1
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Mizuta K, Sato M. Multiphoton imaging of hippocampal neural circuits: techniques and biological insights into region-, cell-type-, and pathway-specific functions. Neurophotonics 2024; 11:033406. [PMID: 38464393 PMCID: PMC10923542 DOI: 10.1117/1.nph.11.3.033406] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/25/2023] [Revised: 01/31/2024] [Accepted: 02/06/2024] [Indexed: 03/12/2024]
Abstract
Significance The function of the hippocampus in behavior and cognition has long been studied primarily through electrophysiological recordings from freely moving rodents. However, the application of optical recording methods, particularly multiphoton fluorescence microscopy, in the last decade or two has dramatically advanced our understanding of hippocampal function. This article provides a comprehensive overview of techniques and biological findings obtained from multiphoton imaging of hippocampal neural circuits. Aim This review aims to summarize and discuss the recent technical advances in multiphoton imaging of hippocampal neural circuits and the accumulated biological knowledge gained through this technology. Approach First, we provide a brief overview of various techniques of multiphoton imaging of the hippocampus and discuss its advantages, drawbacks, and associated key innovations and practices. Then, we review a large body of findings obtained through multiphoton imaging by region (CA1 and dentate gyrus), cell type (pyramidal neurons, inhibitory interneurons, and glial cells), and cellular compartment (dendrite and axon). Results Multiphoton imaging of the hippocampus is primarily performed under head-fixed conditions and can reveal detailed mechanisms of circuit operation owing to its high spatial resolution and specificity. As the hippocampus lies deep below the cortex, its imaging requires elaborate methods. These include imaging cannula implantation, microendoscopy, and the use of long-wavelength light sources. Although many studies have focused on the dorsal CA1 pyramidal cells, studies of other local and inter-areal circuitry elements have also helped provide a more comprehensive picture of the information processing performed by the hippocampal circuits. Imaging of circuit function in mouse models of Alzheimer's disease and other brain disorders such as autism spectrum disorder has also contributed greatly to our understanding of their pathophysiology. Conclusions Multiphoton imaging has revealed much regarding region-, cell-type-, and pathway-specific mechanisms in hippocampal function and dysfunction in health and disease. Future technological advances will allow further illustration of the operating principle of the hippocampal circuits via the large-scale, high-resolution, multimodal, and minimally invasive imaging.
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Affiliation(s)
- Kotaro Mizuta
- RIKEN BDR, Kobe, Japan
- New York University Abu Dhabi, Department of Biology, Abu Dhabi, United Arab Emirates
| | - Masaaki Sato
- Hokkaido University Graduate School of Medicine, Department of Neuropharmacology, Sapporo, Japan
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2
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Zhang X, Tan M, Nabil M, Shukla R, Vasavada S, Anandasabapathy S, Anastasio MA, Petrova E. Deep-learning-based image super-resolution of an end-expandable optical fiber probe for application in esophageal cancer diagnostics. J Biomed Opt 2024; 29:046001. [PMID: 38585417 PMCID: PMC10993061 DOI: 10.1117/1.jbo.29.4.046001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/03/2023] [Revised: 03/10/2024] [Accepted: 03/18/2024] [Indexed: 04/09/2024]
Abstract
Significance Endoscopic screening for esophageal cancer (EC) may enable early cancer diagnosis and treatment. While optical microendoscopic technology has shown promise in improving specificity, the limited field of view (< 1 mm ) significantly reduces the ability to survey large areas efficiently in EC screening. Aim To improve the efficiency of endoscopic screening, we propose a novel concept of end-expandable endoscopic optical fiber probe for larger field of visualization and for the first time evaluate a deep-learning-based image super-resolution (DL-SR) method to overcome the issue of limited sampling capability. Approach To demonstrate feasibility of the end-expandable optical fiber probe, DL-SR was applied on simulated low-resolution microendoscopic images to generate super-resolved (SR) ones. Varying the degradation model of image data acquisition, we identified the optimal parameters for optical fiber probe prototyping. The proposed screening method was validated with a human pathology reading study. Results For various degradation parameters considered, the DL-SR method demonstrated different levels of improvement of traditional measures of image quality. The endoscopists' interpretations of the SR images were comparable to those performed on the high-resolution ones. Conclusions This work suggests avenues for development of DL-SR-enabled sparse image reconstruction to improve high-yield EC screening and similar clinical applications.
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Affiliation(s)
- Xiaohui Zhang
- University of Illinois Urbana-Champaign, Department of Bioengineering, Urbana, Illinois, United States
| | - Mimi Tan
- Baylor College of Medicine, Section of Gastroenterology and Hepatology, Department of Medicine, Texas, United States
| | - Mansour Nabil
- Baylor College of Medicine, Section of Gastroenterology and Hepatology, Department of Medicine, Texas, United States
| | - Richa Shukla
- Baylor College of Medicine, Section of Gastroenterology and Hepatology, Department of Medicine, Texas, United States
| | - Shaleen Vasavada
- Baylor College of Medicine, Section of Gastroenterology and Hepatology, Department of Medicine, Texas, United States
| | - Sharmila Anandasabapathy
- Baylor College of Medicine, Section of Gastroenterology and Hepatology, Department of Medicine, Texas, United States
- Baylor College of Medicine, Baylor Global Health, Texas, United States
| | - Mark A. Anastasio
- University of Illinois Urbana-Champaign, Department of Bioengineering, Urbana, Illinois, United States
| | - Elena Petrova
- Baylor College of Medicine, Section of Gastroenterology and Hepatology, Department of Medicine, Texas, United States
- Baylor College of Medicine, Baylor Global Health, Texas, United States
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3
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Yu X, Zhou L, Qi T, Zhao H, Xie H. MEMS Enabled Miniature Two-Photon Microscopy for Biomedical Imaging. Micromachines (Basel) 2023; 14:470. [PMID: 36838170 PMCID: PMC9958604 DOI: 10.3390/mi14020470] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/22/2023] [Revised: 02/07/2023] [Accepted: 02/07/2023] [Indexed: 06/18/2023]
Abstract
Over the last decade, two-photon microscopy (TPM) has been the technique of choice for in vivo noninvasive optical brain imaging for neuroscientific study or intra-vital microendoscopic imaging for clinical diagnosis or surgical guidance because of its intrinsic capability of optical sectioning for imaging deeply below the tissue surface with sub-cellular resolution. However, most of these research activities and clinical applications are constrained by the bulky size of traditional TMP systems. An attractive solution is to develop miniaturized TPMs, but this is challenged by the difficulty of the integration of dynamically scanning optical and mechanical components into a small space. Fortunately, microelectromechanical systems (MEMS) technology, together with other emerging micro-optics techniques, has offered promising opportunities in enabling miniaturized TPMs. In this paper, the latest advancements in both lateral scan and axial scan techniques and the progress of miniaturized TPM imaging will be reviewed in detail. Miniature TPM probes with lateral 2D scanning mechanisms, including electrostatic, electromagnetic, and electrothermal actuation, are reviewed. Miniature TPM probes with axial scanning mechanisms, such as MEMS microlenses, remote-focus, liquid lenses, and deformable MEMS mirrors, are also reviewed.
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Affiliation(s)
- Xiaomin Yu
- Key Laboratory of Biological Effect of Physical Field and Instrument, Department of Electrical and Electronic Engineering, Chengdu University of Information Technology, Chengdu 610225, China
| | - Liang Zhou
- Department of Electrical and Computer Engineering, University of Florida, Gainesville, FL 32611, USA
| | - Tingxiang Qi
- BIT Chongqing Institute of Microelectronics and Microsystems, Chongqing 401332, China
| | - Hui Zhao
- BIT Chongqing Institute of Microelectronics and Microsystems, Chongqing 401332, China
- Foshan Lightview Technology Co., Ltd., Foshan 528000, China
| | - Huikai Xie
- BIT Chongqing Institute of Microelectronics and Microsystems, Chongqing 401332, China
- Foshan Lightview Technology Co., Ltd., Foshan 528000, China
- School of Integrated Circuits and Electronics, Beijing Institute of Technology, Beijing 100081, China
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4
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Accanto N, Blot FGC, Lorca-Cámara A, Zampini V, Bui F, Tourain C, Badt N, Katz O, Emiliani V. A flexible two-photon fiberscope for fast activity imaging and precise optogenetic photostimulation of neurons in freely moving mice. Neuron 2023; 111:176-189.e6. [PMID: 36395773 DOI: 10.1016/j.neuron.2022.10.030] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2021] [Revised: 07/28/2022] [Accepted: 10/19/2022] [Indexed: 11/17/2022]
Abstract
We developed a flexible two-photon microendoscope (2P-FENDO) capable of all-optical brain investigation at near cellular resolution in freely moving mice. The system performs fast two-photon (2P) functional imaging and 2P holographic photostimulation of single and multiple cells using axially confined extended spots. Proof-of-principle experiments were performed in freely moving mice co-expressing jGCaMP7s and the opsin ChRmine in the visual or barrel cortex. On a field of view of 250 μm in diameter, we demonstrated functional imaging at a frame rate of up to 50 Hz and precise photostimulation of selected groups of cells. With the capability to simultaneously image and control defined neuronal networks in freely moving animals, 2P-FENDO will enable a precise investigation of neuronal functions in the brain during naturalistic behaviors.
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Affiliation(s)
- Nicolò Accanto
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, F-75012 Paris, France.
| | - François G C Blot
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, F-75012 Paris, France
| | | | - Valeria Zampini
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, F-75012 Paris, France
| | - Florence Bui
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, F-75012 Paris, France
| | - Christophe Tourain
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, F-75012 Paris, France
| | - Noam Badt
- Department of Applied Physics, Hebrew University of Jerusalem, Jerusalem 9190401, Israel
| | - Ori Katz
- Department of Applied Physics, Hebrew University of Jerusalem, Jerusalem 9190401, Israel
| | - Valentina Emiliani
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, F-75012 Paris, France.
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5
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Paulson B, Darian SB, Kim Y, Oh J, Ghasemi M, Lee K, Kim JK. Spectral Multiplexing of Fluorescent Endoscopy for Simultaneous Imaging with Multiple Fluorophores and Multiple Fields of View. Biosensors (Basel) 2022; 13:33. [PMID: 36671868 PMCID: PMC9855833 DOI: 10.3390/bios13010033] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/05/2022] [Revised: 12/22/2022] [Accepted: 12/22/2022] [Indexed: 06/17/2023]
Abstract
Complex clinical procedures and small-animal research procedures can benefit from dual-site imaging provided by multiple endoscopic devices. Here, an endoscopic system is proposed which enables multiple fluorescence microendoscopes to be spectrally multiplexed on a single microscope base, enabling light sources and optical relays to be shared between endoscopes. The presented system is characterized for resolution using USAF-1951 resolution test charts and for modulation transfer function using the slanted edge method. Imaging is demonstrated both directly and with microendoscopes attached. Imaging of phantoms was demonstrated by targeting USAF charts and fiber tissues dyed for FITC and Texas Red fluorescence. Afterwards, simultaneous liver and kidney imaging was demonstrated in mice expressing mitochondrial Dendra2 and injected with Texas Red-dextran. The results indicate that the system achieves high channel isolation and submicron and subcellular resolution, with resolution limited by the endoscopic probe and by physiological movement during endoscopic imaging. Multi-channel microendoscopy provides a potentially low-cost means of simultaneous multiple endoscopic imaging during biological experiments, resulting in reduced animal harm and potentially increasing insight into temporal connections between connected biological systems.
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Affiliation(s)
- Bjorn Paulson
- Biomedical Engineering Research Center, Asan Institute for Life Science, Asan Medical Center, Seoul 05505, Republic of Korea
| | - Saeed Bohlooli Darian
- Department of Convergence Medicine, University of Ulsan College of Medicine, Seoul 05505, Republic of Korea
| | - Youngkyu Kim
- Department of Convergence Medicine, University of Ulsan College of Medicine, Seoul 05505, Republic of Korea
| | - Jeongmin Oh
- Department of Convergence Medicine, University of Ulsan College of Medicine, Seoul 05505, Republic of Korea
| | - Marjan Ghasemi
- Department of Physics, Yonsei University, Seoul 03722, Republic of Korea
| | - Kwanhee Lee
- Department of Convergence Medicine, University of Ulsan College of Medicine, Seoul 05505, Republic of Korea
| | - Jun Ki Kim
- Biomedical Engineering Research Center, Asan Institute for Life Science, Asan Medical Center, Seoul 05505, Republic of Korea
- Department of Convergence Medicine, University of Ulsan College of Medicine, Seoul 05505, Republic of Korea
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6
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Wu J, Wang T, Uckermann O, Galli R, Schackert G, Cao L, Czarske J, Kuschmierz R. Learned end-to-end high-resolution lensless fiber imaging towards real-time cancer diagnosis. Sci Rep 2022; 12:18846. [PMID: 36344626 DOI: 10.1038/s41598-022-23490-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2022] [Accepted: 11/01/2022] [Indexed: 11/09/2022] Open
Abstract
Recent advances in label-free histology promise a new era for real-time diagnosis in neurosurgery. Deep learning using autofluorescence is promising for tumor classification without histochemical staining process. The high image resolution and minimally invasive diagnostics with negligible tissue damage is of great importance. The state of the art is raster scanning endoscopes, but the distal lens optics limits the size. Lensless fiber bundle endoscopy offers both small diameters of a few 100 microns and the suitability as single-use probes, which is beneficial in sterilization. The problem is the inherent honeycomb artifacts of coherent fiber bundles (CFB). For the first time, we demonstrate an end-to-end lensless fiber imaging with exploiting the near-field. The framework includes resolution enhancement and classification networks that use single-shot CFB images to provide both high-resolution imaging and tumor diagnosis. The well-trained resolution enhancement network not only recovers high-resolution features beyond the physical limitations of CFB, but also helps improving tumor recognition rate. Especially for glioblastoma, the resolution enhancement network helps increasing the classification accuracy from 90.8 to 95.6%. The novel technique enables histological real-time imaging with lensless fiber endoscopy and is promising for a quick and minimally invasive intraoperative treatment and cancer diagnosis in neurosurgery.
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7
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Badt N, Katz O. Real-time holographic lensless micro-endoscopy through flexible fibers via fiber bundle distal holography. Nat Commun 2022; 13:6055. [PMID: 36229450 DOI: 10.1038/s41467-022-33462-y] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2021] [Accepted: 09/15/2022] [Indexed: 12/24/2022] Open
Abstract
Fiber-based micro-endoscopes are a critically important tool for minimally-invasive deep-tissue imaging. However, current micro-endoscopes cannot perform three-dimensional imaging through dynamically-bent fibers without the use of bulky optical elements such as lenses and scanners at the distal end, increasing the footprint and tissue-damage. Great efforts have been invested in developing approaches that avoid distal bulky optical elements. However, the fundamental barrier of dynamic optical wavefront-distortions in propagation through flexible fibers limits current approaches to nearly-static or non-flexible fibers. Here, we present an approach that allows holographic, bend-insensitive, coherence-gated, micro-endoscopic imaging using commercially available multi-core fibers (MCFs). We achieve this by adding a partially-reflecting mirror to the distal fiber-tip, allowing to perform low-coherence full-field phase-shifting holography. We demonstrate widefield diffraction-limited reflection imaging of amplitude and phase targets through dynamically bent fibers at video-rate. Our approach holds potential for label-free investigations of dynamic samples.
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8
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Paquelet GE, Carrion K, Lacefield CO, Zhou P, Hen R, Miller BR. Single-cell activity and network properties of dorsal raphe nucleus serotonin neurons during emotionally salient behaviors. Neuron 2022; 110:2664-2679.e8. [PMID: 35700737 PMCID: PMC9575686 DOI: 10.1016/j.neuron.2022.05.015] [Citation(s) in RCA: 28] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2019] [Revised: 11/23/2021] [Accepted: 05/13/2022] [Indexed: 12/20/2022]
Abstract
The serotonin system modulates a wide variety of emotional behaviors and states, including reward processing, anxiety, and social interaction. To reveal the underlying patterns of neural activity, we visualized serotonergic neurons in the dorsal raphe nucleus (DRN5-HT) of mice using miniaturized microscopy during diverse emotional behaviors. We discovered ensembles of cells with highly correlated activity and found that DRN5-HT neurons are preferentially recruited by emotionally salient stimuli as opposed to neutral stimuli. Individual DRN5-HT neurons responded to diverse combinations of salient stimuli, with some preference for valence and sensory modality. Anatomically defined subpopulations projecting to either a reward-related structure (the ventral tegmental area) or an anxiety-related structure (the bed nucleus of the stria terminalis) contained all response types but were enriched in reward- and anxiety-responsive cells, respectively. Our results suggest that the DRN serotonin system responds to emotional salience using ensembles with mixed selectivity and biases in downstream connectivity.
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Affiliation(s)
- Grace E Paquelet
- Department of Neuroscience, Columbia University, New York, NY 10032, USA
| | - Kassandra Carrion
- Division of Systems Neuroscience, New York State Psychiatric Institute, New York, NY 10032, USA
| | - Clay O Lacefield
- Division of Systems Neuroscience, New York State Psychiatric Institute, New York, NY 10032, USA; Department of Psychiatry, Columbia University Medical Center, New York, NY 10032, USA
| | - Pengcheng Zhou
- Department of Neuroscience, Columbia University, New York, NY 10032, USA; Department of Statistics, Columbia University, New York, NY 10027, USA; Zuckerman Mind Brain Behavior Institute, Columbia University, New York, NY 10027
| | - René Hen
- Department of Neuroscience, Columbia University, New York, NY 10032, USA; Division of Systems Neuroscience, New York State Psychiatric Institute, New York, NY 10032, USA; Department of Psychiatry, Columbia University Medical Center, New York, NY 10032, USA
| | - Bradley R Miller
- Division of Systems Neuroscience, New York State Psychiatric Institute, New York, NY 10032, USA; Department of Psychiatry, Columbia University Medical Center, New York, NY 10032, USA.
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9
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Bollimunta A, Santacruz SR, Eaton RW, Xu PS, Morrison JH, Moxon KA, Carmena JM, Nassi JJ. Head-mounted microendoscopic calcium imaging in dorsal premotor cortex of behaving rhesus macaque. Cell Rep 2021; 35:109239. [PMID: 34133921 PMCID: PMC8236375 DOI: 10.1016/j.celrep.2021.109239] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2020] [Revised: 04/07/2021] [Accepted: 05/18/2021] [Indexed: 01/07/2023] Open
Abstract
Microendoscopic calcium imaging with one-photon miniature microscopes enables unprecedented readout of neural circuit dynamics during active behavior in rodents. In this study, we describe successful application of this technology in the rhesus macaque, demonstrating plug-and-play, head-mounted recordings of cellular-resolution calcium dynamics from large populations of neurons simultaneously in bilateral dorsal premotor cortices during performance of a naturalistic motor reach task. Imaging is stable over several months, allowing us to longitudinally track individual neurons and monitor their relationship to motor behavior over time. We observe neuronal calcium dynamics selective for reach direction, which we could use to decode the animal's trial-by-trial motor behavior. This work establishes head-mounted microendoscopic calcium imaging in macaques as a powerful approach for studying the neural circuit mechanisms underlying complex and clinically relevant behaviors, and it promises to greatly advance our understanding of human brain function, as well as its dysfunction in neurological disease.
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Affiliation(s)
- Anil Bollimunta
- Inscopix, Inc., 2462 Embarcadero Way, Palo Alto, CA 94303, USA,These authors contributed equally
| | - Samantha R. Santacruz
- Department of Electrical Engineering and Computer Science, Helen Wills Neuroscience Institute, University of California, Berkeley, 286 Li Ka Shing, MC #3370, Berkeley, CA 94720, USA,Department of Biomedical Engineering, Institute for Neuroscience, The University of Texas at Austin, 107 W. Dean Keeton Street, Stop C0800, Austin, TX 78712, USA,These authors contributed equally
| | - Ryan W. Eaton
- Department of Biomedical Engineering, University of California, Davis, 3141 Health Sciences Drive, Davis, CA 95616, USA,California National Primate Research Center, University of California, Davis, One Shields Avenue, Davis, CA 95616, USA
| | - Pei S. Xu
- Inscopix, Inc., 2462 Embarcadero Way, Palo Alto, CA 94303, USA
| | - John H. Morrison
- California National Primate Research Center, University of California, Davis, One Shields Avenue, Davis, CA 95616, USA,Department of Neurology, School of Medicine, University of California Davis, Davis, One Shields Avenue, Davis, CA 95616, USA
| | - Karen A. Moxon
- Department of Biomedical Engineering, University of California, Davis, 3141 Health Sciences Drive, Davis, CA 95616, USA,California National Primate Research Center, University of California, Davis, One Shields Avenue, Davis, CA 95616, USA
| | - Jose M. Carmena
- Department of Electrical Engineering and Computer Science, Helen Wills Neuroscience Institute, University of California, Berkeley, 286 Li Ka Shing, MC #3370, Berkeley, CA 94720, USA,Senior author
| | - Jonathan J. Nassi
- Inscopix, Inc., 2462 Embarcadero Way, Palo Alto, CA 94303, USA,Senior author,Lead contact,Correspondence:
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10
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Abstract
It was in the influenza pandemic of 1918 that von Economo identified specific brain regions regulating sleep and wake. Since then researchers have used a variety of tools to determine how the brain shifts between states of consciousness. In every enterprise new tools have validated existing data, corrected errors and made new discoveries to advance science. The brain is a challenge but new tools can disentangle the brain network. We summarize the newest tool, a miniature microscope, that provides unprecedented view of activity of glia and neurons in freely behaving mice. With this tool we have observed that the activity of a majority of GABA and MCH neurons in the lateral hypothalamus is heavily biased toward sleep. We suggest that miniscope data identifies activity at the cellular level in normal versus diseased brains, and also in response to specific hypnotics. Shifts in activity in small networks across the brain will help identify point of criticality that switches the brain from wake to sleep.
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Affiliation(s)
- Priyattam J Shiromani
- Ralph H. Johnson VA Medical Center, Charleston, SC, United States.,Department of Psychiatry and Biobehavioral Science, Medical University of South Carolina, Charleston, SC, United States
| | - Carlos Blanco-Centurion
- Department of Psychiatry and Biobehavioral Science, Medical University of South Carolina, Charleston, SC, United States
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11
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Wang B, Zhang Q, Chen X, Luan H, Gu M. Perspective of fibre-optical microendoscopy with microlenses. J Microsc 2020; 288:87-94. [PMID: 33169362 DOI: 10.1111/jmi.12977] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2020] [Revised: 10/29/2020] [Accepted: 10/29/2020] [Indexed: 11/27/2022]
Abstract
Fibre-optical microendoscopy is based on fibre-optical confocal scanning microscopy, where optical fibres are introduced for delivery of the source and collection of the signal. Fibre-optical microendoscopy has led to innovations in imaging of freely moving animals, long-term imaging, minimally invasive diagnostics, and microsurgery. The lens system in fibre-optical microendoscopy is significant because of the imaging resolution and miniaturisation possibility. State-of-the-art fibre-optical microendoscopy based on various types of lens systems is introduced and compared. The lens system contains an objective lens, a gradient index microlens, and other novel lens systems fabricated by electric arc discharge or two-photon lithography.
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Affiliation(s)
- Baokai Wang
- Laboratory of Artificial-Intelligence Nanophotonics, School of Science, RMIT University, Melbourne, Victoria, Australia
| | - Qiming Zhang
- Centre for Artificial-Intelligence Nanophotonics, School of Optical-Electrical and Computer Engineering, University of Shanghai for Science and Technology, Shanghai, China
| | - Xi Chen
- Centre for Artificial-Intelligence Nanophotonics, School of Optical-Electrical and Computer Engineering, University of Shanghai for Science and Technology, Shanghai, China
| | - Haitao Luan
- Centre for Artificial-Intelligence Nanophotonics, School of Optical-Electrical and Computer Engineering, University of Shanghai for Science and Technology, Shanghai, China
| | - Min Gu
- Laboratory of Artificial-Intelligence Nanophotonics, School of Science, RMIT University, Melbourne, Victoria, Australia.,Centre for Artificial-Intelligence Nanophotonics, School of Optical-Electrical and Computer Engineering, University of Shanghai for Science and Technology, Shanghai, China
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12
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Tran LM, Mocle AJ, Ramsaran AI, Jacob AD, Frankland PW, Josselyn SA. Automated Curation of CNMF-E-Extracted ROI Spatial Footprints and Calcium Traces Using Open-Source AutoML Tools. Front Neural Circuits 2020; 14:42. [PMID: 32792911 PMCID: PMC7384547 DOI: 10.3389/fncir.2020.00042] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2020] [Accepted: 06/19/2020] [Indexed: 11/17/2022] Open
Abstract
In vivo 1-photon (1p) calcium imaging is an increasingly prevalent method in behavioral neuroscience. Numerous analysis pipelines have been developed to improve the reliability and scalability of pre-processing and ROI extraction for these large calcium imaging datasets. Despite these advancements in pre-processing methods, manual curation of the extracted spatial footprints and calcium traces of neurons remains important for quality control. Here, we propose an additional semi-automated curation step for sorting spatial footprints and calcium traces from putative neurons extracted using the popular constrained non-negative matrixfactorization for microendoscopic data (CNMF-E) algorithm. We used the automated machine learning (AutoML) tools TPOT and AutoSklearn to generate classifiers to curate the extracted ROIs trained on a subset of human-labeled data. AutoSklearn produced the best performing classifier, achieving an F1 score >92% on the ground truth test dataset. This automated approach is a useful strategy for filtering ROIs with relatively few labeled data points and can be easily added to pre-existing pipelines currently using CNMF-E for ROI extraction.
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Affiliation(s)
- Lina M Tran
- Hospital for Sick Children, Neurosciences and Mental Health, Toronto, ON, Canada.,Department of Physiology, University of Toronto, Toronto, ON, Canada.,Postgraduate Affiliates Program, Vector Institute, Toronto, ON, Canada
| | - Andrew J Mocle
- Hospital for Sick Children, Neurosciences and Mental Health, Toronto, ON, Canada.,Department of Physiology, University of Toronto, Toronto, ON, Canada
| | - Adam I Ramsaran
- Hospital for Sick Children, Neurosciences and Mental Health, Toronto, ON, Canada.,Department of Psychology, University of Toronto, Toronto, ON, Canada
| | - Alexander D Jacob
- Hospital for Sick Children, Neurosciences and Mental Health, Toronto, ON, Canada.,Department of Psychology, University of Toronto, Toronto, ON, Canada
| | - Paul W Frankland
- Hospital for Sick Children, Neurosciences and Mental Health, Toronto, ON, Canada.,Department of Physiology, University of Toronto, Toronto, ON, Canada.,Department of Psychology, University of Toronto, Toronto, ON, Canada.,Institute of Medical Sciences, University of Toronto, Toronto, ON, Canada.,Child & Brain Development Program, Canadian Institute for Advanced Research (CIFAR), Toronto, ON, Canada
| | - Sheena A Josselyn
- Hospital for Sick Children, Neurosciences and Mental Health, Toronto, ON, Canada.,Department of Physiology, University of Toronto, Toronto, ON, Canada.,Department of Psychology, University of Toronto, Toronto, ON, Canada.,Institute of Medical Sciences, University of Toronto, Toronto, ON, Canada.,Brain, Mind & Consciousness Program, Canadian Institute for Advanced Research (CIFAR), Toronto, ON, Canada
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13
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Ughi GJ, Marosfoi MG, King RM, Caroff J, Peterson LM, Duncan BH, Langan ET, Collins A, Leporati A, Rousselle S, Lopes DK, Gounis MJ, Puri AS. A neurovascular high-frequency optical coherence tomography system enables in situ cerebrovascular volumetric microscopy. Nat Commun 2020; 11:3851. [PMID: 32737314 PMCID: PMC7395105 DOI: 10.1038/s41467-020-17702-7] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2019] [Accepted: 07/09/2020] [Indexed: 01/11/2023] Open
Abstract
Intravascular imaging has emerged as a valuable tool for the treatment of coronary and peripheral artery disease; however, no solution is available for safe and reliable use in the tortuous vascular anatomy of the brain. Endovascular treatment of stroke is delivered under image guidance with insufficient resolution to adequately assess underlying arterial pathology and therapeutic devices. High-resolution imaging, enabling surgeons to visualize cerebral arteries' microstructure and micron-level features of neurovascular devices, would have a profound impact in the research, diagnosis, and treatment of cerebrovascular diseases. Here, we present a neurovascular high-frequency optical coherence tomography (HF-OCT) system, including an imaging console and an endoscopic probe designed to rapidly acquire volumetric microscopy data at a resolution approaching 10 microns in tortuous cerebrovascular anatomies. Using a combination of in vitro, ex vivo, and in vivo models, the feasibility of HF-OCT for cerebrovascular imaging was demonstrated.
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Affiliation(s)
- Giovanni J Ughi
- New England Center for Stroke Research, Department of Radiology, University of Massachusetts Medical School, Worcester, MA, USA
- Gentuity LLC, Sudbury, MA, USA
| | - Miklos G Marosfoi
- New England Center for Stroke Research, Department of Radiology, University of Massachusetts Medical School, Worcester, MA, USA
- Department of Neurointerventional Radiology, Beth Israel Lahey Clinic, Burlington, MA, USA
| | - Robert M King
- New England Center for Stroke Research, Department of Radiology, University of Massachusetts Medical School, Worcester, MA, USA
- Department of Biomedical Engineering, Worcester Polytechnic Institute, Worcester, MA, USA
| | - Jildaz Caroff
- New England Center for Stroke Research, Department of Radiology, University of Massachusetts Medical School, Worcester, MA, USA
- Department of Interventional Neuroradiology, NEURI Center, Bicêtre Hospital, Le Kremlin-Bicêtre, France
| | | | | | - Erin T Langan
- New England Center for Stroke Research, Department of Radiology, University of Massachusetts Medical School, Worcester, MA, USA
| | - Amanda Collins
- Division of Translational Anatomy, Department of Radiology, University of Massachusetts Medical School, Worcester, MA, USA
| | - Anita Leporati
- New England Center for Stroke Research, Department of Radiology, University of Massachusetts Medical School, Worcester, MA, USA
| | | | | | - Matthew J Gounis
- New England Center for Stroke Research, Department of Radiology, University of Massachusetts Medical School, Worcester, MA, USA.
| | - Ajit S Puri
- New England Center for Stroke Research, Department of Radiology, University of Massachusetts Medical School, Worcester, MA, USA
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14
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Qiu Z, Piyawattanametha W. MEMS Actuators for Optical Microendoscopy. Micromachines (Basel) 2019; 10:E85. [PMID: 30682852 DOI: 10.3390/mi10020085] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/28/2018] [Revised: 12/26/2018] [Accepted: 12/28/2018] [Indexed: 01/21/2023]
Abstract
Growing demands for affordable, portable, and reliable optical microendoscopic imaging devices are attracting research institutes and industries to find new manufacturing methods. However, the integration of microscopic components into these subsystems is one of today's challenges in manufacturing and packaging. Together with this kind of miniaturization more and more functional parts have to be accommodated in ever smaller spaces. Therefore, solving this challenge with the use of microelectromechanical systems (MEMS) fabrication technology has opened the promising opportunities in enabling a wide variety of novel optical microendoscopy to be miniaturized. MEMS fabrication technology enables abilities to apply batch fabrication methods with high-precision and to include a wide variety of optical functionalities to the optical components. As a result, MEMS technology has enabled greater accessibility to advance optical microendoscopy technology to provide high-resolution and high-performance imaging matching with traditional table-top microscopy. In this review the latest advancements of MEMS actuators for optical microendoscopy will be discussed in detail.
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15
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Paulson B, Kim IH, Namgoong JM, Kim YG, Lee S, Moon Y, Shin DM, Choo MS, Kim JK. Longitudinal micro-endoscopic monitoring of high-success intramucosal xenografts for mouse models of colorectal cancer. Int J Med Sci 2019; 16:1453-1460. [PMID: 31673236 PMCID: PMC6818213 DOI: 10.7150/ijms.35666] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/11/2019] [Accepted: 08/02/2019] [Indexed: 12/24/2022] Open
Abstract
Colorectal cancer (CRC) is one of the most frequently lethal forms of cancer. Intramucosal injection allows development of better mouse models of CRC, as orthotopic xenografts allow development of adenocarcinoma in the submucosa of the mouse colon wall. In this paper, a method of orthotopic injection is monitored longitudinally using cellular-resolution real-time in vivo fluorescence microendoscopy, following the injection of three different cell lines: 3T3-GFP to confirm immunosuppression and HCT116-RFP cells to model CRC. Adenoma formation is first observable after 7 to 10 days, and by use of 33 G needles a tumor induction rate of greater than 85% is documented. An additional experiment on the injection of rapamycin reveals drug efficacy and localization between 24 and 48 hours, and suggests the promise of real-time cellular-resolution fluorescence micro-endoscopy for developing longitudinal therapy regimes in mural models of CRC.
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Affiliation(s)
- Bjorn Paulson
- Biomedical Engineering Research Center, Asan Institute for Life Sciences, Asan Medical Center, 88, Olympic-ro 43-gil, Songpa-gu, Seoul 05055, Republic of Korea
| | - Ick Hee Kim
- Wake Forest Institute for Regenerative Medicine, Wake Forest School of Medicine, 391 Technology Way, Winston-Salem, NC 27101, USA
| | - Jung-Man Namgoong
- Department of Surgery, Asan Medical Center, University of Ulsan College of Medicine, 88, Olympic-ro 43-gil, Songpa-gu, Seoul 05055, Republic of Korea
| | - Young Gyu Kim
- Biomedical Engineering Research Center, Asan Institute for Life Sciences, Asan Medical Center, 88, Olympic-ro 43-gil, Songpa-gu, Seoul 05055, Republic of Korea
| | - Sanghwa Lee
- Biomedical Engineering Research Center, Asan Institute for Life Sciences, Asan Medical Center, 88, Olympic-ro 43-gil, Songpa-gu, Seoul 05055, Republic of Korea
| | - Youngjin Moon
- Biomedical Engineering Research Center, Asan Institute for Life Sciences, Asan Medical Center, 88, Olympic-ro 43-gil, Songpa-gu, Seoul 05055, Republic of Korea.,Department of Convergence Medicine, University of Ulsan College of Medicine, 88, Olympic-ro 43-gil, Songpa-gu, Seoul 05055, Republic of Korea
| | - Dong-Myung Shin
- Department of Biomedical Sciences, Asan Medical Center, University of Ulsan College of Medicine, 88, Olympic-ro 43-gil, Songpa-gu, Seoul 05055, Republic of Korea.,Department of Physiology, Asan Medical Center, University of Ulsan College of Medicine, 88, Olympic-ro 43-gil, Songpa-gu, Seoul 05055, Republic of Korea
| | - Myung-Soo Choo
- Department of Urology, Asan Medical Center, University of Ulsan College of Medicine, 88, Olympic-ro 43-gil, Songpa-gu, Seoul 05055, Republic of Korea
| | - Jun Ki Kim
- Biomedical Engineering Research Center, Asan Institute for Life Sciences, Asan Medical Center, 88, Olympic-ro 43-gil, Songpa-gu, Seoul 05055, Republic of Korea.,Department of Convergence Medicine, University of Ulsan College of Medicine, 88, Olympic-ro 43-gil, Songpa-gu, Seoul 05055, Republic of Korea
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16
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Byun MR, Lee SW, Paulson B, Lee S, Lee W, Lee KK, Kim YR, Kim JK, Choi JW. Micro-endoscopic In Vivo Monitoring in the Blood and Lymphatic Vessels of the Oral Cavity after Radiation Therapy. Int J Med Sci 2019; 16:1525-1533. [PMID: 31673245 PMCID: PMC6818205 DOI: 10.7150/ijms.36470] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/08/2019] [Accepted: 08/23/2019] [Indexed: 11/30/2022] Open
Abstract
Radiotherapy, although used worldwide for the treatment of head, neck, and oral cancers, causes acute complications, including effects on vasculature and immune response due to cellular stress. Thus, the ability to diagnose side-effects and monitor vascular response in real-time during radiotherapy would be highly beneficial for clinical and research applications. In this study, recently-developed fluorescence micro-endoscopic technology provides non-invasive, high-resolution, real-time imaging at the cellular level. Moreover, with the application of high-resolution imaging technologies and micro-endoscopy, which enable improved monitoring of adverse effects in GFP-expressing mouse models, changes in the oral vasculature and lymphatic vessels are quantified in real time for 10 days following a mild localized single fractionation, 10 Gy radiotherapy treatments. Fluorescence micro-endoscopy enables quantification of the cardiovascular recovery and immune response, which shows short-term reduction in mean blood flow velocity, in lymph flow, and in transient immune infiltration even after this mild radiation dose, in addition to long-term reduction in blood vessel capacity. The data provided may serve as a reference for the expected cellular-level physiological, cardiovascular, and immune changes in animal disease models after radiotherapy.
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Affiliation(s)
- Mi Ran Byun
- Department of Pharmacology, College of Pharmacy, Kyung Hee University, Seoul, 02447, Republic of Korea
| | - Seok Won Lee
- Department of Pharmacology, College of Pharmacy, Kyung Hee University, Seoul, 02447, Republic of Korea.,Department of Life and Nanopharmaceutical Science, Graduate School, Kyung Hee University, Seoul, 02447, Republic of Korea
| | - Bjorn Paulson
- Biomedical Engineering Research Center, Asan Institute for Life Sciences, Asan Medical Center, University of Ulsan College of Medicine, Seoul, 05505, Republic of Korea
| | - Sanghwa Lee
- Biomedical Engineering Research Center, Asan Institute for Life Sciences, Asan Medical Center, University of Ulsan College of Medicine, Seoul, 05505, Republic of Korea
| | - Wan Lee
- Department of Oral and Maxillofacial Radiology, College of Dentistry, Wonkwang University, Iksan, 54538, Republic of Korea
| | - Kang Kyoo Lee
- Department of Radiation Oncology, School of Medicine, Wonkwang University, Iksan, 54538, Republic of Korea
| | - Yi Rang Kim
- Department of Hemato-Oncology, Yuseong Sun Hospital, Daejeon, 34084, Republic of Korea
| | - Jun Ki Kim
- Biomedical Engineering Research Center, Asan Institute for Life Sciences, Asan Medical Center, University of Ulsan College of Medicine, Seoul, 05505, Republic of Korea.,Department of Convergence Medicine, University of Ulsan College of Medicine, Seoul, 05505, Republic of Korea
| | - Jin Woo Choi
- Department of Pharmacology, College of Pharmacy, Kyung Hee University, Seoul, 02447, Republic of Korea.,Department of Life and Nanopharmaceutical Science, Graduate School, Kyung Hee University, Seoul, 02447, Republic of Korea
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17
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Krstajić N, Mills B, Murray I, Marshall A, Norberg D, Craven TH, Emanuel P, Choudhary TR, Williams GOS, Scholefield E, Akram AR, Davie A, Hirani N, Bruce A, Moore A, Bradley M, Dhaliwal K. Low-cost high sensitivity pulsed endomicroscopy to visualize tricolor optical signatures. J Biomed Opt 2018; 23:1-12. [PMID: 29992799 DOI: 10.1117/1.jbo.23.7.076005] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/23/2017] [Accepted: 05/16/2018] [Indexed: 05/20/2023]
Abstract
A highly sensitive, modular three-color fluorescence endomicroscopy imaging platform spanning the visible to near-infrared (NIR) range is demonstrated. Light-emitting diodes (LEDs) were sequentially pulsed along with the camera acquisition to provide up to 20 frames per second (fps) three-color imaging performance or 60 fps single color imaging. The system was characterized for bacterial and cellular molecular imaging in ex vivo human lung tissue and for bacterial and indocyanine green imaging in ex vivo perfused sheep lungs. A practical method to reduce background tissue autofluorescence is also proposed. The platform was clinically translated into six patients with pulmonary disease to delineate healthy, cancerous, and fibrotic tissue autofluorescent structures. The instrument is the most broadband clinical endomicroscopy system developed to date (covering visible to the NIR, 500 to 900 nm) and demonstrates significant potential for future clinical utility due to its low cost and modular capability to suit a wide variety of molecular imaging applications.
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Affiliation(s)
- Nikola Krstajić
- University of Edinburgh, Queen's Medical Research Institute, EPSRC IRC Hub in Optical Molecular Sens, United Kingdom
- University of Edinburgh, Institute for Integrated Micro and Nano Systems, School of Engineering, Edi, United Kingdom
- University of Dundee, School of Science and Engineering, Dundee, United Kingdom
| | - Bethany Mills
- University of Edinburgh, Queen's Medical Research Institute, EPSRC IRC Hub in Optical Molecular Sens, United Kingdom
| | - Ian Murray
- University of Edinburgh, Queen's Medical Research Institute, EPSRC IRC Hub in Optical Molecular Sens, United Kingdom
| | - Adam Marshall
- University of Edinburgh, Queen's Medical Research Institute, EPSRC IRC Hub in Optical Molecular Sens, United Kingdom
| | - Dominic Norberg
- University of Edinburgh, Queen's Medical Research Institute, EPSRC IRC Hub in Optical Molecular Sens, United Kingdom
| | - Thomas H Craven
- University of Edinburgh, Queen's Medical Research Institute, EPSRC IRC Hub in Optical Molecular Sens, United Kingdom
| | - Philip Emanuel
- University of Edinburgh, Queen's Medical Research Institute, EPSRC IRC Hub in Optical Molecular Sens, United Kingdom
| | - Tushar R Choudhary
- University of Edinburgh, Queen's Medical Research Institute, EPSRC IRC Hub in Optical Molecular Sens, United Kingdom
- Heriot-Watt University, Institute of Biological Chemistry, Biophysics and Bioengineering, Edinburgh, United Kingdom
| | - Gareth O S Williams
- University of Edinburgh, Queen's Medical Research Institute, EPSRC IRC Hub in Optical Molecular Sens, United Kingdom
| | - Emma Scholefield
- University of Edinburgh, Queen's Medical Research Institute, EPSRC IRC Hub in Optical Molecular Sens, United Kingdom
| | - Ahsan R Akram
- University of Edinburgh, Queen's Medical Research Institute, EPSRC IRC Hub in Optical Molecular Sens, United Kingdom
| | - Andrew Davie
- Royal Infirmary of Edinburgh, NHS Lothian, Department of Medical Physics, Edinburgh, United Kingdom
| | - Nik Hirani
- University of Edinburgh, Department of Respiratory Medicine, Edinburgh, United Kingdom
| | - Annya Bruce
- University of Edinburgh, Queen's Medical Research Institute, EPSRC IRC Hub in Optical Molecular Sens, United Kingdom
| | - Anne Moore
- University of Edinburgh, Queen's Medical Research Institute, EPSRC IRC Hub in Optical Molecular Sens, United Kingdom
| | - Mark Bradley
- University of Edinburgh, Queen's Medical Research Institute, EPSRC IRC Hub in Optical Molecular Sens, United Kingdom
- University of Edinburgh, School of Chemistry, EaStChem, Edinburgh, United Kingdom
| | - Kevin Dhaliwal
- University of Edinburgh, Queen's Medical Research Institute, EPSRC IRC Hub in Optical Molecular Sens, United Kingdom
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18
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Sheintuch L, Rubin A, Brande-Eilat N, Geva N, Sadeh N, Pinchasof O, Ziv Y. Tracking the Same Neurons across Multiple Days in Ca 2+ Imaging Data. Cell Rep 2018; 21:1102-1115. [PMID: 29069591 PMCID: PMC5670033 DOI: 10.1016/j.celrep.2017.10.013] [Citation(s) in RCA: 150] [Impact Index Per Article: 25.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2017] [Revised: 08/14/2017] [Accepted: 10/03/2017] [Indexed: 12/28/2022] Open
Abstract
Ca2+ imaging techniques permit time-lapse recordings of neuronal activity from large populations over weeks. However, without identifying the same neurons across imaging sessions (cell registration), longitudinal analysis of the neural code is restricted to population-level statistics. Accurate cell registration becomes challenging with increased numbers of cells, sessions, and inter-session intervals. Current cell registration practices, whether manual or automatic, do not quantitatively evaluate registration accuracy, possibly leading to data misinterpretation. We developed a probabilistic method that automatically registers cells across multiple sessions and estimates the registration confidence for each registered cell. Using large-scale Ca2+ imaging data recorded over weeks from the hippocampus and cortex of freely behaving mice, we show that our method performs more accurate registration than previously used routines, yielding estimated error rates <5%, and that the registration is scalable for many sessions. Thus, our method allows reliable longitudinal analysis of the same neurons over long time periods. A method for tracking neurons across days (cell registration) in Ca2+ imaging data The method is probabilistic and quantitatively evaluates registration accuracy The method is applicable to various imaging techniques and cell detection algorithms Registration accuracy remains high with an increased number of registered sessions
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Affiliation(s)
- Liron Sheintuch
- Department of Neurobiology, Weizmann Institute of Science, Rehovot 76100, Israel
| | - Alon Rubin
- Department of Neurobiology, Weizmann Institute of Science, Rehovot 76100, Israel
| | - Noa Brande-Eilat
- Department of Neurobiology, Weizmann Institute of Science, Rehovot 76100, Israel
| | - Nitzan Geva
- Department of Neurobiology, Weizmann Institute of Science, Rehovot 76100, Israel
| | - Noa Sadeh
- Department of Neurobiology, Weizmann Institute of Science, Rehovot 76100, Israel
| | - Or Pinchasof
- Department of Neurobiology, Weizmann Institute of Science, Rehovot 76100, Israel
| | - Yaniv Ziv
- Department of Neurobiology, Weizmann Institute of Science, Rehovot 76100, Israel.
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19
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Li Y, Mathis A, Grewe BF, Osterhout JA, Ahanonu B, Schnitzer MJ, Murthy VN, Dulac C. Neuronal Representation of Social Information in the Medial Amygdala of Awake Behaving Mice. Cell 2017; 171:1176-1190.e17. [PMID: 29107332 PMCID: PMC5731476 DOI: 10.1016/j.cell.2017.10.015] [Citation(s) in RCA: 140] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2017] [Revised: 07/27/2017] [Accepted: 10/11/2017] [Indexed: 12/16/2022]
Abstract
The medial amygdala (MeA) plays a critical role in processing species- and sex-specific signals that trigger social and defensive behaviors. However, the principles by which this deep brain structure encodes social information is poorly understood. We used a miniature microscope to image the Ca2+ dynamics of large neural ensembles in awake behaving mice and tracked the responses of MeA neurons over several months. These recordings revealed spatially intermingled subsets of MeA neurons with distinct temporal dynamics. The encoding of social information in the MeA differed between males and females and relied on information from both individual cells and neuronal populations. By performing long-term Ca2+ imaging across different social contexts, we found that sexual experience triggers lasting and sex-specific changes in MeA activity, which, in males, involve signaling by oxytocin. These findings reveal basic principles underlying the brain's representation of social information and its modulation by intrinsic and extrinsic factors.
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Affiliation(s)
- Ying Li
- Howard Hughes Medical Institute, Harvard University, Cambridge, MA, USA; Department of Molecular and Cellular Biology and Center for Brain Science, Harvard University, Cambridge, MA, USA
| | - Alexander Mathis
- Department of Molecular and Cellular Biology and Center for Brain Science, Harvard University, Cambridge, MA, USA
| | - Benjamin F Grewe
- Howard Hughes Medical Institute, CNC Program, James H. Clark Center Biomedical Engineering & Sciences, Stanford University, Stanford, CA, USA
| | - Jessica A Osterhout
- Howard Hughes Medical Institute, Harvard University, Cambridge, MA, USA; Department of Molecular and Cellular Biology and Center for Brain Science, Harvard University, Cambridge, MA, USA
| | - Biafra Ahanonu
- Howard Hughes Medical Institute, CNC Program, James H. Clark Center Biomedical Engineering & Sciences, Stanford University, Stanford, CA, USA
| | - Mark J Schnitzer
- Howard Hughes Medical Institute, CNC Program, James H. Clark Center Biomedical Engineering & Sciences, Stanford University, Stanford, CA, USA
| | - Venkatesh N Murthy
- Department of Molecular and Cellular Biology and Center for Brain Science, Harvard University, Cambridge, MA, USA
| | - Catherine Dulac
- Howard Hughes Medical Institute, Harvard University, Cambridge, MA, USA; Department of Molecular and Cellular Biology and Center for Brain Science, Harvard University, Cambridge, MA, USA.
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20
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Olsovsky C, Hinsdale T, Cuenca R, Cheng YSL, Wright JM, Rees TD, Jo JA, Maitland KC. Handheld tunable focus confocal microscope utilizing a double-clad fiber coupler for in vivo imaging of oral epithelium. J Biomed Opt 2017; 22:56008. [PMID: 28541447 PMCID: PMC5444308 DOI: 10.1117/1.jbo.22.5.056008] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/16/2016] [Accepted: 05/08/2017] [Indexed: 05/08/2023]
Abstract
A reflectance confocal endomicroscope with double-clad fiber coupler and electrically tunable focus lens is applied to imaging of the oral mucosa. The instrument is designed to be lightweight and robust for clinical use. The tunable lens allows axial scanning through > 250 ?? ? m in the epithelium when the probe tip is placed in contact with tissue. Images are acquired at 6.6 frames per second with a field of view diameter up to 850 ?? ? m . In vivo imaging of a wide range of normal sites in the oral cavity demonstrates the accessibility of the handheld probe. In vivo imaging of clinical lesions diagnosed as inflammation and dysplasia illustrates the ability of reflectance confocal endomicroscopy to image cellular changes associated with pathology.
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Affiliation(s)
- Cory Olsovsky
- Texas A&M University, Biomedical Engineering Department, College Station, Texas, United States
| | - Taylor Hinsdale
- Texas A&M University, Biomedical Engineering Department, College Station, Texas, United States
| | - Rodrigo Cuenca
- Texas A&M University, Biomedical Engineering Department, College Station, Texas, United States
| | - Yi-Shing Lisa Cheng
- Texas A&M University College of Dentistry, Department of Diagnostic Sciences, Dallas, Texas, United States
| | - John M. Wright
- Texas A&M University College of Dentistry, Department of Diagnostic Sciences, Dallas, Texas, United States
| | - Terry D. Rees
- Texas A&M University College of Dentistry, Department of Periodontics, Dallas, Texas, United States
| | - Javier A. Jo
- Texas A&M University, Biomedical Engineering Department, College Station, Texas, United States
| | - Kristen C. Maitland
- Texas A&M University, Biomedical Engineering Department, College Station, Texas, United States
- Address all correspondence to: Kristen C. Maitland, E-mail:
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21
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Keahey P, Ramalingam P, Schmeler K, Richards-Kortum RR. Differential structured illumination microendoscopy for in vivo imaging of molecular contrast agents. Proc Natl Acad Sci U S A 2016; 113:10769-73. [PMID: 27621464 DOI: 10.1073/pnas.1613497113] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Fiber optic microendoscopy has shown promise for visualization of molecular contrast agents used to study disease in vivo. However, fiber optic microendoscopes have limited optical sectioning capability, and image contrast is limited by out-of-focus light generated in highly scattering tissue. Optical sectioning techniques have been used in microendoscopes to remove out-of-focus light but reduce imaging speed or rely on bulky optical elements that prevent in vivo imaging. Here, we present differential structured illumination microendoscopy (DSIMe), a fiber optic system that can perform structured illumination in real time for optical sectioning without any opto-mechanical components attached to the distal tip of the fiber bundle. We demonstrate the use of DSIMe during in vivo fluorescence imaging in patients undergoing surgery for cervical adenocarcinoma in situ. Images acquired using DSIMe show greater contrast than standard microendoscopy, improving the ability to detect cellular atypia associated with neoplasia.
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22
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Prieto SP, Lai KK, Laryea JA, Mizell JS, Muldoon TJ. Quantitative analysis of ex vivo colorectal epithelium using an automated feature extraction algorithm for microendoscopy image data. J Med Imaging (Bellingham) 2016; 3:024502. [PMID: 27335893 DOI: 10.1117/1.jmi.3.2.024502] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2015] [Accepted: 04/28/2016] [Indexed: 12/20/2022] Open
Abstract
Qualitative screening for colorectal polyps via fiber bundle microendoscopy imaging has shown promising results, with studies reporting high rates of sensitivity and specificity, as well as low interobserver variability with trained clinicians. A quantitative image quality control and image feature extraction algorithm (QFEA) was designed to lessen the burden of training and provide objective data for improved clinical efficacy of this method. After a quantitative image quality control step, QFEA extracts field-of-view area, crypt area, crypt circularity, and crypt number per image. To develop and validate this QFEA, a training set of microendoscopy images was collected from freshly resected porcine colon epithelium. The algorithm was then further validated on ex vivo image data collected from eight human subjects, selected from clinically normal appearing regions distant from grossly visible tumor in surgically resected colorectal tissue. QFEA has proven flexible in application to both mosaics and individual images, and its automated crypt detection sensitivity ranges from 71 to 94% despite intensity and contrast variation within the field of view. It also demonstrates the ability to detect and quantify differences in grossly normal regions among different subjects, suggesting the potential efficacy of this approach in detecting occult regions of dysplasia.
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Affiliation(s)
- Sandra P Prieto
- University of Arkansas , Department of Biomedical Engineering, 1 University Boulevard, Fayetteville, Arkansas 72701, United States
| | - Keith K Lai
- University of Arkansas for Medical Sciences , Department of Pathology, 4301 West Markham Street, Little Rock, Arkansas 72205, United States
| | - Jonathan A Laryea
- University of Arkansas for Medical Sciences , Department of Gastrointestinal Surgery, 4301 West Markham Street, Little Rock, Arkansas 72205, United States
| | - Jason S Mizell
- University of Arkansas for Medical Sciences , Department of Gastrointestinal Surgery, 4301 West Markham Street, Little Rock, Arkansas 72205, United States
| | - Timothy J Muldoon
- University of Arkansas , Department of Biomedical Engineering, 1 University Boulevard, Fayetteville, Arkansas 72701, United States
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23
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Greening GJ, Rajaram N, Muldoon TJ. In vivo measurement of non-keratinized squamous epithelium using a spectroscopic microendoscope with multiple source-detector separations. Proc SPIE Int Soc Opt Eng 2016; 9715. [PMID: 27134337 DOI: 10.1117/12.2211866] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
In the non-keratinized epithelia, dysplasia typically arises near the basement membrane and proliferates into the upper epithelial layers over time. We present a non-invasive, multimodal technique combining high-resolution fluorescence imaging and broadband sub-diffuse reflectance spectroscopy (sDRS) to monitor health at various tissue layers. This manuscript focuses on characterization of the sDRS modality, which contains two source-detector separations (SDSs) of 374 μm and 730 μm, so that it can be used to extract in vivo optical parameters from human oral mucosa at two tissue thicknesses. First, we present empirical lookup tables (LUTs) describing the relationship between reduced scattering (μs') and absorption coefficients (μa) and absolute reflectance. LUTS were shown to extract μs' and μa with accuracies of approximately 4% and 8%, respectively. We then present LUTs describing the relationship between μs', μa and sampling depth. Sampling depths range between 210-480 and 260-620 μm for the 374 and 730 μm SDSs, respectively. We then demonstrate the ability to extract in vivo μs', μa, hemoglobin concentration, bulk tissue oxygen saturation, scattering exponent, and sampling depth from the inner lip of thirteen healthy volunteers to elucidate the differences in the extracted optical parameters from each SDS (374 and 730 μm) within non-keratinized squamous epithelia.
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Affiliation(s)
- Gage J Greening
- Department of Biomedical Engineering, University of Arkansas, Fayetteville, AR, USA 72701
| | - Narasimhan Rajaram
- Department of Biomedical Engineering, University of Arkansas, Fayetteville, AR, USA 72701
| | - Timothy J Muldoon
- Department of Biomedical Engineering, University of Arkansas, Fayetteville, AR, USA 72701
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Wilson C, Saunter CD, Girkin JM, McCarron JG. Clusters of specialized detector cells provide sensitive and high fidelity receptor signaling in the intact endothelium. FASEB J 2016; 30:2000-13. [PMID: 26873937 PMCID: PMC4836367 DOI: 10.1096/fj.201500090] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2015] [Accepted: 01/27/2016] [Indexed: 02/06/2023]
Abstract
Agonist-mediated signaling by the endothelium controls virtually all vascular functions. Because of the large diversity of agonists, each with varying concentrations, background noise often obscures individual cellular signals. How the endothelium distinguishes low-level fluctuations from noise and decodes and integrates physiologically relevant information remains unclear. Here, we recorded changes in intracellular Ca(2+) concentrations in response to acetylcholine in areas encompassing hundreds of endothelial cells from inside intact pressurized arteries. Individual cells responded to acetylcholine with a concentration-dependent increase in Ca(2+) signals spanning a single order of magnitude. Interestingly, however, intercellular response variation extended over 3 orders of magnitude of agonist concentration, thus crucially enhancing the collective bandwidth of endothelial responses to agonists. We also show the accuracy of this collective mode of detection is facilitated by spatially restricted clusters of comparably sensitive cells arising from heterogeneous receptor expression. Simultaneous stimulation of clusters triggered Ca(2+) signals that were transmitted to neighboring cells in a manner that scaled with agonist concentration. Thus, the endothelium detects agonists by acting as a distributed sensing system. Specialized clusters of detector cells, analogous to relay nodes in modern communication networks, integrate populationwide inputs, and enable robust noise filtering for efficient high-fidelity signaling.-Wilson, C., Saunter, C. D., Girkin, J. M., McCarron, J. G. Clusters of specialized detector cells provide sensitive and high fidelity receptor signaling in the intact endothelium.
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Affiliation(s)
- Calum Wilson
- Strathclyde Institute of Pharmacy and Biomedical Sciences, University of Strathclyde, Glasgow, United Kingdom; and
| | - Christopher D Saunter
- Centre for Advanced Instrumentation, Biophysical Sciences Institute, Department of Physics, Durham University, Durham, United Kingdom
| | - John M Girkin
- Centre for Advanced Instrumentation, Biophysical Sciences Institute, Department of Physics, Durham University, Durham, United Kingdom
| | - John G McCarron
- Strathclyde Institute of Pharmacy and Biomedical Sciences, University of Strathclyde, Glasgow, United Kingdom; and
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Parikh ND, Perl D, Lee MH, Chang SS, Polydorides AD, Moshier E, Godbold J, Zhou E, Mitcham J, Richards-Kortum R, Anandasabapathy S. In vivo classification of colorectal neoplasia using high-resolution microendoscopy: Improvement with experience. J Gastroenterol Hepatol 2015; 30:1155-60. [PMID: 25753782 PMCID: PMC4504008 DOI: 10.1111/jgh.12937] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 02/21/2015] [Indexed: 01/27/2023]
Abstract
BACKGROUND AND AIMS High-resolution microendoscopy (HRME) is a novel, low-cost "optical biopsy" technology that allows for subcellular imaging. The study aim was to evaluate the learning curve of HRME for the differentiation of neoplastic from non-neoplastic colorectal polyps. METHODS In a prospective cohort fashion, a total of 162 polyps from 97 patients at a single tertiary care center were imaged by HRME and classified in real time as neoplastic (adenomatous, cancer) or non-neoplastic (normal, hyperplastic, inflammatory). Histopathology was the gold standard for comparison. Diagnostic accuracy was examined at three intervals over time throughout the study; the initial interval included the first 40 polyps, the middle interval included the next 40 polyps examined, and the final interval included the last 82 polyps examined. RESULTS Sensitivity increased significantly from the initial interval (50%) to the middle interval (94%, P = 0.02) and the last interval (97%, P = 0.01). Similarly, specificity was 69% for the initial interval but increased to 92% (P = 0.07) in the middle interval and 96% (P = 0.02) in the last interval. Overall accuracy was 63% for the initial interval and then improved to 93% (P = 0.003) in the middle interval and 96% (P = 0.0007) in the last interval. CONCLUSIONS In conclusion, this in vivo study demonstrates that an endoscopist without prior colon HRME experience can achieve greater than 90% accuracy for identifying neoplastic colorectal polyps after 40 polyps imaged. HRME is a promising modality to complement white light endoscopy in differentiating neoplastic from non-neoplastic colorectal polyps.
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Affiliation(s)
- Neil D. Parikh
- Division of Digestive Diseases, Yale New Haven Hospital, New Haven, CT, U.S.A
| | - Daniel Perl
- Department of Medicine, Icahn School of Medicine at Mount Sinai, New York, NY, U.S.A
| | - Michelle H. Lee
- Division of Gastroenterology, Icahn School of Medicine at Mount Sinai, New York, NY, U.S.A
| | - Shannon S Chang
- Division of Gastroenterology, New York University Langone Medical Center, New York, NY, U.S.A
| | | | - Erin Moshier
- Department of Preventive Medicine, Icahn School of Medicine at Mount Sinai, NY, NY, U.S.A
| | - James Godbold
- Department of Preventive Medicine, Icahn School of Medicine at Mount Sinai, NY, NY, U.S.A
| | - Elinor Zhou
- Department of Medicine, Icahn School of Medicine at Mount Sinai, New York, NY, U.S.A
| | - Josephine Mitcham
- Division of Gastroenterology, Icahn School of Medicine at Mount Sinai, New York, NY, U.S.A
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26
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Patsias A, Giraldez-Rodriguez L, Polydorides AD, Richards-Kortum R, Anandasabapathy S, Quang T, Sikora AG, Miles B. Feasibility of transoral robotic-assisted high-resolution microendoscopic imaging of oropharyngeal squamous cell carcinoma. Head Neck 2015; 37:E99-102. [PMID: 25327825 DOI: 10.1002/hed.23892] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/14/2014] [Indexed: 11/06/2022] Open
Abstract
BACKGROUND Transoral robotic-assisted oncologic surgery of the head and neck offers promising functional results. Nonetheless, the efficacy of oncologic surgery remains critically dependent on obtaining negative margins. We aimed to integrate a miniaturized high-resolution fiber-optic microendoscope (HRME), which provides real-time histological assessment, with the da Vinci robotic system (Intuitive Surgical, Sunnyvale, CA). METHODS Three patients undergoing transoral robotic surgery (TORS) were prospectively enrolled in this study. Optical imaging of the oropharynx was performed intraoperatively with the robotic-assisted HRME. RESULTS All patients underwent the procedure successfully with no complications. The HRME was successfully integrated with the da Vinci robotic system. Several sites of the oropharynx and associated malignancy were imaged, which correlated with the standard histopathological analysis. CONCLUSION Transoral robotic-assisted HRME imaging of the oropharynx is a safe and technically feasible approach, providing a real-time histological assessment and may serve as a valuable aid in oncologic surgery.
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Affiliation(s)
- Alexis Patsias
- Department of Otolaryngology - Head and Neck Surgery, Head and Neck Cancer Translational Research Program, The Icahn School of Medicine at Mount Sinai, New York, New York
| | - Laureano Giraldez-Rodriguez
- Department of Otolaryngology - Head and Neck Surgery, Head and Neck Cancer Translational Research Program, The Icahn School of Medicine at Mount Sinai, New York, New York
| | | | | | | | - Timothy Quang
- Department of Bioengineering, Rice University, Houston, Texas
| | - Andrew G Sikora
- Department of Otolaryngology - Head and Neck Surgery, Head and Neck Cancer Translational Research Program, The Icahn School of Medicine at Mount Sinai, New York, New York
| | - Brett Miles
- Department of Otolaryngology - Head and Neck Surgery, Head and Neck Cancer Translational Research Program, The Icahn School of Medicine at Mount Sinai, New York, New York
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Meza D, Wang D, Wang Y, Borwege S, Sanai N, Liu JTC. Comparing high-resolution microscopy techniques for potential intraoperative use in guiding low-grade glioma resections. Lasers Surg Med 2015; 47:289-95. [PMID: 25872487 DOI: 10.1002/lsm.22347] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/14/2015] [Indexed: 11/10/2022]
Abstract
BACKGROUND AND OBJECTIVES Fluorescence image-guided surgery (FIGS), with contrast provided by 5-ALA-induced PpIX, has been shown to enable a higher extent of resection of high-grade gliomas. However, conventional FIGS with low-power microscopy lacks the sensitivity to aid in low-grade glioma (LGG) resection because PpIX signal is weak and sparse in such tissues. Intraoperative high-resolution microscopy of PpIX fluorescence has been proposed as a method to guide LGG resection, where sub-cellular resolution allows for the visualization of sparse and punctate mitochondrial PpIX production in tumor cells. Here, we assess the performance of three potentially portable high-resolution microscopy techniques that may be used for the intraoperative imaging of human LGG tissue samples with PpIX contrast: high-resolution fiber-optic microscopy (HRFM), high-resolution wide-field microscopy (WFM), and dual-axis confocal (DAC) microscopy. MATERIALS AND METHODS Thick unsectioned human LGG tissue samples (n = 7) with 5-ALA-induced PpIX contrast were imaged using three imaging techniques (HRFM, WFM, DAC). The average signal-to-background ratio (SBR) was then calculated for each imaging modality (5 images per tissue, per modality). RESULTS HRFM provides the ease of use and portability of a flexible fiber bundle, and is simple and inexpensive to build. However, in most cases (6/7), HRFM is not capable of detecting PpIX signal from LGGs due to high autofluorescence, generated by the fiber bundle under laser illumination at 405 nm, which overwhelms the PpIX signal and impedes its visualization. WFM is a camera-based method possessing high lateral resolution but poor axial resolution, resulting in sub-optimal image contrast. CONCLUSIONS Consistent successful detection of PpIX signal throughout our human LGG tissue samples (n = 7), with an acceptable image contrast (SBR >2), was only achieved using DAC microscopy, which offers superior image resolution and contrast that is comparable to histology, but requires a laser-scanning mechanism to achieve optical sectioning.
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Affiliation(s)
- Daphne Meza
- Department of Biomedical Engineering, Stony Brook University (SUNY), Stony Brook, New York, 11794
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Prieto SP, Powless AJ, Lai K, Laryea JA, Mizell JS, Muldoon TJ. Qualitative and quantitative comparison of colonic microendoscopy image features to histopathology. Proc SPIE Int Soc Opt Eng 2015; 9328:93280B. [PMID: 25983371 DOI: 10.1117/12.2079816] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Colorectal cancer is the second leading cause of cancer deaths in the United States, affecting more than 130,000 Americans every year1. Determining tumor margins prior to surgical resection is essential to providing optimal treatment and reducing recurrence rates. Colorectal cancer recurrence can occur in up to 20% of cases, commonly within three years after curative treatment. Typically, when colorectal cancers are resected, a margin of normal tissue on both sides of the tumor is required. The minimum margin required for colon cancer is 5 cm and for the lower rectum 2 cm. However, usually more normal tissue is taken on both sides of the tumor because the blood supply to the entire segment is removed with the surgery and therefore the entire segment must be removed. Anastomotic recurrences may result from inadequate margins. Pathologists look at the margins to ensure that there is no residual tumor and this is usually documented in the pathology report. We have developed a portable, point-of-care fiber bundle microendoscopy imaging system for detection of abnormalities in colonic epithelial microstructure. The system comprises a laptop, a modified fiber bundle image guide with a 1mm active area diameter and custom Lab VIEW interface, and is approved for imaging surgically resected colon tissue at the University of Arkansas for Medical Sciences. The microendoscopy probe provides high-resolution images of superficial epithelial histology in real-time to assist surgical guidance and to localize occult regions of dysplasia which may not be visible. Microendoscopy images of freshly resected human colonic epithelium were acquired using the microendoscopy device and subsequently mosaicked using custom post-processing software. Architectural changes in the glands were mapped to histopathology H&E slides taken from the precise location of the microendoscopy images. Qualitatively, glandular distortion and placement of image guide was used to map normal and dysplastic areas of the colonic tumor and surrounding region from microendoscopy images to H&E slides. Quantitative metrics for correlating images were also explored and were obtained by analyzing glandular diameter and spatial distribution as well as image texture.
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Affiliation(s)
- Sandra P Prieto
- Biomedical Engineering Dept., University of Arkansas, Fayetteville, AR 72701
| | - Amy J Powless
- Biomedical Engineering Dept., University of Arkansas, Fayetteville, AR 72701
| | - Keith Lai
- Dept. of Pathology, University of Arkansas for Medical Sciences, 4301 West Markham St., Little Rock, AR
| | - Jonathan A Laryea
- Dept. of Surgery, Division of Colorectal Surgery, University of Arkansas for Medical Sciences, 400 West Capitol Ave., Little Rock, AR 72205
| | - Jason S Mizell
- Dept. of Surgery, Division of Colorectal Surgery, University of Arkansas for Medical Sciences, 400 West Capitol Ave., Little Rock, AR 72205
| | - Timothy J Muldoon
- Biomedical Engineering Dept., University of Arkansas, Fayetteville, AR 72701
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Ishijima A, Schwarz RA, Shin D, Mondrik S, Vigneswaran N, Gillenwater AM, Anandasabapathy S, Richards-Kortum R. Automated frame selection process for high-resolution microendoscopy. J Biomed Opt 2015; 20:46014. [PMID: 25919426 PMCID: PMC4412137 DOI: 10.1117/1.jbo.20.4.046014] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/27/2014] [Accepted: 04/09/2015] [Indexed: 05/21/2023]
Abstract
We developed an automated frame selection algorithm for high-resolution microendoscopy video sequences. The algorithm rapidly selects a representative frame with minimal motion artifact from a short video sequence, enabling fully automated image analysis at the point-of-care. The algorithm was evaluated by quantitative comparison of diagnostically relevant image features and diagnostic classification results obtained using automated frame selection versus manual frame selection. A data set consisting of video sequences collected in vivo from 100 oral sites and 167 esophageal sites was used in the analysis. The area under the receiver operating characteristic curve was 0.78 (automated selection) versus 0.82 (manual selection) for oral sites, and 0.93 (automated selection) versus 0.92 (manual selection) for esophageal sites. The implementation of fully automated high-resolution microendoscopy at the point-of-care has the potential to reduce the number of biopsies needed for accurate diagnosis of precancer and cancer in low-resource settings where there may be limited infrastructure and personnel for standard histologic analysis.
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Affiliation(s)
- Ayumu Ishijima
- Rice University, Department of Bioengineering MS 142, 6100 Main Street, Houston, Texas 77005, United States
- University of Tokyo, Department of Precision Engineering, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Richard A. Schwarz
- Rice University, Department of Bioengineering MS 142, 6100 Main Street, Houston, Texas 77005, United States
| | - Dongsuk Shin
- Rice University, Department of Bioengineering MS 142, 6100 Main Street, Houston, Texas 77005, United States
| | - Sharon Mondrik
- Rice University, Department of Bioengineering MS 142, 6100 Main Street, Houston, Texas 77005, United States
| | - Nadarajah Vigneswaran
- University of Texas School of Dentistry, 7500 Cambridge Street, Houston, Texas 77054, United States
| | - Ann M. Gillenwater
- University of Texas M. D. Anderson Cancer Center, 1515 Holcombe Boulevard, Houston, Texas 77030, United States
| | - Sharmila Anandasabapathy
- Mount Sinai Medical Center, Division of Gastroenterology, One Gustave L. Levy Place, New York, New York 10029, United States
| | - Rebecca Richards-Kortum
- Rice University, Department of Bioengineering MS 142, 6100 Main Street, Houston, Texas 77005, United States
- Address all correspondence to: Rebecca Richards-Kortum, E-mail:
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30
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Meza D, Wang D, Wang Y, Borwege S, Sanai N, Liu JTC. Comparing high-resolution microscopy techniques for potential intraoperative use in guiding low-grade glioma resections. Lasers Surg Med 2015; 47:289-295. [PMID: 25872487 DOI: 10.1002/lsm.v47.4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/14/2015] [Indexed: 05/18/2023]
Abstract
BACKGROUND AND OBJECTIVES Fluorescence image-guided surgery (FIGS), with contrast provided by 5-ALA-induced PpIX, has been shown to enable a higher extent of resection of high-grade gliomas. However, conventional FIGS with low-power microscopy lacks the sensitivity to aid in low-grade glioma (LGG) resection because PpIX signal is weak and sparse in such tissues. Intraoperative high-resolution microscopy of PpIX fluorescence has been proposed as a method to guide LGG resection, where sub-cellular resolution allows for the visualization of sparse and punctate mitochondrial PpIX production in tumor cells. Here, we assess the performance of three potentially portable high-resolution microscopy techniques that may be used for the intraoperative imaging of human LGG tissue samples with PpIX contrast: high-resolution fiber-optic microscopy (HRFM), high-resolution wide-field microscopy (WFM), and dual-axis confocal (DAC) microscopy. MATERIALS AND METHODS Thick unsectioned human LGG tissue samples (n = 7) with 5-ALA-induced PpIX contrast were imaged using three imaging techniques (HRFM, WFM, DAC). The average signal-to-background ratio (SBR) was then calculated for each imaging modality (5 images per tissue, per modality). RESULTS HRFM provides the ease of use and portability of a flexible fiber bundle, and is simple and inexpensive to build. However, in most cases (6/7), HRFM is not capable of detecting PpIX signal from LGGs due to high autofluorescence, generated by the fiber bundle under laser illumination at 405 nm, which overwhelms the PpIX signal and impedes its visualization. WFM is a camera-based method possessing high lateral resolution but poor axial resolution, resulting in sub-optimal image contrast. CONCLUSIONS Consistent successful detection of PpIX signal throughout our human LGG tissue samples (n = 7), with an acceptable image contrast (SBR >2), was only achieved using DAC microscopy, which offers superior image resolution and contrast that is comparable to histology, but requires a laser-scanning mechanism to achieve optical sectioning.
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Affiliation(s)
- Daphne Meza
- Department of Biomedical Engineering, Stony Brook University (SUNY), Stony Brook, New York, 11794
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31
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Greening GJ, Powless AJ, Hutcheson JA, Prieto SP, Majid AA, Muldoon TJ. Design and validation of a diffuse reflectance and spectroscopic microendoscope with poly(dimethylsioxane)-based phantoms. Proc SPIE Int Soc Opt Eng 2015; 9332:93320R. [PMID: 25983372 DOI: 10.1117/12.2076300] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Many cases of epithelial cancer originate in basal layers of tissue and are initially undetected by conventional microendoscopy techniques. We present a bench-top, fiber-bundle microendoscope capable of providing high resolution images of surface cell morphology. Additionally, the microendoscope has the capability to interrogate deeper into material by using diffuse reflectance and broadband diffuse reflectance spectroscopy. The purpose of this multimodal technique was to overcome the limitation of microendoscopy techniques that are limited to only visualizing morphology at the tissue or cellular level. Using a custom fiber optic probe, high resolution surface images were acquired using topical proflavine to fluorescently stain non-keratinized epithelia. A 635 nm laser coupled to a 200 μm multimode fiber delivers light to the sample and the diffuse reflectance signal was captured by a 1 mm image guide fiber. Finally, a tungsten-halogen lamp coupled to a 200 μm multimode fiber delivers broadband light to the sample to acquire spectra at source-detector separations of 374, 729, and 1051 μm. To test the instrumentation, a high resolution proflavine-induced fluorescent image of resected healthy mouse colon was acquired. Additionally, five monolayer poly(dimethylsiloxane)-based optical phantoms with varying absorption and scattering properties were created to acquire diffuse reflectance profiles and broadband spectra.
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Affiliation(s)
- Gage J Greening
- Department of Biomedical Engineering, University of Arkansas, Fayetteville, AR, USA 72701
| | - Amy J Powless
- Department of Biomedical Engineering, University of Arkansas, Fayetteville, AR, USA 72701
| | - Joshua A Hutcheson
- Department of Biomedical Engineering, University of Arkansas, Fayetteville, AR, USA 72701
| | - Sandra P Prieto
- Department of Biomedical Engineering, University of Arkansas, Fayetteville, AR, USA 72701
| | - Aneeka A Majid
- Department of Biomedical Engineering, University of Arkansas, Fayetteville, AR, USA 72701
| | - Timothy J Muldoon
- Department of Biomedical Engineering, University of Arkansas, Fayetteville, AR, USA 72701
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Abstract
Confocal fluorescence microendoscopy provides high-resolution cellular-level imaging via a minimally invasive procedure, but requires fast scanning to achieve real-time imaging in vivo. Ideal confocal imaging performance is obtained with a point scanning system, but the scan rates required for in vivo biomedical imaging can be difficult to achieve. By scanning a line of illumination in one direction in conjunction with a stationary confocal slit aperture, very high image acquisition speeds can be achieved, but at the cost of a reduction in image quality. Here, the design, implementation, and experimental verification of a custom multi-point aperture modification to a line-scanning multi-spectral confocal microendoscope is presented. This new design improves the axial resolution of a line-scan system while maintaining high imaging rates. In addition, compared to the line-scanning configuration, previously reported simulations predicted that the multi-point aperture geometry greatly reduces the effects of tissue scatter on image quality. Experimental results confirming this prediction are presented.
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Klimas A, Entcheva E. Toward microendoscopy-inspired cardiac optogenetics in vivo: technical overview and perspective. J Biomed Opt 2014; 19:080701. [PMID: 25117076 PMCID: PMC4161000 DOI: 10.1117/1.jbo.19.8.080701] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/22/2014] [Accepted: 07/17/2014] [Indexed: 05/13/2023]
Abstract
The ability to perform precise, spatially localized actuation and measurements of electrical activity in the heart is crucial in understanding cardiac electrophysiology and devising new therapeutic solutions for control of cardiac arrhythmias. Current cardiac imaging techniques (i.e. optical mapping) employ voltage- or calcium-sensitive fluorescent dyes to visualize the electrical signal propagation through cardiac syncytium in vitro or in situ with very high-spatiotemporal resolution. The extension of optogenetics into the cardiac field, where cardiac tissue is genetically altered to express light-sensitive ion channels allowing electrical activity to be elicited or suppressed in a precise cell-specific way, has opened the possibility for all-optical interrogation of cardiac electrophysiology. In vivo application of cardiac optogenetics faces multiple challenges and necessitates suitable optical systems employing fiber optics to actuate and sense electrical signals. In this technical perspective, we present a compendium of clinically relevant access routes to different parts of the cardiac electrical conduction system based on currently employed catheter imaging systems and determine the quantitative size constraints for endoscopic cardiac optogenetics. We discuss the relevant technical advancements in microendoscopy, cardiac imaging, and optogenetics and outline the strategies for combining them to create a portable, miniaturized fiber-based system for all-optical interrogation of cardiac electrophysiology in vivo.
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Affiliation(s)
- Aleksandra Klimas
- Stony Brook University, Department of Biomedical Engineering, Stony Brook, New York 11794, United States
| | - Emilia Entcheva
- Stony Brook University, Department of Biomedical Engineering, Stony Brook, New York 11794, United States
- Stony Brook University, Department of Physiology and Biophysics, Stony Brook, New York 11794, United States
- Stony Brook University, Institute for Molecular Cardiology, Stony Brook, New York 11794, United States
- Address all correspondence to: Emilia Entcheva, E-mail:
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Charalampaki P, Igressa A, Mahvash M, Pechlivanis I, Schick B. Optimal invasive key-hole neurosurgery with a miniaturized 3D chip on the tip: Microendoscopic device. Asian J Neurosurg 2014; 8:125-31. [PMID: 24403954 PMCID: PMC3877498 DOI: 10.4103/1793-5482.121681] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Objective: The goal of the performed study was to evaluate the possibility of a three-dimensional endoscope to become a combined microscope-endoscope device in one. We analyzed the ergonomy of the device, the implementation into the surgical workflow, the image quality, and the future perspectives such devices could have for the next generation of neurosurgeons. Materials and Methods: Within 6 months, 22 patients (10 male, 12 female, 20-65 age) underwent surgery in neuroaxis using the new 3D-microendoscope (ME). The new 3D-ME has (a) the ability to visualize the surgical field from out- to inside with all advantages offered by a microscope, and in the same moment, (b) its design is like a small diameter endoscope that allows stereoscopic views extracorporal, intracorporal, and panoramic “para-side” of the lesion. Results: In general, transcranial 3D-“microendoscopy” was performed in all patients with high-resolution 3D quality. No severe complications were observed intra- or postoperatively. With the addition of depth perception, the anatomic structures were well seen and observed. Conclusion: The 3D-microendoscopy is a very promising surgical concept associated with new technological developments. The surgeon is able to switch to a modern visualization instrument reaching the most optimal surgical approach without compromising safety, effectiveness, and visual information.
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Affiliation(s)
- Patra Charalampaki
- Department of Neurosurgery, Hospital Merheim, University of Witten-Herdecke, Cologne, Germany
| | - Alhadi Igressa
- Department of Neurosurgery, Hospital Merheim, University of Witten-Herdecke, Cologne, Germany
| | - Mehran Mahvash
- Department of Neurosurgery, Hospital Merheim, University of Witten-Herdecke, Cologne, Germany
| | - Ioannis Pechlivanis
- Department of Neurosurgery, Hospital Merheim, University of Witten-Herdecke, Cologne, Germany
| | - Bernhard Schick
- Department of Otorhinolaryngology, Saarland University Medical Center, Homburg/Saar, Germany
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35
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Parikh N, Perl D, Lee MH, Shah B, Young Y, Chang SS, Shukla R, Polydorides AD, Moshier E, Godbold J, Zhou E, Mitchaml J, Richards-Kortum R, Anandasabapathy S. In vivo diagnostic accuracy of high-resolution microendoscopy in differentiating neoplastic from non-neoplastic colorectal polyps: a prospective study. Am J Gastroenterol 2014; 109:68-75. [PMID: 24296752 PMCID: PMC3947255 DOI: 10.1038/ajg.2013.387] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/07/2013] [Accepted: 10/01/2013] [Indexed: 12/11/2022]
Abstract
OBJECTIVES High-resolution microendoscopy (HRME) is a low-cost, "optical biopsy" technology that allows for subcellular imaging. The purpose of this study was to determine the in vivo diagnostic accuracy of the HRME for the differentiation of neoplastic from non-neoplastic colorectal polyps and compare it to that of high-definition white-light endoscopy (WLE) with histopathology as the gold standard. METHODS Three endoscopists prospectively detected a total of 171 polyps from 94 patients that were then imaged by HRME and classified in real-time as neoplastic (adenomatous, cancer) or non-neoplastic (normal, hyperplastic, inflammatory). RESULTS HRME had a significantly higher accuracy (94%), specificity (95%), and positive predictive value (PPV, 87%) for the determination of neoplastic colorectal polyps compared with WLE (65%, 39%, and 55%, respectively). When looking at small colorectal polyps (less than 10 mm), HRME continued to significantly outperform WLE in terms of accuracy (95% vs. 64%), specificity (98% vs. 40%) and PPV (92% vs. 55%). These trends continued when evaluating diminutive polyps (less than 5 mm) as HRME's accuracy (95%), specificity (98%), and PPV (93%) were all significantly greater than their WLE counterparts (62%, 41%, and 53%, respectively). CONCLUSIONS In conclusion, this in vivo study demonstrates that HRME can be a very effective modality in the differentiation of neoplastic and non-neoplastic colorectal polyps. A combination of standard white-light colonoscopy for polyp detection and HRME for polyp classification has the potential to truly allow the endoscopist to selectively determine which lesions can be left in situ, which lesions can simply be discarded, and which lesions need formal histopathologic analysis.
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Affiliation(s)
- Neil Parikh
- Division of Gastroenterology, Icahn School of Medicine at Mount Sinai, NY, NY, U.S.A
| | - Daniel Perl
- Department of Medicine, Icahn School of Medicine at Mount Sinai, New York, NY, U.S.A
| | - Michelle H. Lee
- Division of Gastroenterology, Icahn School of Medicine at Mount Sinai, NY, NY, U.S.A
| | - Brijen Shah
- Division of Gastroenterology, Icahn School of Medicine at Mount Sinai, NY, NY, U.S.A
| | - Yuki Young
- Division of Gastroenterology, Icahn School of Medicine at Mount Sinai, NY, NY, U.S.A
| | - Shannon S. Chang
- Department of Medicine, Icahn School of Medicine at Mount Sinai, New York, NY, U.S.A
| | - Richa Shukla
- Department of Medicine, Icahn School of Medicine at Mount Sinai, New York, NY, U.S.A
| | | | - Erin Moshier
- Department of Preventive Medicine, Icahn School of Medicine at Mount Sinai, NY, NY, U.S.A
| | - James Godbold
- Department of Preventive Medicine, Icahn School of Medicine at Mount Sinai, NY, NY, U.S.A
| | - Elinor Zhou
- Department of Medicine, Icahn School of Medicine at Mount Sinai, New York, NY, U.S.A
| | - Josephine Mitchaml
- Division of Gastroenterology, Icahn School of Medicine at Mount Sinai, NY, NY, U.S.A
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Adelsberger H, Zainos A, Alvarez M, Romo R, Konnerth A. Local domains of motor cortical activity revealed by fiber-optic calcium recordings in behaving nonhuman primates. Proc Natl Acad Sci U S A 2014; 111:463-8. [PMID: 24344287 DOI: 10.1073/pnas.1321612111] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Brain mapping experiments involving electrical microstimulation indicate that the primary motor cortex (M1) directly regulates muscle contraction and thereby controls specific movements. Possibly, M1 contains a small circuit "map" of the body that is formed by discrete local networks that code for specific movements. Alternatively, movements may be controlled by distributed, larger-scale overlapping circuits. Because of technical limitations, it remained unclear how movement-determining circuits are organized in M1. Here we introduce a method that allows the functional mapping of small local neuronal circuits in awake behaving nonhuman primates. For this purpose, we combined optic-fiber-based calcium recordings of neuronal activity and cortical microstimulation. The method requires targeted bulk loading of synthetic calcium indicators (e.g., OGB-1 AM) for the staining of neuronal microdomains. The tip of a thin (200 µm) optical fiber can detect the coherent activity of a small cluster of neurons, but is insensitive to the asynchronous activity of individual cells. By combining such optical recordings with microstimulation at two well-separated sites of M1, we demonstrate that local cortical activity was tightly associated with distinct and stereotypical simple movements. Increasing stimulation intensity increased both the amplitude of the movements and the level of neuronal activity. Importantly, the activity remained local, without invading the recording domain of the second optical fiber. Furthermore, there was clear response specificity at the two recording sites in a trained behavioral task. Thus, the results provide support for movement control in M1 by local neuronal clusters that are organized in discrete cortical domains.
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Liu JTC, Mandella MJ, Loewke NO, Haeberle H, Ra H, Piyawattanametha W, Solgaard O, Kino GS, Contag CH. Micromirror-scanned dual-axis confocal microscope utilizing a gradient-index relay lens for image guidance during brain surgery. J Biomed Opt 2010; 15:026029. [PMID: 20459274 PMCID: PMC2869369 DOI: 10.1117/1.3386055] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/19/2009] [Revised: 01/30/2010] [Accepted: 03/10/2010] [Indexed: 05/18/2023]
Abstract
A fluorescence confocal microscope incorporating a 1.8-mm-diam gradient-index relay lens is developed for in vivo histological guidance during resection of brain tumors. The microscope utilizes a dual-axis confocal architecture to efficiently reject out-of-focus light for high-contrast optical sectioning. A biaxial microelectromechanical system (MEMS) scanning mirror is actuated at resonance along each axis to achieve a large field of view with low-voltage waveforms. The unstable Lissajous scan, which results from actuating the orthogonal axes of the MEMS mirror at highly disparate resonance frequencies, is optimized to fully sample 500x500 pixels at two frames per second. Optically sectioned fluorescence images of brain tissues are obtained in living mice to demonstrate the utility of this microscope for image-guided resections.
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Affiliation(s)
- Jonathan T C Liu
- Stanford University School of Medicine, Clark Center for Biomedical Engineering and Science, Stanford, California 94305, USA.
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Abstract
Fiber-optic image guides in confocal reflectance endomicroscopes introduce background backscatter that limits the achievable contrast in these devices. We show the dominant source of backscatter from the image guide is due to Rayleigh scattering at short wavelengths and terminal reflections of the fibers at long wavelengths. The effective Rayleigh scattering coefficient and the wavelength-independent reflectivity due terminal reflections are measured experimentally in a commercial image guide. The Rayleigh scattering component of backscatter can be accurately predicted using the fractional refractive-index difference and length of the fibers in the image guide. We also presented a simple model that can be used to predict signal-to-background ratio in a fiber-optic confocal reflectance endomicroscope for biologically relevant tissues and contrast agents that cover a wide range of reflectivity.
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Affiliation(s)
- Pierre M Lane
- British Columbia Cancer Agency, 675 West 10th Avenue, Vancouver, British Columbia V5Z 1L3, Canada.
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Abstract
Intravital microscopy using two-photon excitation is proven to be a valuable tool for studying the kidney and associated disease processes. However, routine performance of intravital kidney imaging is limited by the fact that fluorescence signal is attenuated by the tissue and at certain tissue depth lost its strength completely. For most of the animal tissues, this finite imaging depth is limited to a few hundred microns. Currently it is not possible to non-invasively image the kidney beyond the superficial tissue layers of the cortex. This has imposed significant limitations on the animal models one can use for imaging since structure such the glomerulus is typically located below the superficial layer of the cortex that can not be imaged using a conventional fluorescence microscope. Here we report the use of a needle-like lens system based on gradient-index (GRIN) microlenses capable of transferring high quality fluorescence images of the tissue through a regular microscope objective for deep tissue imaging of the kidney. By combining this GRIN lens system with a Zeiss LSM 510 NLO microscope, we are able to extend the imaging depth for kidney tissues far beyond the few hundred microns limit. This GRIN lens imaging system provides an alternative microendoscopic imaging tool that will enhance current intravital kidney imaging techniques for studying structural and functional properties of local tissues at locations below the superficial layers of the kidney.
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Affiliation(s)
- Xin Li
- Indiana University School of Medicine, Department of Medicine, Division of Nephrology
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