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Campbell JM, Gosnell M, Agha A, Handley S, Knab A, Anwer AG, Bhargava A, Goldys EM. Label-Free Assessment of Key Biological Autofluorophores: Material Characteristics and Opportunities for Clinical Applications. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2024:e2403761. [PMID: 38775184 DOI: 10.1002/adma.202403761] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/13/2024] [Revised: 05/04/2024] [Indexed: 06/13/2024]
Abstract
Autofluorophores are endogenous fluorescent compounds that naturally occur in the intra and extracellular spaces of all tissues and organs. Most have vital biological functions - like the metabolic cofactors NAD(P)H and FAD+, as well as the structural protein collagen. Others are considered to be waste products - like lipofuscin and advanced glycation end products - which accumulate with age and are associated with cellular dysfunction. Due to their natural fluorescence, these materials have great utility for enabling non-invasive, label-free assays with direct ties to biological function. Numerous technologies, with different advantages and drawbacks, are applied to their assessment, including fluorescence lifetime imaging microscopy, hyperspectral microscopy, and flow cytometry. Here, the applications of label-free autofluorophore assessment are reviewed for clinical and health-research applications, with specific attention to biomaterials, disease detection, surgical guidance, treatment monitoring, and tissue assessment - fields that greatly benefit from non-invasive methodologies capable of continuous, in vivo characterization.
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Affiliation(s)
- Jared M Campbell
- Australian Research Council Centre of Excellence for Nanoscale BioPhotonics, Graduate School of Biomedical Engineering, University of New South Wales, Sydney, NSW, 2033, Australia
| | | | - Adnan Agha
- Australian Research Council Centre of Excellence for Nanoscale BioPhotonics, Graduate School of Biomedical Engineering, University of New South Wales, Sydney, NSW, 2033, Australia
| | - Shannon Handley
- Australian Research Council Centre of Excellence for Nanoscale BioPhotonics, Graduate School of Biomedical Engineering, University of New South Wales, Sydney, NSW, 2033, Australia
| | - Aline Knab
- Australian Research Council Centre of Excellence for Nanoscale BioPhotonics, Graduate School of Biomedical Engineering, University of New South Wales, Sydney, NSW, 2033, Australia
| | - Ayad G Anwer
- Australian Research Council Centre of Excellence for Nanoscale BioPhotonics, Graduate School of Biomedical Engineering, University of New South Wales, Sydney, NSW, 2033, Australia
| | - Akanksha Bhargava
- Australian Research Council Centre of Excellence for Nanoscale BioPhotonics, Graduate School of Biomedical Engineering, University of New South Wales, Sydney, NSW, 2033, Australia
| | - Ewa M Goldys
- Australian Research Council Centre of Excellence for Nanoscale BioPhotonics, Graduate School of Biomedical Engineering, University of New South Wales, Sydney, NSW, 2033, Australia
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Campbell JM, Habibalahi A, Handley S, Agha A, Mahbub SB, Anwer AG, Goldys EM. Emerging clinical applications in oncology for non-invasive multi- and hyperspectral imaging of cell and tissue autofluorescence. JOURNAL OF BIOPHOTONICS 2023; 16:e202300105. [PMID: 37272291 DOI: 10.1002/jbio.202300105] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/30/2023] [Revised: 05/02/2023] [Accepted: 05/16/2023] [Indexed: 06/06/2023]
Abstract
Hyperspectral and multispectral imaging of cell and tissue autofluorescence is an emerging technology in which fluorescence imaging is applied to biological materials across multiple spectral channels. This produces a stack of images where each matched pixel contains information about the sample's spectral properties at that location. This allows precise collection of molecularly specific data from a broad range of native fluorophores. Importantly, complex information, directly reflective of biological status, is collected without staining and tissues can be characterised in situ, without biopsy. For oncology, this can spare the collection of biopsies from sensitive regions and enable accurate tumour mapping. For in vivo tumour analysis, the greatest focus has been on oral cancer, whereas for ex vivo assessment head-and-neck cancers along with colon cancer have been the most studied, followed by oral and eye cancer. This review details the scope and progress of research undertaken towards clinical translation in oncology.
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Affiliation(s)
- Jared M Campbell
- Graduate School of Biomedical Engineering, University of New South Wales, Sydney, New South Wales, Australia
- Australian Research Council Centre of Excellence for Nanoscale BioPhotonics, The University of Adelaide, Adelaide, South Australia, Australia
| | - Abbas Habibalahi
- Graduate School of Biomedical Engineering, University of New South Wales, Sydney, New South Wales, Australia
- Australian Research Council Centre of Excellence for Nanoscale BioPhotonics, The University of Adelaide, Adelaide, South Australia, Australia
| | - Shannon Handley
- Graduate School of Biomedical Engineering, University of New South Wales, Sydney, New South Wales, Australia
- Australian Research Council Centre of Excellence for Nanoscale BioPhotonics, The University of Adelaide, Adelaide, South Australia, Australia
| | - Adnan Agha
- Graduate School of Biomedical Engineering, University of New South Wales, Sydney, New South Wales, Australia
- Australian Research Council Centre of Excellence for Nanoscale BioPhotonics, The University of Adelaide, Adelaide, South Australia, Australia
| | - Saabah B Mahbub
- Graduate School of Biomedical Engineering, University of New South Wales, Sydney, New South Wales, Australia
- Australian Research Council Centre of Excellence for Nanoscale BioPhotonics, The University of Adelaide, Adelaide, South Australia, Australia
| | - Ayad G Anwer
- Graduate School of Biomedical Engineering, University of New South Wales, Sydney, New South Wales, Australia
- Australian Research Council Centre of Excellence for Nanoscale BioPhotonics, The University of Adelaide, Adelaide, South Australia, Australia
| | - Ewa M Goldys
- Graduate School of Biomedical Engineering, University of New South Wales, Sydney, New South Wales, Australia
- Australian Research Council Centre of Excellence for Nanoscale BioPhotonics, The University of Adelaide, Adelaide, South Australia, Australia
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Campbell JM, Mahbub SB, Habibalahi A, Agha A, Handley S, Anwer AG, Goldys EM. Clinical applications of non-invasive multi and hyperspectral imaging of cell and tissue autofluorescence beyond oncology. JOURNAL OF BIOPHOTONICS 2023; 16:e202200264. [PMID: 36602432 DOI: 10.1002/jbio.202200264] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/23/2022] [Revised: 12/20/2022] [Accepted: 12/24/2022] [Indexed: 06/17/2023]
Abstract
Hyperspectral and multispectral imaging of cell and tissue autofluorescence employs fluorescence imaging, without exogenous fluorophores, across multiple excitation/emission combinations (spectral channels). This produces an image stack where each pixel (matched by location) contains unique information about the sample's spectral properties. Analysis of this data enables access to a rich, molecularly specific data set from a broad range of cell-native fluorophores (autofluorophores) directly reflective of biochemical status, without use of fixation or stains. This non-invasive, non-destructive technology has great potential to spare the collection of biopsies from sensitive regions. As both staining and biopsy may be impossible, or undesirable, depending on the context, this technology great diagnostic potential for clinical decision making. The main research focus has been on the identification of neoplastic tissues. However, advances have been made in diverse applications-including ophthalmology, cardiovascular health, neurology, infection, assisted reproduction technology and organ transplantation.
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Affiliation(s)
- Jared M Campbell
- Graduate School of Biomedical Engineering, University of New South Wales, Sydney, New South Wales, Australia
- Australian Research Council Centre of Excellence for Nanoscale BioPhotonics, Sydney, Australia
| | - Saabah B Mahbub
- Graduate School of Biomedical Engineering, University of New South Wales, Sydney, New South Wales, Australia
- Australian Research Council Centre of Excellence for Nanoscale BioPhotonics, Sydney, Australia
| | - Abbas Habibalahi
- Graduate School of Biomedical Engineering, University of New South Wales, Sydney, New South Wales, Australia
- Australian Research Council Centre of Excellence for Nanoscale BioPhotonics, Sydney, Australia
| | - Adnan Agha
- Graduate School of Biomedical Engineering, University of New South Wales, Sydney, New South Wales, Australia
- Australian Research Council Centre of Excellence for Nanoscale BioPhotonics, Sydney, Australia
| | - Shannon Handley
- Graduate School of Biomedical Engineering, University of New South Wales, Sydney, New South Wales, Australia
- Australian Research Council Centre of Excellence for Nanoscale BioPhotonics, Sydney, Australia
| | - Ayad G Anwer
- Graduate School of Biomedical Engineering, University of New South Wales, Sydney, New South Wales, Australia
- Australian Research Council Centre of Excellence for Nanoscale BioPhotonics, Sydney, Australia
| | - Ewa M Goldys
- Graduate School of Biomedical Engineering, University of New South Wales, Sydney, New South Wales, Australia
- Australian Research Council Centre of Excellence for Nanoscale BioPhotonics, Sydney, Australia
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Ayala L, Isensee F, Wirkert SJ, Vemuri AS, Maier-Hein KH, Fei B, Maier-Hein L. Band selection for oxygenation estimation with multispectral/hyperspectral imaging. BIOMEDICAL OPTICS EXPRESS 2022; 13:1224-1242. [PMID: 35414995 PMCID: PMC8973188 DOI: 10.1364/boe.441214] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/25/2021] [Revised: 10/25/2021] [Accepted: 10/25/2021] [Indexed: 05/24/2023]
Abstract
Multispectral imaging provides valuable information on tissue composition such as hemoglobin oxygen saturation. However, the real-time application of this technique in interventional medicine can be challenging due to the long acquisition times needed for large amounts of hyperspectral data with hundreds of bands. While this challenge can partially be addressed by choosing a discriminative subset of bands, the band selection methods proposed to date are mainly restricted by the availability of often hard to obtain reference measurements. We address this bottleneck with a new approach to band selection that leverages highly accurate Monte Carlo (MC) simulations. We hypothesize that a so chosen small subset of bands can reproduce or even improve upon the results of a quasi continuous spectral measurement. We further investigate whether novel domain adaptation techniques can address the inevitable domain shift stemming from the use of simulations. Initial results based on in silico and in vivo experiments suggest that 10-20 bands are sufficient to closely reproduce results from spectral measurements with 101 bands in the 500-700 nm range. The investigated domain adaptation technique, which only requires unlabeled in vivo measurements, yielded better results than the pure in silico band selection method. Overall, our method could guide development of fast multispectral imaging systems suited for interventional use without relying on complex hardware setups or manually labeled data.
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Affiliation(s)
- Leonardo Ayala
- Division of Computer Assisted Medical Interventions (CAMI), German Cancer Research Center (DKFZ), Heidelberg, Germany
- Medical Faculty, Heidelberg University, Heidelberg, Germany
- Authors contributed equally
| | - Fabian Isensee
- Division of Medical Image Computing (MIC), German Cancer Research Center (DKFZ), Heidelberg, Germany
- Applied Computer Vision Lab, Helmholtz Imaging, Dallas, Texas 75001, USA
- Authors contributed equally
| | - Sebastian J Wirkert
- Division of Computer Assisted Medical Interventions (CAMI), German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Anant S Vemuri
- Division of Computer Assisted Medical Interventions (CAMI), German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Klaus H Maier-Hein
- Division of Medical Image Computing (MIC), German Cancer Research Center (DKFZ), Heidelberg, Germany
- Medical Faculty, Heidelberg University, Heidelberg, Germany
- Faculty of Mathematics and Computer Science, Heidelberg University, Heidelberg, Germany
| | - Baowei Fei
- Department of Bioengineering, The University of Texas at Dallas, Richardson, Texas 75080-4551, USA
- Advanced Imaging Research Center, The University of Texas Southwestern Medical Center, Dallas, Texas 75001, USA
- Department of Radiology, The University of Texas Southwestern Medical Center, Dallas, Texas 75001, USA
| | - Lena Maier-Hein
- Division of Computer Assisted Medical Interventions (CAMI), German Cancer Research Center (DKFZ), Heidelberg, Germany
- Medical Faculty, Heidelberg University, Heidelberg, Germany
- Faculty of Mathematics and Computer Science, Heidelberg University, Heidelberg, Germany
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Park SY, Singh-Moon R, Yang H, Saluja D, Hendon C. Quantification of irrigated lesion morphology using near-infrared spectroscopy. Sci Rep 2021; 11:20160. [PMID: 34635764 PMCID: PMC8505541 DOI: 10.1038/s41598-021-99725-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2021] [Accepted: 09/29/2021] [Indexed: 12/20/2022] Open
Abstract
There are currently limited means by which lesion formation can be confirmed during radiofrequency ablation procedures. The purpose of this study was to evaluate the use of NIRS-integrated RFA catheters for monitoring irrigated lesion progression, ex vivo and in vivo. Open-irrigated NIRS-ablation catheters with optical fibers were fabricated to sample tissue diffuse reflectance. Spectra from 44 irrigated lesions and 44 non-lesion sites from ex vivo swine hearts (n = 15) were used to train and evaluate a predictive model for lesion dimensions based on key spectral features. Additional studies were performed in diluted blood to assess NIRS signatures of catheter-tissue contact status. Finally, the potential of NIRS-RFA catheters for guiding lesion delivery was evaluated in a set of in vivo pilot studies conducted in healthy pigs (n = 4). Model predictions for lesion depth (R = 0.968), width (R = 0.971), and depth percentage (R = 0.924) correlated well with measured lesion dimensions. In vivo deployment in preliminary trials showed robust translational consistency of contact discrimination (P < 0.0001) and lesion depth parameters (< 3% error). NIRS empowered catheters are well suited for monitoring myocardial response to RF ablation and may provide useful intraprocedural feedback for optimizing treatment efficacy alongside current practices.
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Affiliation(s)
- Soo Young Park
- Department of Electrical Engineering, Columbia University, 500 West 120th Street, New York, NY, 10027, USA
| | - Rajinder Singh-Moon
- Department of Electrical Engineering, Columbia University, 500 West 120th Street, New York, NY, 10027, USA
| | - Haiqiu Yang
- Department of Electrical Engineering, Columbia University, 500 West 120th Street, New York, NY, 10027, USA
| | - Deepak Saluja
- Department of Medicine (Cardiology), Columbia University College of Physicians and Surgeons, 630 W. 168th St, New York, NY, 10032, USA
| | - Christine Hendon
- Department of Electrical Engineering, Columbia University, 500 West 120th Street, New York, NY, 10027, USA.
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Armstrong K, Larson C, Asfour H, Ransbury T, Sarvazyan N. A Percutaneous Catheter for In Vivo Hyperspectral Imaging of Cardiac Tissue: Challenges, Solutions and Future Directions. Cardiovasc Eng Technol 2020; 11:560-575. [PMID: 32666326 PMCID: PMC7530025 DOI: 10.1007/s13239-020-00476-w] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/24/2019] [Accepted: 06/30/2020] [Indexed: 12/16/2022]
Abstract
PURPOSE Multiple studies have shown that spectral analysis of tissue autofluorescence can be used as a live indicator for various pathophysiological states of cardiac tissue, including ischemia, ablation-induced damage, or scar formation. Yet today there are no percutaneous devices that can detect autofluorescence signals from inside a beating heart. Our aim was to develop a prototype catheter to demonstrate the feasibility of doing so. METHODS AND RESULTS Here we summarize technical solutions leading to the development of a percutaneous catheter capable of multispectral imaging of intracardiac surfaces. The process included several iterations of light sources, optical filtering, and image acquisition techniques. The developed system included a compliant balloon, 355 nm laser irradiance, a high-sensitivity CCD, bandpass filtering, and image acquisition synchronized with the cardiac cycle. It enabled us to capture autofluorescence images from multiple spectral bands within the visible range while illuminating the endocardial surface with ultraviolet light. Principal component analysis and other spectral unmixing post-processing algorithms were then used to reveal target tissue. CONCLUSION Based on the success of our prototype system, we are confident that the development of ever more sensitive cameras, recent advances in tunable filters, fiber bundles, and other optical and computational components makes it possible to create percutaneous catheters capable of acquiring hyper or multispectral hypercubes, including those based on autofluorescence, in real-time. This opens the door for widespread use of this methodology for high-resolution intraoperative imaging of internal tissues and organs-including cardiovascular applications.
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Affiliation(s)
- Kenneth Armstrong
- Nocturnal Product Development, LLC, 8128 Renaissance Pkwy #210, Durham, NC, 27713, USA.
| | - Cinnamon Larson
- Nocturnal Product Development, LLC, 8128 Renaissance Pkwy #210, Durham, NC, 27713, USA
| | - Huda Asfour
- Department of Pharmacology and Physiology, The George Washington University, 2300 Eye Street NW, Washington, DC, 20037, USA
| | - Terry Ransbury
- LuxMed Systems, Inc, 124 Country Drive, Weston, MA, 02493, USA
| | - Narine Sarvazyan
- Department of Pharmacology and Physiology, The George Washington University, 2300 Eye Street NW, Washington, DC, 20037, USA.
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Key factors behind autofluorescence changes caused by ablation of cardiac tissue. Sci Rep 2020; 10:15369. [PMID: 32958843 PMCID: PMC7506017 DOI: 10.1038/s41598-020-72351-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2020] [Accepted: 08/25/2020] [Indexed: 11/30/2022] Open
Abstract
Radiofrequency ablation is a commonly used clinical procedure that destroys arrhythmogenic sources in patients suffering from atrial fibrillation and other types of cardiac arrhythmias. To improve the success of this procedure, new approaches for real-time visualization of ablation sites are being developed. One of these promising methods is hyperspectral imaging, an approach that detects lesions based on changes in the endogenous tissue autofluorescence profile. To facilitate the clinical implementation of this approach, we examined the key variables that can influence ablation-induced spectral changes, including the drop in myocardial NADH levels, the release of lipofuscin-like pigments, and the increase in diffuse reflectance of the cardiac muscle beneath the endocardial layer. Insights from these experiments suggested simpler algorithms that can be used to acquire and post-process the spectral information required to reveal the lesion sites. Our study is relevant to a growing number of multilayered clinical targets to which spectral approaches are being applied.
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Guan S, Asfour H, Sarvazyan N, Loew M. Application of unsupervised learning to hyperspectral imaging of cardiac ablation lesions. J Med Imaging (Bellingham) 2018; 5:046003. [PMID: 30840727 DOI: 10.1117/1.jmi.5.4.046003] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2018] [Accepted: 11/12/2018] [Indexed: 12/24/2022] Open
Abstract
Atrial fibrillation is the most common cardiac arrhythmia. It is being effectively treated using the radiofrequency ablation (RFA) procedure, which destroys culprit tissue and creates scars that prevent the spread of abnormal electrical activity. Long-term success of RFA could be improved further if ablation lesions can be directly visualized during the surgery. We have shown that autofluorescence-based hyperspectral imaging (aHSI) can help to identify lesions based on spectral unmixing. We show that use of k -means clustering, an unsupervised learning method, is capable of detecting RFA lesions without a priori knowledge of the lesions' spectral characteristics. We also show that the number of spectral bands required for successful lesion identification can be significantly reduced, enabling the use of increased spectral bandwidth. Together, these findings can help with clinical implementation of a percutaneous aHSI catheter, since by reducing the number of spectral bands one can reduce hypercube acquisition and processing times, and by increasing the spectral width of individual bands one can collect more photons. The latter is of critical importance in low-light applications such as intracardiac aHSI. The ultimate goal of our studies is to help improve clinical outcomes for atrial fibrillation patients.
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Affiliation(s)
- Shuyue Guan
- George Washington University, Department of Biomedical Engineering, Washington, DC, United States
| | - Huda Asfour
- George Washington University Medical Center, Department of Pharmacology and Physiology, Washington, DC, United States
| | - Narine Sarvazyan
- George Washington University Medical Center, Department of Pharmacology and Physiology, Washington, DC, United States
| | - Murray Loew
- George Washington University, Department of Biomedical Engineering, Washington, DC, United States
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