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Munck S, Cawthorne C, Escamilla‐Ayala A, Kerstens A, Gabarre S, Wesencraft K, Battistella E, Craig R, Reynaud EG, Swoger J, McConnell G. Challenges and advances in optical 3D mesoscale imaging. J Microsc 2022; 286:201-219. [PMID: 35460574 PMCID: PMC9325079 DOI: 10.1111/jmi.13109] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2021] [Revised: 03/02/2022] [Accepted: 04/14/2022] [Indexed: 12/14/2022]
Abstract
Optical mesoscale imaging is a rapidly developing field that allows the visualisation of larger samples than is possible with standard light microscopy, and fills a gap between cell and organism resolution. It spans from advanced fluorescence imaging of micrometric cell clusters to centimetre-size complete organisms. However, with larger volume specimens, new problems arise. Imaging deeper into tissues at high resolution poses challenges ranging from optical distortions to shadowing from opaque structures. This manuscript discusses the latest developments in mesoscale imaging and highlights limitations, namely labelling, clearing, absorption, scattering, and also sample handling. We then focus on approaches that seek to turn mesoscale imaging into a more quantitative technique, analogous to quantitative tomography in medical imaging, highlighting a future role for digital and physical phantoms as well as artificial intelligence.
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Affiliation(s)
- Sebastian Munck
- VIB‐KU Leuven Center for Brain & Disease ResearchLight Microscopy Expertise Unit & VIB BioImaging CoreLeuvenBelgium
- KU Leuven Department of NeurosciencesLeuven Brain InstituteLeuvenBelgium
| | | | - Abril Escamilla‐Ayala
- VIB‐KU Leuven Center for Brain & Disease ResearchLight Microscopy Expertise Unit & VIB BioImaging CoreLeuvenBelgium
- KU Leuven Department of NeurosciencesLeuven Brain InstituteLeuvenBelgium
| | - Axelle Kerstens
- VIB‐KU Leuven Center for Brain & Disease ResearchLight Microscopy Expertise Unit & VIB BioImaging CoreLeuvenBelgium
- KU Leuven Department of NeurosciencesLeuven Brain InstituteLeuvenBelgium
| | - Sergio Gabarre
- VIB‐KU Leuven Center for Brain & Disease ResearchLight Microscopy Expertise Unit & VIB BioImaging CoreLeuvenBelgium
- KU Leuven Department of NeurosciencesLeuven Brain InstituteLeuvenBelgium
| | | | | | - Rebecca Craig
- Department of Physics, SUPAUniversity of StrathclydeGlasgowUK
| | - Emmanuel G. Reynaud
- School of Biomolecular and Biomedical ScienceUniversity College DublinDublinBelfieldIreland
| | - Jim Swoger
- European Molecular Biology Laboratory (EMBL) BarcelonaBarcelonaSpain
| | - Gail McConnell
- Department of Physics, SUPAUniversity of StrathclydeGlasgowUK
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2
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Schmidt C, Planchette AL, Nguyen D, Giardina G, Neuenschwander Y, Franco MD, Mylonas A, Descloux AC, Pomarico E, Radenovic A, Extermann J. High resolution optical projection tomography platform for multispectral imaging of the mouse gut. BIOMEDICAL OPTICS EXPRESS 2021; 12:3619-3629. [PMID: 34221683 PMCID: PMC8221953 DOI: 10.1364/boe.423284] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/26/2021] [Revised: 05/06/2021] [Accepted: 05/18/2021] [Indexed: 06/13/2023]
Abstract
Optical projection tomography (OPT) is a powerful tool for three-dimensional imaging of mesoscopic biological samples with great use for biomedical phenotyping studies. We present a fluorescent OPT platform that enables direct visualization of biological specimens and processes at a centimeter scale with high spatial resolution, as well as fast data throughput and reconstruction. We demonstrate nearly isotropic sub-28 µm resolution over more than 60 mm3 after reconstruction of a single acquisition. Our setup is optimized for imaging the mouse gut at multiple wavelengths. Thanks to a new sample preparation protocol specifically developed for gut specimens, we can observe the spatial arrangement of the intestinal villi and the vasculature network of a 3-cm long healthy mouse gut. Besides the blood vessel network surrounding the gastrointestinal tract, we observe traces of vasculature at the villi ends close to the lumen. The combination of rapid acquisition and a large field of view with high spatial resolution in 3D mesoscopic imaging holds an invaluable potential for gastrointestinal pathology research.
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Affiliation(s)
- Cédric Schmidt
- HEPIA/HES-SO, University of Applied Sciences of Western Switzerland, Rue de la Prairie 4, 1202 Geneva, Switzerland
| | - Arielle L. Planchette
- Laboratoire de Biologie à l’Échelle Nanométrique, School of Engineering, École Polytechnique Fédérale de Lausanne, CH-1015 Lausanne, Switzerland
| | - David Nguyen
- Zlatic Lab, Neurobiology, MRC-Laboratory of Molecular Biology, Cambridge CB2 0QH, United Kingdom
| | - Gabriel Giardina
- HEPIA/HES-SO, University of Applied Sciences of Western Switzerland, Rue de la Prairie 4, 1202 Geneva, Switzerland
| | - Yoan Neuenschwander
- HEPIA/HES-SO, University of Applied Sciences of Western Switzerland, Rue de la Prairie 4, 1202 Geneva, Switzerland
| | - Mathieu Di Franco
- HEPIA/HES-SO, University of Applied Sciences of Western Switzerland, Rue de la Prairie 4, 1202 Geneva, Switzerland
| | - Alessio Mylonas
- Laboratoire de Biologie à l’Échelle Nanométrique, School of Engineering, École Polytechnique Fédérale de Lausanne, CH-1015 Lausanne, Switzerland
| | - Adrien C. Descloux
- Laboratoire de Biologie à l’Échelle Nanométrique, School of Engineering, École Polytechnique Fédérale de Lausanne, CH-1015 Lausanne, Switzerland
| | - Enrico Pomarico
- HEPIA/HES-SO, University of Applied Sciences of Western Switzerland, Rue de la Prairie 4, 1202 Geneva, Switzerland
| | - Aleksandra Radenovic
- Laboratoire de Biologie à l’Échelle Nanométrique, School of Engineering, École Polytechnique Fédérale de Lausanne, CH-1015 Lausanne, Switzerland
| | - Jérôme Extermann
- HEPIA/HES-SO, University of Applied Sciences of Western Switzerland, Rue de la Prairie 4, 1202 Geneva, Switzerland
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3
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LIU A, XIAO W, LI R, LIU L, CHEN L. Comparison of optical projection tomography and light‐sheet fluorescence microscopy. J Microsc 2019; 275:3-10. [DOI: 10.1111/jmi.12796] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2019] [Revised: 04/18/2019] [Accepted: 04/18/2019] [Indexed: 01/21/2023]
Affiliation(s)
- A. LIU
- College of Health Science and Environmental EngineeringShenzhen Technology University Shenzhen China
- College of Optoelectronics EngineeringShenzhen University Shenzhen China
| | - W. XIAO
- College of Health Science and Environmental EngineeringShenzhen Technology University Shenzhen China
- College of Optoelectronics EngineeringShenzhen University Shenzhen China
| | - R. LI
- College of Health Science and Environmental EngineeringShenzhen Technology University Shenzhen China
- College of Optoelectronics EngineeringShenzhen University Shenzhen China
| | - L. LIU
- College of Health Science and Environmental EngineeringShenzhen Technology University Shenzhen China
- College of Optoelectronics EngineeringShenzhen University Shenzhen China
| | - L. CHEN
- College of Health Science and Environmental EngineeringShenzhen Technology University Shenzhen China
- College of Optoelectronics EngineeringShenzhen University Shenzhen China
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4
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Chen L, Li G, Tang L, Zhang M, Liu L, Liu A, McGinty J, Ruan S. Hyperspectral scanning laser optical tomography. JOURNAL OF BIOPHOTONICS 2019; 12:e201800221. [PMID: 30187691 DOI: 10.1002/jbio.201800221] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/16/2018] [Accepted: 09/04/2018] [Indexed: 06/08/2023]
Abstract
In order to study physical relationships within tissue volumes or even organism-level systems, the spatial distribution of multiple fluorescent markers needs to be resolved efficiently in three dimensions. Here, rather than acquiring discrete spectral images sequentially using multiple emission filters, a hyperspectral scanning laser optical tomography system is developed to obtain hyperspectral volumetric data sets with 2-nm spectral resolution of optically transparent mesoscopic (millimeter-centimeter) specimens. This is achieved by acquiring a series of point-scanning hyperspectral extended depth of field images at different angles and subsequently tomographically reconstructing the 3D intensity distribution for each wavelength. This technique is demonstrated to provide robust measurements via the comparison of spectral and intensity profiles of fluorescent bead phantoms. Due to its enhanced spectral resolving ability, this technique is also demonstrated to resolve largely overlapping fluorophores, as demonstrated by the 3D fluorescence hyperspectral reconstruction of a dual-labeled mouse thymus gland sample and the ability to distinguish tumorous and normal tissues of an unlabeled mouse intestine sample.
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Affiliation(s)
- Lingling Chen
- College of Health Science and Environmental Engineering, Shenzhen Technology University, Shenzhen, China
- College of Optoelectronics Engineering, Shenzhen University, Shenzhen, China
- Key Laboratory of Advanced Optical Precision Manufacturing Technology of Guangdong Higher Education Institutes, Shenzhen Technology University, Shenzhen, China
| | - Guiye Li
- College of Optoelectronics Engineering, Shenzhen University, Shenzhen, China
- Key Laboratory of Advanced Optical Precision Manufacturing Technology of Guangdong Higher Education Institutes, Shenzhen Technology University, Shenzhen, China
| | - Li Tang
- College of Optoelectronics Engineering, Shenzhen University, Shenzhen, China
- Department of Medicine, Shenzhen University, Shenzhen, China
| | - Meng Zhang
- School of Electronics and information Engineering, Beihang University, Beijing, China
| | - Lina Liu
- College of Optoelectronics Engineering, Shenzhen University, Shenzhen, China
| | - Ang Liu
- College of Optoelectronics Engineering, Shenzhen University, Shenzhen, China
| | - James McGinty
- Photonics Group, Department of Physics, Imperial College London, London, UK
| | - Shuangchen Ruan
- Key Laboratory of Advanced Optical Precision Manufacturing Technology of Guangdong Higher Education Institutes, Shenzhen Technology University, Shenzhen, China
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5
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Chan KG, Liebling M. Direct inversion algorithm for focal plane scanning optical projection tomography. BIOMEDICAL OPTICS EXPRESS 2017; 8:5349-5358. [PMID: 29188125 PMCID: PMC5695975 DOI: 10.1364/boe.8.005349] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/26/2017] [Revised: 09/20/2017] [Accepted: 09/28/2017] [Indexed: 05/09/2023]
Abstract
To achieve approximately parallel projection geometry, traditional optical projection tomography (OPT) requires the use of low numerical aperture (NA) objectives, which have a long depth-of-field at the expense of poor lateral resolution. Particularly promising methods to improve spatial resolution include ad-hoc post-processing filters that limit the effect of the system's MTF and focal-plane-scanning OPT (FPS-OPT), an alternative acquisition procedure that allows the use of higher NA objectives by limiting the effect of their shallow depth of field yet still assumes parallel projection rays during reconstruction. Here, we provide a detailed derivation that establishes the existence of a direct inversion formula for FPS-OPT. Based on this formula, we propose a point spread function-aware algorithm that is similar in form and complexity to traditional filtered backprojection (FBP). With simulations, we demonstrate that our point-spread-function aware FBP for FPS-OPT leads to more accurate images than both traditional OPT with deconvolution and FPS-OPT with naive FBP reconstruction. We further illustrate the technique on experimental zebrafish data, which shows that our approach reduces out-of-focus blur compared to a direct FBP reconstruction with FPS-OPT.
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Affiliation(s)
- Kevin G. Chan
- Electrical & Computer Engineering Department, University of California, Santa Barbara, CA 93106,
USA
| | - Michael Liebling
- Electrical & Computer Engineering Department, University of California, Santa Barbara, CA 93106,
USA
- Idiap Research Institute, CH-1920 Martigny,
Switzerland
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6
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Trull AK, van der Horst J, Palenstijn WJ, van Vliet LJ, van Leeuwen T, Kalkman J. Point spread function based image reconstruction in optical projection tomography. Phys Med Biol 2017; 62:7784-7797. [PMID: 28854154 DOI: 10.1088/1361-6560/aa8945] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
As a result of the shallow depth of focus of the optical imaging system, the use of standard filtered back projection in optical projection tomography causes space-variant tangential blurring that increases with the distance to the rotation axis. We present a novel optical tomographic image reconstruction technique that incorporates the point spread function of the imaging lens in an iterative reconstruction. The technique is demonstrated using numerical simulations, tested on experimental optical projection tomography data of single fluorescent beads, and applied to high-resolution emission optical projection tomography imaging of an entire zebrafish larva. Compared to filtered back projection our results show greatly reduced radial and tangential blurring over the entire [Formula: see text] mm2 field of view, and a significantly improved signal to noise ratio.
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Affiliation(s)
- Anna K Trull
- Department of Imaging Physics, Delft University of Technology, Lorentzweg 1, 2628 CJ Delft, Netherlands
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7
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Lee C, Baek J. Inverse filtering approach to measure directional in-plane modulation transfer function using a sphere phantom for a digital tomosynthesis system. OPTICS EXPRESS 2017; 25:17280-17293. [PMID: 28789221 DOI: 10.1364/oe.25.017280] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/14/2017] [Accepted: 07/04/2017] [Indexed: 06/07/2023]
Abstract
We propose a method to measure the directional in-plane modulation transfer function (MTF) of a digital tomosynthesis system using a sphere phantom. To assess the spatial resolution of an in-plane image of the tomosynthesis system, projection data of a sphere phantom were generated within a limited data acquisition range of 40°, and reconstructed by the FDK algorithm. To measure the in-plane MTF, we divided the Fourier transform of the reconstructed sphere phantom by that of the ideal sphere phantom, and then performed plane integral along the fz-direction. When dividing, small values in the denominator can introduce estimation errors, and these errors were reduced by the proposed method. To evaluate the performance of the proposed method, the in-plane MTF estimated by simulation and experimental data was compared to the ideal in-plane MTF generated by computer simulations using a point object. For quantitative evaluation, we measured frequency values at half-maximum and full-maximum of the directional in-plane MTF along the three different directions (i.e., f0° -, f30° -, and f60° -directions) and compared them with those of the ideal in-plane MTF. Although the sphere phantom has been regarded as an inappropriate object due to the anisotropic characteristics of tomosynthesis image, our results show that the proposed method has a reliable estimation performance, demonstrating the sphere phantom is still suitable for measuring the directional in-plane MTF for a digital tomosynthesis system.
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8
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van der Horst J, Kalkman J. Image resolution and deconvolution in optical tomography. OPTICS EXPRESS 2016; 24:24460-24472. [PMID: 27828174 DOI: 10.1364/oe.24.024460] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
We present a frequency domain analysis of the image resolution of optical tomography systems. The result of our analysis is a description of the spatially-variant resolution in optical tomographic image after reconstruction as a function of the properties of the imaging system geometry. We validate our model using optical projection tomography (OPT) measurements of fluorescent beads embedded in agarose gel. Our model correctly describes both the radial and tangential resolution of the measured images. In addition, we present a correction of the tomographic images for the spatially-varying resolution using a deconvolution algorithm. The resulting corrected tomographic reconstruction shows a homogeneous and isotropic pixel-limited resolution across the entire image. Our method is applied to OPT measurements of a zebrafish, showing improved resolution. Aside from allowing image correction and providing a resolution measure for OPT systems, our model provides a powerful tool for the design of optical tomographic systems.
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9
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Singh M, Raghunathan R, Piazza V, Davis-Loiacono AM, Cable A, Vedakkan TJ, Janecek T, Frazier MV, Nair A, Wu C, Larina IV, Dickinson ME, Larin KV. Applicability, usability, and limitations of murine embryonic imaging with optical coherence tomography and optical projection tomography. BIOMEDICAL OPTICS EXPRESS 2016; 7:2295-310. [PMID: 27375945 PMCID: PMC4918583 DOI: 10.1364/boe.7.002295] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/24/2016] [Revised: 05/09/2016] [Accepted: 05/10/2016] [Indexed: 05/17/2023]
Abstract
We present an analysis of imaging murine embryos at various embryonic developmental stages (embryonic day 9.5, 11.5, and 13.5) by optical coherence tomography (OCT) and optical projection tomography (OPT). We demonstrate that while OCT was capable of rapid high-resolution live 3D imaging, its limited penetration depth prevented visualization of deeper structures, particularly in later stage embryos. In contrast, OPT was able to image the whole embryos, but could not be used in vivo because the embryos must be fixed and cleared. Moreover, the fixation process significantly altered the embryo morphology, which was quantified by the volume of the eye-globes before and after fixation. All of these factors should be weighed when determining which imaging modality one should use to achieve particular goals of a study.
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Affiliation(s)
- Manmohan Singh
- Department of Biomedical Engineering, University of Houston, 3605 Cullen Boulevard, Houston, 77204, USA
| | - Raksha Raghunathan
- Department of Biomedical Engineering, University of Houston, 3605 Cullen Boulevard, Houston, 77204, USA
| | - Victor Piazza
- Molecular Physiology and Biophysics, Baylor College of Medicine, One Baylor Plaza, Houston, 77584, USA
| | | | - Alex Cable
- Thorlabs, Inc., 56 Sparta Ave., Newton, 07860, USA
| | - Tegy J. Vedakkan
- Molecular Physiology and Biophysics, Baylor College of Medicine, One Baylor Plaza, Houston, 77584, USA
| | - Trevor Janecek
- Department of Biomedical Engineering, University of Houston, 3605 Cullen Boulevard, Houston, 77204, USA
| | - Michael V. Frazier
- Department of Biomedical Engineering, University of Houston, 3605 Cullen Boulevard, Houston, 77204, USA
| | - Achuth Nair
- Department of Biomedical Engineering, University of Houston, 3605 Cullen Boulevard, Houston, 77204, USA
| | - Chen Wu
- Department of Biomedical Engineering, University of Houston, 3605 Cullen Boulevard, Houston, 77204, USA
| | - Irina V. Larina
- Molecular Physiology and Biophysics, Baylor College of Medicine, One Baylor Plaza, Houston, 77584, USA
| | - Mary E. Dickinson
- Molecular Physiology and Biophysics, Baylor College of Medicine, One Baylor Plaza, Houston, 77584, USA
| | - Kirill V. Larin
- Department of Biomedical Engineering, University of Houston, 3605 Cullen Boulevard, Houston, 77204, USA
- Molecular Physiology and Biophysics, Baylor College of Medicine, One Baylor Plaza, Houston, 77584, USA
- Department of Electrical Engineering, Samara National Research University, Samara, 34 Moskovskoye sh., 443086, Russia
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10
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Andrews N, Ramel MC, Kumar S, Alexandrov Y, Kelly DJ, Warren SC, Kerry L, Lockwood N, Frolov A, Frankel P, Bugeon L, McGinty J, Dallman MJ, French PMW. Visualising apoptosis in live zebrafish using fluorescence lifetime imaging with optical projection tomography to map FRET biosensor activity in space and time. JOURNAL OF BIOPHOTONICS 2016; 9:414-24. [PMID: 26753623 PMCID: PMC4858816 DOI: 10.1002/jbio.201500258] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/30/2015] [Revised: 11/25/2015] [Accepted: 11/27/2015] [Indexed: 05/14/2023]
Abstract
Fluorescence lifetime imaging (FLIM) combined with optical projection tomography (OPT) has the potential to map Förster resonant energy transfer (FRET) readouts in space and time in intact transparent or near transparent live organisms such as zebrafish larvae, thereby providing a means to visualise cell signalling processes in their physiological context. Here the first application of FLIM OPT to read out biological function in live transgenic zebrafish larvae using a genetically expressed FRET biosensor is reported. Apoptosis, or programmed cell death, is mapped in 3-D by imaging the activity of a FRET biosensor that is cleaved by Caspase 3, which is a key effector of apoptosis. Although apoptosis is a naturally occurring process during development, it can also be triggered in a variety of ways, including through gamma irradiation. FLIM OPT is shown here to enable apoptosis to be monitored over time, in live zebrafish larvae via changes in Caspase 3 activation following gamma irradiation at 24 hours post fertilisation. Significant apoptosis was observed at 3.5 hours post irradiation, predominantly in the head region.
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Affiliation(s)
- Natalie Andrews
- Institute of Chemical Biology, Department of Chemistry, Imperial College London, SW7 2AZ, UK
- Department of Life Sciences, , Imperial College London, SW7 2AZ, UK
- Photonics Group, Department of Physics, Prince Consort Road, Imperial College London, SW7 2AZ, UK
| | - Marie-Christine Ramel
- Department of Life Sciences, , Imperial College London, SW7 2AZ, UK
- Division of Medicine, University College London, Gower Street, London, WC1E 6BT, UK
| | - Sunil Kumar
- Photonics Group, Department of Physics, Prince Consort Road, Imperial College London, SW7 2AZ, UK
| | - Yuriy Alexandrov
- Photonics Group, Department of Physics, Prince Consort Road, Imperial College London, SW7 2AZ, UK
| | - Douglas J Kelly
- Photonics Group, Department of Physics, Prince Consort Road, Imperial College London, SW7 2AZ, UK
| | - Sean C Warren
- Photonics Group, Department of Physics, Prince Consort Road, Imperial College London, SW7 2AZ, UK
| | - Louise Kerry
- Department of Life Sciences, , Imperial College London, SW7 2AZ, UK
| | - Nicola Lockwood
- Division of Medicine, University College London, Gower Street, London, WC1E 6BT, UK
- COMPLEX, University College London, Gower Street, London, WC1E 6BT, UK
| | - Antonina Frolov
- Division of Medicine, University College London, Gower Street, London, WC1E 6BT, UK
| | - Paul Frankel
- Division of Medicine, University College London, Gower Street, London, WC1E 6BT, UK
| | - Laurence Bugeon
- Department of Life Sciences, , Imperial College London, SW7 2AZ, UK
| | - James McGinty
- Photonics Group, Department of Physics, Prince Consort Road, Imperial College London, SW7 2AZ, UK
| | | | - Paul M W French
- Photonics Group, Department of Physics, Prince Consort Road, Imperial College London, SW7 2AZ, UK.
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11
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McErlean CM, Bräuer-Krisch E, Adamovics J, Doran SJ. Assessment of optical CT as a future QA tool for synchrotron x-ray microbeam therapy. Phys Med Biol 2016; 61:320-37. [PMID: 26657052 DOI: 10.1088/0031-9155/61/1/320] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Synchrotron microbeam radiation therapy (MRT) is an advanced form of radiotherapy for which it is extremely difficult to provide adequate quality assurance. This may delay or limit its clinical uptake, particularly in the paediatric patient populations for whom it could be especially suitable. This study investigates the extent to which new developments in 3D dosimetry using optical computed tomography (CT) can visualise MRT dose distributions, and assesses what further developments are necessary before fully quantitative 3D measurements can be achieved. Two experiments are reported. In the first cylindrical samples of the radiochromic polymer PRESAGE(®) were irradiated with different complex MRT geometries including multiport treatments of collimated 'pencil' beams, interlaced microplanar arrays and a multiport treatment using an anthropomorphic head phantom. Samples were scanned using transmission optical CT. In the second experiment, optical CT measurements of the biologically important peak-to-valley dose ratio (PVDR) were compared with expected values from Monte Carlo simulations. The depth-of-field (DOF) of the optical CT system was characterised using a knife-edge method and the possibility of spatial resolution improvement through deconvolution of a measured point spread function (PSF) was investigated. 3D datasets from the first experiment revealed excellent visualisation of the 50 μm beams and various discrepancies from the planned delivery dose were found. The optical CT PVDR measurements were found to be consistently 30% of the expected Monte Carlo values and deconvolution of the microbeam profiles was found to lead to increased noise. The reason for the underestimation of the PVDR by optical CT was attributed to lack of spatial resolution, supported by the results of the DOF characterisation. Solutions are suggested for the outstanding challenges and the data are shown already to be useful in identifying potential treatment anomalies.
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Affiliation(s)
- Ciara M McErlean
- CRUK Cancer Imaging Centre, Institute of Cancer Research, London, SM2 5NG, UK
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12
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Otón J, Sorzano COS, Marabini R, Pereiro E, Carazo JM. Measurement of the modulation transfer function of an X-ray microscope based on multiple Fourier orders analysis of a Siemens star. OPTICS EXPRESS 2015; 23:9567-72. [PMID: 25968993 DOI: 10.1364/oe.23.009567] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Soft X-ray tomography (SXT) is becoming a powerful imaging technique to analyze eukaryotic whole cells close to their native state. Central to the analysis of the quality of SXT 3D reconstruction is the estimation of the spatial resolution and Depth of Field of the X-ray microscope. In turn, the characterization of the Modulation Transfer Function (MTF) of the optical system is key to calculate both parameters. Consequently, in this work we introduce a fully automated technique to accurately estimate the transfer function of such an optical system. Our proposal is based on the preprocessing of the experimental images to obtain an estimate of the input pattern, followed by the analysis in Fourier space of multiple orders of a Siemens Star test sample, extending in this way its measured frequency range.
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13
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Arranz A, Dong D, Zhu S, Rudin M, Tsatsanis C, Tian J, Ripoll J. Helical optical projection tomography. OPTICS EXPRESS 2013; 21:25912-25. [PMID: 24216818 DOI: 10.1364/oe.21.025912] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
A new technique termed Helical Optical Projection Tomography (hOPT) has been developed with the aim to overcome some of the limitations of current 3D optical imaging techniques. hOPT is based on Optical Projection Tomography (OPT) with the major difference that there is a translation of the sample in the vertical direction during the image acquisition process, requiring a new approach to image reconstruction. Contrary to OPT, hOPT makes possible to obtain 3D-optical images of intact long samples without imposing limits on the sample length. This has been tested using hOPT to image long murine tissue samples such as spinal cords and large intestines. Moreover, 3D-reconstructed images of the colon of DSS-treated mice, a model for Inflammatory Bowel Disease, allowed the identification of the structural alterations. Finally, the geometry of the hOPT device facilitates the addition of a Selective Plane Illumination Microscopy (SPIM) arm, providing the possibility of delivering high resolution images of selected areas together with complete volumetric information.
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14
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Chen L, Andrews N, Kumar S, Frankel P, McGinty J, French PMW. Simultaneous angular multiplexing optical projection tomography at shifted focal planes. OPTICS LETTERS 2013; 38:851-3. [PMID: 23503237 DOI: 10.1364/ol.38.000851] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
We describe an angular multiplexing technique for optical projection tomography that improves resolution, signal-to-noise ratio, and imaging speed by ameliorating the trade-off between spatial resolution and depth of field and improving the light collection efficiency. Here we demonstrate that imaging at two orthogonal angular projections simultaneously, focused on shifted planes in the sample, improves the average spatial resolution by ~20% and the light collection efficiency by a factor of ~4, thereby enabling increased acquisition speed and reduced light dose.
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Affiliation(s)
- Lingling Chen
- Photonics Group, Department of Physics, Imperial College London, London, UK.
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