1
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Quicke P, Reynolds S, Neil M, Knöpfel T, Schultz SR, Foust AJ. High speed functional imaging with source localized multifocal two-photon microscopy. Biomed Opt Express 2018; 9:3678-3693. [PMID: 30338147 PMCID: PMC6191622 DOI: 10.1364/boe.9.003678] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/19/2018] [Revised: 05/04/2018] [Accepted: 06/04/2018] [Indexed: 05/11/2023]
Abstract
Multifocal two-photon microscopy (MTPM) increases imaging speed over single-focus scanning by parallelizing fluorescence excitation. The imaged fluorescence's susceptibility to crosstalk, however, severely degrades contrast in scattering tissue. Here we present a source-localized MTPM scheme optimized for high speed functional fluorescence imaging in scattering mammalian brain tissue. A rastered line array of beamlets excites fluorescence imaged with a complementary metal-oxide-semiconductor (CMOS) camera. We mitigate scattering-induced crosstalk by temporally oversampling the rastered image, generating grouped images with structured illumination, and applying Richardson-Lucy deconvolution to reassign scattered photons. Single images are then retrieved with a maximum intensity projection through the deconvolved image groups. This method increased image contrast at depths up to 112 μm in scattering brain tissue and reduced functional crosstalk between pixels during neuronal calcium imaging. Source-localization did not affect signal-to-noise ratio (SNR) in densely labeled tissue under our experimental conditions. SNR decreased at low frame rates in sparsely labeled tissue, with no effect at frame rates above 50 Hz. Our non-descanned source-localized MTPM system enables high SNR, 100 Hz capture of fluorescence transients in scattering brain, increasing the scope of MTPM to faster and smaller functional signals.
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Affiliation(s)
- Peter Quicke
- Department of Bioengineering, Imperial College London, SW7 2AZ,
UK
- Centre for Neurotechnology, Imperial College London, SW7 2AZ,
UK
| | - Stephanie Reynolds
- Department of Electrical and Electronic Engineering, Imperial College London, SW7 2AZ,
UK
| | - Mark Neil
- Centre for Neurotechnology, Imperial College London, SW7 2AZ,
UK
- Department of Physics, Imperial College London, SW7 2AZ,
UK
| | - Thomas Knöpfel
- Centre for Neurotechnology, Imperial College London, SW7 2AZ,
UK
- Department of Medicine, Imperial College London, SW7 2AZ,
UK
| | - Simon R. Schultz
- Department of Bioengineering, Imperial College London, SW7 2AZ,
UK
- Centre for Neurotechnology, Imperial College London, SW7 2AZ,
UK
| | - Amanda J. Foust
- Department of Bioengineering, Imperial College London, SW7 2AZ,
UK
- Centre for Neurotechnology, Imperial College London, SW7 2AZ,
UK
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2
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Dvornikov A, Gratton E. Hyperspectral imaging in highly scattering media by the spectral phasor approach using two filters. Biomed Opt Express 2018; 9:3503-3511. [PMID: 30338135 PMCID: PMC6191637 DOI: 10.1364/boe.9.003503] [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] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/23/2018] [Revised: 06/14/2018] [Accepted: 06/18/2018] [Indexed: 05/25/2023]
Abstract
Hyperspectral imaging is a common technique in fluorescence microscopy to obtain the emission spectrum at each pixel of an image. However, methods to obtain spectral resolution based on diffraction gratings or integrated prisms work poorly when the sample is strongly scattering. We developed a microscope named the DIVER that collects the fluorescence emission over a very large angle. Since the fluorescence light after passing through the multiple scattering sample is not collimated, the use of grating or prisms strongly limits the amount of light that can be used with available hyperspectral devices. Here we show that 2 filters that accept uncollimated light over a large aperture are sufficient to calculate the spectral phasor rather than displaying the entire spectrum. Using the properties of the spectral phasors, we can resolve spectral components and perform the type of data analyses that are usually performed in hyperspectral image analysis.
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Affiliation(s)
- Alexander Dvornikov
- Laboratory for Fluorescence Dynamics, Department of Biomedical Engineering, University of California Irvine, Irvine, CA 92697, USA
| | - Enrico Gratton
- Laboratory for Fluorescence Dynamics, Department of Biomedical Engineering, University of California Irvine, Irvine, CA 92697, USA
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3
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Miura T, Mikami H, Isozaki A, Ito T, Ozeki Y, Goda K. On-chip light-sheet fluorescence imaging flow cytometry at a high flow speed of 1 m/s. Biomed Opt Express 2018; 9:3424-3433. [PMID: 29984107 PMCID: PMC6033546 DOI: 10.1364/boe.9.003424] [Citation(s) in RCA: 9] [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] [Subscribe] [Scholar Register] [Received: 05/01/2018] [Revised: 06/03/2018] [Accepted: 06/13/2018] [Indexed: 05/02/2023]
Abstract
We present on-chip fluorescence imaging flow cytometry by light-sheet excitation on a mirror-embedded microfluidic chip. The method allows us to obtain microscopy-grade fluorescence images of cells flowing at a high speed of 1 m/s, which is comparable to the flow speed of conventional non-imaging flow cytometers. To implement the light-sheet excitation of flowing cells in a microchannel, we designed and fabricated a mirror-embedded PDMS-based microfluidic chip. To show its broad utility, we used the method to classify large populations of microalgal cells (Euglena gracilis) and human cancer cells (human adenocarcinoma cells). Our method holds promise for large-scale single-cell analysis.
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Affiliation(s)
- Taichi Miura
- Department of Chemistry, University of Tokyo, Tokyo 113-0033, Japan
| | - Hideharu Mikami
- Department of Chemistry, University of Tokyo, Tokyo 113-0033, Japan
| | - Akihiro Isozaki
- Department of Chemistry, University of Tokyo, Tokyo 113-0033, Japan
| | - Takuro Ito
- Japan Science and Technology Agency, Saitama 332-0012, Japan
| | - Yasuyuki Ozeki
- Department of Electrical Engineering and Information Systems, University of Tokyo, Tokyo 113-8656, Japan
| | - Keisuke Goda
- Department of Chemistry, University of Tokyo, Tokyo 113-0033, Japan
- Japan Science and Technology Agency, Saitama 332-0012, Japan
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4
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Jagtap J, Sharma G, Parchur AK, Gogineni V, Bergom C, White S, Flister MJ, Joshi A. Erratum: Methods for detecting host genetic modifiers of tumor vascular function using dynamic near-infrared fluorescence imaging: errata. Biomed Opt Express 2018; 9:2543. [PMID: 30258671 PMCID: PMC6154194 DOI: 10.1364/boe.9.002543] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/04/2018] [Indexed: 06/08/2023]
Abstract
[This corrects the article on p. 543 in vol. 9, PMID: 29552392.].
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Affiliation(s)
- Jaidip Jagtap
- Department of Biomedical Engineering, Medical College of Wisconsin, Milwaukee, WI 53226, USA
| | - Gayatri Sharma
- Department of Biomedical Engineering, Medical College of Wisconsin, Milwaukee, WI 53226, USA
| | - Abdul K. Parchur
- Department of Biomedical Engineering, Medical College of Wisconsin, Milwaukee, WI 53226, USA
| | | | - Carmen Bergom
- Department of Radiation Oncology, Medical College of Wisconsin, Milwaukee, WI 53226, USA
| | - Sarah White
- Department of Radiology, Medical College of Wisconsin, Milwaukee, WI 53226, USA
| | - Michael J. Flister
- Department of Physiology, Medical College of Wisconsin, Milwaukee, WI 53226, USA
| | - Amit Joshi
- Department of Biomedical Engineering, Medical College of Wisconsin, Milwaukee, WI 53226, USA
- Department of Radiology, Medical College of Wisconsin, Milwaukee, WI 53226, USA
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5
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Chaturvedi A, Shukair SA, Le Rolland P, Vijayvergia M, Gunn JW, Subramanian H. Blood vessel detection, localization and estimation using a smart laparoscopic grasper: a Monte Carlo study. Biomed Opt Express 2018; 9:2027-2040. [PMID: 29760967 PMCID: PMC5946768 DOI: 10.1364/boe.9.002027] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/05/2018] [Revised: 03/18/2018] [Accepted: 03/20/2018] [Indexed: 06/08/2023]
Abstract
For centuries, surgeons have relied on their sense of touch to identify vital structures such as blood vessels in traditional open surgery. Over the past two decades, surgeons have shifted to minimally invasive surgical (MIS) approaches, including laparoscopic surgery, which include benefits such as less scarring, less risk for infection, and quicker recovery times. In fact, some surgeries such as cholecystectomies have seen more than an 80% adoption of this technique because of those benefits. However, due to the fundamental challenges associated with using laparoscopic surgery, there has been a lower adoption in more complex specialties, such as colorectal and thoracic surgery, where the field of surgery has bleeding, fat, scar tissue, and adhesions. These problems are exacerbated by complicating factors such as inflammation, cancer, chronic disease, obesity, and re-operations. Importantly, surgeons will often convert from laparoscopy to open surgery if they can no longer proceed using the minimally invasive approach because of issues described with these complicating factors, thereby negating the benefits that the patient would have seen. When the surgeon does attempt these procedures with those issues, the surgery takes on average 30 min - 1 hour longer. A new method by which surgeons can visualize structures like blood vessels could reduce the conversion rates and operating time, thereby driving a greater adoption of laparoscopic surgery in these complex procedures. Here, we show that by adding near infrared (NIR) LEDs and a linear image sensor onto the opposing jaws of the laparoscopic graspers, blood vessels that are embedded within tissues can be detected and localized efficiently, even those not visible using current imaging techniques. We show the results of Monte Carlo simulations to support our claim, including that blood vessels ranging from 2 to 6 mm and buried under up to 1 cm of tissue can be detected. We also report developing a smart grasper handheld prototype to run ex vivo experiments. The results of these experiments matched with those of the Monte Carlo simulations and the estimated blood vessel size showed a strong correlation with the actual size. This technology will be incorporated into already existing laparoscopic tools to assist surgeons during MIS procedures.
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6
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Ahmad J, Jayet B, Hill PJ, Mather ML, Dehghani H, Morgan SP. Ultrasound-mediation of self-illuminating reporters improves imaging resolution in optically scattering media. Biomed Opt Express 2018; 9:1664-1679. [PMID: 29675309 PMCID: PMC5905913 DOI: 10.1364/boe.9.001664] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/02/2017] [Revised: 12/13/2017] [Accepted: 02/12/2018] [Indexed: 06/08/2023]
Abstract
In vivo imaging of self-illuminating bio-and chemiluminescent reporters is used to observe the physiology of small animals. However, strong light scattering by biological tissues results in poor spatial resolution of the optical imaging, which also degrades the quantitative accuracy. To overcome this challenging problem, focused ultrasound is used to modulate the light from the reporter at the ultrasound frequency. This produces an ultrasound switchable light 'beacon' that reduces the influence of light scattering in order to improve spatial resolution. The experimental results demonstrate that apart from light modulation at the ultrasound frequency (AC signal at 3.5 MHz), ultrasound also increases the DC intensity of the reporters. This is shown to be due to a temperature rise caused by insonification that was minimized to be within acceptable mammalian tissue safety thresholds by adjusting the duty cycle of the ultrasound. Line scans of bio-and chemiluminescent objects embedded within a scattering medium were obtained using ultrasound modulated (AC) and ultrasound enhanced (DC) signals. Lateral resolution is improved by a factor of 12 and 7 respectively, as compared to conventional CCD imaging. Two chemiluminescent sources separated by ~10 mm at ~20 mm deep inside a 50 mm thick chicken breast have been successfully resolved with an average signal-to-noise ratio of approximately 8-10 dB.
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Affiliation(s)
- Junaid Ahmad
- Optics and Photonics Research Group, Faculty of Engineering, University of Nottingham, University Park, NG7 2RD, UK
- Department of Electrical Engineering, University of Engineering and Technology, Lahore, KSK Campus, 54890, Pakistan
| | - Baptiste Jayet
- Optics and Photonics Research Group, Faculty of Engineering, University of Nottingham, University Park, NG7 2RD, UK
| | - Philip J Hill
- School of Biosciences, University of Nottingham, LE12 5RD, UK
| | - Melissa L Mather
- Institute of Science and Technology in Medicine, Keele University, ST4 7QB, UK
| | - Hamid Dehghani
- School of Computer Science, University of Birmingham, Edgbaston, B15 2TT, UK
| | - Stephen P Morgan
- Optics and Photonics Research Group, Faculty of Engineering, University of Nottingham, University Park, NG7 2RD, UK
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7
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Lu R, Tanimoto M, Koyama M, Ji N. 50 Hz volumetric functional imaging with continuously adjustable depth of focus. Biomed Opt Express 2018; 9:1964-1976. [PMID: 29675332 PMCID: PMC5905937 DOI: 10.1364/boe.9.001964] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/12/2017] [Revised: 03/08/2018] [Accepted: 03/16/2018] [Indexed: 05/22/2023]
Abstract
Understanding how neural circuits control behavior requires monitoring a large population of neurons with high spatial resolution and volume rate. Here we report an axicon-based Bessel beam module with continuously adjustable depth of focus (CADoF), that turns frame rate into volume rate by extending the excitation focus in the axial direction while maintaining high lateral resolutions. Cost-effective and compact, this CADoF Bessel module can be easily integrated into existing two-photon fluorescence microscopes. Simply translating one of the relay lenses along its optical axis enabled continuous adjustment of the axial length of the Bessel focus. We used this module to simultaneously monitor activity of spinal projection neurons extending over 60 µm depth in larval zebrafish at 50 Hz volume rate with adjustable axial extent of the imaged volume.
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Affiliation(s)
- Rongwen Lu
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA, USA
- Contributed equally
| | - Masashi Tanimoto
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA, USA
- Division of Biological Science, Graduate School of Science, Nagoya University, Nagoya, Japan
- Contributed equally
| | - Minoru Koyama
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA, USA
| | - Na Ji
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA, USA
- Department of Physics and Department of Molecular & Cellular Biology, University of California, Berkeley, CA, USA
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8
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Lu R, Tanimoto M, Koyama M, Ji N. 50 Hz volumetric functional imaging with continuously adjustable depth of focus. Biomed Opt Express 2018; 9:1964-1976. [PMID: 29675332 DOI: 10.1101/240069] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/12/2017] [Revised: 03/08/2018] [Accepted: 03/16/2018] [Indexed: 05/22/2023]
Abstract
Understanding how neural circuits control behavior requires monitoring a large population of neurons with high spatial resolution and volume rate. Here we report an axicon-based Bessel beam module with continuously adjustable depth of focus (CADoF), that turns frame rate into volume rate by extending the excitation focus in the axial direction while maintaining high lateral resolutions. Cost-effective and compact, this CADoF Bessel module can be easily integrated into existing two-photon fluorescence microscopes. Simply translating one of the relay lenses along its optical axis enabled continuous adjustment of the axial length of the Bessel focus. We used this module to simultaneously monitor activity of spinal projection neurons extending over 60 µm depth in larval zebrafish at 50 Hz volume rate with adjustable axial extent of the imaged volume.
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Affiliation(s)
- Rongwen Lu
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA, USA
- Contributed equally
| | - Masashi Tanimoto
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA, USA
- Division of Biological Science, Graduate School of Science, Nagoya University, Nagoya, Japan
- Contributed equally
| | - Minoru Koyama
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA, USA
| | - Na Ji
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA, USA
- Department of Physics and Department of Molecular & Cellular Biology, University of California, Berkeley, CA, USA
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9
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Schulz-Hildebrandt H, Pieper M, Stehmar C, Ahrens M, Idel C, Wollenberg B, König P, Hüttmann G. Novel endoscope with increased depth of field for imaging human nasal tissue by microscopic optical coherence tomography. Biomed Opt Express 2018; 9:636-647. [PMID: 29552400 PMCID: PMC5854065 DOI: 10.1364/boe.9.000636] [Citation(s) in RCA: 11] [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] [Subscribe] [Scholar Register] [Received: 11/21/2017] [Revised: 12/29/2017] [Accepted: 01/08/2018] [Indexed: 05/13/2023]
Abstract
Intravital microscopy (IVM) offers the opportunity to visualize static and dynamic changes of tissue on a cellular level. It is a valuable tool in research and may considerably improve clinical diagnosis. In contrast to confocal and non-linear microscopy, optical coherence tomography (OCT) with microscopic resolution (mOCT) provides intrinsically cross-sectional imaging. Changing focus position is not needed, which simplifies especially endoscopic imaging. For in-vivo imaging, here we are presenting endo-microscopic OCT (emOCT). A graded-index-lens (GRIN) based 2.75 mm outer diameter rigid endoscope is providing 1.5 - 2 µm nearly isotropic resolution over an extended field of depth. Spherical and chromatic aberrations are used to elongate the focus length. Simulation of the OCT image formation, suggests a better overall image quality in this range compared to a focused Gaussian beam. Total imaging depth at a reduced sensitivity and lateral resolution is more than 200 µm. Using a frame rate of 80 Hz cross-sectional images of concha nasalis were demonstrated in humans, which could resolve cilial motion, cellular structures of the epithelium, vessels and blood cells. Mucus transport velocity was successfully determined. The endoscope may be used for diagnosis and treatment control of different lung diseases like cystic fibrosis or primary ciliary dyskinesia, which manifest already at the nasal mucosa.
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Affiliation(s)
- Hinnerk Schulz-Hildebrandt
- Institute for Biomedical Optics, University of Lübeck, Peter-Monnik-Weg 4, 23562 Lübeck, Germany
- Airway Research Center North (ARCN), German Center for Lung Research (DZL), 22927 Großhansdorf, Germany
- Medical Laser Center Lübeck GmbH, Peter-Monnik-Weg 4, 23562 Lübeck, Germany
| | - Mario Pieper
- Airway Research Center North (ARCN), German Center for Lung Research (DZL), 22927 Großhansdorf, Germany
- Institute of Anatomy, University of Lübeck, Ratzeburger Allee 160, 23562 Lübeck, Germany
| | - Charlotte Stehmar
- Institute for Biomedical Optics, University of Lübeck, Peter-Monnik-Weg 4, 23562 Lübeck, Germany
| | - Martin Ahrens
- Institute for Biomedical Optics, University of Lübeck, Peter-Monnik-Weg 4, 23562 Lübeck, Germany
- Airway Research Center North (ARCN), German Center for Lung Research (DZL), 22927 Großhansdorf, Germany
| | - Christian Idel
- ENT Clinics, University Hospital Schleswig-Holstein, Ratzeburger Allee 160, 23562 Lübeck, Germany
| | - Barbara Wollenberg
- Airway Research Center North (ARCN), German Center for Lung Research (DZL), 22927 Großhansdorf, Germany
- ENT Clinics, University Hospital Schleswig-Holstein, Ratzeburger Allee 160, 23562 Lübeck, Germany
| | - Peter König
- Airway Research Center North (ARCN), German Center for Lung Research (DZL), 22927 Großhansdorf, Germany
- Institute of Anatomy, University of Lübeck, Ratzeburger Allee 160, 23562 Lübeck, Germany
| | - Gereon Hüttmann
- Institute for Biomedical Optics, University of Lübeck, Peter-Monnik-Weg 4, 23562 Lübeck, Germany
- Airway Research Center North (ARCN), German Center for Lung Research (DZL), 22927 Großhansdorf, Germany
- Medical Laser Center Lübeck GmbH, Peter-Monnik-Weg 4, 23562 Lübeck, Germany
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10
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Wang P, Turcatel G, Arnesano C, Warburton D, Fraser SE, Cutrale F. Fiber pattern removal and image reconstruction method for snapshot mosaic hyperspectral endoscopic images. Biomed Opt Express 2018; 9:780-790. [PMID: 29552412 PMCID: PMC5854078 DOI: 10.1364/boe.9.000780] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/22/2017] [Revised: 01/20/2018] [Accepted: 01/21/2018] [Indexed: 05/04/2023]
Abstract
Hyperspectral endoscopic imaging has the potential to enhance clinical diagnostics and outcome. Most commercial endoscopes utilize imaging fiber bundles to transmit the collected signal from the patient to the medical operator. These bundles consist of several fiber cores surrounded by a cladding layer creating comb structure-like artifacts, which complicate further analysis, both spatially and spectrally. Here we present an optical fiber pattern removal algorithm which we applied to hyperspectral bronchoscopic images robustly and quantitatively without the need for specific optical or electrical hardware. We validate the performance of the pattern removal by using a novel hyperspectral phasor approach. This algorithm can be generalized to all forms of fiber bundle hyperspectral endoscopy.
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Affiliation(s)
- Pu Wang
- Translational Imaging Center, University of Southern California, Los Angeles, California, 90089, USA
- Biomedical Engineering, University of Southern California, Los Angeles, California, 90089, USA
| | - Gianluca Turcatel
- Developmental Biology and Regenerative Medicine Program, Saban Research Institute, Children’s Hospital Los Angeles, Los Angeles, California 90027, USA
- Keck School of Medicine and Ostrow School of Dentistry, University of Southern California, Los Angeles, California 90033, USA
| | - Cosimo Arnesano
- Translational Imaging Center, University of Southern California, Los Angeles, California, 90089, USA
- Biomedical Engineering, University of Southern California, Los Angeles, California, 90089, USA
| | - David Warburton
- Developmental Biology and Regenerative Medicine Program, Saban Research Institute, Children’s Hospital Los Angeles, Los Angeles, California 90027, USA
- Keck School of Medicine and Ostrow School of Dentistry, University of Southern California, Los Angeles, California 90033, USA
| | - Scott E. Fraser
- Translational Imaging Center, University of Southern California, Los Angeles, California, 90089, USA
- Biomedical Engineering, University of Southern California, Los Angeles, California, 90089, USA
| | - Francesco Cutrale
- Translational Imaging Center, University of Southern California, Los Angeles, California, 90089, USA
- Biomedical Engineering, University of Southern California, Los Angeles, California, 90089, USA
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11
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Jagtap J, Sharma G, Parchur AK, Gogineni V, Bergom C, White S, Flister MJ, Joshi A. Methods for detecting host genetic modifiers of tumor vascular function using dynamic near-infrared fluorescence imaging. Biomed Opt Express 2018; 9:543-556. [PMID: 29552392 PMCID: PMC5854057 DOI: 10.1364/boe.9.000543] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/18/2017] [Revised: 12/07/2017] [Accepted: 01/03/2018] [Indexed: 05/06/2023]
Abstract
Vascular supply is a critical component of the tumor microenvironment (TME) and is essential for tumor growth and metastasis, yet the endogenous genetic modifiers that impact vascular function in the TME are largely unknown. To identify the host TME modifiers of tumor vascular function, we combined a novel genetic mapping strategy [Consomic Xenograft Model] with near-infrared (NIR) fluorescence imaging and multiparametric analysis of pharmacokinetic modeling. To detect vascular flow, an intensified cooled camera based dynamic NIR imaging system with 785 nm laser diode based excitation was used to image the whole-body fluorescence emission of intravenously injected indocyanine green dye. Principal component analysis was used to extract the spatial segmentation information for the lungs, liver, and tumor regions-of-interest. Vascular function was then quantified by pK modeling of the imaging data, which revealed significantly altered tissue perfusion and vascular permeability that were caused by host genetic modifiers in the TME. Collectively, these data demonstrate that NIR fluorescent imaging can be used as a non-invasive means for characterizing host TME modifiers of vascular function that have been linked with tumor risk, progression, and response to therapy.
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Affiliation(s)
- Jaidip Jagtap
- Department of Biomedical Engineering, Medical College of Wisconsin, Milwaukee, WI 53226, USA
| | - Gayatri Sharma
- Department of Biomedical Engineering, Medical College of Wisconsin, Milwaukee, WI 53226, USA
| | - Abdul K. Parchur
- Department of Biomedical Engineering, Medical College of Wisconsin, Milwaukee, WI 53226, USA
| | | | - Carmen Bergom
- Department of Radiation Oncology, Medical College of Wisconsin, Milwaukee, WI 53226, USA
| | - Sarah White
- Department of Radiology, Medical College of Wisconsin, Milwaukee, WI 53226, USA
| | - Michael J. Flister
- Department of Physiology, Medical College of Wisconsin, Milwaukee, WI 53226, USA
| | - Amit Joshi
- Department of Biomedical Engineering, Medical College of Wisconsin, Milwaukee, WI 53226, USA
- Department of Radiology, Medical College of Wisconsin, Milwaukee, WI 53226, USA
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12
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Braaf B, Donner S, Nam AS, Bouma BE, Vakoc BJ. Complex differential variance angiography with noise-bias correction for optical coherence tomography of the retina. Biomed Opt Express 2018; 9:486-506. [PMID: 29552388 PMCID: PMC5854053 DOI: 10.1364/boe.9.000486] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/06/2017] [Revised: 01/03/2018] [Accepted: 01/03/2018] [Indexed: 05/05/2023]
Abstract
Complex differential variance (CDV) provides phase-sensitive angiographic imaging for optical coherence tomography (OCT) with immunity to phase-instabilities of the imaging system and small-scale axial bulk motion. However, like all angiographic methods, measurement noise can result in erroneous indications of blood flow that confuse the interpretation of angiographic images. In this paper, a modified CDV algorithm that corrects for this noise-bias is presented. This is achieved by normalizing the CDV signal by analytically derived upper and lower limits. The noise-bias corrected CDV algorithm was implemented into an experimental 1 μm wavelength OCT system for retinal imaging that used an eye tracking scanner laser ophthalmoscope at 815 nm for compensation of lateral eye motions. The noise-bias correction improved the CDV imaging of the blood flow in tissue layers with a low signal-to-noise ratio and suppressed false indications of blood flow outside the tissue. In addition, the CDV signal normalization suppressed noise induced by galvanometer scanning errors and small-scale lateral motion. High quality cross-section and motion-corrected en face angiograms of the retina and choroid are presented.
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Affiliation(s)
- Boy Braaf
- Wellman Center for Photomedicine, Massachusetts General Hospital, 50 Blossom St., Boston, Massachusetts 02114, USA
- Harvard Medical School, 25 Shattuck Street, Boston, Massachusetts 02115, USA
| | - Sabine Donner
- Heidelberg Engineering GmbH, Max-Jarecki-Straße 8, 69115 Heidelberg, Germany
| | - Ahhyun S. Nam
- Wellman Center for Photomedicine, Massachusetts General Hospital, 50 Blossom St., Boston, Massachusetts 02114, USA
- Harvard Medical School, 25 Shattuck Street, Boston, Massachusetts 02115, USA
| | - Brett E. Bouma
- Wellman Center for Photomedicine, Massachusetts General Hospital, 50 Blossom St., Boston, Massachusetts 02114, USA
- Harvard Medical School, 25 Shattuck Street, Boston, Massachusetts 02115, USA
- Harvard-MIT Division of Health Sciences and Technology, Cambridge, Massachusetts 02139, USA
| | - Benjamin J. Vakoc
- Wellman Center for Photomedicine, Massachusetts General Hospital, 50 Blossom St., Boston, Massachusetts 02114, USA
- Harvard Medical School, 25 Shattuck Street, Boston, Massachusetts 02115, USA
- Harvard-MIT Division of Health Sciences and Technology, Cambridge, Massachusetts 02139, USA
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13
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Chen X, Zhang X, Zhong Q, Sun Q, Peng J, Gong H, Yuan J. Simultaneous acquisition of neuronal morphology and cytoarchitecture in the same Golgi-stained brain. Biomed Opt Express 2018; 9:230-244. [PMID: 29359099 PMCID: PMC5772577 DOI: 10.1364/boe.9.000230] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/21/2017] [Revised: 12/06/2017] [Accepted: 12/12/2017] [Indexed: 05/14/2023]
Abstract
Acquiring an accurate orientation reference is a prerequisite for precisely analysing the morphological features of Golgi-stained neurons in the whole brain. However, the same reflective imaging contrast of Golgi staining for morphology and Nissl staining for cytoarchitecture leads to the failure of distinguishing soma morphology and simultaneously co-locate cytoarchitecture. Here, we developed the dual-mode micro-optical sectioning tomography (dMOST) method to simultaneously image the reflective and fluorescent signals in three dimensions. We evaluated the feasibility of real-time fluorescent counterstaining on Golgi-stained brain tissue. With our system, we acquired whole-brain data sets of physiological and pathological Golgi-stained mouse model brains with fluorescence-labelled anatomical annotation at single-neuron resolution. We also obtained the neuronal morphology of macaque monkey brain tissue using this method. The results show that real-time acquisition of the co-located cytoarchitecture reference in the same brain greatly facilitates the precise morphological analysis of Golgi-stained neurons.
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Affiliation(s)
- Xiao Chen
- Collaborative Innovation Center for Biomedical Engineering, Wuhan National Laboratory for Optoelectronics-Huazhong University of Science and Technology, Wuhan, Hubei 430074, China
- Britton Chance Center and MOE Key Laboratory for Biomedical Photonics, School of Engineering Sciences, Huazhong University of Science and Technology, Wuhan, Hubei 430074, China
| | - Xiaoyu Zhang
- Collaborative Innovation Center for Biomedical Engineering, Wuhan National Laboratory for Optoelectronics-Huazhong University of Science and Technology, Wuhan, Hubei 430074, China
- Britton Chance Center and MOE Key Laboratory for Biomedical Photonics, School of Engineering Sciences, Huazhong University of Science and Technology, Wuhan, Hubei 430074, China
| | - Qiuyuan Zhong
- Collaborative Innovation Center for Biomedical Engineering, Wuhan National Laboratory for Optoelectronics-Huazhong University of Science and Technology, Wuhan, Hubei 430074, China
- Britton Chance Center and MOE Key Laboratory for Biomedical Photonics, School of Engineering Sciences, Huazhong University of Science and Technology, Wuhan, Hubei 430074, China
| | - Qingtao Sun
- Collaborative Innovation Center for Biomedical Engineering, Wuhan National Laboratory for Optoelectronics-Huazhong University of Science and Technology, Wuhan, Hubei 430074, China
- Britton Chance Center and MOE Key Laboratory for Biomedical Photonics, School of Engineering Sciences, Huazhong University of Science and Technology, Wuhan, Hubei 430074, China
| | - Jie Peng
- Collaborative Innovation Center for Biomedical Engineering, Wuhan National Laboratory for Optoelectronics-Huazhong University of Science and Technology, Wuhan, Hubei 430074, China
- Britton Chance Center and MOE Key Laboratory for Biomedical Photonics, School of Engineering Sciences, Huazhong University of Science and Technology, Wuhan, Hubei 430074, China
| | - Hui Gong
- Collaborative Innovation Center for Biomedical Engineering, Wuhan National Laboratory for Optoelectronics-Huazhong University of Science and Technology, Wuhan, Hubei 430074, China
- Britton Chance Center and MOE Key Laboratory for Biomedical Photonics, School of Engineering Sciences, Huazhong University of Science and Technology, Wuhan, Hubei 430074, China
| | - Jing Yuan
- Collaborative Innovation Center for Biomedical Engineering, Wuhan National Laboratory for Optoelectronics-Huazhong University of Science and Technology, Wuhan, Hubei 430074, China
- Britton Chance Center and MOE Key Laboratory for Biomedical Photonics, School of Engineering Sciences, Huazhong University of Science and Technology, Wuhan, Hubei 430074, China
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14
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He Y, Wang MY, Li D, Yuan Z. Optical mapping of brain activation during the English to Chinese and Chinese to English sight translation. Biomed Opt Express 2017; 8:5399-5411. [PMID: 29296476 PMCID: PMC5745091 DOI: 10.1364/boe.8.005399] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/21/2017] [Revised: 10/28/2017] [Accepted: 10/28/2017] [Indexed: 05/28/2023]
Abstract
Translating from Chinese into another language or vice versa is becoming a widespread phenomenon. However, current neuroimaging studies are insufficient to reveal the neural mechanism underlying translation asymmetry during Chinese/English sight translation. In this study, functional near infrared spectroscopy (fNIRS) was used to extract the brain activation patterns associated with Chinese/English sight translation. Eleven unbalanced Chinese (L1)/English (L2) bilinguals participated in this study based on an intra-group experimental design, in which two translation and two reading aloud tasks were administered: forward translation (from L1 to L2), backward translation (from L2 to L1), L1 reading, and L2 reading. As predicted, our findings revealed that forward translation elicited more pronounced brain activation in Broca's area, suggesting that neural correlates of translation vary according to the direction of translation. Additionally, significant brain activation in the left PFC was involved in backward translation, indicating the importance of this brain region during the translation process. The identical activation patterns could not be discovered in forward translation, indicating the cognitive processing of reading logographic languages (i.e. Chinese) might recruit incongruent brain regions.
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Affiliation(s)
- Yan He
- Centre for Studies of Translation, Interpreting and Cognition, University of Macau, Taipa, Macau SAR, China
- These authors contributed equally to this work
| | - Meng-Yun Wang
- Bioimaging Core, Faculty of Health Sciences, University of Macau, Taipa, Macau SAR, China
- These authors contributed equally to this work
| | - Defeng Li
- Centre for Studies of Translation, Interpreting and Cognition, University of Macau, Taipa, Macau SAR, China
| | - Zhen Yuan
- Bioimaging Core, Faculty of Health Sciences, University of Macau, Taipa, Macau SAR, China
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15
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Nguyen D, Marchand PJ, Planchette AL, Nilsson J, Sison M, Extermann J, Lopez A, Sylwestrzak M, Sordet-Dessimoz J, Schmidt-Christensen A, Holmberg D, Van De Ville D, Lasser T. Optical projection tomography for rapid whole mouse brain imaging. Biomed Opt Express 2017; 8:5637-5650. [PMID: 29296493 PMCID: PMC5745108 DOI: 10.1364/boe.8.005637] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/11/2017] [Revised: 10/31/2017] [Accepted: 10/31/2017] [Indexed: 05/21/2023]
Abstract
In recent years, three-dimensional mesoscopic imaging has gained significant importance in life sciences for fundamental studies at the whole-organ level. In this manuscript, we present an optical projection tomography (OPT) method designed for imaging of the intact mouse brain. The system features an isotropic resolution of ~50 µm and an acquisition time of four to eight minutes, using a 3-day optimized clearing protocol. Imaging of the brain autofluorescence in 3D reveals details of the neuroanatomy, while the use of fluorescent labels displays the vascular network and amyloid deposition in 5xFAD mice, an important model of Alzheimer's disease (AD). Finally, the OPT images are compared with histological slices.
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Affiliation(s)
- David Nguyen
- Laboratoire d’Optique Biomédicale, School of Engineering, École Polytechnique Fédérale de Lausanne, CH-1015 Lausanne,
Switzerland
| | - Paul J. Marchand
- Laboratoire d’Optique Biomédicale, School of Engineering, École Polytechnique Fédérale de Lausanne, CH-1015 Lausanne,
Switzerland
| | - Arielle L. Planchette
- Laboratoire d’Optique Biomédicale, School of Engineering, École Polytechnique Fédérale de Lausanne, CH-1015 Lausanne,
Switzerland
| | - Julia Nilsson
- Autoimmunity, Department of Experimental Medical Sciences, Lund University Diabetes Centre, 20502 Malmö,
Sweden
| | - Miguel Sison
- Laboratoire d’Optique Biomédicale, School of Engineering, École Polytechnique Fédérale de Lausanne, CH-1015 Lausanne,
Switzerland
| | - Jérôme Extermann
- Laboratoire d’Optique Biomédicale, School of Engineering, École Polytechnique Fédérale de Lausanne, CH-1015 Lausanne,
Switzerland
| | - Antonio Lopez
- Laboratoire d’Optique Biomédicale, School of Engineering, École Polytechnique Fédérale de Lausanne, CH-1015 Lausanne,
Switzerland
| | - Marcin Sylwestrzak
- Laboratoire d’Optique Biomédicale, School of Engineering, École Polytechnique Fédérale de Lausanne, CH-1015 Lausanne,
Switzerland
| | - Jessica Sordet-Dessimoz
- Laboratoire d’Optique Biomédicale, School of Engineering, École Polytechnique Fédérale de Lausanne, CH-1015 Lausanne,
Switzerland
| | - Anja Schmidt-Christensen
- Autoimmunity, Department of Experimental Medical Sciences, Lund University Diabetes Centre, 20502 Malmö,
Sweden
| | - Dan Holmberg
- Autoimmunity, Department of Experimental Medical Sciences, Lund University Diabetes Centre, 20502 Malmö,
Sweden
| | - Dimitri Van De Ville
- Medical Image Processing Lab, School of Engineering, École Polytechnique Fédérale de Lausanne, CH-1202 Genève,
Switzerland
| | - Theo Lasser
- Laboratoire d’Optique Biomédicale, School of Engineering, École Polytechnique Fédérale de Lausanne, CH-1015 Lausanne,
Switzerland
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16
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Chen X, Lin W, Wang C, Chen S, Sheng J, Zeng B, Xu M. In vivo real-time imaging of cutaneous hemoglobin concentration, oxygen saturation, scattering properties, melanin content, and epidermal thickness with visible spatially modulated light. Biomed Opt Express 2017; 8:5468-5482. [PMID: 29296481 PMCID: PMC5745096 DOI: 10.1364/boe.8.005468] [Citation(s) in RCA: 4] [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] [Received: 08/24/2017] [Revised: 10/20/2017] [Accepted: 10/24/2017] [Indexed: 05/04/2023]
Abstract
We present the real-time single snapshot multiple frequency demodulation - spatial frequency domain imaging (SSMD-SFDI) platform implemented with a visible digital mirror device that is capable of imaging and monitoring dynamic turbid medium and processes over a large field of view. One challenge in quantitative imaging of biological tissue such as the skin is the complex structure rendering techniques based on homogeneous medium models to fail. To address this difficulty we have also developed a novel method that maps the layered structure to a homogeneous medium for spatial frequency domain imaging. The varying penetration depth of spatially modulated light on its wavelength and modulation frequency is used to resolve the layered structure. The efficacy of the real-time SSMD-SFDI platform and this two-layer model is demonstrated by imaging forearms of 6 healthy subjects under the reactive hyperemia protocol. The results show that our approach not only successfully decouples light absorption by melanin from that by hemoglobin and yields accurate determination of cutaneous hemoglobin concentration and oxygen saturation, but also provides reliable estimation of the scattering properties, the melanin content and the epidermal thickness in real time. Potential applications of our system in imaging skin physiological and functional states, cancer screening, and microcirculation monitoring are discussed at the end.
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Affiliation(s)
- Xinlin Chen
- Institute of Lasers and Biomedical Photonics, Biomedical Engineering College, Wenzhou Medical University, Wenzhou, Zhejiang, 325035, China
| | - Weihao Lin
- Institute of Lasers and Biomedical Photonics, Biomedical Engineering College, Wenzhou Medical University, Wenzhou, Zhejiang, 325035, China
| | - Chenge Wang
- Institute of Lasers and Biomedical Photonics, Biomedical Engineering College, Wenzhou Medical University, Wenzhou, Zhejiang, 325035, China
| | - Shaoheng Chen
- Institute of Lasers and Biomedical Photonics, Biomedical Engineering College, Wenzhou Medical University, Wenzhou, Zhejiang, 325035, China
| | - Jing Sheng
- Institute of Lasers and Biomedical Photonics, Biomedical Engineering College, Wenzhou Medical University, Wenzhou, Zhejiang, 325035, China
| | - Bixin Zeng
- Institute of Lasers and Biomedical Photonics, Biomedical Engineering College, Wenzhou Medical University, Wenzhou, Zhejiang, 325035, China
| | - M. Xu
- Institute of Lasers and Biomedical Photonics, Biomedical Engineering College, Wenzhou Medical University, Wenzhou, Zhejiang, 325035, China
- Dept. of Physics, Fairfield University, 1073 North Road, Fairfield, CT 06824, USA
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17
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Lichtenegger A, Harper DJ, Augustin M, Eugui P, Muck M, Gesperger J, Hitzenberger CK, Woehrer A, Baumann B. Spectroscopic imaging with spectral domain visible light optical coherence microscopy in Alzheimer's disease brain samples. Biomed Opt Express 2017; 8:4007-4025. [PMID: 28966843 PMCID: PMC5611919 DOI: 10.1364/boe.8.004007] [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] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/30/2017] [Revised: 08/02/2017] [Accepted: 08/02/2017] [Indexed: 05/18/2023]
Abstract
A visible light spectral domain optical coherence microscopy system was developed. A high axial resolution of 0.88 μm in tissue was achieved using a broad visible light spectrum (425 - 685 nm). Healthy human brain tissue was imaged to quantify the difference between white (WM) and grey matter (GM) in intensity and attenuation. The high axial resolution enables the investigation of amyloid-beta plaques of various sizes in human brain tissue and animal models of Alzheimer's disease (AD). By performing a spectroscopic analysis of the OCM data, differences in the characteristics for WM, GM, and neuritic amyloid-beta plaques were found. To gain additional contrast, Congo red stained AD brain tissue was investigated. A first effort was made to investigate optically cleared mouse brain tissue to increase the penetration depth and visualize hyperscattering structures in deeper cortical regions.
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Affiliation(s)
- Antonia Lichtenegger
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Waehringer Guertel 18-20, 1090 Vienna,
Austria
| | - Danielle J. Harper
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Waehringer Guertel 18-20, 1090 Vienna,
Austria
| | - Marco Augustin
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Waehringer Guertel 18-20, 1090 Vienna,
Austria
| | - Pablo Eugui
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Waehringer Guertel 18-20, 1090 Vienna,
Austria
| | - Martina Muck
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Waehringer Guertel 18-20, 1090 Vienna,
Austria
- Institute of Neurology, General Hospital and Medical University of Vienna, Waehringer Guertel 18-20, 1090 Vienna,
Austria
| | - Johanna Gesperger
- Institute of Neurology, General Hospital and Medical University of Vienna, Waehringer Guertel 18-20, 1090 Vienna,
Austria
| | - Christoph K. Hitzenberger
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Waehringer Guertel 18-20, 1090 Vienna,
Austria
| | - Adelheid Woehrer
- Institute of Neurology, General Hospital and Medical University of Vienna, Waehringer Guertel 18-20, 1090 Vienna,
Austria
| | - Bernhard Baumann
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Waehringer Guertel 18-20, 1090 Vienna,
Austria
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18
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Wirth D, Kolste K, Kanick S, Roberts DW, Leblond F, Paulsen KD. Fluorescence depth estimation from wide-field optical imaging data for guiding brain tumor resection: a multi-inclusion phantom study. Biomed Opt Express 2017; 8:3656-3670. [PMID: 28856042 PMCID: PMC5560832 DOI: 10.1364/boe.8.003656] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/14/2017] [Revised: 06/17/2017] [Accepted: 07/01/2017] [Indexed: 05/08/2023]
Abstract
Studies have shown that fluorescent agents demarcate tumor from surrounding brain tissue and offer intraoperative guidance during resection. However, visualization of fluorescence signal from tumor below the surgical surface or through the appearance of blood in the surgical field is challenging. We have previously described red light imaging techniques for estimating fluorescent depths in turbid media. In this study, we evaluate these methods over a broader range of fluorophore concentrations, and investigate the ability to resolve multiple fluorescent emissions in the same plane or at different depths along the axis of imaging. A tungsten halogen lamp is used as a broadband white light source for reflectance imaging. Fluorescence from Alexa Fluor 647 is excited with a 635 nm diode laser. Reflectance and fluorescence spectral data are gathered between 670 and 720 nm with the use of a liquid crystal tunable filter and recorded on a sCMOS camera. Results show that two fluorescent emissions can be resolved within 2 mm if they are in the same plane or within 3 mm if they are at different depths along the axis of imaging up to 6 mm below the surface.
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Affiliation(s)
- Dennis Wirth
- Department of Surgery, Dartmouth-Hitchcock Medical Center, 1 Medical Center Dr. Lebanon, NH 03766, USA
| | - Kolbein Kolste
- Thayer School of Engineering, Dartmouth College, 14 Engineering Dr. Hanover, NH 03755, USA
| | - Stephen Kanick
- Thayer School of Engineering, Dartmouth College, 14 Engineering Dr. Hanover, NH 03755, USA
| | - David W. Roberts
- Section of Neurosurgery, Dartmouth-Hitchcock Medical Center, 1 Medical Center Dr. Lebanon, NH 03766, USA
| | - Frédéric Leblond
- Polytechnique Montreal, Engineering Physics Department, Montreal, Québec H3C 3A7, Canada
| | - Keith D. Paulsen
- Thayer School of Engineering, Dartmouth College, 14 Engineering Dr. Hanover, NH 03755, USA
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19
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Jalal UM, Kim SC, Shim JS. Histogram analysis for smartphone-based rapid hematocrit determination. Biomed Opt Express 2017; 8:3317-3328. [PMID: 28717569 PMCID: PMC5508830 DOI: 10.1364/boe.8.003317] [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] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/05/2017] [Revised: 05/20/2017] [Accepted: 06/07/2017] [Indexed: 06/07/2023]
Abstract
A novel and rapid analysis technique using histogram has been proposed for the colorimetric quantification of blood hematocrits. A smartphone-based "Histogram" app for the detection of hematocrits has been developed integrating the smartphone embedded camera with a microfluidic chip via a custom-made optical platform. The developed histogram analysis shows its effectiveness in the automatic detection of sample channel including auto-calibration and can analyze the single-channel as well as multi-channel images. Furthermore, the analyzing method is advantageous to the quantification of blood-hematocrit both in the equal and varying optical conditions. The rapid determination of blood hematocrits carries enormous information regarding physiological disorders, and the use of such reproducible, cost-effective, and standard techniques may effectively help with the diagnosis and prevention of a number of human diseases.
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20
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Wang Q, Wang J, Zhou M, Li Q, Wang Y. Spectral-spatial feature-based neural network method for acute lymphoblastic leukemia cell identification via microscopic hyperspectral imaging technology. Biomed Opt Express 2017; 8:3017-3028. [PMID: 28663923 PMCID: PMC5480446 DOI: 10.1364/boe.8.003017] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/27/2017] [Revised: 05/11/2017] [Accepted: 05/11/2017] [Indexed: 05/04/2023]
Abstract
Microscopic examination is one of the most common methods for acute lymphoblastic leukemia (ALL) diagnosis. Most traditional methods of automized blood cell identification are based on RGB color or gray images captured by light microscopes. This paper presents an identification method combining both spectral and spatial features to identify lymphoblasts from lymphocytes in hyperspectral images. Normalization and encoding method is applied for spectral feature extraction and the support vector machine-recursive feature elimination (SVM-RFE) algorithm is presented for spatial feature determination. A marker-based learning vector quantization (MLVQ) neural network is proposed to perform identification with the integrated features. Experimental results show that this algorithm yields identification accuracy, sensitivity, and specificity of 92.9%, 93.3%, and 92.5%, respectively. Hyperspectral microscopic blood imaging combined with neural network identification technique has the potential to provide a feasible tool for ALL pre-diagnosis.
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Affiliation(s)
- Qian Wang
- Shanghai Key Laboratory of Multidimensional Information Processing, East China Normal University, Shanghai 200241, China
| | | | - Mei Zhou
- Shanghai Key Laboratory of Multidimensional Information Processing, East China Normal University, Shanghai 200241, China
| | - Qingli Li
- Shanghai Key Laboratory of Multidimensional Information Processing, East China Normal University, Shanghai 200241, China
| | - Yiting Wang
- Shanghai Key Laboratory of Multidimensional Information Processing, East China Normal University, Shanghai 200241, China
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21
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Yang S, Qin W, Guo H, Jin T, Huang N, He M, Xi L. Design and evaluation of a compound acoustic lens for photoacoustic computed tomography. Biomed Opt Express 2017; 8:2756-2765. [PMID: 28663904 PMCID: PMC5480511 DOI: 10.1364/boe.8.002756] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/17/2017] [Revised: 03/23/2017] [Accepted: 04/19/2017] [Indexed: 05/19/2023]
Abstract
In photoacoustic computed tomography, the limited directivity of the detectors may cause deformation of off-center targets and lead to an imbalanced resolution in the imaging area. To improve the directivity of the acoustic detectors, several negative acoustic lenses have been proposed. In this study, we develop a new compound acoustic lens fabricated by integrating a concave polydimethylsiloxane (PDMS) lens and a convex epoxy lens. Both theoretical simulations and experimental evaluations demonstrate that the compound lens provides a larger directivity compared to single lenses made of PDMS, epoxy, and liquid. The measured acceptance angles of a 6-mm piezoelectric acoustic transducer equipped with the compound, epoxy, liquid, and PDMS lenses are 55°, 36°, 25°, and 20°, respectively. No deformation is observed in the off-center targets by using compound lens. However, serious deformation appears in the cases using single lenses.
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Affiliation(s)
- Shirui Yang
- School of Physical Electronics, University of Electronic Science and Technology of China, Chengdu 610054, China
- These authors contributed equally to this work
| | - Wei Qin
- School of Physical Electronics, University of Electronic Science and Technology of China, Chengdu 610054, China
- These authors contributed equally to this work
| | - Heng Guo
- School of Physical Electronics, University of Electronic Science and Technology of China, Chengdu 610054, China
| | - Tian Jin
- School of Physical Electronics, University of Electronic Science and Technology of China, Chengdu 610054, China
| | - Na Huang
- School of Physical Electronics, University of Electronic Science and Technology of China, Chengdu 610054, China
| | - Ming He
- School of Physical Electronics, University of Electronic Science and Technology of China, Chengdu 610054, China
| | - Lei Xi
- School of Physical Electronics, University of Electronic Science and Technology of China, Chengdu 610054, China
- Center for Information in Biomedicine, University of Electronic Science and Technology of China, Chengdu 610054, China
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22
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Li A, Liang W, Guan H, Gau YTA, Bergles DE, Li X. Focus scanning with feedback-control for fiber-optic nonlinear endomicroscopy. Biomed Opt Express 2017; 8:2519-2527. [PMID: 28663888 PMCID: PMC5480495 DOI: 10.1364/boe.8.002519] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/06/2017] [Revised: 04/10/2017] [Accepted: 04/11/2017] [Indexed: 05/26/2023]
Abstract
Fiber-optic endomicroscopes open new avenues for the application of non-linear optics to novel in vivo applications. To achieve focus scanning in vivo, shape memory alloy (SMA) wires have been used to move optical elements in miniature endomicroscopes. However, this method has various limitations, making it difficult to achieve accurate and reliable depth scanning. Here we present a feedback-controlled SMA depth scanner. With a Hall effect sensor, contraction of the SMA wire can be tracked in real time, rendering accurate and robust control of motion. The SMA depth scanner can achieve up to 490 µm travel and with open-loop operation, it can move more than 350 µm within one second. With the feedback loop engaged, submicron positioning accuracy was achieved along with superior positioning stability. The high-precision positioning capability of the SMA depth scanner was verified by depth-resolved nonlinear endomicroscopic imaging of mouse brain samples.
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Affiliation(s)
- Ang Li
- Department of Biomedical Engineering, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Wenxuan Liang
- Department of Biomedical Engineering, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Honghua Guan
- Department of Biomedical Engineering, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Yung-Tian A. Gau
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Dwight E. Bergles
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Xingde Li
- Department of Biomedical Engineering, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
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23
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Oh G, Park Y, Yoo SW, Hwang S, Chin-Yu AVD, Ryu YM, Kim SY, Do EJ, Kim KH, Kim S, Myung SJ, Chung E. Clinically compatible flexible wide-field multi-color fluorescence endoscopy with a porcine colon model. Biomed Opt Express 2017; 8:764-775. [PMID: 28270983 PMCID: PMC5330595 DOI: 10.1364/boe.8.000764] [Citation(s) in RCA: 3] [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] [Received: 11/25/2016] [Revised: 01/03/2017] [Accepted: 01/03/2017] [Indexed: 05/04/2023]
Abstract
Early detection of structural or molecular changes in dysplastic epithelial tissues is crucial for cancer screening and surveillance. Multi-targeting molecular endoscopic fluorescence imaging may improve noninvasive detection of precancerous lesions in the colon. Here, we report the first clinically compatible, wide-field-of-view, multi-color fluorescence endoscopy with a leached fiber bundle scope using a porcine model. A porcine colon model that resembles the human colon is used for the detection of surrogate tumors composed of multiple biocompatible fluorophores (FITC, ICG, and heavy metal-free quantum dots (hfQDs)). With an ex vivo porcine colon tumor model, molecular imaging with hfQDs conjugated with MMP14 antibody was achieved by spraying molecular probes on a mucosa layer that contains xenograft tumors. With an in vivo porcine colon embedded with surrogate tumors, target-to-background ratios of 3.36 ± 0.43, 2.70 ± 0.72, and 2.10 ± 0.13 were achieved for FITC, ICG, and hfQD probes, respectively. This promising endoscopic technology with molecular contrast shows the capacity to reveal hidden tumors and guide treatment strategy decisions.
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Affiliation(s)
- Gyugnseok Oh
- School of Mechanical Engineering, Gwangju Institute of Science and Technology, Gwangju, South Korea
| | - Youngrong Park
- Department of Chemistry, Pohang University of Science and Technology, Pohang, South Korea
| | - Su Woong Yoo
- Department of Biomedical Science and Engineering, Institute of Integrated Technology (IIT), Gwangju Institute of Science and Technology, Gwangju, South Korea
| | - Soonjoo Hwang
- Department of Biomedical Science and Engineering, Institute of Integrated Technology (IIT), Gwangju Institute of Science and Technology, Gwangju, South Korea
| | | | - Yeon-Mi Ryu
- Asan Institute for Life Sciences, Asan Medical Center, Seoul, South Korea
| | - Sang-Yeob Kim
- Asan Institute for Life Sciences, Asan Medical Center, Seoul, South Korea
- Department of Convergence Medicine, University of Ulsan College of Medicine, Seoul, South Korea
| | - Eun-Ju Do
- Asan Institute for Life Sciences, Asan Medical Center, Seoul, South Korea
| | - Ki Hean Kim
- Department of Mechanical Engineering, Pohang University of Science and Technology, Pohang, South Korea
| | - Sungjee Kim
- Department of Chemistry, Pohang University of Science and Technology, Pohang, South Korea
| | - Seung-Jae Myung
- Asan Institute for Life Sciences, Asan Medical Center, Seoul, South Korea
- Department of Gastroenterology and Convergence Medicine, Asan Medical Center, University of Ulsan College of Medicine, Seoul, South Korea
| | - Euiheon Chung
- School of Mechanical Engineering, Gwangju Institute of Science and Technology, Gwangju, South Korea
- Department of Biomedical Science and Engineering, Institute of Integrated Technology (IIT), Gwangju Institute of Science and Technology, Gwangju, South Korea
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24
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Sangha GS, Phillips EH, Goergen CJ. In vivo photoacoustic lipid imaging in mice using the second near-infrared window. Biomed Opt Express 2017; 8:736-742. [PMID: 28270980 PMCID: PMC5330553 DOI: 10.1364/boe.8.000736] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/03/2016] [Revised: 12/09/2016] [Accepted: 12/23/2016] [Indexed: 05/18/2023]
Abstract
Photoacoustic imaging has emerged as a promising technique to improve preclinical and clinical imaging by providing users with label-free optical contrast of tissue. Here, we present a proof-of-concept study for noninvasive in vivo murine lipid imaging using 1210 nm light to investigate differences in periaortic fat among mice of different gender, genotypes, and maturation. Acquired lipid signals suggest that adult male apoE-/- mice have greater periaortic fat accumulation compared to adolescent males, apoE-/- females, and wild-type mice. These results demonstrate the potential of photoacoustic tomography for studying vascular pathophysiology and improving the diagnosis of lipid-based diseases.
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Affiliation(s)
- Gurneet S. Sangha
- Weldon School of Biomedical Engineering, Purdue University, 206 S. Martin Jischke Dr., West Lafayette, IN 47907, USA
| | - Evan H. Phillips
- Weldon School of Biomedical Engineering, Purdue University, 206 S. Martin Jischke Dr., West Lafayette, IN 47907, USA
| | - Craig J. Goergen
- Weldon School of Biomedical Engineering, Purdue University, 206 S. Martin Jischke Dr., West Lafayette, IN 47907, USA
- Purdue University Center for Cancer Research, Purdue University, 201 S. University St., West Lafayette, IN 46907, USA
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25
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Cernat R, Bradu A, Israelsen NM, Bang O, Rivet S, Keane PA, Heath DG, Rajendram R, Podoleanu A. Gabor fusion master slave optical coherence tomography. Biomed Opt Express 2017; 8:813-827. [PMID: 28270987 PMCID: PMC5330593 DOI: 10.1364/boe.8.000813] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/07/2016] [Revised: 01/06/2017] [Accepted: 01/06/2017] [Indexed: 06/01/2023]
Abstract
This paper describes the application of the Gabor filtering protocol to a Master/Slave (MS) swept source optical coherence tomography (SS)-OCT system at 1300 nm. The MS-OCT system delivers information from selected depths, a property that allows operation similar to that of a time domain OCT system, where dynamic focusing is possible. The Gabor filtering processing following collection of multiple data from different focus positions is different from that utilized by a conventional swept source OCT system using a Fast Fourier transform (FFT) to produce an A-scan. Instead of selecting the bright parts of A-scans for each focus position, to be placed in a final B-scan image (or in a final volume), and discarding the rest, the MS principle can be employed to advantageously deliver signal from the depths within each focus range only. The MS procedure is illustrated on creating volumes of data of constant transversal resolution from a cucumber and from an insect by repeating data acquisition for 4 different focus positions. In addition, advantage is taken from the tolerance to dispersion of the MS principle that allows automatic compensation for dispersion created by layers above the object of interest. By combining the two techniques, Gabor filtering and Master/Slave, a powerful imaging instrument is demonstrated. The master/slave technique allows simultaneous display of three categories of images in one frame: multiple depth en-face OCT images, two cross-sectional OCT images and a confocal like image obtained by averaging the en-face ones. We also demonstrate the superiority of MS-OCT over its FFT based counterpart when used with a Gabor filtering OCT instrument in terms of the speed of assembling the fused volume. For our case, we show that when more than 4 focus positions are required to produce the final volume, MS is faster than the conventional FFT based procedure.
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Affiliation(s)
- Ramona Cernat
- Applied Optics Group, School of Physical Sciences, University of Kent, Canterbury CT2 7NH, Kent, UK
| | - Adrian Bradu
- Applied Optics Group, School of Physical Sciences, University of Kent, Canterbury CT2 7NH, Kent, UK
| | - Niels Møller Israelsen
- DTU Fotonik, Department of Photonics Engineering, Technical University of Denmark, DK-2800 Kongens Lyngby, Denmark
| | - Ole Bang
- DTU Fotonik, Department of Photonics Engineering, Technical University of Denmark, DK-2800 Kongens Lyngby, Denmark
| | - Sylvain Rivet
- Université de Bretagne Occidentale, EA 938 Laboratoire de Spectrométrie et Optique Laser, 6 Avenue Le Gorgeu, C.S. 93837, 29238 Brest Cedex 3, France
| | - Pearse A. Keane
- NIHR Biomedical Research Centre at Moorfields Eye Hospital NHS Foundation Trust and UCL Institute of Ophthalmology, London, EC1V 9EL UK
| | - David-Garway Heath
- NIHR Biomedical Research Centre at Moorfields Eye Hospital NHS Foundation Trust and UCL Institute of Ophthalmology, London, EC1V 9EL UK
| | - Ranjan Rajendram
- NIHR Biomedical Research Centre at Moorfields Eye Hospital NHS Foundation Trust and UCL Institute of Ophthalmology, London, EC1V 9EL UK
| | - Adrian Podoleanu
- Applied Optics Group, School of Physical Sciences, University of Kent, Canterbury CT2 7NH, Kent, UK
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26
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Klein T, Huber R. High-speed OCT light sources and systems [Invited]. Biomed Opt Express 2017; 8:828-859. [PMID: 28270988 PMCID: PMC5330584 DOI: 10.1364/boe.8.000828] [Citation(s) in RCA: 106] [Impact Index Per Article: 15.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/30/2016] [Revised: 01/02/2017] [Accepted: 01/03/2017] [Indexed: 05/18/2023]
Abstract
Imaging speed is one of the most important parameters that define the performance of optical coherence tomography (OCT) systems. During the last two decades, OCT speed has increased by over three orders of magnitude. New developments in wavelength-swept lasers have repeatedly been crucial for this development. In this review, we discuss the historical evolution and current state of the art of high-speed OCT systems, with focus on wavelength swept light sources and swept source OCT systems.
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Affiliation(s)
- Thomas Klein
- Optores GmbH, Gollierstr. 70, 80339 Munich, Germany
| | - Robert Huber
- Institut für Biomedizinische Optik, Universität zu Lübeck, Peter-Monnik-Weg 4, 23562 Lübeck, Germany
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27
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Wu M, Springeling G, Lovrak M, Mastik F, Iskander-Rizk S, Wang T, van Beusekom HMM, van der Steen AFW, Van Soest G. Real-time volumetric lipid imaging in vivo by intravascular photoacoustics at 20 frames per second. Biomed Opt Express 2017; 8:943-953. [PMID: 28270995 PMCID: PMC5330573 DOI: 10.1364/boe.8.000943] [Citation(s) in RCA: 60] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/15/2016] [Revised: 01/10/2017] [Accepted: 01/11/2017] [Indexed: 05/03/2023]
Abstract
Lipid deposition can be assessed with combined intravascular photoacoustic/ultrasound (IVPA/US) imaging. To date, the clinical translation of IVPA/US imaging has been stalled by a low imaging speed and catheter complexity. In this paper, we demonstrate imaging of lipid targets in swine coronary arteries in vivo, at a clinically useful frame rate of 20 s-1. We confirmed image contrast for atherosclerotic plaque in human samples ex vivo. The system is on a mobile platform and provides real-time data visualization during acquisition. We achieved an IVPA signal-to-noise ratio of 20 dB. These data show that clinical translation of IVPA is possible in principle.
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Affiliation(s)
- Min Wu
- Department of Biomedical Engineering, Thorax Center, Erasmus University Medical Center, PO Box 2040, 3000 CA Rotterdam, The Netherlands
| | - Geert Springeling
- Department of Experimental Medical Instrumentation, Erasmus University Medical Center PO Box 2040, 3000 CA Rotterdam, The Netherlands
| | - Matija Lovrak
- Department of Chemical Engineering, Delft University of Technology, van der Maasweg 9, 2629 HZ Delft, The Netherlands
| | - Frits Mastik
- Department of Biomedical Engineering, Thorax Center, Erasmus University Medical Center, PO Box 2040, 3000 CA Rotterdam, The Netherlands
| | - Sophinese Iskander-Rizk
- Department of Biomedical Engineering, Thorax Center, Erasmus University Medical Center, PO Box 2040, 3000 CA Rotterdam, The Netherlands
| | - Tianshi Wang
- Department of Biomedical Engineering, Thorax Center, Erasmus University Medical Center, PO Box 2040, 3000 CA Rotterdam, The Netherlands
| | - Heleen M. M. van Beusekom
- Department of Biomedical Engineering, Thorax Center, Erasmus University Medical Center, PO Box 2040, 3000 CA Rotterdam, The Netherlands
| | - A. F. W. van der Steen
- Department of Biomedical Engineering, Thorax Center, Erasmus University Medical Center, PO Box 2040, 3000 CA Rotterdam, The Netherlands
- Department of Imaging Science and Technology, Delft University of Technology, Lorentzweg 1, 2628 CJ Delft, The Netherlands
- Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, 518055 Shenzhen, China
| | - Gijs Van Soest
- Department of Biomedical Engineering, Thorax Center, Erasmus University Medical Center, PO Box 2040, 3000 CA Rotterdam, The Netherlands
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28
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Xu D, Zhou W, Peng L. Cellular resolution multiplexed FLIM tomography with dual-color Bessel beam. Biomed Opt Express 2017; 8:570-578. [PMID: 28270968 PMCID: PMC5330577 DOI: 10.1364/boe.8.000570] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/14/2016] [Revised: 12/19/2016] [Accepted: 12/20/2016] [Indexed: 05/23/2023]
Abstract
Fourier multiplexed FLIM (FmFLIM) tomography enables multiplexed 3D lifetime imaging of whole embryos. In our previous FmFLIM system, the spatial resolution was limited to 25 μm because of the trade-off between the spatial resolution and the imaging depth. In order to achieve cellular resolution imaging of thick specimens, we built a tomography system with dual-color Bessel beam. In combination with FmFLIM, the Bessel FmFLIM tomography system can perform parallel 3D lifetime imaging on multiple excitation-emission channels at a cellular resolution of 2.8 μm. The image capability of the Bessel FmFLIM tomography system was demonstrated by 3D lifetime imaging of dual-labeled transgenic zebrafish embryos.
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Affiliation(s)
- Dongli Xu
- College of Optical Sciences, the University of Arizona, 1630 East University Blvd., Tucson, AZ 85721, USA
| | - Weibin Zhou
- Department of Pediatrics and Communicable Diseases, University of Michigan, Ann Arbor, Michigan, MI 48109, USA
| | - Leilei Peng
- College of Optical Sciences, the University of Arizona, 1630 East University Blvd., Tucson, AZ 85721, USA
- Department of Molecular and Cell Biology, University of Arizona, 1007 E. Lowell Street, Tucson. AZ 85721, USA
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29
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Tang AHL, Yeung P, Chan GCF, Chan BP, Wong KKY, Tsia KK. Time-stretch microscopy on a DVD for high-throughput imaging cell-based assay. Biomed Opt Express 2017; 8:640-652. [PMID: 28270973 PMCID: PMC5330545 DOI: 10.1364/boe.8.000640] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/19/2016] [Revised: 12/21/2016] [Accepted: 12/25/2016] [Indexed: 06/06/2023]
Abstract
Cell-based assay based on time-stretch imaging is recognized to be well-suited for high-throughput phenotypic screening. However, this ultrafast imaging technique has primarily been limited to suspension-cell assay, leaving a wide range of solid-substrate assay formats uncharted. Moreover, time-stretch imaging is generally restricted to intrinsic biophysical phenotyping, but lacks the biomolecular signatures of the cells. To address these challenges, we develop a spinning time-stretch imaging assay platform based on the functionalized digital versatile disc (DVD). We demonstrate that adherent cell culture and biochemically-specific cell-capture can now be assayed with time-stretch microscopy, thanks to the high-speed DVD spinning motion that naturally enables on-the-fly cellular imaging at an ultrafast line-scan rate of >10MHz. As scanning the whole DVD at such a high speed enables ultra-large field-of-view imaging, it could be favorable for scaling both the assay throughput and content as demanded in many applications, e.g. drug discovery, and rare cancer cell screening.
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Affiliation(s)
- Anson H. L. Tang
- Department of Electrical and Electronic Engineering, The University of Hong Kong, Pokfulam, Hong Kong, China
| | - P. Yeung
- Department of Mechanical Engineering, The University of Hong Kong, Pokfulam, Hong Kong, China
| | - Godfrey C. F. Chan
- Department of Paediatrics & Adolescent Medicine, The University of Hong Kong, Pokfulam, Hong Kong, China
| | - Barbara P. Chan
- Department of Mechanical Engineering, The University of Hong Kong, Pokfulam, Hong Kong, China
| | - Kenneth K. Y. Wong
- Department of Electrical and Electronic Engineering, The University of Hong Kong, Pokfulam, Hong Kong, China
| | - Kevin K. Tsia
- Department of Electrical and Electronic Engineering, The University of Hong Kong, Pokfulam, Hong Kong, China
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30
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Abdolmanafi A, Duong L, Dahdah N, Cheriet F. Deep feature learning for automatic tissue classification of coronary artery using optical coherence tomography. Biomed Opt Express 2017; 8:1203-1220. [PMID: 28271012 PMCID: PMC5330543 DOI: 10.1364/boe.8.001203] [Citation(s) in RCA: 79] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/27/2016] [Revised: 01/20/2017] [Accepted: 01/20/2017] [Indexed: 05/03/2023]
Abstract
Kawasaki disease (KD) is an acute childhood disease complicated by coronary artery aneurysms, intima thickening, thrombi, stenosis, lamellar calcifications, and disappearance of the media border. Automatic classification of the coronary artery layers (intima, media, and scar features) is important for analyzing optical coherence tomography (OCT) images recorded in pediatric patients. OCT has been known as an intracoronary imaging modality using near-infrared light which has recently been used to image the inner coronary artery tissues of pediatric patients, providing high spatial resolution (ranging from 10 to 20 μm). This study aims to develop a robust and fully automated tissue classification method by using the convolutional neural networks (CNNs) as feature extractor and comparing the predictions of three state-of-the-art classifiers, CNN, random forest (RF), and support vector machine (SVM). The results show the robustness of CNN as the feature extractor and random forest as the classifier with classification rate up to 96%, especially to characterize the second layer of coronary arteries (media), which is a very thin layer and it is challenging to be recognized and specified from other tissues.
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Affiliation(s)
- Atefeh Abdolmanafi
- Dept. of Software and IT Engineering, École de Technologie Supérieure, Montréal,
Canada
| | - Luc Duong
- Dept. of Software and IT Engineering, École de Technologie Supérieure, Montréal,
Canada
| | - Nagib Dahdah
- Div. of Pediatric Cardiology and Research Center, Centre Hospitalier Universitaire Sainte-Justine, Montréal,
Canada
| | - Farida Cheriet
- Dept. of Computer Engineering, École Polytechnique de Montréal, Montréal,
Canada
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31
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Wang D, Wang Y, Wang W, Luo D, Chitgupi U, Geng J, Zhou Y, Wang L, Lovell JF, Xia J. Deep tissue photoacoustic computed tomography with a fast and compact laser system. Biomed Opt Express 2017; 8:112-123. [PMID: 28101405 PMCID: PMC5231285 DOI: 10.1364/boe.8.000112] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/17/2016] [Revised: 12/02/2016] [Accepted: 12/04/2016] [Indexed: 05/04/2023]
Abstract
Photoacoustic computed tomography (PACT) holds great promise for biomedical imaging, but wide-spread implementation is impeded by the bulkiness of flash-lamp-pumped laser systems, which typically weigh between 50 - 200 kg, require continuous water cooling, and operate at a low repetition rate. Here, we demonstrate that compact lasers based on emerging diode technologies are well-suited for preclinical and clinical PACT. The diode-pumped laser used in this study had a miniature footprint (13 × 14 × 7 cm3), weighed only 1.6 kg, and outputted up to 80 mJ per pulse at 1064 nm. In vitro, the laser system readily provided over 4 cm PACT depth in chicken breast tissue. In vivo, in addition to high resolution, non-invasive brain imaging in living mice, the system can operate at 50 Hz, which enabled high-speed cross-sectional imaging of murine cardiac and respiratory function. The system also provided high quality, high-frame rate, and non-invasive three-dimensional mapping of arm, palm, and breast vasculature at multi centimeter depths in living human subjects, demonstrating the clinical viability of compact lasers for PACT.
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Affiliation(s)
- Depeng Wang
- Department of Biomedical Engineering, University at Buffalo, State University of New York, Buffalo, USA
| | - Yuehang Wang
- Department of Biomedical Engineering, University at Buffalo, State University of New York, Buffalo, USA
| | - Weiran Wang
- Department of Electronic Engineering, City University of Hong Kong, Hong Kong, China
| | - Dandan Luo
- Department of Biomedical Engineering, University at Buffalo, State University of New York, Buffalo, USA
| | - Upendra Chitgupi
- Department of Biomedical Engineering, University at Buffalo, State University of New York, Buffalo, USA
| | - Jumin Geng
- Department of Biomedical Engineering, University at Buffalo, State University of New York, Buffalo, USA
| | - Yang Zhou
- Department of Biomedical Engineering, University at Buffalo, State University of New York, Buffalo, USA
- College of Chemistry, Chemical Engineering and Materials Science, Collaborative Innovation Center of Functionalized Probes for Chemical Imaging in Universities of Shandong, Key Laboratory of Molecular and Nano Probes, Ministry of Education, Shandong Provincial Key Laboratory of Clean Production of Fine Chemicals, Shandong Normal University, Jinan, China
| | - Lidai Wang
- Department of Mechanical and Biomedical Engineering, City University of Hong Kong, Hong Kong, China
| | - Jonathan F Lovell
- Department of Biomedical Engineering, University at Buffalo, State University of New York, Buffalo, USA
| | - Jun Xia
- Department of Biomedical Engineering, University at Buffalo, State University of New York, Buffalo, USA
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32
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Bajwa N, Au J, Jarrahy R, Sung S, Fishbein MC, Riopelle D, Ennis DB, Aghaloo T, St. John MA, Grundfest WS, Taylor ZD. Non-invasive terahertz imaging of tissue water content for flap viability assessment. Biomed Opt Express 2017; 8:460-474. [PMID: 28101431 PMCID: PMC5231313 DOI: 10.1364/boe.8.000460] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/02/2016] [Revised: 12/04/2016] [Accepted: 12/05/2016] [Indexed: 05/18/2023]
Abstract
Accurate and early prediction of tissue viability is the most significant determinant of tissue flap survival in reconstructive surgery. Perturbation in tissue water content (TWC) is a generic component of the tissue response to such surgeries, and, therefore, may be an important diagnostic target for assessing the extent of flap viability in vivo. We have previously shown that reflective terahertz (THz) imaging, a non-ionizing technique, can generate spatially resolved maps of TWC in superficial soft tissues, such as cornea and wounds, on the order of minutes. Herein, we report the first in vivo pilot study to investigate the utility of reflective THz TWC imaging for early assessment of skin flap viability. We obtained longitudinal visible and reflective THz imagery comparing 3 bipedicled flaps (i.e. survival model) and 3 fully excised flaps (i.e. failure model) in the dorsal skin of rats over a postoperative period of 7 days. While visual differences between both models manifested 48 hr after surgery, statistically significant (p < 0.05, independent t-test) local differences in TWC contrast were evident in THz flap image sets as early as 24 hr. Excised flaps, histologically confirmed as necrotic, demonstrated a significant, yet localized, reduction in TWC in the flap region compared to non-traumatized skin. In contrast, bipedicled flaps, histologically verified as viable, displayed mostly uniform, unperturbed TWC across the flap tissue. These results indicate the practical potential of THz TWC sensing to accurately predict flap failure 24 hours earlier than clinical examination.
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Affiliation(s)
- Neha Bajwa
- Department of Bioengineering, University of Los Angeles, California (UCLA), 410 Westwood Plaza, Los Angeles, CA 90025, USA
| | - Joshua Au
- Department of Head and Neck Surgery, UCLA, 200 Medical Plaza, Los Angeles, CA 90025, USA
| | - Reza Jarrahy
- Department of Plastic Surgery, UCLA, California, 200 Medical Plaza, Los Angeles, CA 90025, USA
| | - Shijun Sung
- Department of Electrical Engineering, UCLA, 410 Westwood Plaza, Los Angeles, CA 90025, USA
| | - Michael C. Fishbein
- Department of Pathology and Laboratory Medicine, UCLA, 200 Medical Plaza, Los Angeles, CA 90025, USA
| | - David Riopelle
- Department of Bioengineering, University of Los Angeles, California (UCLA), 410 Westwood Plaza, Los Angeles, CA 90025, USA
| | - Daniel B. Ennis
- Department of Bioengineering, University of Los Angeles, California (UCLA), 410 Westwood Plaza, Los Angeles, CA 90025, USA
- Department of Radiological Sciences, UCLA, 300 Medical Plaza, Los Angeles, CA 90025, USA
| | - Tara Aghaloo
- Department of Head and Neck Surgery, UCLA, 200 Medical Plaza, Los Angeles, CA 90025, USA
| | - Maie A. St. John
- Department of Head and Neck Surgery, UCLA, 200 Medical Plaza, Los Angeles, CA 90025, USA
| | - Warren S. Grundfest
- Department of Bioengineering, University of Los Angeles, California (UCLA), 410 Westwood Plaza, Los Angeles, CA 90025, USA
- Department of Electrical Engineering, UCLA, 410 Westwood Plaza, Los Angeles, CA 90025, USA
- Department of Surgery, UCLA, California, 200 Medical Plaza, Los Angeles, CA 90025, USA
| | - Zachary D. Taylor
- Department of Electrical Engineering, UCLA, 410 Westwood Plaza, Los Angeles, CA 90025, USA
- Department of Surgery, UCLA, California, 200 Medical Plaza, Los Angeles, CA 90025, USA
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33
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Ma P, Chan DC, Gu S, Watanabe M, Jenkins MW, Rollins AM. Volumetric optical mapping in early embryonic hearts using light-sheet microscopy. Biomed Opt Express 2016; 7:5120-5128. [PMID: 28018729 PMCID: PMC5175556 DOI: 10.1364/boe.7.005120] [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] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/22/2016] [Revised: 09/28/2016] [Accepted: 10/03/2016] [Indexed: 05/18/2023]
Abstract
Optical mapping (OM) of electrical activity using voltage-sensitive fluorescent dyes is a powerful tool for the investigation of embryonic cardiac electrophysiology. However, because conventional OM integrates the signal in depth and projects it to a two-dimensional plane, information acquired is incomplete and dependent upon the orientation of the sample. This complicates interpretation of data, especially when comparing one heart to another. To overcome this limitation, we present volumetric OM using light-sheet microscopy, which enables high-speed capture of optically sectioned slices. Voltage-sensitive fluorescence images from multiple planes across entire early embryonic quail hearts were acquired, and complete, orientation-independent, four-dimensional maps of transmembrane potential are demonstrated. Volumetric OM data were collected while using optical pacing to control the heart rate, paving the way for physiological measurements and precise manipulation of the heartbeat in the future.
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Affiliation(s)
- Pei Ma
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, Ohio 44106, USA
- Shanghai Key Laboratory of Modern Optical Systems, College of Optical-Electrical and Computer Engineering, University of Shanghai for Science and Technology, Shanghai, 200093, China
| | - Dennis C. Chan
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, Ohio 44106, USA
| | - Shi Gu
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, Ohio 44106, USA
| | - Michiko Watanabe
- Department of Pediatrics, Case Western Reserve University, Cleveland, Ohio 44106, USA
| | - Michael W. Jenkins
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, Ohio 44106, USA
- Department of Pediatrics, Case Western Reserve University, Cleveland, Ohio 44106, USA
| | - Andrew M. Rollins
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, Ohio 44106, USA
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34
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Castanares ML, Gautam V, Drury J, Bachor H, Daria VR. Efficient multi-site two-photon functional imaging of neuronal circuits. Biomed Opt Express 2016; 7:5325-5334. [PMID: 28018745 PMCID: PMC5175572 DOI: 10.1364/boe.7.005325] [Citation(s) in RCA: 3] [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] [Received: 10/18/2016] [Revised: 11/11/2016] [Accepted: 11/16/2016] [Indexed: 05/11/2023]
Abstract
Two-photon imaging using high-speed multi-channel detectors is a promising approach for optical recording of cellular membrane dynamics at multiple sites. A main bottleneck of this technique is the limited number of photons captured within a short exposure time (~1ms). Here, we implement temporal gating to improve the two-photon fluorescence yield from holographically projected multiple foci whilst maintaining a biologically safe incident average power. We observed up to 6x improvement in the signal-to-noise ratio (SNR) in Fluorescein and cultured hippocampal neurons showing evoked calcium transients. With improved SNR, we could pave the way to achieving multi-site optical recording of fluorogenic probes with response times in the order of ~1ms.
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Affiliation(s)
| | - Vini Gautam
- The John Curtin School of Medical Research, Australian National University, Canberra, ACT 2601, Australia
| | - Jack Drury
- The John Curtin School of Medical Research, Australian National University, Canberra, ACT 2601, Australia
| | - Hans Bachor
- Research School of Physics and Engineering, Australian National University, Canberra, ACT 2601, Australia
| | - Vincent R. Daria
- The John Curtin School of Medical Research, Australian National University, Canberra, ACT 2601, Australia
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35
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Perinchery SM, Shinde A, Matham MV. Imaging behind opaque obstacle: a potential method for guided in vitro needle placement. Biomed Opt Express 2016; 7:5308-5324. [PMID: 28018744 PMCID: PMC5175571 DOI: 10.1364/boe.7.005308] [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] [Subscribe] [Scholar Register] [Received: 08/22/2016] [Revised: 11/21/2016] [Accepted: 11/21/2016] [Indexed: 05/08/2023]
Abstract
We report a simple real time optical imaging concept using an axicon lens to image the object kept behind opaque obstacles in free space. The proposed concept underlines the importance and advantages of using an axicon lens compared to a conventional lens to image behind the obstacle. The potential of this imaging concept is demonstrated by imaging the insertion of surgical needle in biological specimen in real time, without blocking the field of view. It is envisaged that this proposed concepts and methodology can make a telling impact in a wide variety of areas especially for diagnostics, therapeutics and microscopy applications.
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36
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Lin CY, Lin WH, Chien JH, Tsai JC, Luo Y. In vivo volumetric fluorescence sectioning microscopy with mechanical-scan-free hybrid illumination imaging. Biomed Opt Express 2016; 7:3968-3978. [PMID: 27867708 PMCID: PMC5102523 DOI: 10.1364/boe.7.003968] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/13/2016] [Revised: 08/20/2016] [Accepted: 08/20/2016] [Indexed: 05/26/2023]
Abstract
Optical sectioning microscopy in wide-field fashion has been widely used to obtain three-dimensional images of biological samples; however, it requires scanning in depth and considerable time to acquire multiple depth information of a volumetric sample. In this paper, in vivo optical sectioning microscopy with volumetric hybrid illumination, with no mechanical moving parts, is presented. The proposed system is configured such that the optical sectioning is provided by hybrid illumination using a digital micro-mirror device (DMD) for uniform and non-uniform pattern projection, while the depth of imaging planes is varied by using an electrically tunable-focus lens with invariant magnification and resolution. We present and characterize the design, implementation, and experimentally demonstrate the proposed system's ability through 3D imaging of in vivo Canenorhabditis elegans' growth cones.
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Affiliation(s)
- Chen-Yen Lin
- Department of Electrical Engineering and Graduate Institute of Photonics and Optoelectronics, National Taiwan University, Taipei 10617, Taiwan
- Institute of Medical Device and Imaging, National Taiwan University, Taipei, 10051, Taiwan
| | - Wei-Hsin Lin
- Institute of Medical Device and Imaging, National Taiwan University, Taipei, 10051, Taiwan
- School of Medicine, National Taiwan University, Taipei, 10051, Taiwan
| | - Ju-Hsuan Chien
- Institute of Medical Device and Imaging, National Taiwan University, Taipei, 10051, Taiwan
| | - Jui-Chang Tsai
- Institute of Medical Device and Imaging, National Taiwan University, Taipei, 10051, Taiwan
| | - Yuan Luo
- Institute of Medical Device and Imaging, National Taiwan University, Taipei, 10051, Taiwan
- Molecular Imaging Center, National Taiwan University, Taipei 10055, Taiwan
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37
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Dvornikov A, Gratton E. Imaging in turbid media: a transmission detector gives 2-3 order of magnitude enhanced sensitivity compared to epi-detection schemes. Biomed Opt Express 2016; 7:3747-3755. [PMID: 27699135 PMCID: PMC5030047 DOI: 10.1364/boe.7.003747] [Citation(s) in RCA: 6] [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] [Subscribe] [Scholar Register] [Received: 07/01/2016] [Revised: 08/25/2016] [Accepted: 08/25/2016] [Indexed: 05/26/2023]
Abstract
Imaging depth in turbid media by two-photon fluorescence microscopy depends on the ability of the optical system to detect weak fluorescence signals. We have shown that use of a wide area detector in transmission geometry allows increasing imaging depth in turbid media due to efficient photon collection. Compared to the conventional epi-detection scheme used in most commercial microscopes, the transmission detector was found to be 2-3 orders of magnitude more sensitive when used for in depth imaging in scattering samples simulating brain optical properties.
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38
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Li Z, Zhou Q, Zhou J, Duan X, Zhu J, Wang TD. In vivo fluorescence imaging of hepatocellular carcinoma xenograft using near-infrared labeled epidermal growth factor receptor (EGFR) peptide. Biomed Opt Express 2016; 7:3163-3169. [PMID: 27699089 PMCID: PMC5030001 DOI: 10.1364/boe.7.003163] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/09/2016] [Revised: 07/24/2016] [Accepted: 07/25/2016] [Indexed: 06/06/2023]
Abstract
Minimally-invasive surgery of hepatocellular carcinoma (HCC) can be limited by poor tumor visualization with white light. We demonstrate systemic administration of a Cy5.5-labeled peptide specific for epidermal growth factor receptor (EGFR) to target HCC in vivo in a mouse xenograft model. We attached a compact imaging module to the proximal end of a medical laparoscope to collect near-infrared fluorescence and reflectance images concurrently at 15 frames/sec. We measured a mean target-to-background ratio of 2.99 ± 0.22 from 13 surgically exposed subcutaneous human HCC tumors in vivo in 5 mice. This integrated imaging methodology is promising to guide laparoscopic resection of HCC.
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Affiliation(s)
- Z. Li
- Department of Hepatobiliary Surgery, Peking University People’s Hospital, Beijing, 100044, China
| | - Q. Zhou
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI 48109, USA
| | - J. Zhou
- Department of Internal Medicine, University of Michigan, Ann Arbor, MI 48109, USA
| | - X. Duan
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI 48109, USA
| | - J. Zhu
- Department of Hepatobiliary Surgery, Peking University People’s Hospital, Beijing, 100044, China
| | - T. D. Wang
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI 48109, USA
- Department of Internal Medicine, University of Michigan, Ann Arbor, MI 48109, USA
- Department of Mechanical Engineering, University of Michigan, Ann Arbor, MI 48109, USA
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39
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Nguyen HD, Hong KS. Bundled-optode implementation for 3D imaging in functional near-infrared spectroscopy. Biomed Opt Express 2016; 7:3491-3507. [PMID: 27699115 PMCID: PMC5030027 DOI: 10.1364/boe.7.003491] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/13/2016] [Revised: 08/04/2016] [Accepted: 08/10/2016] [Indexed: 05/03/2023]
Abstract
The paper presents a functional near-infrared spectroscopy (fNIRS)-based bundled-optode method for detection of the changes of oxy-hemoglobin (HbO) and deoxy-hemoglobin (HbR) concentrations. fNIRS with 32 optodes is utilized to measure five healthy male subjects' brain-hemodynamic responses to arithmetic tasks. Specifically, the coordinates of 256 voxels in the three-dimensional (3D) volume are computed according to the known probe geometry. The mean path length factor in the Beer-Lambert equation is estimated as a function of the emitter-detector distance, which is utilized for computation of the absorption coefficient. The mean values of HbO and HbR obtained from the absorption coefficient are then applied for construction of a 3D fNIRS image. Our results show that the proposed method, as compared with the conventional approach, can detect brain activity with higher spatial resolution. This method can be extended for 3D fNIRS imaging in real-time applications.
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Affiliation(s)
- Hoang-Dung Nguyen
- Department of Cogno-Mechatronics Engineering, Pusan National University, 2 Busandaehak-ro, Geumjeong-gu, Busan 46241, South Korea
| | - Keum-Shik Hong
- Department of Cogno-Mechatronics Engineering, Pusan National University, 2 Busandaehak-ro, Geumjeong-gu, Busan 46241, South Korea
- School of Mechanical Engineering, Pusan National University, 2 Busandaehak-ro, Geumjeong-gu, Busan 46241, South Korea
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40
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Liu Y, Yuan Z. Multi-spectral photoacoustic elasticity tomography. Biomed Opt Express 2016; 7:3323-3334. [PMID: 27699101 PMCID: PMC5030013 DOI: 10.1364/boe.7.003323] [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] [Subscribe] [Scholar Register] [Received: 06/09/2016] [Revised: 08/03/2016] [Accepted: 08/08/2016] [Indexed: 05/26/2023]
Abstract
The goal of this work was to develop and validate a spectrally resolved photoacoustic imaging method, namely multi-spectral photoacoustic elasticity tomography (PAET) for quantifying the physiological parameters and elastic modulus of biological tissues. We theoretically and experimentally examined the PAET imaging method using simulations and in vitro experimental tests. Our simulation and in vitro experimental results indicated that the reconstructions were quantitatively accurate in terms of sizes, the physiological and elastic properties of the targets.
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41
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Ai D, Yang J, Fan J, Zhao Y, Song X, Shen J, Shao L, Wang Y. Augmented reality based real-time subcutaneous vein imaging system. Biomed Opt Express 2016; 7:2565-85. [PMID: 27446690 PMCID: PMC4948614 DOI: 10.1364/boe.7.002565] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/21/2016] [Revised: 05/31/2016] [Accepted: 06/05/2016] [Indexed: 05/22/2023]
Abstract
A novel 3D reconstruction and fast imaging system for subcutaneous veins by augmented reality is presented. The study was performed to reduce the failure rate and time required in intravenous injection by providing augmented vein structures that back-project superimposed veins on the skin surface of the hand. Images of the subcutaneous vein are captured by two industrial cameras with extra reflective near-infrared lights. The veins are then segmented by a multiple-feature clustering method. Vein structures captured by the two cameras are matched and reconstructed based on the epipolar constraint and homographic property. The skin surface is reconstructed by active structured light with spatial encoding values and fusion displayed with the reconstructed vein. The vein and skin surface are both reconstructed in the 3D space. Results show that the structures can be precisely back-projected to the back of the hand for further augmented display and visualization. The overall system performance is evaluated in terms of vein segmentation, accuracy of vein matching, feature points distance error, duration times, accuracy of skin reconstruction, and augmented display. All experiments are validated with sets of real vein data. The imaging and augmented system produces good imaging and augmented reality results with high speed.
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Affiliation(s)
- Danni Ai
- Beijing Engineering Research Center of Mixed Reality and Advanced Display, School of Optics and Electronics, Beijing Institute of Technology, Beijing 100081,
China
| | - Jian Yang
- Beijing Engineering Research Center of Mixed Reality and Advanced Display, School of Optics and Electronics, Beijing Institute of Technology, Beijing 100081,
China
| | - Jingfan Fan
- Beijing Engineering Research Center of Mixed Reality and Advanced Display, School of Optics and Electronics, Beijing Institute of Technology, Beijing 100081,
China
| | - Yitian Zhao
- Beijing Engineering Research Center of Mixed Reality and Advanced Display, School of Optics and Electronics, Beijing Institute of Technology, Beijing 100081,
China
| | - Xianzheng Song
- Beijing Engineering Research Center of Mixed Reality and Advanced Display, School of Optics and Electronics, Beijing Institute of Technology, Beijing 100081,
China
| | - Jianbing Shen
- Beijing Laboratory of Intelligent Information Technology, School of Computer Science and Technology, Beijing Institute of Technology, Beijing 100081,
China
| | - Ling Shao
- Department of Computer Science and Digital Technologies, Northumbria University, Newcastle upon Tyne NE1 8ST,
U.K.
| | - Yongtian Wang
- Beijing Engineering Research Center of Mixed Reality and Advanced Display, School of Optics and Electronics, Beijing Institute of Technology, Beijing 100081,
China
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42
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Artoni P, Landi S, Sato SS, Luin S, Ratto GM. Arduino Due based tool to facilitate in vivo two-photon excitation microscopy. Biomed Opt Express 2016; 7:1604-1613. [PMID: 27446677 PMCID: PMC4933559 DOI: 10.1364/boe.7.001604] [Citation(s) in RCA: 6] [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] [Subscribe] [Scholar Register] [Received: 01/13/2016] [Revised: 02/18/2016] [Accepted: 02/18/2016] [Indexed: 06/06/2023]
Abstract
Two-photon excitation spectroscopy is a powerful technique for the characterization of the optical properties of genetically encoded and synthetic fluorescent molecules. Excitation spectroscopy requires tuning the wavelength of the Ti:sapphire laser while carefully monitoring the delivered power. To assist laser tuning and the control of delivered power, we developed an Arduino Due based tool for the automatic acquisition of high quality spectra. This tool is portable, fast, affordable and precise. It allowed studying the impact of scattering and of blood absorption on two-photon excitation light. In this way, we determined the wavelength-dependent deformation of excitation spectra occurring in deep tissues in vivo.
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43
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Fialová S, Augustin M, Glösmann M, Himmel T, Rauscher S, Gröger M, Pircher M, Hitzenberger CK, Baumann B. Polarization properties of single layers in the posterior eyes of mice and rats investigated using high resolution polarization sensitive optical coherence tomography. Biomed Opt Express 2016; 7:1479-95. [PMID: 27446670 PMCID: PMC4929656 DOI: 10.1364/boe.7.001479] [Citation(s) in RCA: 15] [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] [Subscribe] [Scholar Register] [Received: 01/13/2016] [Revised: 03/11/2016] [Accepted: 03/14/2016] [Indexed: 05/19/2023]
Abstract
We present a high resolution polarization sensitive optical coherence tomography (PS-OCT) system for ocular imaging in rodents. The system operates at 840 nm and uses a broadband superluminescent diode providing an axial resolution of 5.1 µm in air. PS-OCT data was acquired at 83 kHz A-scan rate by two identical custom-made spectrometers for orthogonal polarization states. Pigmented (Brown Norway, Long Evans) and non-pigmented (Sprague Dawley) rats as well as pigmented mice (C57BL/6) were imaged. Melanin pigment related depolarization was analyzed in the retinal pigment epithelium (RPE) and choroid of these animals using the degree of polarization uniformity (DOPU). For all rat strains, significant differences between RPE and choroidal depolarization were observed. In contrast, DOPU characteristics of RPE and choroid were similar for C57BL/6 mice. Moreover, the depolarization within the same tissue type varied significantly between different rodent strains. Retinal nerve fiber layer thickness, phase retardation, and birefringence were mapped and quantitatively measured in Long Evans rats in vivo for the first time. In a circumpapillary annulus, retinal nerve fiber layer birefringence amounted to 0.16°/µm ± 0.02°/µm and 0.17°/µm ± 0.01°/µm for the left and right eyes, respectively.
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Affiliation(s)
- Stanislava Fialová
- Medical University of Vienna, Center for Medical Physics and Biomedical Engineering, Währinger Gürtel 18-20, 1090 Vienna, Austria
| | - Marco Augustin
- Medical University of Vienna, Center for Medical Physics and Biomedical Engineering, Währinger Gürtel 18-20, 1090 Vienna, Austria
| | - Martin Glösmann
- University of Veterinary Medicine Vienna, Core Facility for Research and Technology, Veterinärplatz 1, 1210 Vienna, Austria
| | - Tanja Himmel
- University of Veterinary Medicine Vienna, Core Facility for Research and Technology, Veterinärplatz 1, 1210 Vienna, Austria
| | - Sabine Rauscher
- Medical University of Vienna, Core Facility Imaging, Lazarettgasse 14, 1090 Vienna, Austria
| | - Marion Gröger
- Medical University of Vienna, Core Facility Imaging, Lazarettgasse 14, 1090 Vienna, Austria
| | - Michael Pircher
- Medical University of Vienna, Center for Medical Physics and Biomedical Engineering, Währinger Gürtel 18-20, 1090 Vienna, Austria
| | - Christoph K. Hitzenberger
- Medical University of Vienna, Center for Medical Physics and Biomedical Engineering, Währinger Gürtel 18-20, 1090 Vienna, Austria
| | - Bernhard Baumann
- Medical University of Vienna, Center for Medical Physics and Biomedical Engineering, Währinger Gürtel 18-20, 1090 Vienna, Austria
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44
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Burgess L, Chen J, Wolter NE, Wilson B, Zheng G. Topical MMP beacon enabled fluorescence-guided resection of oral carcinoma. Biomed Opt Express 2016; 7:1089-1099. [PMID: 27231609 PMCID: PMC4866449 DOI: 10.1364/boe.7.001089] [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] [Received: 12/02/2015] [Revised: 02/20/2016] [Accepted: 02/24/2016] [Indexed: 06/05/2023]
Abstract
Each year almost 300,000 individuals worldwide are diagnosed with oral cancer, more than 90% of these being oral carcinoma [N. Engl. J. Med.328, 1841993]. Surgical resection is the standard of care, but accurate delineation of the tumor boundaries is challenging, resulting in either under-resection with risk of local recurrence or over-resection with increased functional loss and negative impact on quality of life. This study evaluates, in two pre-clinical in vivo tumor models, the potential of fluorescence-guided resection using molecular beacons activated by metalloproteinases, which are frequently upregulated in human oral cancer. In both models there was rapid (<15 min) beacon activation upon local application, allowing clear fluoresecence imaging in vivo and confirmed by ex vivo fluorescence microscopy and HPLC, with minimal activation in normal oral tissues. Although the tissue penetration was limited using topical application, these findings support further development of this approach towards translation to first-in-human trials.
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Affiliation(s)
- Laura Burgess
- Princess Margaret Cancer Centre, University Health Network, 101 College Street, Toronto ON M5G 1L7, Canada
- Department of Medical Biophysics, University of Toronto, 101 College Street, Toronto ON M5G 1L7, Canada
| | - Juan Chen
- Princess Margaret Cancer Centre, University Health Network, 101 College Street, Toronto ON M5G 1L7, Canada
| | - Nikolaus E. Wolter
- Department of Otolaryngology – Head & Neck Surgery, University of Toronto, 190 Elizabeth St, Rm 3S438, RFE Building Toronto, ON, M5G 2N2, Canada
| | - Brian Wilson
- Princess Margaret Cancer Centre, University Health Network, 101 College Street, Toronto ON M5G 1L7, Canada
- Department of Medical Biophysics, University of Toronto, 101 College Street, Toronto ON M5G 1L7, Canada
| | - Gang Zheng
- Princess Margaret Cancer Centre, University Health Network, 101 College Street, Toronto ON M5G 1L7, Canada
- Department of Medical Biophysics, University of Toronto, 101 College Street, Toronto ON M5G 1L7, Canada
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45
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Gorczynska I, Migacz JV, Zawadzki RJ, Capps AG, Werner JS. Comparison of amplitude-decorrelation, speckle-variance and phase-variance OCT angiography methods for imaging the human retina and choroid. Biomed Opt Express 2016; 7:911-42. [PMID: 27231598 PMCID: PMC4866465 DOI: 10.1364/boe.7.000911] [Citation(s) in RCA: 98] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/14/2015] [Revised: 02/03/2016] [Accepted: 02/12/2016] [Indexed: 05/18/2023]
Abstract
We compared the performance of three OCT angiography (OCTA) methods: speckle variance, amplitude decorrelation and phase variance for imaging of the human retina and choroid. Two averaging methods, split spectrum and volume averaging, were compared to assess the quality of the OCTA vascular images. All data were acquired using a swept-source OCT system at 1040 nm central wavelength, operating at 100,000 A-scans/s. We performed a quantitative comparison using a contrast-to-noise (CNR) metric to assess the capability of the three methods to visualize the choriocapillaris layer. For evaluation of the static tissue noise suppression in OCTA images we proposed to calculate CNR between the photoreceptor/RPE complex and the choriocapillaris layer. Finally, we demonstrated that implementation of intensity-based OCT imaging and OCT angiography methods allows for visualization of retinal and choroidal vascular layers known from anatomic studies in retinal preparations. OCT projection imaging of data flattened to selected retinal layers was implemented to visualize retinal and choroidal vasculature. User guided vessel tracing was applied to segment the retinal vasculature. The results were visualized in a form of a skeletonized 3D model.
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Affiliation(s)
- Iwona Gorczynska
- Department of Ophthalmology & Vision Science, University of California Davis, Sacramento, CA 95817, USA
- Faculty of Physics, Astronomy and Informatics, Nicolaus Copernicus University, Torun 87-100, Poland
| | - Justin V. Migacz
- Department of Ophthalmology & Vision Science, University of California Davis, Sacramento, CA 95817, USA
| | - Robert J. Zawadzki
- Department of Ophthalmology & Vision Science, University of California Davis, Sacramento, CA 95817, USA
| | - Arlie G. Capps
- Department of Ophthalmology & Vision Science, University of California Davis, Sacramento, CA 95817, USA
- Physics Division, Lawrence Livermore National Laboratory Livermore, CA 94550, USA
| | - John S. Werner
- Department of Ophthalmology & Vision Science, University of California Davis, Sacramento, CA 95817, USA
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46
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Sivasubramanian K, Pramanik M. High frame rate photoacoustic imaging at 7000 frames per second using clinical ultrasound system. Biomed Opt Express 2016; 7:312-23. [PMID: 26977342 PMCID: PMC4771451 DOI: 10.1364/boe.7.000312] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/11/2015] [Revised: 12/22/2015] [Accepted: 12/23/2015] [Indexed: 05/02/2023]
Abstract
Photoacoustic tomography, a hybrid imaging modality combining optical and ultrasound imaging, is gaining attention in the field of medical imaging. Typically, a Q-switched Nd:YAG laser is used to excite the tissue and generate photoacoustic signals. But, such photoacoustic imaging systems are difficult to translate into clinical applications owing to their high cost, bulky size often requiring an optical table to house such lasers. Moreover, the low pulse repetition rate of few tens of hertz prevents them from being used in high frame rate photoacoustic imaging. In this work, we have demonstrated up to 7000 Hz photoacoustic imaging (B-mode) and measured the flow rate of a fast moving object. We used a ~140 nanosecond pulsed laser diode as an excitation source and a clinical ultrasound imaging system to capture and display the photoacoustic images. The excitation laser is ~803 nm in wavelength with ~1.4 mJ energy per pulse. So far, the reported 2-dimensional photoacoustic B-scan imaging is only a few tens of frames per second using a clinical ultrasound system. Therefore, this is the first report on 2-dimensional photoacoustic B-scan imaging with 7000 frames per second. We have demonstrated phantom imaging to view and measure the flow rate of ink solution inside a tube. This fast photoacoustic imaging can be useful for various clinical applications including cardiac related problems, where the blood flow rate is quite high, or other dynamic studies.
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Affiliation(s)
| | - Manojit Pramanik
- School of Chemical and Biomedical Engineering, Nanyang Technological University, 637459 Singapore
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47
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Sibai M, Veilleux I, Elliott JT, Leblond F, Wilson BC. Quantitative spatial frequency fluorescence imaging in the sub-diffusive domain for image-guided glioma resection. Biomed Opt Express 2015; 6:4923-33. [PMID: 26713206 PMCID: PMC4679266 DOI: 10.1364/boe.6.004923] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/02/2015] [Revised: 09/24/2015] [Accepted: 09/24/2015] [Indexed: 05/19/2023]
Abstract
Intraoperative 5- aminolevulinic acid induced-Protoporphyrin IX (PpIX) fluorescence guidance enables maximum safe resection of glioblastomas by providing surgeons with real-time tumor optical contrast. However, visual assessment of PpIX fluorescence is subjective and limited by the distorting effects of light attenuation and tissue autofluorescence. We have previously shown that non-invasive point measurements of absolute PpIX concentration identifies residual tumor that is otherwise non-detectable. Here, we extend this approach to wide-field quantitative fluorescence imaging by implementing spatial frequency domain imaging to recover tissue optical properties across the field-of-view in phantoms and ex vivo tissue.
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Affiliation(s)
- Mira Sibai
- Department of Medical Biophysics, University of Toronto, 101 College Street, Toronto, ON M5G 1L7
Canada
- Princess Margaret Cancer Center/University Health Network, 610 University Avenue, Toronto, ON M5G 2M3
Canada
| | - Israel Veilleux
- Princess Margaret Cancer Center/University Health Network, 610 University Avenue, Toronto, ON M5G 2M3
Canada
| | - Jonathan T. Elliott
- Thayer School of Engineering at Dartmouth, Thayer School of Engineering at Dartmouth 14 Engineering Drive Hanover, NH USA 03755
USA
| | - Frederic Leblond
- École Polytechnique De Montreal, 2900, boul. Édouard-Montpetit Montréal, Québec H3T 1J4
Canada
| | - Brian C. Wilson
- Department of Medical Biophysics, University of Toronto, 101 College Street, Toronto, ON M5G 1L7
Canada
- Princess Margaret Cancer Center/University Health Network, 610 University Avenue, Toronto, ON M5G 2M3
Canada
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48
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Hui J, Yu Q, Ma T, Wang P, Cao Y, Bruning RS, Qu Y, Chen Z, Zhou Q, Sturek M, Cheng JX, Chen W. High-speed intravascular photoacoustic imaging at 1.7 μm with a KTP-based OPO. Biomed Opt Express 2015; 6:4557-66. [PMID: 26601018 PMCID: PMC4646562 DOI: 10.1364/boe.6.004557] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/21/2015] [Revised: 10/18/2015] [Accepted: 10/19/2015] [Indexed: 05/03/2023]
Abstract
Lipid deposition inside the arterial wall is a hallmark of plaque vulnerability. Based on overtone absorption of C-H bonds, intravascular photoacoustic (IVPA) catheter is a promising technology for quantifying the amount of lipid and its spatial distribution inside the arterial wall. Thus far, the clinical translation of IVPA technology is limited by its slow imaging speed due to lack of a high-pulse-energy high-repetition-rate laser source for lipid-specific first overtone excitation at 1.7 μm. Here, we demonstrate a potassium titanyl phosphate (KTP)-based optical parametric oscillator with output pulse energy up to 2 mJ at a wavelength of 1724 nm and with a repetition rate of 500 Hz. Using this laser and a ring-shape transducer, IVPA imaging at speed of 1 frame per sec was demonstrated. Performance of the IVPA imaging system's resolution, sensitivity, and specificity were characterized by carbon fiber and a lipid-mimicking phantom. The clinical utility of this technology was further evaluated ex vivo in an excised atherosclerotic human femoral artery with comparison to histology.
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Affiliation(s)
- Jie Hui
- Department of Physics and Astronomy, Purdue University, West Lafayette, IN, 47906, USA ; These authors contributed equally to this work
| | - Qianhuan Yu
- Key Laboratory of Space Laser Communication and Detection Technology, Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai 201800, China ; University of Chinese Academy of Science, Beijing 100049, China ; These authors contributed equally to this work
| | - Teng Ma
- Department of Biomedical Engineering, NIH Ultrasonic Transducer Resource Center, University of Southern California, Los Angeles, CA, 90089, USA ; These authors contributed equally to this work
| | - Pu Wang
- Weldon School of Biomedical Engineering, Purdue University, West Lafayette, IN, 47906, USA
| | - Yingchun Cao
- Weldon School of Biomedical Engineering, Purdue University, West Lafayette, IN, 47906, USA
| | - Rebecca S Bruning
- Department of Cellular & Integrative Physiology, Indiana University School of Medicine, Indianapolis, IN, 46202, USA
| | - Yueqiao Qu
- Department of Biomedical Engineering, University of California, Irvine, Irvine, CA, 92612, USA
| | - Zhongping Chen
- Department of Biomedical Engineering, University of California, Irvine, Irvine, CA, 92612, USA
| | - Qifa Zhou
- Department of Biomedical Engineering, NIH Ultrasonic Transducer Resource Center, University of Southern California, Los Angeles, CA, 90089, USA
| | - Michael Sturek
- Department of Cellular & Integrative Physiology, Indiana University School of Medicine, Indianapolis, IN, 46202, USA
| | - Ji-Xin Cheng
- Weldon School of Biomedical Engineering, Purdue University, West Lafayette, IN, 47906, USA ;
| | - Weibiao Chen
- Key Laboratory of Space Laser Communication and Detection Technology, Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai 201800, China ;
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49
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Wang Z, Lei M, Yao B, Cai Y, Liang Y, Yang Y, Yang X, Li H, Xiong D. Compact multi-band fluorescent microscope with an electrically tunable lens for autofocusing. Biomed Opt Express 2015; 6:4353-64. [PMID: 26601001 PMCID: PMC4646545 DOI: 10.1364/boe.6.004353] [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] [Received: 07/21/2015] [Revised: 10/10/2015] [Accepted: 10/11/2015] [Indexed: 05/09/2023]
Abstract
Autofocusing is a routine technique in redressing focus drift that occurs in time-lapse microscopic image acquisition. To date, most automatic microscopes are designed on the distance detection scheme to fulfill the autofocusing operation, which may suffer from the low contrast of the reflected signal due to the refractive index mismatch at the water/glass interface. To achieve high autofocusing speed with minimal motion artifacts, we developed a compact multi-band fluorescent microscope with an electrically tunable lens (ETL) device for autofocusing. A modified searching algorithm based on equidistant scanning and curve fitting is proposed, which no longer requires a single-peak focus curve and then efficiently restrains the impact of external disturbance. This technique enables us to achieve an autofocusing time of down to 170 ms and the reproductivity of over 97%. The imaging head of the microscope has dimensions of 12 cm × 12 cm × 6 cm. This portable instrument can easily fit inside standard incubators for real-time imaging of living specimens.
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Affiliation(s)
- Zhaojun Wang
- State Key Laboratory of Transient Optics and Photonics, Xi' an Institute of Optics and Precision Mechanics, Chinese Academy of Sciences, Xi' an 710119, China
| | - Ming Lei
- State Key Laboratory of Transient Optics and Photonics, Xi' an Institute of Optics and Precision Mechanics, Chinese Academy of Sciences, Xi' an 710119, China ;
| | - Baoli Yao
- State Key Laboratory of Transient Optics and Photonics, Xi' an Institute of Optics and Precision Mechanics, Chinese Academy of Sciences, Xi' an 710119, China ;
| | - Yanan Cai
- State Key Laboratory of Transient Optics and Photonics, Xi' an Institute of Optics and Precision Mechanics, Chinese Academy of Sciences, Xi' an 710119, China
| | - Yansheng Liang
- State Key Laboratory of Transient Optics and Photonics, Xi' an Institute of Optics and Precision Mechanics, Chinese Academy of Sciences, Xi' an 710119, China
| | - Yanlong Yang
- State Key Laboratory of Transient Optics and Photonics, Xi' an Institute of Optics and Precision Mechanics, Chinese Academy of Sciences, Xi' an 710119, China
| | - Xibin Yang
- Jiangsu Key Laboratory of Medical Optics, Suzhou Institute of Biomedical Engineering and Technology, Chinese Academy of Sciences, Suzhou 215163, China
| | - Hui Li
- Jiangsu Key Laboratory of Medical Optics, Suzhou Institute of Biomedical Engineering and Technology, Chinese Academy of Sciences, Suzhou 215163, China
| | - Daxi Xiong
- Jiangsu Key Laboratory of Medical Optics, Suzhou Institute of Biomedical Engineering and Technology, Chinese Academy of Sciences, Suzhou 215163, China
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Gautam V, Drury J, Choy JMC, Stricker C, Bachor HA, Daria VR. Improved two-photon imaging of living neurons in brain tissue through temporal gating. Biomed Opt Express 2015; 6:4027-36. [PMID: 26504651 PMCID: PMC4605060 DOI: 10.1364/boe.6.004027] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/06/2015] [Revised: 09/11/2015] [Accepted: 09/11/2015] [Indexed: 05/05/2023]
Abstract
We optimize two-photon imaging of living neurons in brain tissue by temporally gating an incident laser to reduce the photon flux while optimizing the maximum fluorescence signal from the acquired images. Temporal gating produces a bunch of ~10 femtosecond pulses and the fluorescence signal is improved by increasing the bunch-pulse energy. Gating is achieved using an acousto-optic modulator with a variable gating frequency determined as integral multiples of the imaging sampling frequency. We hypothesize that reducing the photon flux minimizes the photo-damage to the cells. Our results, however, show that despite producing a high fluorescence signal, cell viability is compromised when the gating and sampling frequencies are equal (or effectively one bunch-pulse per pixel). We found an optimum gating frequency range that maintains the viability of the cells while preserving a pre-set fluorescence signal of the acquired two-photon images. The neurons are imaged while under whole-cell patch, and the cell viability is monitored as a change in the membrane's input resistance.
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Affiliation(s)
- Vini Gautam
- John Curtin School of Medical Research, The Australian National University, Canberra, ACT 2601, Australia
| | - Jack Drury
- John Curtin School of Medical Research, The Australian National University, Canberra, ACT 2601, Australia
| | - Julian M. C. Choy
- John Curtin School of Medical Research, The Australian National University, Canberra, ACT 2601, Australia
| | - Christian Stricker
- John Curtin School of Medical Research, The Australian National University, Canberra, ACT 2601, Australia
- Medical School, The Australian National University, Canberra, ACT 2601, Australia
| | - Hans-A. Bachor
- Research School of Physics and Engineering, The Australian National University, Canberra, ACT 2601, Australia
| | - Vincent R. Daria
- John Curtin School of Medical Research, The Australian National University, Canberra, ACT 2601, Australia
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