclerosis.2019.04.223] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/09/2018] [Revised: 04/08/2019] [Accepted: 04/16/2019] [Indexed: 01/08/2023]
Abstract
BACKGROUND AND AIMS Macrophages play an important role in the development and destabilization of advanced atherosclerotic plaques. Hence, the clinical imaging of macrophage content in advanced plaques could potentially aid in identifying patients most at risk of future clinical events. The lifetime of the autofluorescence emission from atherosclerotic plaques has been correlated with lipids and macrophage accumulation in ex vivo human coronary arteries, suggesting the potential of intravascular endogenous fluorescence or autofluorescence lifetime imaging (FLIM) for macrophage imaging. The aim of this study was to quantify the accuracy of the coronary intima autofluorescence lifetime to detect superficial macrophage accumulation in atherosclerotic plaques. METHODS Endogenous FLIM imaging was performed on 80 fresh postmortem coronary segments from 23 subjects. The plaque autofluorescence lifetime at an emission spectral band of 494 ± 20.5 nm was used as a discriminatory feature to detect superficial macrophage accumulation in atherosclerotic plaques. Detection of superficial macrophage accumulation in the imaged coronary segments based on immunohistochemistry (CD68 staining) evaluation was taken as the gold standard. Receiver Operating Characteristic (ROC) curve analysis was applied to select an autofluorescence lifetime threshold value to detect superficial macrophages accumulation. RESULTS A threshold of 6 ns in the plaque autofluorescence lifetime at the emission spectral band of 494 ± 20.5 nm was applied to detect plaque superficial macrophages accumulation, resulting in ∼91.5% accuracy. CONCLUSIONS This study demonstrates the capability of endogenous FLIM imaging to accurately identify superficial macrophages accumulation in human atherosclerotic plaques, a key biomarker of atherosclerotic plaque vulnerability.
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Comprehensive intravascular imaging of atherosclerotic plaque in vivo using optical coherence tomography and fluorescence lifetime imaging. Sci Rep 2018; 8:14561. [PMID: 30267024 PMCID: PMC6162321 DOI: 10.1038/s41598-018-32951-9] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2018] [Accepted: 09/18/2018] [Indexed: 02/08/2023] Open
Abstract
Comprehensive imaging of both the structural and biochemical characteristics of atherosclerotic plaque is essential for the diagnosis and study of coronary artery disease because both a plaque's morphology and its biochemical composition affect the level of risk it poses. Optical coherence tomography (OCT) and fluorescence lifetime imaging (FLIm) are promising optical imaging methods for characterizing coronary artery plaques morphologically and biochemically, respectively. In this study, we present a hybrid intravascular imaging device, including a custom-built OCT/FLIm system, a hybrid optical rotary joint, and an imaging catheter, to visualize the structure and biochemical composition of the plaque in an atherosclerotic rabbit artery in vivo. Especially, the autofluorescence lifetime of the endogenous tissue molecules can be used to characterize the biochemical composition; thus no exogenous contrast agent is required. Also, the physical properties of the imaging catheter and the imaging procedures are similar to those already used clinically, facilitating rapid translation into clinical use. This new intravascular imaging catheter can open up new opportunities for clinicians and researchers to investigate and diagnose coronary artery disease by simultaneously providing tissue microstructure and biochemical composition data in vivo without the use of exogenous contrast agent.
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Scanning Acoustic Microscopy and Time-Resolved Fluorescence Spectroscopy for Characterization of Atherosclerotic Plaques. Sci Rep 2018; 8:14378. [PMID: 30258115 PMCID: PMC6158264 DOI: 10.1038/s41598-018-32788-2] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2018] [Accepted: 09/17/2018] [Indexed: 11/11/2022] Open
Abstract
Atherosclerotic plaques constitute the primary cause of heart attack and stroke. However, we still lack a clear identification of the plaques. Here, we evaluate the feasibility of scanning acoustic microscopy (SAM) and time-resolved fluorescence spectroscopy (TRFS) in atherosclerotic plaque characterization. We perform dual-modality microscopic imaging of the human carotid atherosclerotic plaques. We first show that the acoustic impedance values are statistically higher in calcified regions compared with the collagen-rich areas. We then use CdTe/CdS quantum dots for imaging the atherosclerotic plaques by TRFS and show that fluorescence lifetime values of the quantum dots in collagen-rich areas are notably different from the ones in calcified areas. In summary, both modalities are successful in differentiating the calcified regions from the collagen-rich areas within the plaques indicating that these techniques are confirmatory and may be combined to characterize atherosclerotic plaques in the future.
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Nam HS, Kang WJ, Lee MW, Song JW, Kim JW, Oh WY, Yoo H. Multispectral analog-mean-delay fluorescence lifetime imaging combined with optical coherence tomography. BIOMEDICAL OPTICS EXPRESS 2018; 9:1930-1947. [PMID: 29675330 PMCID: PMC5905935 DOI: 10.1364/boe.9.001930] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/14/2017] [Revised: 03/15/2018] [Accepted: 03/18/2018] [Indexed: 05/19/2023]
Abstract
The pathophysiological progression of chronic diseases, including atherosclerosis and cancer, is closely related to compositional changes in biological tissues containing endogenous fluorophores such as collagen, elastin, and NADH, which exhibit strong autofluorescence under ultraviolet excitation. Fluorescence lifetime imaging (FLIm) provides robust detection of the compositional changes by measuring fluorescence lifetime, which is an inherent property of a fluorophore. In this paper, we present a dual-modality system combining a multispectral analog-mean-delay (AMD) FLIm and a high-speed swept-source optical coherence tomography (OCT) to simultaneously visualize the cross-sectional morphology and biochemical compositional information of a biological tissue. Experiments using standard fluorescent solutions showed that the fluorescence lifetime could be measured with a precision of less than 40 psec using the multispectral AMD-FLIm without averaging. In addition, we performed ex vivo imaging on rabbit iliac normal-looking and atherosclerotic specimens to demonstrate the feasibility of the combined FLIm-OCT system for atherosclerosis imaging. We expect that the combined FLIm-OCT will be a promising next-generation imaging technique for diagnosing atherosclerosis and cancer due to the advantages of the proposed label-free high-precision multispectral lifetime measurement.
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Affiliation(s)
- Hyeong Soo Nam
- Department of Biomedical Engineering, Hanyang University, 222 Wangsimni-ro, Seongdong-gu, Seoul 04673, South Korea
- Equally contributed to this study
| | - Woo Jae Kang
- Department of Mechanical Engineering, Korea Advanced Institute of Science and Technology, 291 Gwahang-no, Yuseong-gu, Daejeon 34141, South Korea
- Equally contributed to this study
| | - Min Woo Lee
- Department of Biomedical Engineering, Hanyang University, 222 Wangsimni-ro, Seongdong-gu, Seoul 04673, South Korea
| | - Joon Woo Song
- Cardiovascular Center, Korea University Guro Hospital, 148 Gurodong-ro, Guro-gu, Seoul 08308, South Korea
| | - Jin Won Kim
- Cardiovascular Center, Korea University Guro Hospital, 148 Gurodong-ro, Guro-gu, Seoul 08308, South Korea
| | - Wang-Yuhl Oh
- Department of Mechanical Engineering, Korea Advanced Institute of Science and Technology, 291 Gwahang-no, Yuseong-gu, Daejeon 34141, South Korea
| | - Hongki Yoo
- Department of Biomedical Engineering, Hanyang University, 222 Wangsimni-ro, Seongdong-gu, Seoul 04673, South Korea
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Pinkert MA, Hortensius RA, Ogle BM, Eliceiri KW. Imaging the Cardiac Extracellular Matrix. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2018; 1098:21-44. [PMID: 30238364 DOI: 10.1007/978-3-319-97421-7_2] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Cardiovascular disease is the global leading cause of death. One route to address this problem is using biomedical imaging to measure the molecules and structures that surround cardiac cells. This cellular microenvironment, known as the cardiac extracellular matrix, changes in composition and organization during most cardiac diseases and in response to many cardiac treatments. Measuring these changes with biomedical imaging can aid in understanding, diagnosing, and treating heart disease. This chapter supports those efforts by reviewing representative methods for imaging the cardiac extracellular matrix. It first describes the major biological targets of ECM imaging, including the primary imaging target of fibrillar collagen. Then it discusses the imaging methods, describing their current capabilities and limitations. It categorizes the imaging methods into two main categories: organ-scale noninvasive methods and cellular-scale invasive methods. Noninvasive methods can be used on patients, but only a few are clinically available, and others require further development to be used in the clinic. Invasive methods are the most established and can measure a variety of properties, but they cannot be used on live patients. Finally, the chapter concludes with a perspective on future directions and applications of biomedical imaging technologies.
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Affiliation(s)
- Michael A Pinkert
- Laboratory for Optical and Computational Instrumentation and Department of Medical Physics, University of Wisconsin at Madison, Madison, WI, USA.,Morgridge Institute for Research, Madison, WI, USA
| | - Rebecca A Hortensius
- Department of Biomedical Engineering, University of Minnesota, Minneapolis, MN, USA
| | - Brenda M Ogle
- Department of Biomedical Engineering, University of Minnesota, Minneapolis, MN, USA
| | - Kevin W Eliceiri
- Laboratory for Optical and Computational Instrumentation and Department of Medical Physics, University of Wisconsin at Madison, Madison, WI, USA. .,Morgridge Institute for Research, Madison, WI, USA.
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Small DM, Jones JS, Tendler II, Miller PE, Ghetti A, Nishimura N. Label-free imaging of atherosclerotic plaques using third-harmonic generation microscopy. BIOMEDICAL OPTICS EXPRESS 2018; 9:214-229. [PMID: 29359098 PMCID: PMC5772576 DOI: 10.1364/boe.9.000214] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/22/2017] [Revised: 11/24/2017] [Accepted: 12/02/2017] [Indexed: 05/18/2023]
Abstract
Multiphoton microscopy using laser sources in the mid-infrared range (MIR, 1,300 nm and 1,700 nm) was used to image atherosclerotic plaques from murine and human samples. Third harmonic generation (THG) from atherosclerotic plaques revealed morphological details of cellular and extracellular lipid deposits. Simultaneous nonlinear optical signals from the same laser source, including second harmonic generation and endogenous fluorescence, resulted in label-free images of various layers within the diseased vessel wall. The THG signal adds an endogenous contrast mechanism with a practical degree of specificity for atherosclerotic plaques that complements current nonlinear optical methods for the investigation of cardiovascular disease. Our use of whole-mount tissue and backward scattered epi-detection suggests THG could potentially be used in the future as a clinical tool.
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Affiliation(s)
- David M. Small
- Nancy E. and Peter C. Meinig School of Biomedical Engineering, Cornell University, 526 N. Campus Rd., Ithaca, NY 14853, USA
- Contributed equally
| | - Jason S. Jones
- Nancy E. and Peter C. Meinig School of Biomedical Engineering, Cornell University, 526 N. Campus Rd., Ithaca, NY 14853, USA
- Contributed equally
| | - Irwin I. Tendler
- Nancy E. and Peter C. Meinig School of Biomedical Engineering, Cornell University, 526 N. Campus Rd., Ithaca, NY 14853, USA
| | - Paul E. Miller
- Anabios Corporation, 3030 Bunker Hill St., San Diego, CA 92109, USA
| | - Andre Ghetti
- Anabios Corporation, 3030 Bunker Hill St., San Diego, CA 92109, USA
| | - Nozomi Nishimura
- Nancy E. and Peter C. Meinig School of Biomedical Engineering, Cornell University, 526 N. Campus Rd., Ithaca, NY 14853, USA
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Zhang Y, Cuyt A, Lee WS, Lo Bianco G, Wu G, Chen Y, Li DDU. Towards unsupervised fluorescence lifetime imaging using low dimensional variable projection. OPTICS EXPRESS 2016; 24:26777-26791. [PMID: 27857408 DOI: 10.1364/oe.24.026777] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Analyzing large fluorescence lifetime imaging (FLIM) data is becoming overwhelming; the latest FLIM systems easily produce massive amounts of data, making an efficient analysis more challenging than ever. In this paper we propose the combination of a custom-fit variable projection method, with a Laguerre expansion based deconvolution, to analyze bi-exponential data obtained from time-domain FLIM systems. Unlike nonlinear least squares methods, which require a suitable initial guess from an experienced researcher, the new method is free from manual interventions and hence can support automated analysis. Monte Carlo simulations are carried out on synthesized FLIM data to demonstrate the performance compared to other approaches. The performance is also illustrated on real-life FLIM data obtained from the study of autofluorescence of daisy pollen and the endocytosis of gold nanorods (GNRs) in living cells. In the latter, the fluorescence lifetimes of the GNRs are much shorter than the full width at half maximum of the instrument response function. Overall, our proposed method contains simple steps and shows great promise in realising automated FLIM analysis of large data sets.
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15
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Shrestha S, Serafino MJ, Rico-Jimenez J, Park J, Chen X, Zhaorigetu S, Walton BL, Jo JA, Applegate BE. Multimodal optical coherence tomography and fluorescence lifetime imaging with interleaved excitation sources for simultaneous endogenous and exogenous fluorescence. BIOMEDICAL OPTICS EXPRESS 2016; 7:3184-3197. [PMID: 27699091 PMCID: PMC5030003 DOI: 10.1364/boe.7.003184] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/03/2016] [Revised: 07/26/2016] [Accepted: 07/27/2016] [Indexed: 05/24/2023]
Abstract
Multimodal imaging probes a variety of tissue properties in a single image acquisition by merging complimentary imaging technologies. Exploiting synergies amongst the data, algorithms can be developed that lead to better tissue characterization than could be accomplished by the constituent imaging modalities taken alone. The combination of optical coherence tomography (OCT) with fluorescence lifetime imaging microscopy (FLIM) provides access to detailed tissue morphology and local biochemistry. The optical system described here merges 1310 nm swept-source OCT with time-domain FLIM having excitation at 355 and 532 nm. The pulses from 355 and 532 nm lasers have been interleaved to enable simultaneous acquisition of endogenous and exogenous fluorescence signals, respectively. The multimodal imaging system was validated using tissue phantoms. Nonspecific tagging with Alexa Flour 532 in a Watanbe rabbit aorta and active tagging of the LOX-1 receptor in human coronary artery, demonstrate the capacity of the system for simultaneous acquisition of OCT, endogenous FLIM, and exogenous FLIM in tissues.
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Affiliation(s)
- Sebina Shrestha
- Department of Biomedical Engineering, Texas A&M University, 5045 Emerging Technology Building, College Station, TX, 77843, USA
| | - Michael J. Serafino
- Department of Biomedical Engineering, Texas A&M University, 5045 Emerging Technology Building, College Station, TX, 77843, USA
| | - Jesus Rico-Jimenez
- Department of Biomedical Engineering, Texas A&M University, 5045 Emerging Technology Building, College Station, TX, 77843, USA
| | - Jesung Park
- Department of Biomedical Engineering, Texas A&M University, 5045 Emerging Technology Building, College Station, TX, 77843, USA
| | - Xi Chen
- Department of Biomedical Engineering, Texas A&M University, 5045 Emerging Technology Building, College Station, TX, 77843, USA
| | - Siqin Zhaorigetu
- Cardiovascular Experimental Imaging and Therapeutics, Texas Heart Institute, 6519 Fannin St., Houston, TX, 77030, USA
| | - Brian L. Walton
- Cardiovascular Experimental Imaging and Therapeutics, Texas Heart Institute, 6519 Fannin St., Houston, TX, 77030, USA
| | - Javier A. Jo
- Department of Biomedical Engineering, Texas A&M University, 5045 Emerging Technology Building, College Station, TX, 77843, USA
| | - Brian E. Applegate
- Department of Biomedical Engineering, Texas A&M University, 5045 Emerging Technology Building, College Station, TX, 77843, USA
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16
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Kim W, Chen X, Jo JA, Applegate BE. Lensless, ultra-wideband fiber optic rotary joint for biomedical applications. OPTICS LETTERS 2016; 41:1973-6. [PMID: 27128052 PMCID: PMC6731063 DOI: 10.1364/ol.41.001973] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
The demands of optical fiber-based biomedical applications can, in many cases, outstrip the capabilities of lens-based commercially available fiber optic rotary joints. In some circumstances, it is necessary to use very broad spectral bandwidths (near UV to short-wave IR) and specialized optical fibers, such as double-clad fiber, and have the capacity to accommodate high rotational velocities. The broad spectrum, stretching down into the UV, presents two problems: (1) adequate chromatic correction in the lenses across the entire bandwidth and (2) strong UV absorption by the fluids used to lubricate the rotary joint. To accommodate these types of applications, we have developed an ultra-wideband lensless fiber optic rotary joint based on the principle that when two optical fibers are coaligned and placed in contact (or very close), the optical losses at the junction are very low. The advances demonstrated here enable excellent performance (<0.2 dB insertion loss), even down into the UV and spanning a wavelength range of at least 355-1360 nm with single-mode, multimode, and double-clad fibers. We also demonstrate excellent performance, ∼0.38 dB insertion loss, at rotational velocities up to 8800 rpm (146 Hz). To the best of our knowledge, this is the first demonstration of this type of rotary joint capable of such a wide bandwidth and high rotational velocities.
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Affiliation(s)
- Wihan Kim
- Department of Biomedical Engineering, Texas A&M University, 101 Bizzell St., College Station, TX 77843
| | - Xi Chen
- Department of Biomedical Engineering, Texas A&M University, 101 Bizzell St., College Station, TX 77843
| | - Javier A. Jo
- Department of Biomedical Engineering, Texas A&M University, 101 Bizzell St., College Station, TX 77843
| | - Brian E. Applegate
- Department of Biomedical Engineering, Texas A&M University, 101 Bizzell St., College Station, TX 77843
- Corresponding author:
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