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Li J, Warren-Smith SC, McLaughlin RA, Ebendorff-Heidepriem H. Single-fiber probes for combined sensing and imaging in biological tissue: recent developments and prospects. BIOMEDICAL OPTICS EXPRESS 2024; 15:2392-2405. [PMID: 38633092 PMCID: PMC11019705 DOI: 10.1364/boe.517920] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/26/2024] [Revised: 02/28/2024] [Accepted: 02/29/2024] [Indexed: 04/19/2024]
Abstract
Single-fiber-based sensing and imaging probes enable the co-located and simultaneous observation and measurement (i.e., 'sense' and 'see') of intricate biological processes within deep anatomical structures. This innovation opens new opportunities for investigating complex physiological phenomena and potentially allows more accurate diagnosis and monitoring of disease. This prospective review starts with presenting recent studies of single-fiber-based probes for concurrent and co-located fluorescence-based sensing and imaging. Notwithstanding the successful initial demonstration of integrated sensing and imaging within single-fiber-based miniaturized devices, the realization of these devices with enhanced sensing sensitivity and imaging resolution poses notable challenges. These challenges, in turn, present opportunities for future research, including the design and fabrication of complex lens systems and fiber architectures, the integration of novel materials and other sensing and imaging techniques.
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Affiliation(s)
- Jiawen Li
- School of Electrical and Mechanical Engineering, The University of Adelaide, South Australia, 5005, Australia
- Institute for Photonics and Advanced Sensing, The University of Adelaide, South Australia, 5005, Australia
| | - Stephen C. Warren-Smith
- Institute for Photonics and Advanced Sensing, The University of Adelaide, South Australia, 5005, Australia
- Future Industries Institute, The University of South Australia, Mawson Lakes, South Australia, 5095, Australia
| | - Robert A. McLaughlin
- Institute for Photonics and Advanced Sensing, The University of Adelaide, South Australia, 5005, Australia
- Faculty of Health and Medical Sciences, The University of Adelaide, South Australia, 5005, Australia
| | - Heike Ebendorff-Heidepriem
- Institute for Photonics and Advanced Sensing, The University of Adelaide, South Australia, 5005, Australia
- School of Physics, Chemistry and Earth Sciences, The University of Adelaide, South Australia, 5005, Australia
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2
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Bec J, Zhou X, Villiger M, Southard JA, Bouma B, Marcu L. Dual modality intravascular catheter system combining pulse-sampling fluorescence lifetime imaging and polarization-sensitive optical coherence tomography. BIOMEDICAL OPTICS EXPRESS 2024; 15:2114-2132. [PMID: 38633060 PMCID: PMC11019710 DOI: 10.1364/boe.516515] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/19/2023] [Revised: 02/08/2024] [Accepted: 02/08/2024] [Indexed: 04/19/2024]
Abstract
The clinical management of coronary artery disease and the prevention of acute coronary syndromes require knowledge of the underlying atherosclerotic plaque pathobiology. Hybrid imaging modalities capable of comprehensive assessment of biochemical and morphological plaques features can address this need. Here we report the first implementation of an intravascular catheter system combining fluorescence lifetime imaging (FLIm) with polarization-sensitive optical coherence tomography (PSOCT). This system provides multi-scale assessment of plaque structure and composition via high spatial resolution morphology from OCT, polarimetry-derived tissue microstructure, and biochemical composition from FLIm, without requiring any molecular contrast agent. This result was achieved with a low profile (2.7 Fr) double-clad fiber (DCF) catheter and high speed (100 fps B-scan rate, 40 mm/s pullback speed) console. Use of a DCF and broadband rotary junction required extensive optimization to mitigate the reduction in OCT performance originating from additional reflections and multipath artifacts. This challenge was addressed by the development of a broad-band (UV-visible-IR), high return loss (47 dB) rotary junction. We demonstrate in phantoms, ex vivo swine coronary specimens and in vivo swine heart (percutaneous coronary access) that the FLIm-PSOCT catheter system can simultaneously acquire co-registered FLIm data over four distinct spectral bands (380/20 nm, 400/20 nm, 452/45 nm, 540/45 nm) and PSOCT backscattered intensity, birefringence, and depolarization. The unique ability to collect complementary information from tissue (e.g., morphology, extracellular matrix composition, inflammation) with a device suitable for percutaneous coronary intervention offers new opportunities for cardiovascular research and clinical diagnosis.
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Affiliation(s)
- Julien Bec
- Biomedical Engineering, University of California, Davis, CA 95616, USA
| | - Xiangnan Zhou
- Biomedical Engineering, University of California, Davis, CA 95616, USA
| | - Martin Villiger
- Wellman Center for Photomedicine, Massachusetts General Hospital and Harvard Medical School, Boston, MA 02114, USA
| | - Jeffrey A. Southard
- Division of Cardiovascular Medicine, UC Davis Health System, University of California-Davis, Sacramento, CA 95817, USA
| | - Brett Bouma
- Wellman Center for Photomedicine, Massachusetts General Hospital and Harvard Medical School, Boston, MA 02114, USA
| | - Laura Marcu
- Biomedical Engineering, University of California, Davis, CA 95616, USA
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3
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Kang DO, Nam HS, Kim S, Yoo H, Kim JW. Feasibility and safety of non-contrast optical coherence tomography imaging using hydroxyethyl starch in coronary arteries. Sci Rep 2023; 13:13818. [PMID: 37620359 PMCID: PMC10449772 DOI: 10.1038/s41598-023-40363-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2023] [Accepted: 08/09/2023] [Indexed: 08/26/2023] Open
Abstract
Intracoronary optical coherence tomography (OCT) requires injection of flushing media for image acquisition. Alternative flushing media needs to be investigated to reduce the risk of contrast-induced renal dysfunction. We investigated the feasibility and safety of pentastarch (hydroxyethyl starch) for clinical OCT imaging. We prospectively enrolled 43 patients with 70 coronary lesions (46-stented; 24-native). Total 81 OCT pullback pairs were obtained by manual injection of iodine contrast, followed by pentastarch. Each pullback was assessed frame-by-frame using an automated customized lumen contour/stent strut segmentation algorithm. Paired images were compared for the clear image segments (CIS), blood-flushing capability, and quantitative morphometric measurements. Overall image quality, as assessed by the proportion of CIS, was comparable between the contrast- and pentastarch-flushed images (97.1% vs. 96.5%; p = 0.160). The pixel-based blood-flushing capability was similar between the groups (0.951 [0.947-0.953] vs. 0.950 [0.948-0.952], p = 0.125). Quantitative two- and three-dimensional morphometric measurements of the paired images correlated well (p < 0.001) with excellent inter-measurement variability. All patients safely underwent OCT imaging using pentastarch without resulting in clinically relevant complications or renal deterioration. Non-contrast OCT imaging using pentastarch is clinically safe and technically feasible with excellent image quality and could be a promising alternative strategy for patients at high risk of renal impairment.
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Affiliation(s)
- Dong Oh Kang
- Multimodal Imaging and Theranostic Laboratory, Cardiovascular Center, Korea University Guro Hospital, 148 Gurodong-Ro, Guro-Gu, Seoul, 08308, Republic of Korea
- Cardiovascular Center, Korea University Guro Hospital, 148 Gurodong-Ro, Guro-Gu, Seoul, 08308, Republic of Korea
| | - Hyeong Soo Nam
- Department of Mechanical Engineering, Korea Advanced Institute of Science and Technology, 291 Daehak-Ro, Yuseong-Gu, Daejeon, 34141, Republic of Korea
| | - Sunwon Kim
- Multimodal Imaging and Theranostic Laboratory, Cardiovascular Center, Korea University Guro Hospital, 148 Gurodong-Ro, Guro-Gu, Seoul, 08308, Republic of Korea
- Cardiovascular Center, Korea University Ansan Hospital, 123 Jeokgeum-Ro, Danwon-Gu, Ansan, 15355, Republic of Korea
| | - Hongki Yoo
- Department of Mechanical Engineering, Korea Advanced Institute of Science and Technology, 291 Daehak-Ro, Yuseong-Gu, Daejeon, 34141, Republic of Korea.
| | - Jin Won Kim
- Multimodal Imaging and Theranostic Laboratory, Cardiovascular Center, Korea University Guro Hospital, 148 Gurodong-Ro, Guro-Gu, Seoul, 08308, Republic of Korea.
- Cardiovascular Center, Korea University Guro Hospital, 148 Gurodong-Ro, Guro-Gu, Seoul, 08308, Republic of Korea.
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4
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Li C, Bec J, Zhou X, Marcu L. Dual-modality fluorescence lifetime imaging-optical coherence tomography intravascular catheter system with freeform catheter optics. JOURNAL OF BIOMEDICAL OPTICS 2022; 27:076005. [PMID: 35864574 PMCID: PMC9300477 DOI: 10.1117/1.jbo.27.7.076005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/17/2022] [Accepted: 06/27/2022] [Indexed: 06/15/2023]
Abstract
SIGNIFICANCE Intravascular imaging is key to investigations into atherosclerotic plaque pathobiology and cardiovascular diagnostics overall. The development of multimodal imaging devices compatible with intracoronary applications has the potential to address limitations of currently available single-modality systems. AIM We designed and characterized a robust, high performance multimodal imaging system that combines optical coherence tomography (OCT) and multispectral fluorescence lifetime imaging (FLIm) for intraluminal simultaneous assessment of structural and biochemical properties of coronary arteries. APPROACH Several shortcomings of existing FLIm-OCT catheter systems are addressed by adopting key features, namely (1) a custom fiber optic rotary joint based on an air bearing, (2) a broadband catheter using a freeform reflective optics, and (3) integrated solid-state FLIm detectors. Improvements are quantified using a combination of experimental characterization and simulations. RESULTS Excellent UV and IR coupling efficiencies and stability (IR: 75.7 % ± 0.4 % , UV: 45.7 % ± 0.35 % ) are achieved; high FLIm optical performance is obtained (UV beam FWHM: 50 μm) contemporaneously with excellent OCT beam quality (IR beam FWHM: 17 μm). High-quality FLIm OCT image of a human coronary artery specimen was acquired. CONCLUSION The ability of this intravascular imaging system to provide comprehensive structural and biochemical properties will be valuable to further our understanding of plaque pathophysiology and improve cardiovascular diagnostics.
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Affiliation(s)
- Cai Li
- University of California, Department of Biomedical Engineering, Davis, California, United States
| | - Julien Bec
- University of California, Department of Biomedical Engineering, Davis, California, United States
| | - Xiangnan Zhou
- University of California, Department of Biomedical Engineering, Davis, California, United States
| | - Laura Marcu
- University of California, Department of Biomedical Engineering, Davis, California, United States
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5
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Koman VB, Bakh NA, Jin X, Nguyen FT, Son M, Kozawa D, Lee MA, Bisker G, Dong J, Strano MS. A wavelength-induced frequency filtering method for fluorescent nanosensors in vivo. NATURE NANOTECHNOLOGY 2022; 17:643-652. [PMID: 35637357 DOI: 10.1038/s41565-022-01136-x] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/28/2021] [Accepted: 04/07/2022] [Indexed: 06/15/2023]
Abstract
Fluorescent nanosensors hold the potential to revolutionize life sciences and medicine. However, their adaptation and translation into the in vivo environment is fundamentally hampered by unfavourable tissue scattering and intrinsic autofluorescence. Here we develop wavelength-induced frequency filtering (WIFF) whereby the fluorescence excitation wavelength is modulated across the absorption peak of a nanosensor, allowing the emission signal to be separated from the autofluorescence background, increasing the desired signal relative to noise, and internally referencing it to protect against artefacts. Using highly scattering phantom tissues, an SKH1-E mouse model and other complex tissue types, we show that WIFF improves the nanosensor signal-to-noise ratio across the visible and near-infrared spectra up to 52-fold. This improvement enables the ability to track fluorescent carbon nanotube sensor responses to riboflavin, ascorbic acid, hydrogen peroxide and a chemotherapeutic drug metabolite for depths up to 5.5 ± 0.1 cm when excited at 730 nm and emitting between 1,100 and 1,300 nm, even allowing the monitoring of riboflavin diffusion in thick tissue. As an application, nanosensors aided by WIFF detect the chemotherapeutic activity of temozolomide transcranially at 2.4 ± 0.1 cm through the porcine brain without the use of fibre optic or cranial window insertion. The ability of nanosensors to monitor previously inaccessible in vivo environments will be important for life-sciences research, therapeutics and medical diagnostics.
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Affiliation(s)
- Volodymyr B Koman
- Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Naveed A Bakh
- Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Xiaojia Jin
- Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Freddy T Nguyen
- Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, MA, USA
- Institute for Medical Engineering & Science, Massachusetts Institute of Technology, Cambridge, MA, USA
- Department of Pathology, Molecular and Cell-Based Medicine, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Manki Son
- Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Daichi Kozawa
- Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, MA, USA
- Quantum Optoelectronics Research Team, RIKEN Center for Advanced Photonics, Saitama, Japan
| | - Michael A Lee
- Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Gili Bisker
- Department of Biomedical Engineering, Faculty of Engineering, Center for Physics and Chemistry of Living Systems, Center for Nanoscience and Nanotechnology, Center for Light-Matter Interaction, Tel Aviv University, Tel Aviv, Israel
| | - Juyao Dong
- Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Michael S Strano
- Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, MA, USA.
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Bartolo-Perez C, Ahamed A, Mayet AS, Rawat A, McPhillips L, Ghandiparsi S, Bec J, Ariño-Estrada G, Cherry S, Wang SY, Marcu L, Saif Islam M. Engineering the gain and bandwidth in avalanche photodetectors. OPTICS EXPRESS 2022; 30:16873-16882. [PMID: 36221521 PMCID: PMC9363021 DOI: 10.1364/oe.446507] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
Avalanche and Single-Photon Avalanche photodetectors (APDs and SPADs) rely on the probability of photogenerated carriers to trigger a multiplication process. Photon penetration depth plays a vital role in this process. In silicon APDs, a significant fraction of the short visible wavelengths is absorbed close to the device surface that is typically highly doped to serve as a contact. Most of the photogenerated carriers in this region can be lost by recombination, get slowly transported by diffusion, or multiplied with high excess noise. On the other hand, the extended penetration depth of near-infrared wavelengths requires thick semiconductors for efficient absorption. This diminishes the speed of the devices due to the long transit time in the thick absorption layer that is required for detecting most of these photons. Here, we demonstrate that it is possible to drive photons to a critical depth in a semiconductor film to maximize their gain-bandwidth performance and increase the absorption efficiency. This approach to engineering the penetration depth for different wavelengths in silicon is enabled by integrating photon-trapping nanoholes on the device surface. The penetration depth of short wavelengths such as 450 nm is increased from 0.25 µm to more than 0.62 µm. On the other hand, for a long-wavelength like 850 nm, the penetration depth is reduced from 18.3 µm to only 2.3 µm, decreasing the device transit time considerably. Such capabilities allow increasing the gain in APDs by almost 400× at 450 nm and by almost 9× at 850 nm. This engineering of the penetration depth in APDs would enable device designs requiring higher gain-bandwidth in emerging technologies such as Fluorescence Lifetime Microscopy (FLIM), Time-of-Flight Positron Emission Tomography (TOF-PET), quantum communications systems, and 3D imaging systems.
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Affiliation(s)
- Cesar Bartolo-Perez
- Electrical and Computer Engineering, University of California – Davis, Davis, California 95616, USA
| | - Ahasan Ahamed
- Electrical and Computer Engineering, University of California – Davis, Davis, California 95616, USA
| | - Ahmed S. Mayet
- Electrical and Computer Engineering, University of California – Davis, Davis, California 95616, USA
| | - Amita Rawat
- Electrical and Computer Engineering, University of California – Davis, Davis, California 95616, USA
| | - Lisa McPhillips
- Electrical and Computer Engineering, University of California – Davis, Davis, California 95616, USA
| | - Soroush Ghandiparsi
- Electrical and Computer Engineering, University of California – Davis, Davis, California 95616, USA
| | - Julien Bec
- Department of Biomedical Engineering, University of California – Davis, Davis, California 95616, USA
| | - Gerard Ariño-Estrada
- Department of Biomedical Engineering, University of California – Davis, Davis, California 95616, USA
| | - Simon Cherry
- Department of Biomedical Engineering, University of California – Davis, Davis, California 95616, USA
| | - Shih-Yuan Wang
- W&WSens Devices, Inc., 4546 El Camino, Suite 215, Los Altos, California 94022, USA
| | - Laura Marcu
- Department of Biomedical Engineering, University of California – Davis, Davis, California 95616, USA
| | - M. Saif Islam
- Electrical and Computer Engineering, University of California – Davis, Davis, California 95616, USA
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7
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Banerjee S, Mwangi JG, Stanley TK, Mitra R, Ebong EE. Regeneration and Assessment of the Endothelial Glycocalyx To Address Cardiovascular Disease. Ind Eng Chem Res 2021. [DOI: 10.1021/acs.iecr.1c03074] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Affiliation(s)
- Selina Banerjee
- Department of Chemical Engineering, Northeastern University, Boston, Massachusetts 02115, United States
| | - John G. Mwangi
- Department of Biology, Northeastern University, Boston, Massachusetts 02115, United States
| | - Theodora K. Stanley
- Department of Health Sciences, Northeastern University, Boston, Massachusetts 02115, United States
| | - Ronodeep Mitra
- Department of Chemical Engineering, Northeastern University, Boston, Massachusetts 02115, United States
| | - Eno E. Ebong
- Department of Chemical Engineering, Northeastern University, Boston, Massachusetts 02115, United States
- Department of Health Sciences, Northeastern University, Boston, Massachusetts 02115, United States
- Department of Bioengineering, Northeastern University, Boston, Massachusetts 02115, United States
- Department of Neuroscience, Albert Einstein College of Medicine, New York, New York 10461, United States
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8
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Kim S, Nam HS, Lee MW, Kim HJ, Kang WJ, Song JW, Han J, Kang DO, Oh WY, Yoo H, Kim JW. Comprehensive Assessment of High-Risk Plaques by Dual-Modal Imaging Catheter in Coronary Artery. JACC Basic Transl Sci 2021; 6:948-960. [PMID: 35024500 PMCID: PMC8733747 DOI: 10.1016/j.jacbts.2021.10.005] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/25/2021] [Revised: 10/04/2021] [Accepted: 10/04/2021] [Indexed: 01/22/2023]
Abstract
Fluorescence lifetime imaging (FLIm) allows label-free biochemical visualization of atheromas; however, it remains unknown whether FLIm can characterize high-risk plaque features in coronary arteries in a beating heart. Also, implementation of a novel analytic methodology is required for multispectral FLIm because it yields massive biochemical readouts. This study first demonstrated a simultaneous structural and biochemical assessment of high-risk plaques in the beating swine coronary arteries using a fully integrated optical coherence tomography-FLIm and a 2.9-F low-profile dual-modal catheter. Biochemical components of atherosclerotic plaques, including lipids, macrophages, lipids+macrophages, and fibrotic tissues, had unique fluorescence lifetime signatures that were clearly distinguishable using multispectral FLIm. Machine learning framework was successfully integrated with multispectral FLIm and enabled an automated, quantitative imaging of multiple key components associated with plaque destabilization.
Coronary plaque destabilization involves alterations in microstructure and biochemical composition; however, no imaging approach allows such comprehensive characterization. Herein, the authors demonstrated a simultaneous microstructural and biochemical assessment of high-risk plaques in the coronary arteries in a beating heart using a fully integrated optical coherence tomography and fluorescence lifetime imaging (FLIm). It was found that plaque components such as lipids, macrophages, lipids+macrophages, and fibrotic tissues had unique fluorescence lifetime signatures that were distinguishable using multispectral FLIm. Because FLIm yielded massive biochemical readouts, the authors incorporated machine learning framework into FLIm, and ultimately, their approach enabled an automated, quantitative imaging of multiple key components relevant for plaque destabilization.
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Affiliation(s)
- Sunwon Kim
- Multimodal Imaging and Theranostic Lab, Cardiovascular Center, Korea University Guro Hospital, Seoul, South Korea
- Department of Cardiology, Korea University Ansan Hospital, Ansan-si, South Korea
| | - Hyeong Soo Nam
- Department of Mechanical Engineering, Korea Advanced Institute of Science and Technology, Daejeon, South Korea
| | - Min Woo Lee
- Department of Biomedical Engineering, Hanyang University, Seoul, South Korea
| | - Hyun Jung Kim
- Multimodal Imaging and Theranostic Lab, Cardiovascular Center, Korea University Guro Hospital, Seoul, South Korea
| | - Woo Jae Kang
- Department of Mechanical Engineering, Korea Advanced Institute of Science and Technology, Daejeon, South Korea
- KI for Health Science and Technology, Korea Advanced Institute of Science and Technology, Daejeon, South Korea
| | - Joon Woo Song
- Multimodal Imaging and Theranostic Lab, Cardiovascular Center, Korea University Guro Hospital, Seoul, South Korea
| | - Jeongmoo Han
- Department of Mechanical Engineering, Korea Advanced Institute of Science and Technology, Daejeon, South Korea
| | - Dong Oh Kang
- Multimodal Imaging and Theranostic Lab, Cardiovascular Center, Korea University Guro Hospital, Seoul, South Korea
| | - Wang-Yuhl Oh
- Department of Mechanical Engineering, Korea Advanced Institute of Science and Technology, Daejeon, South Korea
- KI for Health Science and Technology, Korea Advanced Institute of Science and Technology, Daejeon, South Korea
| | - Hongki Yoo
- Department of Mechanical Engineering, Korea Advanced Institute of Science and Technology, Daejeon, South Korea
- Dr Hongki Yoo, Department of Mechanical Engineering, Korea Advanced Institute of Science and Technology, 291 Daehak-ro, Yuseong-gu, Daejeon 34141, South Korea.
| | - Jin Won Kim
- Multimodal Imaging and Theranostic Lab, Cardiovascular Center, Korea University Guro Hospital, Seoul, South Korea
- Address for correspondence: Dr Jin Won Kim, Multimodal Imaging and Theranostic Lab, Cardiovascular Center, Korea University Guro Hospital, 148 Gurodong-ro, Guro-gu, Seoul 08308, South Korea.
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Kellnberger S, Wissmeyer G, Albaghdadi M, Piao Z, Li W, Mauskapf A, Rauschendorfer P, Tearney GJ, Ntziachristos V, Jaffer FA. Intravascular molecular-structural imaging with a miniaturized integrated near-infrared fluorescence and ultrasound catheter. JOURNAL OF BIOPHOTONICS 2021; 14:e202100048. [PMID: 34164943 PMCID: PMC8492488 DOI: 10.1002/jbio.202100048] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/08/2021] [Revised: 05/11/2021] [Accepted: 06/10/2021] [Indexed: 05/29/2023]
Abstract
Coronary artery disease (CAD) remains a leading cause of mortality and warrants new imaging approaches to better guide clinical care. We report on a miniaturized, hybrid intravascular catheter and imaging system for comprehensive coronary artery imaging in vivo. Our catheter exhibits a total diameter of 1.0 mm (3.0 French), equivalent to standalone clinical intravascular ultrasound (IVUS) catheters but enables simultaneous near-infrared fluorescence (NIRF) and IVUS molecular-structural imaging. We demonstrate NIRF-IVUS imaging in vitro in coronary stents using NIR fluorophores, and compare NIRF signal strengths for prism and ball lens sensor designs in both low and high scattering media. Next, in vivo intravascular imaging in pig coronary arteries demonstrates simultaneous, co-registered molecular-structural imaging of experimental CAD inflammation on IVUS and distance-corrected NIRF images. The obtained results suggest substantial potential for the NIRF-IVUS catheter to advance standalone IVUS, and enable comprehensive phenotyping of vascular disease to better assess and treat patients with CAD.
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Affiliation(s)
- Stephan Kellnberger
- Cardiovascular Research Center, Cardiology Division, Massachusetts General Hospital, Boston, MA 02114
| | - Georg Wissmeyer
- Cardiovascular Research Center, Cardiology Division, Massachusetts General Hospital, Boston, MA 02114
| | - Mazen Albaghdadi
- Cardiovascular Research Center, Cardiology Division, Massachusetts General Hospital, Boston, MA 02114
| | - Zhonglie Piao
- Wellman Center for Photomedicine, Massachusetts General Hospital, Boston, MA 02114
| | - Wenzhu Li
- Cardiovascular Research Center, Cardiology Division, Massachusetts General Hospital, Boston, MA 02114
| | - Adam Mauskapf
- Cardiovascular Research Center, Cardiology Division, Massachusetts General Hospital, Boston, MA 02114
| | - Philipp Rauschendorfer
- Institute of Biological and Medical Imaging, Helmholtz Zentrum München, Neuherberg, Germany
- Chair of Biological Imaging, Central Institute for Translational Cancer Research (TranslaTUM), Technical University of Munich, Germany
| | - Guillermo J. Tearney
- Wellman Center for Photomedicine, Massachusetts General Hospital, Boston, MA 02114
| | - Vasilis Ntziachristos
- Institute of Biological and Medical Imaging, Helmholtz Zentrum München, Neuherberg, Germany
- Chair of Biological Imaging, Central Institute for Translational Cancer Research (TranslaTUM), Technical University of Munich, Germany
| | - Farouc A. Jaffer
- Cardiovascular Research Center, Cardiology Division, Massachusetts General Hospital, Boston, MA 02114
- Wellman Center for Photomedicine, Massachusetts General Hospital, Boston, MA 02114
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10
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Zhou X, Bec J, Yankelevich D, Marcu L. Multispectral fluorescence lifetime imaging device with a silicon avalanche photodetector. OPTICS EXPRESS 2021; 29:20105-20120. [PMID: 34266107 PMCID: PMC8237936 DOI: 10.1364/oe.425632] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/24/2021] [Revised: 05/26/2021] [Accepted: 05/28/2021] [Indexed: 05/08/2023]
Abstract
We report the design, development, and characterization of a novel multi-spectral fluorescence lifetime measurement device incorporating solid-state detectors and automated gain control. For every excitation pulse (∼1 µJ, 600 ps), this device records complete fluorescence decay from multiple spectral channels simultaneously within microseconds, using a dedicated UV enhanced avalanche photodetector and analog to digital convert (2.5 GS/s) in each channel. Fast (<2 ms) channel-wise dynamic range adjustment maximizes the signal-to-noise ratio. Fluorophores with known lifetime ranging from 0.5-6.0 ns were used to demonstrate the device accuracy. Current results show the clear benefits of this device compared to existing devices employing microchannel-plate photomultiplier tubes. This is demonstrated by 5-fold reduction of lifetime measurement variability in identical conditions, independent gain adjustment in each spectral band, and 4-times faster imaging speed. The use of solid-state detectors will also facilitate future improved performance and miniaturization of the instrument.
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Affiliation(s)
- Xiangnan Zhou
- Department of Biomedical Engineering, University of California, 451 Health Sciences Drive, Davis, California 95616, USA
| | - Julien Bec
- Department of Biomedical Engineering, University of California, 451 Health Sciences Drive, Davis, California 95616, USA
| | - Diego Yankelevich
- Department of Electrical and Computer Engineering, University of California, 3101 Kemper Hall, Davis, California 95616, USA
| | - Laura Marcu
- Department of Biomedical Engineering, University of California, 451 Health Sciences Drive, Davis, California 95616, USA
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11
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Sung JH, Chang JH. Mechanically Rotating Intravascular Ultrasound (IVUS) Transducer: A Review. SENSORS (BASEL, SWITZERLAND) 2021; 21:3907. [PMID: 34198822 PMCID: PMC8201242 DOI: 10.3390/s21113907] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/30/2021] [Revised: 05/31/2021] [Accepted: 06/03/2021] [Indexed: 12/30/2022]
Abstract
Intravascular ultrasound (IVUS) is a valuable imaging modality for the diagnosis of atherosclerosis. It provides useful clinical information, such as lumen size, vessel wall thickness, and plaque composition, by providing a cross-sectional vascular image. For several decades, IVUS has made remarkable progress in improving the accuracy of diagnosing cardiovascular disease that remains the leading cause of death globally. As the quality of IVUS images mainly depends on the performance of the IVUS transducer, various IVUS transducers have been developed. Therefore, in this review, recently developed mechanically rotating IVUS transducers, especially ones exploiting piezoelectric ceramics or single crystals, are discussed. In addition, this review addresses the history and technical challenges in the development of IVUS transducers and the prospects of next-generation IVUS transducers.
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Affiliation(s)
| | - Jin-Ho Chang
- Department of Information and Communication Engineering, Deagu Gyeongbuk Institute of Science and Technology, Daegu 42988, Korea;
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Alfonso-Garcia A, Bec J, Weyers B, Marsden M, Zhou X, Li C, Marcu L. Mesoscopic fluorescence lifetime imaging: Fundamental principles, clinical applications and future directions. JOURNAL OF BIOPHOTONICS 2021; 14:e202000472. [PMID: 33710785 PMCID: PMC8579869 DOI: 10.1002/jbio.202000472] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/27/2020] [Revised: 03/03/2021] [Accepted: 03/05/2021] [Indexed: 05/16/2023]
Abstract
Fluorescence lifetime imaging (FLIm) is an optical spectroscopic imaging technique capable of real-time assessments of tissue properties in clinical settings. Label-free FLIm is sensitive to changes in tissue structure and biochemistry resulting from pathological conditions, thus providing optical contrast to identify and monitor the progression of disease. Technical and methodological advances over the last two decades have enabled the development of FLIm instrumentation for real-time, in situ, mesoscopic imaging compatible with standard clinical workflows. Herein, we review the fundamental working principles of mesoscopic FLIm, discuss the technical characteristics of current clinical FLIm instrumentation, highlight the most commonly used analytical methods to interpret fluorescence lifetime data and discuss the recent applications of FLIm in surgical oncology and cardiovascular diagnostics. Finally, we conclude with an outlook on the future directions of clinical FLIm.
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Affiliation(s)
- Alba Alfonso-Garcia
- Department of Biomedical Engineering, University of California, Davis, Davis, California
| | - Julien Bec
- Department of Biomedical Engineering, University of California, Davis, Davis, California
| | - Brent Weyers
- Department of Biomedical Engineering, University of California, Davis, Davis, California
| | - Mark Marsden
- Department of Biomedical Engineering, University of California, Davis, Davis, California
| | - Xiangnan Zhou
- Department of Biomedical Engineering, University of California, Davis, Davis, California
| | - Cai Li
- Department of Biomedical Engineering, University of California, Davis, Davis, California
| | - Laura Marcu
- Department of Biomedical Engineering, University of California, Davis, Davis, California
- Department Neurological Surgery, University of California, Davis, California
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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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Positive Remodeling – a Major Feature of Vulnerability in Patients with Non-Obstructive Coronary Artery Disease. JOURNAL OF INTERDISCIPLINARY MEDICINE 2021. [DOI: 10.2478/jim-2021-0005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Abstract
The most common cause of acute coronary syndrome is thrombosis of an atheromatous plaque. Positive remodeling is the compensatory dilatation of the plaque-containing section of the vessel wall. Plaques are most commonly characterized as vulnerable when possessing some of the following features: fibrous cap thickness <65 µm, large necrotic lipid core, high degrees of inflammatory infiltrates, positive remodeling, intraplaque hemorrhage, or neoangio-genesis. The presence of these plaque features is associated with high cardiovascular risk. In the initial stage of vasculopathy, due to positive remodeling, lumen reduction is not typical; it only develops in the advanced phase of the disease, due to which, based on a lumenogram, the vascular system may appear intact. Therefore, coronary angiography can easily miss the diagnosis or underestimate its extent, since it does not inform us of the composition of the arterial wall, because the contrast agent is just filling the vessel lumen. Coronary CT angiography may fill this diagnostic gap, since changes of the vessel wall can directly be visualized. To increase diagnostic accuracy, invasive coronary angiography can be completed by intravascular ultrasound and optical coherence tomography.
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Disease-Relevant Single Cell Photonic Signatures Identify S100β Stem Cells and their Myogenic Progeny in Vascular Lesions. Stem Cell Rev Rep 2021; 17:1713-1740. [PMID: 33730327 PMCID: PMC8446106 DOI: 10.1007/s12015-021-10125-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/20/2021] [Indexed: 10/31/2022]
Abstract
A hallmark of subclinical atherosclerosis is the accumulation of vascular smooth muscle cell (SMC)-like cells leading to intimal thickening and lesion formation. While medial SMCs contribute to vascular lesions, the involvement of resident vascular stem cells (vSCs) remains unclear. We evaluated single cell photonics as a discriminator of cell phenotype in vitro before the presence of vSC within vascular lesions was assessed ex vivo using supervised machine learning and further validated using lineage tracing analysis. Using a novel lab-on-a-Disk(Load) platform, label-free single cell photonic emissions from normal and injured vessels ex vivo were interrogated and compared to freshly isolated aortic SMCs, cultured Movas SMCs, macrophages, B-cells, S100β+ mVSc, bone marrow derived mesenchymal stem cells (MSC) and their respective myogenic progeny across five broadband light wavelengths (λ465 - λ670 ± 20 nm). We found that profiles were of sufficient coverage, specificity, and quality to clearly distinguish medial SMCs from different vascular beds (carotid vs aorta), discriminate normal carotid medial SMCs from lesional SMC-like cells ex vivo following flow restriction, and identify SMC differentiation of a series of multipotent stem cells following treatment with transforming growth factor beta 1 (TGF- β1), the Notch ligand Jagged1, and Sonic Hedgehog using multivariate analysis, in part, due to photonic emissions from enhanced collagen III and elastin expression. Supervised machine learning supported genetic lineage tracing analysis of S100β+ vSCs and identified the presence of S100β+vSC-derived myogenic progeny within vascular lesions. We conclude disease-relevant photonic signatures may have predictive value for vascular disease.
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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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Shaik TA, Alfonso-Garcia A, Richter M, Korinth F, Krafft C, Marcu L, Popp J. FLIm and Raman Spectroscopy for Investigating Biochemical Changes of Bovine Pericardium upon Genipin Cross-Linking. Molecules 2020; 25:E3857. [PMID: 32854230 PMCID: PMC7503846 DOI: 10.3390/molecules25173857] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2020] [Revised: 08/18/2020] [Accepted: 08/19/2020] [Indexed: 12/11/2022] Open
Abstract
Biomaterials used in tissue engineering and regenerative medicine applications benefit from longitudinal monitoring in a non-destructive manner. Label-free imaging based on fluorescence lifetime imaging (FLIm) and Raman spectroscopy were used to monitor the degree of genipin (GE) cross-linking of antigen-removed bovine pericardium (ARBP) at three incubation time points (0.5, 1.0, and 2.5 h). Fluorescence lifetime decreased and the emission spectrum redshifted compared to that of uncross-linked ARBP. The Raman signature of GE-ARBP was resonance-enhanced due to the GE cross-linker that generated new Raman bands at 1165, 1326, 1350, 1380, 1402, 1470, 1506, 1535, 1574, 1630, 1728, and 1741 cm-1. These were validated through density functional theory calculations as cross-linker-specific bands. A multivariate multiple regression model was developed to enhance the biochemical specificity of FLIm parameters fluorescence intensity ratio (R2 = 0.92) and lifetime (R2 = 0.94)) with Raman spectral results. FLIm and Raman spectroscopy detected biochemical changes occurring in the collagenous tissue during the cross-linking process that were characterized by the formation of a blue pigment which affected the tissue fluorescence and scattering properties. In conclusion, FLIm parameters and Raman spectroscopy were used to monitor the degree of cross-linking non-destructively.
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Affiliation(s)
- Tanveer Ahmed Shaik
- Leibniz Institute of Photonic Technology Jena e.V., Albert-Einstein-Str. 9, 07745 Jena, Germany; (T.A.S.); (F.K.); (C.K.)
| | - Alba Alfonso-Garcia
- Biomedical Engineering Department, University of California Davis, Davis, CA 95616, USA;
| | - Martin Richter
- Institute of Physical Chemistry and Abbe Center of Photonics, Friedrich Schiller University Jena, Helmholtzweg 4, 07743 Jena, Germany;
| | - Florian Korinth
- Leibniz Institute of Photonic Technology Jena e.V., Albert-Einstein-Str. 9, 07745 Jena, Germany; (T.A.S.); (F.K.); (C.K.)
| | - Christoph Krafft
- Leibniz Institute of Photonic Technology Jena e.V., Albert-Einstein-Str. 9, 07745 Jena, Germany; (T.A.S.); (F.K.); (C.K.)
| | - Laura Marcu
- Biomedical Engineering Department, University of California Davis, Davis, CA 95616, USA;
| | - Jürgen Popp
- Leibniz Institute of Photonic Technology Jena e.V., Albert-Einstein-Str. 9, 07745 Jena, Germany; (T.A.S.); (F.K.); (C.K.)
- Institute of Physical Chemistry and Abbe Center of Photonics, Friedrich Schiller University Jena, Helmholtzweg 4, 07743 Jena, Germany;
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18
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Shaik TA, Alfonso-García A, Zhou X, Arnold KM, Haudenschild AK, Krafft C, Griffiths LG, Popp J, Marcu L. FLIm-Guided Raman Imaging to Study Cross-Linking and Calcification of Bovine Pericardium. Anal Chem 2020; 92:10659-10667. [PMID: 32598134 PMCID: PMC7539574 DOI: 10.1021/acs.analchem.0c01772] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Bovine pericardium (BP) is a vascular biomaterial used in cardiovascular surgery that is typically cross-linked for masking antigenicity and enhance stability. There is a need for biochemical evaluation of the tissue properties prior to implantation to ensure that quality and reliability standards are met. Here, engineered antigen removed BP (ARBP) that was cross-linked with 0.2% and 0.6% glutaraldehyde (GA), and further calcified in vitro to simulate graft calcifications upon implantation was characterized nondestructively using fluorescence lifetime imaging (FLIm) to identify regions of interest which were then assessed by Raman spectroscopy. We observed that the tissue fluorescence lifetime shortened, and that Raman bands at 856, 935, 1282, and 1682 cm-1 decreased, and at 1032 and 1627 cm-1 increased with increasing GA cross-linking. Independent classification analysis based on fluorescence lifetime and on Raman spectra discriminated between GA-ARBP and untreated ARBP with an accuracy of 91% and 66%, respectively. Pearson's correlation analysis showed a strong correlation between pyridinium cross-links measured with high-performance liquid chromatography and fluorescence lifetime measured at 380-400 nm (R = -0.76, p = 0.00094), as well as Raman bands at 856 cm-1 for hydroxy-proline (R = -0.68, p = 0.0056) and at 1032 cm-1 for hydroxy-pyridinium (R = 0.74, p = 0.0016). Calcified areas of GA cross-linked tissue showed characteristic hydroxyapatite (959 and 1038 cm-1) bands in the Raman spectrum and fluorescence lifetime shortened by 0.4 ns compared to uncalcified regions. FLIm-guided Raman imaging could rapidly identify degrees of cross-linking and detected calcified regions with high chemical specificity, an ability that can be used to monitor tissue engineering processes for applications in regenerative medicine.
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Affiliation(s)
- Tanveer Ahmed Shaik
- Leibniz Institute of Photonic Technology Jena e.V., Albert-Einstein-Strasse 9, 07745 Jena, Germany
| | - Alba Alfonso-García
- Department of Biomedical Engineering, University of California Davis, One Shields Avenue, Davis, California 95616, United States
| | - Xiangnan Zhou
- Department of Biomedical Engineering, University of California Davis, One Shields Avenue, Davis, California 95616, United States
| | - Katherine M Arnold
- Department of Cardiovascular Diseases, Mayo Clinic, Rochester, Minnesota 55905, United States
| | - Anne K Haudenschild
- Department of Biomedical Engineering, University of California Davis, One Shields Avenue, Davis, California 95616, United States
| | - Christoph Krafft
- Leibniz Institute of Photonic Technology Jena e.V., Albert-Einstein-Strasse 9, 07745 Jena, Germany
| | - Leigh G Griffiths
- Department of Cardiovascular Diseases, Mayo Clinic, Rochester, Minnesota 55905, United States
| | - Jürgen Popp
- Leibniz Institute of Photonic Technology Jena e.V., Albert-Einstein-Strasse 9, 07745 Jena, Germany
- Institute of Physical Chemistry and Abbe Center of Photonics, Friedrich Schiller University Jena, Helmholtzweg 4, 07743 Jena, Germany
| | - Laura Marcu
- Department of Biomedical Engineering, University of California Davis, One Shields Avenue, Davis, California 95616, United States
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19
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Bec J, Shaik TA, Krafft C, Bocklitz TW, Alfonso-Garcia A, Margulies KB, Popp J, Marcu L. Investigating Origins of FLIm Contrast in Atherosclerotic Lesions Using Combined FLIm-Raman Spectroscopy. Front Cardiovasc Med 2020; 7:122. [PMID: 32793637 PMCID: PMC7385056 DOI: 10.3389/fcvm.2020.00122] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2019] [Accepted: 06/12/2020] [Indexed: 12/30/2022] Open
Abstract
Background: Fluorescence lifetime imaging (FLIm) is a spectroscopic imaging technique able to characterize the composition of luminal surface of arterial vessels. Studies of human coronary samples demonstrated that distinct atherosclerotic lesion types are characterized by FLIm features associate with distinct tissue molecular makeup. While conventional histology has provided indications about potential sources of molecular contrast, specific information about the origin of FLIm signals is lacking. Here we investigate whether Raman spectroscopy, a technique able to evaluate chemical content of biological samples, can provide additional insight into the origin of FLIm contrast. Methods: Six human coronary artery samples were imaged using FLIm (355 nm excitation)-Raman spectroscopy (785 nm excitation) via a multimodal fiber optic probe. The spatial distribution of molecular contrast in FLIm images was analyzed in relationship with histological findings. Raman data was investigated using an endmember technique and compared with histological findings. A descriptive modeling approach based on multivariate regression was used to identify Raman bands related with changes in lifetime in four spectral channels (violet: 387/35 nm, blue: 443/29 nm, green: 546/38 nm, and red: 628/53 nm). Results: Fluorescence lifetime variations in the violet, blue and green spectral bands were observed for distinct areas of each tissue sample associated with distinct pathologies. Analysis of Raman signals from areas associated with normal, pathological intimal thickening, and fibrocalcific regions demonstrated the presence of hydroxyapatite, collagenous proteins, carotene, cholesterol, and triglycerides. The FLIm and Raman descriptive modeling analysis indicated that lifetime increase in the violet spectral band was associated with increased presence of cholesterol and carotenes, a new finding consistent with LDL accumulation in atherosclerotic lesions, and not with collagen proteins, as expected from earlier studies. Conclusions: The systematic, quantitative analysis of the multimodal FLIm-Raman dataset using a descriptive modeling approach led to the identification of LDL accumulation as the primary source of lifetime contrast in atherosclerotic lesions in the violet spectral range. Earlier FLIm validation studies relying on histopathological findings had associated this contrast to increased collagen content, also present in advanced lesions, thus demonstrating the benefits of alternative validation methods.
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Affiliation(s)
- Julien Bec
- Department of Biomedical Engineering, University of California, Davis, Davis, CA, United States.,Institute of Physical Chemistry and Abbe Center of Photonics (IPC), Friedrich-Schiller-University, Jena, Germany.,Leibniz Institute of Photonic Technology, Jena, Germany
| | | | | | - Thomas W Bocklitz
- Institute of Physical Chemistry and Abbe Center of Photonics (IPC), Friedrich-Schiller-University, Jena, Germany.,Leibniz Institute of Photonic Technology, Jena, Germany
| | - Alba Alfonso-Garcia
- Department of Biomedical Engineering, University of California, Davis, Davis, CA, United States
| | - Kenneth B Margulies
- Cardiovascular Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, United States
| | - Jürgen Popp
- Institute of Physical Chemistry and Abbe Center of Photonics (IPC), Friedrich-Schiller-University, Jena, Germany.,Leibniz Institute of Photonic Technology, Jena, Germany
| | - Laura Marcu
- Department of Biomedical Engineering, University of California, Davis, Davis, CA, United States
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Lagarto JL, Villa F, Tisa S, Zappa F, Shcheslavskiy V, Pavone FS, Cicchi R. Real-time multispectral fluorescence lifetime imaging using Single Photon Avalanche Diode arrays. Sci Rep 2020; 10:8116. [PMID: 32415224 PMCID: PMC7229199 DOI: 10.1038/s41598-020-65218-3] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2020] [Accepted: 04/24/2020] [Indexed: 12/19/2022] Open
Abstract
Autofluorescence spectroscopy has emerged in recent years as a powerful tool to report label-free contrast between normal and diseased tissues, both in vivo and ex vivo. We report the development of an instrument employing Single Photon Avalanche Diode (SPAD) arrays to realize real-time multispectral autofluorescence lifetime imaging at a macroscopic scale using handheld single-point fibre optic probes, under bright background conditions. At the detection end, the fluorescence signal is passed through a transmission grating and both spectral and temporal information are encoded in the SPAD array. This configuration allows interrogation in the spectral range of interest in real time. Spatial information is provided by an external camera together with a guiding beam that provides a visual reference that is tracked in real-time. Through fast image processing and data analysis, fluorescence lifetime maps are augmented on white light images to provide feedback of the measurements in real-time. We validate and demonstrate the practicality of this technique in the reference fluorophores and in articular cartilage samples mimicking the degradation that occurs in osteoarthritis. Our results demonstrate that SPADs together with fibre probes can offer means to report autofluorescence spectral and lifetime contrast in real-time and thus are suitable candidates for in situ tissue diagnostics.
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Affiliation(s)
- João L Lagarto
- National Institute of Optics National Research Council (INO-CNR), Largo Enrico Fermi 6, 50125, Florence, Italy.
- European Laboratory for Non-linear Spectroscopy (LENS), Via Nello Carrara 1, 50019, Sesto Fiorentino, Italy.
| | - Federica Villa
- Dipartimento di Elettronica, Informazione e Bioingegneria (DEIB), Politecnico di Milano, 20133, Milan, Italy
| | - Simone Tisa
- Micro Photon Device SRL, Via Waltraud Gebert Deeg 3g, I-39100, Bolzano, Italy
| | - Franco Zappa
- Dipartimento di Elettronica, Informazione e Bioingegneria (DEIB), Politecnico di Milano, 20133, Milan, Italy
| | - Vladislav Shcheslavskiy
- Becker & Hickl GmbH, Nunsdorfer Ring 7-9, 12277, Berlin, Germany
- Privolzhskiy Medical Research University, 603005, Nizhny Novgorod, Russia
| | - Francesco S Pavone
- National Institute of Optics National Research Council (INO-CNR), Largo Enrico Fermi 6, 50125, Florence, Italy
- European Laboratory for Non-linear Spectroscopy (LENS), Via Nello Carrara 1, 50019, Sesto Fiorentino, Italy
- Department of Physics, University of Florence, Via G. Sansone 1, 50019, Sesto Fiorentino, Italy
| | - Riccardo Cicchi
- National Institute of Optics National Research Council (INO-CNR), Largo Enrico Fermi 6, 50125, Florence, Italy
- European Laboratory for Non-linear Spectroscopy (LENS), Via Nello Carrara 1, 50019, Sesto Fiorentino, Italy
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21
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Unger J, Hebisch C, Phipps JE, Lagarto JL, Kim H, Darrow MA, Bold RJ, Marcu L. Real-time diagnosis and visualization of tumor margins in excised breast specimens using fluorescence lifetime imaging and machine learning. BIOMEDICAL OPTICS EXPRESS 2020; 11:1216-1230. [PMID: 32206404 PMCID: PMC7075618 DOI: 10.1364/boe.381358] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/25/2019] [Revised: 01/14/2020] [Accepted: 01/14/2020] [Indexed: 05/03/2023]
Abstract
Tumor-free surgical margins are critical in breast-conserving surgery. In up to 38% of the cases, however, patients undergo a second surgery since malignant cells are found at the margins of the excised resection specimen. Thus, advanced imaging tools are needed to ensure clear margins at the time of surgery. The objective of this study was to evaluate a random forest classifier that makes use of parameters derived from point-scanning label-free fluorescence lifetime imaging (FLIm) measurements of breast specimens as a means to diagnose tumor at the resection margins and to enable an intuitive visualization of a probabilistic classifier on tissue specimen. FLIm data from fresh lumpectomy and mastectomy specimens from 18 patients were used in this study. The supervised training was based on a previously developed registration technique between autofluorescence imaging data and cross-sectional histology slides. A pathologist's histology annotations provide the ground truth to distinguish between adipose, fibrous, and tumor tissue. Current results demonstrate the ability of this approach to classify the tumor with 89% sensitivity and 93% specificity and to rapidly (∼ 20 frames per second) overlay the probabilistic classifier overlaid on excised breast specimens using an intuitive color scheme. Furthermore, we show an iterative imaging refinement that allows surgeons to switch between rapid scans with a customized, low spatial resolution to quickly cover the specimen and slower scans with enhanced resolution (400 μm per point measurement) in suspicious regions where more details are required. In summary, this technique provides high diagnostic prediction accuracy, rapid acquisition, adaptive resolution, nondestructive probing, and facile interpretation of images, thus holding potential for clinical breast imaging based on label-free FLIm.
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Affiliation(s)
- Jakob Unger
- Department of Biomedical Engineering, University of California Davis, California, CA 95616, USA
- Corresponding authors
| | - Christoph Hebisch
- Department of Biomedical Engineering, University of California Davis, California, CA 95616, USA
| | - Jennifer E. Phipps
- Department of Biomedical Engineering, University of California Davis, California, CA 95616, USA
| | - João L. Lagarto
- Department of Biomedical Engineering, University of California Davis, California, CA 95616, USA
| | - Hanna Kim
- Department of Otolaryngology, University of California Davis, California, CA 95817, USA
| | - Morgan A. Darrow
- Department of Pathology and Laboratory Medicine, University of California Davis, California, CA 95817, USA
| | - Richard J. Bold
- Department of Surgery, University of California Davis, California, CA 95817, USA
| | - Laura Marcu
- Department of Biomedical Engineering, University of California Davis, California, CA 95616, USA
- Corresponding authors
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22
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Lagarto JL, Shcheslavskiy V, Pavone FS, Cicchi R. Real-time fiber-based fluorescence lifetime imaging with synchronous external illumination: A new path for clinical translation. JOURNAL OF BIOPHOTONICS 2020; 13:e201960119. [PMID: 31742905 DOI: 10.1002/jbio.201960119] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/18/2019] [Revised: 11/13/2019] [Accepted: 11/15/2019] [Indexed: 05/22/2023]
Abstract
Time-correlated single photon counting is the "gold-standard" method for fluorescence lifetime measurements and has demonstrated potential for clinical deployment. However, the translation of the technology into clinic is hindered by the use of ultrasensitive detectors, which make the fluorescence acquisition impractical with bright lighting conditions such as in clinical settings. We address this limitation by interleaving periodic fluorescence detection with synchronous out-of-phase externally modulated light source, thus guaranteeing specimen illumination and a fluorescence signal free from bright background light upon temporal separation. Fluorescence lifetime maps are generated in real-time from single-point measurements by tracking a reference beam and using the phasor approach. We demonstrate the feasibility and practicality of this technique in a number of biological specimens, including real-time mapping of degraded articular cartilage. This method is compatible and can be integrated with existing clinical microscopic, endoscopic and robotic modalities, thus offering a new pathway towards label-free diagnostics and surgical guidance in a number of clinical applications.
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Affiliation(s)
- João L Lagarto
- National Institute of Optics, National Research Council (INO-CNR), Sesto Fiorentino, Italy
- European Laboratory for Non-linear Spectroscopy (LENS), Sesto Fiorentino, Italy
| | | | - Francesco S Pavone
- National Institute of Optics, National Research Council (INO-CNR), Sesto Fiorentino, Italy
- European Laboratory for Non-linear Spectroscopy (LENS), Sesto Fiorentino, Italy
- Department of Physics, University of Florence, Sesto Fiorentino, Italy
| | - Riccardo Cicchi
- National Institute of Optics, National Research Council (INO-CNR), Sesto Fiorentino, Italy
- European Laboratory for Non-linear Spectroscopy (LENS), Sesto Fiorentino, Italy
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23
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Li Y, Chen J, Chen Z. Multimodal intravascular imaging technology for characterization of atherosclerosis. JOURNAL OF INNOVATIVE OPTICAL HEALTH SCIENCES 2020; 13:2030001. [PMID: 32308744 PMCID: PMC7164814 DOI: 10.1142/s1793545820300013] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Early detection of vulnerable plaques is the critical step in the prevention of acute coronary events. Morphology, composition, and mechanical property of a coronary artery have been demonstrated to be the key characteristics for the identification of vulnerable plaques. Several intravascular multimodal imaging technologies providing co-registered simultaneous images have been developed and applied in clinical studies to improve the characterization of atherosclerosis. In this paper, the authors review the present system and probe designs of representative intravascular multimodal techniques. In addition, the scientific innovations, potential limitations, and future directions of these technologies are also discussed.
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Affiliation(s)
- Yan Li
- Beckman Laser Institute, University of California, Irvine 1002 Health Sciences Road, Irvine, CA 92617 USA
| | - Jason Chen
- Beckman Laser Institute, University of California, Irvine 1002 Health Sciences Road, Irvine, CA 92617 USA
| | - Zhongping Chen
- Department of Biomedical Engineering University of California, Irvine, CA 92697-2700 USA
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24
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Bec J, Li C, Marcu L. Broadband, freeform focusing micro-optics for a side-viewing imaging catheter. OPTICS LETTERS 2019; 44:4961-4964. [PMID: 31613239 PMCID: PMC9010228 DOI: 10.1364/ol.44.004961] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/10/2019] [Accepted: 08/30/2019] [Indexed: 05/28/2023]
Abstract
Successful implementation of a catheter-based imaging system relies on the integration of high-performance miniaturized distal end optics. Typically, compensation of chromatic dispersion, as well as astigmatism introduced by the device's sheath, can be addressed only by combining multiple optical elements, adversely impacting size and manufacturability. Here, we present a 300×300×800 μm3 monolithic optic that provides high optical performances over an extended wavelength range (near UV-visible-IR) with minimal chromatic aberrations. The design of the optic, fully optimized using standard optical simulation tools, provides the ability to freely determine aperture and working distance. Manufacturing is cost effective and suited for prototyping and production alike. The experimental characterization of the optic demonstrates a good match with simulation results and performances well suited to both optical coherence tomography and fluorescence imaging, thus paving the way for high-performance multimodal endoscopy systems.
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Affiliation(s)
- Julien Bec
- Department of Biomedical Engineering, University of California, Davis, California 95616, USA
- Institute of Physical Chemistry and Abbe Center of Photonics (IPC), Friedrich-Schiller-University, D-07743 Jena, Germany
- Leibniz Institute of Photonic Technology, D-07745 Jena, Germany
| | - Cai Li
- Department of Biomedical Engineering, University of California, Davis, California 95616, USA
| | - Laura Marcu
- Department of Biomedical Engineering, University of California, Davis, California 95616, USA
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25
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Lagarto JL, Dyer BT, Peters NS, French PMW, Dunsby C, Lyon AR. In vivo label-free optical monitoring of structural and metabolic remodeling of myocardium following infarction. BIOMEDICAL OPTICS EXPRESS 2019; 10:3506-3521. [PMID: 31360603 PMCID: PMC6640823 DOI: 10.1364/boe.10.003506] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/05/2019] [Revised: 05/15/2019] [Accepted: 05/29/2019] [Indexed: 05/14/2023]
Abstract
Cardiac remodeling following myocardial infarction (MI) involves structural and functional alterations in the infarcted and remote viable myocardium that can ultimately lead to heart failure. The underlying mechanisms are not fully understood and, following our previous study of the autofluorescence lifetime and diffuse reflectance signatures of the myocardium in vivo at 16 weeks post MI in rats [Biomed. Opt. Express6(2), 324 (2015)], we here present data obtained at 1, 2 and 4 weeks post myocardial infarction that help follow the temporal progression of these changes. Our results demonstrate that both structural and metabolic changes in the heart can be monitored from the earliest time points following MI using label-free optical readouts, not only in the region of infarction but also in the remote non-infarcted myocardium. Changes in the autofluorescence intensity and lifetime parameters associated with collagen type I autofluorescence were indicative of progressive collagen deposition in tissue that was most pronounced at earlier time points and in the region of infarction. In addition to significant collagen deposition in infarcted and non-infarcted myocardium, we also report changes in the autofluorescence parameters associated with reduced nicotinamide adenine (phosphate) dinucleotide (NAD(P)H) and flavin adenine dinucleotide (FAD), which we associate with metabolic alterations throughout the heart. Parallel measurements of the diffuse reflectance spectra indicated an increased contribution of reduced cytochrome c. Our findings suggest that combining time-resolved spectrofluorometry and diffuse reflectance spectroscopy could provide a useful means to monitor cardiac function in vivo at the time of surgery.
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Affiliation(s)
- João L. Lagarto
- Photonics Group, Department of Physics, Imperial College London, Prince Consort Road, London, SW7 2AZ, United Kingdom
- Authors contributed equally to this work
| | - Benjamin T. Dyer
- National Heart and Lung Institute, Imperial College London, Du Cane Road, London, W12 0NN, United Kingdom
- Authors contributed equally to this work
| | - Nicholas S. Peters
- National Heart and Lung Institute, Imperial College London, Du Cane Road, London, W12 0NN, United Kingdom
- Centre for Cardiac Engineering, Imperial College London, Du Cane Road, London, W12 0NN, United Kingdom
| | - Paul M. W. French
- Photonics Group, Department of Physics, Imperial College London, Prince Consort Road, London, SW7 2AZ, United Kingdom
| | - Chris Dunsby
- Photonics Group, Department of Physics, Imperial College London, Prince Consort Road, London, SW7 2AZ, United Kingdom
- Centre for Pathology, Imperial College London Du Cane Road, London W12 0NN, United Kingdom
- Authors contributed equally to this work
| | - Alexander R. Lyon
- National Heart and Lung Institute, Imperial College London, Du Cane Road, London, W12 0NN, United Kingdom
- Authors contributed equally to this work
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26
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Multispectral Depth-Resolved Fluorescence Lifetime Spectroscopy Using SPAD Array Detectors and Fiber Probes. SENSORS 2019; 19:s19122678. [PMID: 31200569 PMCID: PMC6631026 DOI: 10.3390/s19122678] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/27/2019] [Revised: 06/10/2019] [Accepted: 06/12/2019] [Indexed: 01/29/2023]
Abstract
Single Photon Avalanche Diode (SPAD) arrays are increasingly exploited and have demonstrated potential in biochemical and biomedical research, both for imaging and single-point spectroscopy applications. In this study, we explore the application of SPADs together with fiber-optic-based delivery and collection geometry to realize fast and simultaneous single-point time-, spectral-, and depth-resolved fluorescence measurements at 375 nm excitation light. Spectral information is encoded across the columns of the array through grating-based dispersion, while depth information is encoded across the rows thanks to a linear arrangement of probe collecting fibers. The initial characterization and validation were realized against layered fluorescent agarose-based phantoms. To verify the practicality and feasibility of this approach in biological specimens, we measured the fluorescence signature of formalin-fixed rabbit aorta samples derived from an animal model of atherosclerosis. The initial results demonstrate that this detection configuration can report fluorescence spectral and lifetime contrast originating at different depths within the specimens. We believe that our optical scheme, based on SPAD array detectors and fiber-optic probes, constitute a powerful and versatile approach for the deployment of multidimensional fluorescence spectroscopy in clinical applications where information from deeper tissue layers is important for diagnosis.
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27
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Sherlock BE, Li C, Zhou X, Alfonso-Garcia A, Bec J, Yankelevich D, Marcu L. Multiscale, multispectral fluorescence lifetime imaging using a double-clad fiber. OPTICS LETTERS 2019; 44:2302-2305. [PMID: 31042209 PMCID: PMC7539568 DOI: 10.1364/ol.44.002302] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
Fiber-based imaging of tissue autofluorescence using ultraviolet (UV) excitation is a highly flexible tool used to probe structure and composition. In this Letter, we report, to the best of our knowledge, the first results from a single-fiber imaging system employing a custom double-clad fiber to acquire multispectral fluorescence lifetime images at two distinct spatial resolutions. We characterize the lateral point spread function and fluorescent background of the system and show how enhanced resolution can identify features such as trabeculae in ex vivo murine bone samples.
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Affiliation(s)
- Benjamin E. Sherlock
- Genome and Biomedical Sciences Facility, University of California, Davis, 451 Health Sciences Drive, Davis, California 95616, USA
| | - Cai Li
- Genome and Biomedical Sciences Facility, University of California, Davis, 451 Health Sciences Drive, Davis, California 95616, USA
| | - Xiangnan Zhou
- Genome and Biomedical Sciences Facility, University of California, Davis, 451 Health Sciences Drive, Davis, California 95616, USA
| | - Alba Alfonso-Garcia
- Genome and Biomedical Sciences Facility, University of California, Davis, 451 Health Sciences Drive, Davis, California 95616, USA
| | - Julien Bec
- Genome and Biomedical Sciences Facility, University of California, Davis, 451 Health Sciences Drive, Davis, California 95616, USA
| | - Diego Yankelevich
- Genome and Biomedical Sciences Facility, University of California, Davis, 451 Health Sciences Drive, Davis, California 95616, USA
- Department of Electrical and Computer Engineering, University of California, Davis, One Shields Avenue, Davis, California 95616, USA
| | - Laura Marcu
- Genome and Biomedical Sciences Facility, University of California, Davis, 451 Health Sciences Drive, Davis, California 95616, USA
- Corresponding author:
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28
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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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29
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Colchester RJ, Little C, Dwyer G, Noimark S, Alles EJ, Zhang EZ, Loder CD, Parkin IP, Papakonstantinou I, Beard PC, Finlay MC, Rakhit RD, Desjardins AE. All-Optical Rotational Ultrasound Imaging. Sci Rep 2019; 9:5576. [PMID: 30944379 PMCID: PMC6447544 DOI: 10.1038/s41598-019-41970-z] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2018] [Accepted: 03/14/2019] [Indexed: 11/23/2022] Open
Abstract
Miniaturised high-resolution imaging devices are valuable for guiding minimally invasive procedures such as vascular stent placements. Here, we present all-optical rotational B-mode pulse-echo ultrasound imaging. With this device, ultrasound transmission and reception are performed with light. The all-optical transducer in the probe comprised an optical fibre that delivered pulsed excitation light to an optical head at the distal end with a multi-walled carbon nanotube and polydimethylsiloxane composite coating. This coating was photoacoustically excited to generate a highly directional ultrasound beam perpendicular to the optical fibre axis. A concave Fabry-Pérot cavity at the distal end of an optical fibre, which was interrogated with a tuneable continuous-wave laser, served as an omnidirectional ultrasound receiver. The transmitted ultrasound had a -6 dB bandwidth of 31.3 MHz and a peak-to-peak pressure of 1.87 MPa, as measured at 1.5 mm from the probe. The receiver had a noise equivalent pressure <100 Pa over a 20 MHz bandwidth. With a maximum outer probe diameter of 1.25 mm, the probe provided imaging with an axial resolution better than 50 µm, and a real-time imaging rate of 5 frames per second. To investigate the capabilities of the probe, intraluminal imaging was performed in healthy swine carotid arteries. The results demonstrate that the all-optical probe is viable for clinical rotational ultrasound imaging.
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Affiliation(s)
- Richard J Colchester
- Department of Medical Physics and Biomedical Engineering, University College London, Malet Place Engineering Building, London, WC1E 6BT, UK.
- Wellcome/EPSRC Centre for Interventional and Surgical Sciences, University College London, Charles Bell House, 67-73 Riding House Street, London, W1W 7EJ, UK.
| | - Callum Little
- Wellcome/EPSRC Centre for Interventional and Surgical Sciences, University College London, Charles Bell House, 67-73 Riding House Street, London, W1W 7EJ, UK
- Department of Cardiology, Royal Free Hampstead NHS Trust, Pond Street, London, NW3 2QG, UK
- Institute of Cardiovascular Science, University College London, Gower Street, London, WC1E 6BT, UK
| | - George Dwyer
- Department of Medical Physics and Biomedical Engineering, University College London, Malet Place Engineering Building, London, WC1E 6BT, UK
- Wellcome/EPSRC Centre for Interventional and Surgical Sciences, University College London, Charles Bell House, 67-73 Riding House Street, London, W1W 7EJ, UK
- Centre for Medical Image Computing, University College London, Gower Street, London, WC1E 6BT, UK
| | - Sacha Noimark
- Department of Medical Physics and Biomedical Engineering, University College London, Malet Place Engineering Building, London, WC1E 6BT, UK
- Wellcome/EPSRC Centre for Interventional and Surgical Sciences, University College London, Charles Bell House, 67-73 Riding House Street, London, W1W 7EJ, UK
- Materials Chemistry Research Centre, Department of Chemistry, University College London, London, WC1H 0AJ, UK
| | - Erwin J Alles
- Department of Medical Physics and Biomedical Engineering, University College London, Malet Place Engineering Building, London, WC1E 6BT, UK
- Wellcome/EPSRC Centre for Interventional and Surgical Sciences, University College London, Charles Bell House, 67-73 Riding House Street, London, W1W 7EJ, UK
| | - Edward Z Zhang
- Department of Medical Physics and Biomedical Engineering, University College London, Malet Place Engineering Building, London, WC1E 6BT, UK
| | - Christopher D Loder
- Department of Cardiology, Royal Free Hampstead NHS Trust, Pond Street, London, NW3 2QG, UK
- Institute of Cardiovascular Science, University College London, Gower Street, London, WC1E 6BT, UK
| | - Ivan P Parkin
- Materials Chemistry Research Centre, Department of Chemistry, University College London, London, WC1H 0AJ, UK
| | - Ioannis Papakonstantinou
- Photonic Innovations Lab, Department of Electronic and Electrical Engineering, University College London, Roberts Building, London, WC1E 7JE, UK
| | - Paul C Beard
- Department of Medical Physics and Biomedical Engineering, University College London, Malet Place Engineering Building, London, WC1E 6BT, UK
- Wellcome/EPSRC Centre for Interventional and Surgical Sciences, University College London, Charles Bell House, 67-73 Riding House Street, London, W1W 7EJ, UK
| | - Malcolm C Finlay
- Department of Medical Physics and Biomedical Engineering, University College London, Malet Place Engineering Building, London, WC1E 6BT, UK
- Wellcome/EPSRC Centre for Interventional and Surgical Sciences, University College London, Charles Bell House, 67-73 Riding House Street, London, W1W 7EJ, UK
- William Harvey Cardiovascular Research Institute, Queen Mary University of London and Barts Health Centre, London, EC1A 7BE, UK
| | - Roby D Rakhit
- Department of Cardiology, Royal Free Hampstead NHS Trust, Pond Street, London, NW3 2QG, UK
- Institute of Cardiovascular Science, University College London, Gower Street, London, WC1E 6BT, UK
| | - Adrien E Desjardins
- Department of Medical Physics and Biomedical Engineering, University College London, Malet Place Engineering Building, London, WC1E 6BT, UK
- Wellcome/EPSRC Centre for Interventional and Surgical Sciences, University College London, Charles Bell House, 67-73 Riding House Street, London, W1W 7EJ, UK
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30
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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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31
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Alfonso-Garcia A, Shklover J, Sherlock BE, Panitch A, Griffiths LG, Marcu L. Fiber-based fluorescence lifetime imaging of recellularization processes on vascular tissue constructs. JOURNAL OF BIOPHOTONICS 2018; 11:e201700391. [PMID: 29781171 PMCID: PMC7700018 DOI: 10.1002/jbio.201700391] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/22/2017] [Accepted: 05/16/2018] [Indexed: 05/22/2023]
Abstract
New techniques able to monitor the maturation of tissue engineered constructs over time are needed for a more efficient control of developmental parameters. Here, a label-free fluorescence lifetime imaging (FLIm) approach implemented through a single fiber-optic interface is reported for nondestructive in situ assessment of vascular biomaterials. Recellularization processes of antigen removed bovine pericardium scaffolds with endothelial cells and mesenchymal stem cells were evaluated on the serous and the fibrous sides of the scaffolds, 2 distinct extracellular matrix niches, over the course of a 7 day culture period. Results indicated that fluorescence lifetime successfully report cell presence resolved from extracellular matrix fluorescence. The recellularization process was more rapid on the serous side than on the fibrous side for both cell types, and endothelial cells expanded faster than mesenchymal stem cells on antigen-removed bovine pericardium. Fiber-based FLIm has the potential to become a nondestructive tool for the assessment of tissue maturation by allowing in situ imaging of intraluminal vascular biomaterials.
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Affiliation(s)
- Alba Alfonso-Garcia
- Department of Biomedical Engineering, University of California Davis, Davis, California
| | - Jeny Shklover
- Department of Biomedical Engineering, University of California Davis, Davis, California
| | - Benjamin E. Sherlock
- Department of Biomedical Engineering, University of California Davis, Davis, California
| | - Alyssa Panitch
- Department of Biomedical Engineering, University of California Davis, Davis, California
| | - Leigh G. Griffiths
- Department of Cardiovascular Medicine, Mayo Clinic, Rochester, Minnesota
| | - Laura Marcu
- Department of Biomedical Engineering, University of California Davis, Davis, California
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32
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Alfonso-Garcia A, Haudenschild AK, Marcu L. Label-free assessment of carotid artery biochemical composition using fiber-based fluorescence lifetime imaging. BIOMEDICAL OPTICS EXPRESS 2018; 9:4064-4076. [PMID: 30615748 PMCID: PMC6157793 DOI: 10.1364/boe.9.004064] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/18/2018] [Revised: 07/11/2018] [Accepted: 07/12/2018] [Indexed: 05/08/2023]
Abstract
Novel diagnostic tools with the ability to monitor variations in biochemical composition and provide benchmark indicators of vascular tissue maturation are needed to create functional tissue replacements. We investigated the ability of fiber-based, label-free multispectral fluorescent lifetime imaging (FLIm) to quantify the anatomical variations in biochemical composition of native carotid arteries and validated these results against biochemical assays. FLIm-derived parameters in spectral band 415-455 nm correlated with tissue collagen content (R2 = 0.64) and cell number (R2 = 0.61) and in spectral band 465-553 nm strongly correlated with elastin content (R2 = 0.89). These results suggest that FLIm holds great potential for assessing vascular tissue maturation and functional properties based on tissue autofluorescence.
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Affiliation(s)
- Alba Alfonso-Garcia
- Department of Biomedical Engineering, University of California, Davis, 451 E. Health Sciences Dr., Davis, CA 95616,
USA
- Authors contributed equally to this work
| | - Anne K. Haudenschild
- Department of Biomedical Engineering, University of California, Davis, 451 E. Health Sciences Dr., Davis, CA 95616,
USA
- Authors contributed equally to this work
| | - Laura Marcu
- Department of Biomedical Engineering, University of California, Davis, 451 E. Health Sciences Dr., Davis, CA 95616,
USA
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33
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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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34
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Wang P, Turcatel G, Arnesano C, Warburton D, Fraser SE, Cutrale F. Fiber pattern removal and image reconstruction method for snapshot mosaic hyperspectral endoscopic images. BIOMEDICAL OPTICS EXPRESS 2018; 9:780-790. [PMID: 29552412 PMCID: PMC5854078 DOI: 10.1364/boe.9.000780] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/22/2017] [Revised: 01/20/2018] [Accepted: 01/21/2018] [Indexed: 05/04/2023]
Abstract
Hyperspectral endoscopic imaging has the potential to enhance clinical diagnostics and outcome. Most commercial endoscopes utilize imaging fiber bundles to transmit the collected signal from the patient to the medical operator. These bundles consist of several fiber cores surrounded by a cladding layer creating comb structure-like artifacts, which complicate further analysis, both spatially and spectrally. Here we present an optical fiber pattern removal algorithm which we applied to hyperspectral bronchoscopic images robustly and quantitatively without the need for specific optical or electrical hardware. We validate the performance of the pattern removal by using a novel hyperspectral phasor approach. This algorithm can be generalized to all forms of fiber bundle hyperspectral endoscopy.
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Affiliation(s)
- Pu Wang
- Translational Imaging Center, University of Southern California, Los Angeles, California, 90089, USA
- Biomedical Engineering, University of Southern California, Los Angeles, California, 90089, USA
| | - Gianluca Turcatel
- Developmental Biology and Regenerative Medicine Program, Saban Research Institute, Children’s Hospital Los Angeles, Los Angeles, California 90027, USA
- Keck School of Medicine and Ostrow School of Dentistry, University of Southern California, Los Angeles, California 90033, USA
| | - Cosimo Arnesano
- Translational Imaging Center, University of Southern California, Los Angeles, California, 90089, USA
- Biomedical Engineering, University of Southern California, Los Angeles, California, 90089, USA
| | - David Warburton
- Developmental Biology and Regenerative Medicine Program, Saban Research Institute, Children’s Hospital Los Angeles, Los Angeles, California 90027, USA
- Keck School of Medicine and Ostrow School of Dentistry, University of Southern California, Los Angeles, California 90033, USA
| | - Scott E. Fraser
- Translational Imaging Center, University of Southern California, Los Angeles, California, 90089, USA
- Biomedical Engineering, University of Southern California, Los Angeles, California, 90089, USA
| | - Francesco Cutrale
- Translational Imaging Center, University of Southern California, Los Angeles, California, 90089, USA
- Biomedical Engineering, University of Southern California, Los Angeles, California, 90089, USA
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