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Staufer T, Körnig C, Liu B, Liu Y, Lanzloth C, Schmutzler O, Bedke T, Machicote A, Parak WJ, Feliu N, Bosurgi L, Huber S, Grüner F. Enabling X-ray fluorescence imaging for in vivo immune cell tracking. Sci Rep 2023; 13:11505. [PMID: 37460665 DOI: 10.1038/s41598-023-38536-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2023] [Accepted: 07/10/2023] [Indexed: 07/20/2023] Open
Abstract
The infiltration of immune cells into sites of inflammation is one key feature of immune mediated inflammatory diseases. A detailed assessment of the in vivo dynamics of relevant cell subtypes could booster the understanding of this disease and the development of novel therapies. We show in detail how advanced X-ray fluorescence imaging enables such quantitative in vivo cell tracking, offering solutions that could pave the way beyond what other imaging modalities provide today. The key for this achievement is a detailed study of the spectral background contribution from multiple Compton scattering in a mouse-scaled object when this is scanned with a monochromatic pencil X-ray beam from a synchrotron. Under optimal conditions, the detection sensitivity is sufficient for detecting local accumulations of the labelled immune cells, hence providing experimental demonstration of in vivo immune cell tracking in mice.
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Affiliation(s)
- Theresa Staufer
- Fachbereich Physik, Universität Hamburg, 22761, Hamburg, Germany.
- Center for Free-Electron Laser Science (CFEL), 22761, Hamburg, Germany.
| | - Christian Körnig
- Fachbereich Physik, Universität Hamburg, 22761, Hamburg, Germany
- Center for Free-Electron Laser Science (CFEL), 22761, Hamburg, Germany
| | - Beibei Liu
- I. Department of Medicine, University Medical Center Hamburg-Eppendorf, 20246, Hamburg, Germany
- Hamburg Center for Translational Immunology (HCTI), University Medical Center Hamburg-Eppendorf, 20246, Hamburg, Germany
| | - Yang Liu
- Fachbereich Physik, Universität Hamburg, 22761, Hamburg, Germany
- Center for Hybrid Nanostructures (CHyN), Luruper Chaussee 149, 22761, Hamburg, Germany
| | - Clarissa Lanzloth
- I. Department of Medicine, University Medical Center Hamburg-Eppendorf, 20246, Hamburg, Germany
- Protozoa Immunology, Bernhard Nocht Institute for Tropical Medicine, 20359, Hamburg, Germany
| | - Oliver Schmutzler
- Fachbereich Physik, Universität Hamburg, 22761, Hamburg, Germany
- Center for Free-Electron Laser Science (CFEL), 22761, Hamburg, Germany
| | - Tanja Bedke
- I. Department of Medicine, University Medical Center Hamburg-Eppendorf, 20246, Hamburg, Germany
- Hamburg Center for Translational Immunology (HCTI), University Medical Center Hamburg-Eppendorf, 20246, Hamburg, Germany
| | - Andres Machicote
- I. Department of Medicine, University Medical Center Hamburg-Eppendorf, 20246, Hamburg, Germany
- Hamburg Center for Translational Immunology (HCTI), University Medical Center Hamburg-Eppendorf, 20246, Hamburg, Germany
| | - Wolfgang J Parak
- Fachbereich Physik, Universität Hamburg, 22761, Hamburg, Germany
- Center for Hybrid Nanostructures (CHyN), Luruper Chaussee 149, 22761, Hamburg, Germany
| | - Neus Feliu
- Fraunhofer Center for Applied Nanotechnology (IAP-CAN), 20146, Hamburg, Germany
| | - Lidia Bosurgi
- I. Department of Medicine, University Medical Center Hamburg-Eppendorf, 20246, Hamburg, Germany
- Hamburg Center for Translational Immunology (HCTI), University Medical Center Hamburg-Eppendorf, 20246, Hamburg, Germany
- Protozoa Immunology, Bernhard Nocht Institute for Tropical Medicine, 20359, Hamburg, Germany
| | - Samuel Huber
- I. Department of Medicine, University Medical Center Hamburg-Eppendorf, 20246, Hamburg, Germany
- Hamburg Center for Translational Immunology (HCTI), University Medical Center Hamburg-Eppendorf, 20246, Hamburg, Germany
| | - Florian Grüner
- Fachbereich Physik, Universität Hamburg, 22761, Hamburg, Germany
- Center for Free-Electron Laser Science (CFEL), 22761, Hamburg, Germany
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Staufer T, Grüner F. Review of Development and Recent Advances in Biomedical X-ray Fluorescence Imaging. Int J Mol Sci 2023; 24:10990. [PMID: 37446168 DOI: 10.3390/ijms241310990] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2023] [Revised: 06/27/2023] [Accepted: 06/29/2023] [Indexed: 07/15/2023] Open
Abstract
The use of X-rays for non-invasive imaging has a long history, which has resulted in several well-established methods in preclinical as well as clinical applications, such as tomographic imaging or computed tomography. While projection radiography provides anatomical information, X-ray fluorescence analysis allows quantitative mapping of different elements in samples of interest. Typical applications so far comprise the identification and quantification of different elements and are mostly located in material sciences, archeology and environmental sciences, whereas the use of the technique in life sciences has been strongly limited by intrinsic spectral background issues arising in larger objects, so far. This background arises from multiple Compton-scattering events in the objects of interest and strongly limits the achievable minimum detectable marker concentrations. Here, we review the history and report on the recent promising developments of X-ray fluorescence imaging (XFI) in preclinical applications, and provide an outlook on the clinical translation of the technique, which can be realized by reducing the above-mentioned intrinsic background with dedicated algorithms and by novel X-ray sources.
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Affiliation(s)
- Theresa Staufer
- Fachbereich Physik, Universität Hamburg and Center for Free-Electron Laser Science (CFEL), Luruper Chaussee 149, 22761 Hamburg, Germany
| | - Florian Grüner
- Fachbereich Physik, Universität Hamburg and Center for Free-Electron Laser Science (CFEL), Luruper Chaussee 149, 22761 Hamburg, Germany
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3
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A Laser Frequency Transverse Modulation Might Compensate for the Spectral Broadening Due to Large Electron Energy Spread in Thomson Sources. PHOTONICS 2022. [DOI: 10.3390/photonics9020062] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Compact laser plasma accelerators generate high-energy electron beams with increasing quality. When used in inverse Compton backscattering, however, the relatively large electron energy spread jeopardizes potential applications requiring small bandwidths. We present here a novel interaction scheme that allows us to compensate for the negative effects of the electron energy spread on the spectrum, by introducing a transverse spatial frequency modulation in the laser pulse. Such a laser chirp, together with a properly dispersed electron beam, can substantially reduce the broadening of the Compton bandwidth due to the electron energy spread. We show theoretical analysis and numerical simulations for hard X-ray Thomson sources based on laser plasma accelerators.
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X-ray Fluorescence Computed Tomography (XFCT) Imaging with a Superfine Pencil Beam X-ray Source. PHOTONICS 2021. [DOI: 10.3390/photonics8070236] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
X-ray fluorescence computed tomography (XFCT) is a molecular imaging technique that can be used to sense different elements or nanoparticle (NP) agents inside deep samples or tissues. However, XFCT has not been a popular molecular imaging tool because it has limited molecular sensitivity and spatial resolution. We present a benchtop XFCT imaging system in which a superfine pencil-beam X-ray source and a ring of X-ray spectrometers were simulated using GATE (Geant4 Application for Tomographic Emission) Monte Carlo software. An accelerated majorization minimization (MM) algorithm with an L1 regularization scheme was used to reconstruct the XFCT image of molybdenum (Mo) NP targets. Good target localization was achieved with a DICE coefficient of 88.737%. The reconstructed signal of the targets was found to be proportional to the target concentrations if detector number, detector placement, and angular projection number are optimized. The MM algorithm performance was compared with the maximum likelihood expectation maximization (ML-EM) and filtered back projection (FBP) algorithms. Our results indicate that the MM algorithm is superior to the ML-EM and FBP algorithms. We found that the MM algorithm was able to reconstruct XFCT targets as small as 0.25 mm in diameter. We also found that measurements with three angular projections and a 20-detector ring are enough to reconstruct the XFCT images.
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Romero IO, Li C. A feasibility study of time of flight cone beam computed tomography imaging. JOURNAL OF X-RAY SCIENCE AND TECHNOLOGY 2021; 29:867-880. [PMID: 34275923 DOI: 10.3233/xst-210918] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
BACKGROUND The time of flight (TOF) cone beam computed tomography (CBCT) was recently shown to reduce the X-ray scattering effects by 95% and improve the image CNR by 110% for large volume objects. The advancements in X-ray sources like in compact Free Electron Lasers (FEL) and advancements in detector technology show potential for the TOF method to be feasible in CBCT when imaging large objects. OBJECTIVE To investigate the feasibility and efficacy of TOF CBCT in imaging smaller objects with different targets such as bones and tumors embedded inside the background. METHODS The TOF method used in this work was verified using a 24 cm phantom. Then, the GATE software was used to simulate the CBCT imaging of an 8 cm diameter cylindrical water phantom with two bone targets using a modeled 20 keV quasi-energetic FEL source and various TOF resolutions ranging from 1 to 1000 ps. An inhomogeneous breast phantom of similar size with tumor targets was also imaged using the same system setup. RESULTS The same results were obtained in the 24 cm phantom, which validated the applied CBCT simulation approach. For the case of 8 cm cylindrical phantom and bone target, a TOF resolution of 10 ps improved the image contrast-to-noise ratio (CNR) by 57% and reduced the scatter-to-primary ratio (SPR) by 8.63. For the case of breast phantom and tumor target, image CNR was enhanced by 12% and SPR was reduced by 1.35 at 5 ps temporal resolution. CONCLUSIONS This study indicates that a TOF resolution below 10 ps is required to observe notable enhancements in the image quality and scatter reduction for small objects around 8 cm in diameter. The strong scattering targets such as bone can result in substantial improvements by using TOF CBCT.
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Affiliation(s)
- Ignacio O Romero
- Department of Bioengineering, University of California Merced, Merced, CA, USA
| | - Changqing Li
- Department of Bioengineering, University of California Merced, Merced, CA, USA
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Kulpe S, Dierolf M, Günther B, Brantl J, Busse M, Achterhold K, Pfeiffer F, Pfeiffer D. Spectroscopic imaging at compact inverse Compton X-ray sources. Phys Med 2020; 79:137-144. [PMID: 33271418 DOI: 10.1016/j.ejmp.2020.11.015] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/29/2020] [Revised: 10/22/2020] [Accepted: 11/07/2020] [Indexed: 10/22/2022] Open
Abstract
While K-edge subtraction (KES) imaging is a commonly applied technique at synchrotron sources, the application of this imaging method in clinical imaging is limited although results have shown its superiority to conventional clinical subtraction imaging. Over the past decades, compact synchrotron X-ray sources, based on inverse Compton scattering, have been developed to fill the gap between conventional X-ray tubes and synchrotron facilities. These so called inverse Compton sources (ICSs) provide a tunable, quasi-monochromatic X-ray beam in a laboratory setting with reduced spatial and financial requirements. This allows for the transfer of imaging techniques that have been limited to synchrotrons until now, like KES imaging, into a laboratory environment. This review article presents the first studies that have successfully performed KES at ICSs. These have shown that KES provides improved image quality in comparison to conventional X-ray imaging. The results indicate that medical imaging could benefit from monochromatic imaging and KES techniques. Currently, the clinical application of KES is limited by the low K-edge energy of available iodine contrast agents. However, several ICSs are under development or already in commissioning which will provide monochromatic X-ray beams with higher X-ray energies and will enable KES using high-Z elements as contrast media. With these developments, KES at an ICS has the ability to become an important tool in pre-clinical research and potentially advancing existing clinical imaging techniques.
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Affiliation(s)
- Stephanie Kulpe
- Chair of Biomedical Physics, Department of Physics and Munich School of BioEngineering, Technical University of Munich, James-Franck-Str. 1, 85748 Garching, Germany.
| | - Martin Dierolf
- Chair of Biomedical Physics, Department of Physics and Munich School of BioEngineering, Technical University of Munich, James-Franck-Str. 1, 85748 Garching, Germany
| | - Benedikt Günther
- Chair of Biomedical Physics, Department of Physics and Munich School of BioEngineering, Technical University of Munich, James-Franck-Str. 1, 85748 Garching, Germany
| | - Johannes Brantl
- Chair of Biomedical Physics, Department of Physics and Munich School of BioEngineering, Technical University of Munich, James-Franck-Str. 1, 85748 Garching, Germany
| | - Madleen Busse
- Chair of Biomedical Physics, Department of Physics and Munich School of BioEngineering, Technical University of Munich, James-Franck-Str. 1, 85748 Garching, Germany
| | - Klaus Achterhold
- Chair of Biomedical Physics, Department of Physics and Munich School of BioEngineering, Technical University of Munich, James-Franck-Str. 1, 85748 Garching, Germany
| | - Franz Pfeiffer
- Chair of Biomedical Physics, Department of Physics and Munich School of BioEngineering, Technical University of Munich, James-Franck-Str. 1, 85748 Garching, Germany; Department of Diagnostic and Interventional Radiology, Munich School of Medicine and Klinikum rechts der Isar, Ismaniger Str. 22, 81675 Munich, Germany
| | - Daniela Pfeiffer
- Department of Diagnostic and Interventional Radiology, Munich School of Medicine and Klinikum rechts der Isar, Ismaniger Str. 22, 81675 Munich, Germany
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Zimmermann P, Peredkov S, Abdala PM, DeBeer S, Tromp M, Müller C, van Bokhoven JA. Modern X-ray spectroscopy: XAS and XES in the laboratory. Coord Chem Rev 2020. [DOI: 10.1016/j.ccr.2020.213466] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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8
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Schuemann J, Bagley AF, Berbeco R, Bromma K, Butterworth KT, Byrne HL, Chithrani BD, Cho SH, Cook JR, Favaudon V, Gholami YH, Gargioni E, Hainfeld JF, Hespeels F, Heuskin AC, Ibeh UM, Kuncic Z, Kunjachan S, Lacombe S, Lucas S, Lux F, McMahon S, Nevozhay D, Ngwa W, Payne JD, Penninckx S, Porcel E, Prise KM, Rabus H, Ridwan SM, Rudek B, Sanche L, Singh B, Smilowitz HM, Sokolov KV, Sridhar S, Stanishevskiy Y, Sung W, Tillement O, Virani N, Yantasee W, Krishnan S. Roadmap for metal nanoparticles in radiation therapy: current status, translational challenges, and future directions. Phys Med Biol 2020; 65:21RM02. [PMID: 32380492 DOI: 10.1088/1361-6560/ab9159] [Citation(s) in RCA: 79] [Impact Index Per Article: 19.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
This roadmap outlines the potential roles of metallic nanoparticles (MNPs) in the field of radiation therapy. MNPs made up of a wide range of materials (from Titanium, Z = 22, to Bismuth, Z = 83) and a similarly wide spectrum of potential clinical applications, including diagnostic, therapeutic (radiation dose enhancers, hyperthermia inducers, drug delivery vehicles, vaccine adjuvants, photosensitizers, enhancers of immunotherapy) and theranostic (combining both diagnostic and therapeutic), are being fabricated and evaluated. This roadmap covers contributions from experts in these topics summarizing their view of the current status and challenges, as well as expected advancements in technology to address these challenges.
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Affiliation(s)
- Jan Schuemann
- Department of Radiation Oncology, Massachusetts General Hospital & Harvard Medical School, Boston, MA 02114, United States of America
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Günther B, Gradl R, Jud C, Eggl E, Huang J, Kulpe S, Achterhold K, Gleich B, Dierolf M, Pfeiffer F. The versatile X-ray beamline of the Munich Compact Light Source: design, instrumentation and applications. JOURNAL OF SYNCHROTRON RADIATION 2020; 27:1395-1414. [PMID: 32876618 PMCID: PMC7467334 DOI: 10.1107/s1600577520008309] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/19/2020] [Accepted: 06/22/2020] [Indexed: 05/08/2023]
Abstract
Inverse Compton scattering provides means to generate low-divergence partially coherent quasi-monochromatic, i.e. synchrotron-like, X-ray radiation on a laboratory scale. This enables the transfer of synchrotron techniques into university or industrial environments. Here, the Munich Compact Light Source is presented, which is such a compact synchrotron radiation facility based on an inverse Compton X-ray source (ICS). The recent improvements of the ICS are reported first and then the various experimental techniques which are most suited to the ICS installed at the Technical University of Munich are reviewed. For the latter, a multipurpose X-ray application beamline with two end-stations was designed. The beamline's design and geometry are presented in detail including the different set-ups as well as the available detector options. Application examples of the classes of experiments that can be performed are summarized afterwards. Among them are dynamic in vivo respiratory imaging, propagation-based phase-contrast imaging, grating-based phase-contrast imaging, X-ray microtomography, K-edge subtraction imaging and X-ray spectroscopy. Finally, plans to upgrade the beamline in order to enhance its capabilities are discussed.
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Affiliation(s)
- Benedikt Günther
- Department of Physics, Technical University of Munich, James-Franck-Straße 1, 85748 Garching, Germany
- Munich School of BioEngineering, Technical University of Munich, Boltzmannstraße 11, 85748 Garching, Germany
| | - Regine Gradl
- Department of Physics, Technical University of Munich, James-Franck-Straße 1, 85748 Garching, Germany
- Munich School of BioEngineering, Technical University of Munich, Boltzmannstraße 11, 85748 Garching, Germany
| | - Christoph Jud
- Department of Physics, Technical University of Munich, James-Franck-Straße 1, 85748 Garching, Germany
- Munich School of BioEngineering, Technical University of Munich, Boltzmannstraße 11, 85748 Garching, Germany
| | - Elena Eggl
- Department of Physics, Technical University of Munich, James-Franck-Straße 1, 85748 Garching, Germany
- Munich School of BioEngineering, Technical University of Munich, Boltzmannstraße 11, 85748 Garching, Germany
| | - Juanjuan Huang
- Department of Physics, Technical University of Munich, James-Franck-Straße 1, 85748 Garching, Germany
- Munich School of BioEngineering, Technical University of Munich, Boltzmannstraße 11, 85748 Garching, Germany
| | - Stephanie Kulpe
- Department of Physics, Technical University of Munich, James-Franck-Straße 1, 85748 Garching, Germany
- Munich School of BioEngineering, Technical University of Munich, Boltzmannstraße 11, 85748 Garching, Germany
| | - Klaus Achterhold
- Department of Physics, Technical University of Munich, James-Franck-Straße 1, 85748 Garching, Germany
- Munich School of BioEngineering, Technical University of Munich, Boltzmannstraße 11, 85748 Garching, Germany
| | - Bernhard Gleich
- Munich School of BioEngineering, Technical University of Munich, Boltzmannstraße 11, 85748 Garching, Germany
| | - Martin Dierolf
- Department of Physics, Technical University of Munich, James-Franck-Straße 1, 85748 Garching, Germany
- Munich School of BioEngineering, Technical University of Munich, Boltzmannstraße 11, 85748 Garching, Germany
| | - Franz Pfeiffer
- Department of Physics, Technical University of Munich, James-Franck-Straße 1, 85748 Garching, Germany
- Munich School of BioEngineering, Technical University of Munich, Boltzmannstraße 11, 85748 Garching, Germany
- Department of Diagnostic and Interventional Radiology, Klinikum rechts der Isar, Technical University of Munich, Ismaninger Straße 22, 81675 Munich, Germany
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BriXS, a new X-ray inverse Compton source for medical applications. Phys Med 2020; 77:127-137. [PMID: 32829101 DOI: 10.1016/j.ejmp.2020.08.013] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/11/2020] [Revised: 08/03/2020] [Accepted: 08/11/2020] [Indexed: 12/14/2022] Open
Abstract
MariX is a research infrastructure conceived for multi-disciplinary studies, based on a cutting-edge system of combined electron accelerators at the forefront of the world-wide scenario of X-ray sources. The generation of X-rays over a large photon energy range will be enabled by two unique X-ray sources: a Free Electron Laser and an inverse Compton source, called BriXS (Bright compact X-ray Source). The X-ray beam provided by BriXS is expected to have an average energy tunable in the range 20-180 keV and intensities between 1011 and 1013 photon/s within a relative bandwidth ΔE/E=1-10%. These characteristics, together with a very small source size (~20 μm) and a good transverse coherence, will enable a wide range of applications in the bio-medical field. An additional unique feature of BriXS will be the possibility to make a quick switch of the X-ray energy between two values for dual-energy and K-edge subtraction imaging. In this paper, the expected characteristics of BriXS will be presented, with a particular focus on the features of interest to its possible medical applications.
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11
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Burger K, Urban T, Dombrowsky AC, Dierolf M, Günther B, Bartzsch S, Achterhold K, Combs SE, Schmid TE, Wilkens JJ, Pfeiffer F. Technical and dosimetric realization of in vivo x-ray microbeam irradiations at the Munich Compact Light Source. Med Phys 2020; 47:5183-5193. [PMID: 32757280 DOI: 10.1002/mp.14433] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2019] [Revised: 04/15/2020] [Accepted: 07/20/2020] [Indexed: 12/20/2022] Open
Abstract
PURPOSE X-ray microbeam radiation therapy is a preclinical concept for tumor treatment promising tissue sparing and enhanced tumor control. With its spatially separated, periodic micrometer-sized pattern, this method requires a high dose rate and a collimated beam typically available at large synchrotron radiation facilities. To treat small animals with microbeams in a laboratory-sized environment, we developed a dedicated irradiation system at the Munich Compact Light Source (MuCLS). METHODS A specially made beam collimation optic allows to increase x-ray fluence rate at the position of the target. Monte Carlo simulations and measurements were conducted for accurate microbeam dosimetry. The dose during irradiation is determined by a calibrated flux monitoring system. Moreover, a positioning system including mouse monitoring was built. RESULTS We successfully commissioned the in vivo microbeam irradiation system for an exemplary xenograft tumor model in the mouse ear. By beam collimation, a dose rate of up to 5.3 Gy/min at 25 keV was achieved. Microbeam irradiations using a tungsten collimator with 50 μm slit size and 350 μm center-to-center spacing were performed at a mean dose rate of 0.6 Gy/min showing a high peak-to-valley dose ratio of about 200 in the mouse ear. The maximum circular field size of 3.5 mm in diameter can be enlarged using field patching. CONCLUSIONS This study shows that we can perform in vivo microbeam experiments at the MuCLS with a dedicated dosimetry and positioning system to advance this promising radiation therapy method at commercially available compact microbeam sources. Peak doses of up to 100 Gy per treatment seem feasible considering a recent upgrade for higher photon flux. The system can be adapted for tumor treatment in different animal models, for example, in the hind leg.
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Affiliation(s)
- Karin Burger
- Department of Radiation Oncology, School of Medicine & Klinikum rechts der Isar, Technical University of Munich, Munich, 81675, Germany.,Chair of Biomedical Physics, Department of Physics and Munich School of BioEngineering, Technical University of Munich, Garching, 85748, Germany
| | - Theresa Urban
- Department of Radiation Oncology, School of Medicine & Klinikum rechts der Isar, Technical University of Munich, Munich, 81675, Germany.,Chair of Biomedical Physics, Department of Physics and Munich School of BioEngineering, Technical University of Munich, Garching, 85748, Germany
| | - Annique C Dombrowsky
- Department of Radiation Oncology, School of Medicine & Klinikum rechts der Isar, Technical University of Munich, Munich, 81675, Germany.,Institute of Radiation Medicine (IRM), Department of Radiation Sciences (DRS), Helmholtz Zentrum München, Neuherberg, 85764, Germany
| | - Martin Dierolf
- Chair of Biomedical Physics, Department of Physics and Munich School of BioEngineering, Technical University of Munich, Garching, 85748, Germany
| | - Benedikt Günther
- Chair of Biomedical Physics, Department of Physics and Munich School of BioEngineering, Technical University of Munich, Garching, 85748, Germany
| | - Stefan Bartzsch
- Department of Radiation Oncology, School of Medicine & Klinikum rechts der Isar, Technical University of Munich, Munich, 81675, Germany.,Institute of Radiation Medicine (IRM), Department of Radiation Sciences (DRS), Helmholtz Zentrum München, Neuherberg, 85764, Germany
| | - Klaus Achterhold
- Chair of Biomedical Physics, Department of Physics and Munich School of BioEngineering, Technical University of Munich, Garching, 85748, Germany
| | - Stephanie E Combs
- Department of Radiation Oncology, School of Medicine & Klinikum rechts der Isar, Technical University of Munich, Munich, 81675, Germany.,Institute of Radiation Medicine (IRM), Department of Radiation Sciences (DRS), Helmholtz Zentrum München, Neuherberg, 85764, Germany
| | - Thomas E Schmid
- Department of Radiation Oncology, School of Medicine & Klinikum rechts der Isar, Technical University of Munich, Munich, 81675, Germany.,Institute of Radiation Medicine (IRM), Department of Radiation Sciences (DRS), Helmholtz Zentrum München, Neuherberg, 85764, Germany
| | - Jan J Wilkens
- Department of Radiation Oncology, School of Medicine & Klinikum rechts der Isar, Technical University of Munich, Munich, 81675, Germany.,Chair of Biomedical Physics, Department of Physics and Munich School of BioEngineering, Technical University of Munich, Garching, 85748, Germany
| | - Franz Pfeiffer
- Chair of Biomedical Physics, Department of Physics and Munich School of BioEngineering, Technical University of Munich, Garching, 85748, Germany.,Department of Diagnostic and Interventional Radiology, School of Medicine & Klinikum rechts der Isar, Technical University of Munich, München, 81675, Germany
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12
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Kulpe S, Dierolf M, Braig EM, Günther B, Achterhold K, Gleich B, Herzen J, Rummeny E, Pfeiffer F, Pfeiffer D. K-edge subtraction imaging for iodine and calcium separation at a compact synchrotron x-ray source. J Med Imaging (Bellingham) 2020; 7:023504. [PMID: 32341936 DOI: 10.1117/1.jmi.7.2.023504] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2019] [Accepted: 04/06/2020] [Indexed: 11/14/2022] Open
Abstract
Purpose: About one third of all deaths worldwide can be traced to some form of cardiovascular disease. The gold standard for the diagnosis and interventional treatment of blood vessels is digital subtraction angiography (DSA). An alternative to DSA is K-edge subtraction (KES) imaging, which has been shown to be advantageous for moving organs and for eliminating image artifacts caused by patient movement. As highly brilliant, monochromatic x-rays are required for this method, it has been limited to synchrotron facilities so far, restraining the applicability in the clinical routine. Over the past decades, compact synchrotron x-ray sources based on inverse Compton scattering have been evolving; these provide x-rays with sufficient brilliance and meet spatial and financial requirements for laboratory settings or university hospitals. Approach: We demonstrate a proof-of-principle KES imaging experiment using the Munich Compact Light Source (MuCLS), the first user-dedicated installation of a compact synchrotron x-ray source worldwide. A series of experiments were performed both on a phantom and an excised human carotid to demonstrate the ability of the proposed KES technique to separate the iodine contrast agent and calcifications. Results: It is shown that the proposed filter-based KES method allows for the iodine-contrast agent and calcium to be clearly separated, thereby providing x-ray images only showing one of the two materials. Conclusions: The results show that the quasimonochromatic spectrum of the MuCLS enables filter-based KES imaging and can become an important tool in preclinical research and possible future clinical diagnostics.
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Affiliation(s)
- Stephanie Kulpe
- Technical University of Munich, Chair of Biomedical Physics, Department of Physics, Garching, Germany.,Technical University of Munich, Munich School of BioEngineering, Garching, Germany
| | - Martin Dierolf
- Technical University of Munich, Chair of Biomedical Physics, Department of Physics, Garching, Germany.,Technical University of Munich, Munich School of BioEngineering, Garching, Germany
| | - Eva-Maria Braig
- Technical University of Munich, Chair of Biomedical Physics, Department of Physics, Garching, Germany.,Technical University of Munich, Munich School of BioEngineering, Garching, Germany
| | - Benedikt Günther
- Technical University of Munich, Chair of Biomedical Physics, Department of Physics, Garching, Germany.,Technical University of Munich, Munich School of BioEngineering, Garching, Germany
| | - Klaus Achterhold
- Technical University of Munich, Chair of Biomedical Physics, Department of Physics, Garching, Germany.,Technical University of Munich, Munich School of BioEngineering, Garching, Germany
| | - Bernhard Gleich
- Technical University of Munich, Munich School of BioEngineering, Garching, Germany
| | - Julia Herzen
- Technical University of Munich, Chair of Biomedical Physics, Department of Physics, Garching, Germany.,Technical University of Munich, Munich School of BioEngineering, Garching, Germany
| | - Ernst Rummeny
- Munich School of Medicine and Klinikum rechts der Isar, Department of Diagnostic and Interventional Radiology, Munich, Germany
| | - Franz Pfeiffer
- Technical University of Munich, Chair of Biomedical Physics, Department of Physics, Garching, Germany.,Technical University of Munich, Munich School of BioEngineering, Garching, Germany.,Munich School of Medicine and Klinikum rechts der Isar, Department of Diagnostic and Interventional Radiology, Munich, Germany
| | - Daniela Pfeiffer
- Munich School of Medicine and Klinikum rechts der Isar, Department of Diagnostic and Interventional Radiology, Munich, Germany
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13
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Yang L, Gradl R, Dierolf M, Möller W, Kutschke D, Feuchtinger A, Hehn L, Donnelley M, Günther B, Achterhold K, Walch A, Stoeger T, Razansky D, Pfeiffer F, Morgan KS, Schmid O. Multimodal Precision Imaging of Pulmonary Nanoparticle Delivery in Mice: Dynamics of Application, Spatial Distribution, and Dosimetry. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2019; 15:e1904112. [PMID: 31639283 DOI: 10.1002/smll.201904112] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/27/2019] [Revised: 09/12/2019] [Indexed: 06/10/2023]
Abstract
Targeted delivery of nanomedicine/nanoparticles (NM/NPs) to the site of disease (e.g., the tumor or lung injury) is of vital importance for improved therapeutic efficacy. Multimodal imaging platforms provide powerful tools for monitoring delivery and tissue distribution of drugs and NM/NPs. This study introduces a preclinical imaging platform combining X-ray (two modes) and fluorescence imaging (three modes) techniques for time-resolved in vivo and spatially resolved ex vivo visualization of mouse lungs during pulmonary NP delivery. Liquid mixtures of iodine (contrast agent for X-ray) and/or (nano)particles (X-ray absorbing and/or fluorescent) are delivered to different regions of the lung via intratracheal instillation, nasal aspiration, and ventilator-assisted aerosol inhalation. It is demonstrated that in vivo propagation-based phase-contrast X-ray imaging elucidates the dynamic process of pulmonary NP delivery, while ex vivo fluorescence imaging (e.g., tissue-cleared light sheet fluorescence microscopy) reveals the quantitative 3D drug/particle distribution throughout the entire lung with cellular resolution. The novel and complementary information from this imaging platform unveils the dynamics and mechanisms of pulmonary NM/NP delivery and deposition for each of the delivery routes, which provides guidance on optimizing pulmonary delivery techniques and novel-designed NM for targeting and efficacy.
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Affiliation(s)
- Lin Yang
- Comprehensive Pneumology Center (CPC-M), Member of the German Center for Lung Research (DZL), Munich, 81377, Germany
- Institute of Lung Biology and Disease, Helmholtz Zentrum München-German Research Center for Environmental Health, Neuherberg, 85764, Germany
- Faculty of Medicine, Technical University of Munich, Munich, 80333, Germany
| | - Regine Gradl
- Chair of Biomedical Physics, Department of Physics, Technical University of Munich, Garching, 85748, Germany
- Munich School of BioEngineering, Technical University of Munich, Garching, 85748, Germany
- Institute for Advanced Study, Technical University of Munich, Garching, 85748, Germany
| | - Martin Dierolf
- Chair of Biomedical Physics, Department of Physics, Technical University of Munich, Garching, 85748, Germany
- Munich School of BioEngineering, Technical University of Munich, Garching, 85748, Germany
| | - Winfried Möller
- Comprehensive Pneumology Center (CPC-M), Member of the German Center for Lung Research (DZL), Munich, 81377, Germany
- Institute of Lung Biology and Disease, Helmholtz Zentrum München-German Research Center for Environmental Health, Neuherberg, 85764, Germany
| | - David Kutschke
- Comprehensive Pneumology Center (CPC-M), Member of the German Center for Lung Research (DZL), Munich, 81377, Germany
- Institute of Lung Biology and Disease, Helmholtz Zentrum München-German Research Center for Environmental Health, Neuherberg, 85764, Germany
| | - Annette Feuchtinger
- Research Unit Analytical Pathology, Helmholtz Zentrum München, Neuherberg, 85764, Germany
| | - Lorenz Hehn
- Chair of Biomedical Physics, Department of Physics, Technical University of Munich, Garching, 85748, Germany
- Department of Diagnostic and Interventional Radiology, Klinikum rechts der Isar, Technical University of Munich, München, 81675, Germany
| | - Martin Donnelley
- Robinson Research Institute and Adelaide Medical School, University of Adelaide, Adelaide, 5000, Australia
- Respiratory and Sleep Medicine, Women's and Children's Hospital, North Adelaide, SA, 5006, Australia
| | - Benedikt Günther
- Chair of Biomedical Physics, Department of Physics, Technical University of Munich, Garching, 85748, Germany
- Munich School of BioEngineering, Technical University of Munich, Garching, 85748, Germany
| | - Klaus Achterhold
- Chair of Biomedical Physics, Department of Physics, Technical University of Munich, Garching, 85748, Germany
- Munich School of BioEngineering, Technical University of Munich, Garching, 85748, Germany
| | - Axel Walch
- Research Unit Analytical Pathology, Helmholtz Zentrum München, Neuherberg, 85764, Germany
| | - Tobias Stoeger
- Comprehensive Pneumology Center (CPC-M), Member of the German Center for Lung Research (DZL), Munich, 81377, Germany
- Institute of Lung Biology and Disease, Helmholtz Zentrum München-German Research Center for Environmental Health, Neuherberg, 85764, Germany
| | - Daniel Razansky
- Faculty of Medicine, Technical University of Munich, Munich, 80333, Germany
- Institute for Biological and Medical Imaging (IBMI), Helmholtz Zentrum München, Neuherberg, 85764, Germany
- Faculty of Medicine and Institute of Pharmacology and Toxicology, University of Zurich, Zurich, CH-8057, Switzerland
- Institute for Biomedical Engineering and Department of Information Technology and Electrical Engineering, ETH Zurich, Zurich, 8093, Switzerland
| | - Franz Pfeiffer
- Chair of Biomedical Physics, Department of Physics, Technical University of Munich, Garching, 85748, Germany
- Munich School of BioEngineering, Technical University of Munich, Garching, 85748, Germany
- Institute for Advanced Study, Technical University of Munich, Garching, 85748, Germany
- Department of Diagnostic and Interventional Radiology, Klinikum rechts der Isar, Technical University of Munich, München, 81675, Germany
| | - Kaye S Morgan
- Chair of Biomedical Physics, Department of Physics, Technical University of Munich, Garching, 85748, Germany
- Institute for Advanced Study, Technical University of Munich, Garching, 85748, Germany
- School of Physics and Astronomy, Monash University, Clayton, Victoria, 3800, Australia
| | - Otmar Schmid
- Comprehensive Pneumology Center (CPC-M), Member of the German Center for Lung Research (DZL), Munich, 81377, Germany
- Institute of Lung Biology and Disease, Helmholtz Zentrum München-German Research Center for Environmental Health, Neuherberg, 85764, Germany
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14
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K-edge Subtraction Computed Tomography with a Compact Synchrotron X-ray Source. Sci Rep 2019; 9:13332. [PMID: 31527643 PMCID: PMC6746727 DOI: 10.1038/s41598-019-49899-z] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2019] [Accepted: 08/31/2019] [Indexed: 11/30/2022] Open
Abstract
In clinical diagnosis, X-ray computed tomography (CT) is one of the most important imaging techniques. Yet, this method lacks the ability to differentiate similarly absorbing substances like commonly used iodine contrast agent and calcium which is typically seen in calcifications, kidney stones and bones. K-edge subtraction (KES) imaging can help distinguish these materials by subtracting two CT scans recorded at different X-ray energies. So far, this method mostly relies on monochromatic X-rays produced at large synchrotron facilities. Here, we present the first proof-of-principle experiment of a filter-based KES CT method performed at a compact synchrotron X-ray source based on inverse-Compton scattering, the Munich Compact Light Source (MuCLS). It is shown that iodine contrast agent and calcium can be clearly separated to provide CT volumes only showing one of the two materials. These results demonstrate that KES CT at a compact synchrotron source can become an important tool in pre-clinical research.
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15
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Gradl R, Dierolf M, Yang L, Hehn L, Günther B, Möller W, Kutschke D, Stoeger T, Gleich B, Achterhold K, Donnelley M, Pfeiffer F, Schmid O, Morgan KS. Visualizing treatment delivery and deposition in mouse lungs using in vivo x-ray imaging. J Control Release 2019; 307:282-291. [DOI: 10.1016/j.jconrel.2019.06.035] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2019] [Revised: 06/18/2019] [Accepted: 06/25/2019] [Indexed: 01/17/2023]
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16
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A Soft-Threshold Filtering Approach for Tomography Reconstruction from a Limited Number of Projections with Bilateral Edge Preservation. SENSORS 2019; 19:s19102346. [PMID: 31117299 PMCID: PMC6567033 DOI: 10.3390/s19102346] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/02/2019] [Revised: 05/16/2019] [Accepted: 05/18/2019] [Indexed: 01/02/2023]
Abstract
In X-ray tomography image reconstruction, one of the most successful approaches involves a statistical approach with l2 norm for fidelity function and some regularization function with lp norm, 1<p<2. Among them stands out, both for its results and the computational performance, a technique that involves the alternating minimization of an objective function with l2 norm for fidelity and a regularization term that uses discrete gradient transform (DGT) sparse transformation minimized by total variation (TV). This work proposes an improvement to the reconstruction process by adding a bilateral edge-preserving (BEP) regularization term to the objective function. BEP is a noise reduction method and has the purpose of adaptively eliminating noise in the initial phase of reconstruction. The addition of BEP improves optimization of the fidelity term and, as a consequence, improves the result of DGT minimization by total variation. For reconstructions with a limited number of projections (low-dose reconstruction), the proposed method can achieve higher peak signal-to-noise ratio (PSNR) and structural similarity index measurement (SSIM) results because it can better control the noise in the initial processing phase.
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17
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Kulpe S, Dierolf M, Braig E, Günther B, Achterhold K, Gleich B, Herzen J, Rummeny E, Pfeiffer F, Pfeiffer D. K-edge subtraction imaging for coronary angiography with a compact synchrotron X-ray source. PLoS One 2018; 13:e0208446. [PMID: 30532277 PMCID: PMC6287837 DOI: 10.1371/journal.pone.0208446] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2018] [Accepted: 11/16/2018] [Indexed: 11/19/2022] Open
Abstract
About one third of all deaths worldwide can be traced back to cardiovascular diseases. An interventional radiology procedure for their diagnosis is Digital Subtraction Angiography (DSA). An alternative to DSA is K-Edge subtraction (KES) imaging, which has been shown to be advantageous for moving organs and eliminating image artifacts caused by patient movement. As highly brilliant, monochromatic X-rays are required for this method, it has been limited to synchrotron facilities so far, restraining the feasibility in clinical routine. Compact synchrotron X-ray sources based on inverse Compton scattering, which have been evolving substantially over the past decade, provide X-rays with sufficient brilliance that meet spatial and financial requirements affordable in laboratory settings or for university hospitals. In this work, we demonstrate a first proof-of-principle K-edge subtraction imaging experiment using the Munich Compact Light Source (MuCLS), the first user-dedicated installation of a compact synchrotron X-ray source worldwide. It is shown experimentally that the technique of KES increases the visibility of small blood vessels overlaid by bone structures.
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Affiliation(s)
- Stephanie Kulpe
- Chair of Biomedical Physics, Department of Physics, Technical University of Munich, Garching, Germany
- Munich School of BioEngineering, Technical University of Munich, Garching, Germany
- * E-mail:
| | - Martin Dierolf
- Chair of Biomedical Physics, Department of Physics, Technical University of Munich, Garching, Germany
- Munich School of BioEngineering, Technical University of Munich, Garching, Germany
| | - Eva Braig
- Chair of Biomedical Physics, Department of Physics, Technical University of Munich, Garching, Germany
- Munich School of BioEngineering, Technical University of Munich, Garching, Germany
- Department of Diagnostic and Interventional Radiology, Klinikum rechts der Isar, Technical University of Munich, Munich, Germany
| | - Benedikt Günther
- Chair of Biomedical Physics, Department of Physics, Technical University of Munich, Garching, Germany
- Munich School of BioEngineering, Technical University of Munich, Garching, Germany
| | - Klaus Achterhold
- Chair of Biomedical Physics, Department of Physics, Technical University of Munich, Garching, Germany
- Munich School of BioEngineering, Technical University of Munich, Garching, Germany
| | - Bernhard Gleich
- Munich School of BioEngineering, Technical University of Munich, Garching, Germany
| | - Julia Herzen
- Chair of Biomedical Physics, Department of Physics, Technical University of Munich, Garching, Germany
- Munich School of BioEngineering, Technical University of Munich, Garching, Germany
| | - Ernst Rummeny
- Department of Diagnostic and Interventional Radiology, Klinikum rechts der Isar, Technical University of Munich, Munich, Germany
| | - Franz Pfeiffer
- Chair of Biomedical Physics, Department of Physics, Technical University of Munich, Garching, Germany
- Munich School of BioEngineering, Technical University of Munich, Garching, Germany
- Department of Diagnostic and Interventional Radiology, Klinikum rechts der Isar, Technical University of Munich, Munich, Germany
| | - Daniela Pfeiffer
- Department of Diagnostic and Interventional Radiology, Klinikum rechts der Isar, Technical University of Munich, Munich, Germany
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18
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Quantitative morphometric analysis of adult teleost fish by X-ray computed tomography. Sci Rep 2018; 8:16531. [PMID: 30410001 PMCID: PMC6224569 DOI: 10.1038/s41598-018-34848-z] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2018] [Accepted: 10/22/2018] [Indexed: 12/11/2022] Open
Abstract
Vertebrate models provide indispensable paradigms to study development and disease. Their analysis requires a quantitative morphometric study of the body, organs and tissues. This is often impeded by pigmentation and sample size. X-ray micro-computed tomography (micro-CT) allows high-resolution volumetric tissue analysis, largely independent of sample size and transparency to visual light. Importantly, micro-CT data are inherently quantitative. We report a complete pipeline of high-throughput 3D data acquisition and image analysis, including tissue preparation and contrast enhancement for micro-CT imaging down to cellular resolution, automated data processing and organ or tissue segmentation that is applicable to comparative 3D morphometrics of small vertebrates. Applied to medaka fish, we first create an annotated anatomical atlas of the entire body, including inner organs as a quantitative morphological description of an adult individual. This atlas serves as a reference model for comparative studies. Using isogenic medaka strains we show that comparative 3D morphometrics of individuals permits identification of quantitative strain-specific traits. Thus, our pipeline enables high resolution morphological analysis as a basis for genotype-phenotype association studies of complex genetic traits in vertebrates.
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19
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Localising functionalised gold-nanoparticles in murine spinal cords by X-ray fluorescence imaging and background-reduction through spatial filtering for human-sized objects. Sci Rep 2018; 8:16561. [PMID: 30410002 PMCID: PMC6224495 DOI: 10.1038/s41598-018-34925-3] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2018] [Accepted: 10/26/2018] [Indexed: 12/25/2022] Open
Abstract
Accurate in vivo localisation of minimal amounts of functionalised gold-nanoparticles, enabling e.g. early-tumour diagnostics and pharmacokinetic tracking studies, requires a precision imaging system offering very high sensitivity, temporal and spatial resolution, large depth penetration, and arbitrarily long serial measurements. X-ray fluorescence imaging could offer such capabilities; however, its utilisation for human-sized scales is hampered by a high intrinsic background level. Here we measure and model this anisotropic background and present a spatial filtering scheme for background reduction enabling the localisation of nanoparticle-amounts as reported from small-animal tumour models. As a basic application study towards precision pharmacokinetics, we demonstrate specific localisation to sites of disease by adapting gold-nanoparticles with small targeting ligands in murine spinal cord injury models, at record sensitivity levels using sub-mm resolution. Both studies contribute to the future use of molecularly-targeted gold-nanoparticles as next-generation clinical diagnostic and pharmacokinetic tools.
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20
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Chi Z, Du Y, Yan L, Wang D, Zhang H, Huang W, Tang C. Experimental feasibility of dual-energy computed tomography based on the Thomson scattering X-ray source. JOURNAL OF SYNCHROTRON RADIATION 2018; 25:1797-1802. [PMID: 30407192 DOI: 10.1107/s1600577518012663] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/14/2018] [Accepted: 09/06/2018] [Indexed: 06/08/2023]
Abstract
Unlike large-scale and expensive synchrotron radiation facilities, the Thomson scattering X-ray source can provide quasi-monochromatic, energy-tunable and high-brightness X-ray pulses with a small footprint and moderate cost, making it an excellent candidate for dual-energy and multi-energy imaging at laboratories and hospitals. Here, the first feasibility study on dual-energy computed tomography (CT) based on this type of light source is reported, and the effective atomic number and electron-density distribution of a standard phantom consisting of polytetrafluoroethylene, water and aluminium is derived. The experiment was carried out at the Tsinghua Thomson scattering X-ray source with peak energies of 29 keV and 68 keV. Both the reconstructed effective atomic numbers and the retrieved electron densities of the three materials were compared with their theoretical values. It was found that these values were in agreement by 0.68% and 2.60% on average for effective atomic number and electron density, respectively. These results have verified the feasibility of dual-energy CT based on the Thomson scattering X-ray source and will further expand the scope of X-ray imaging using this type of light source.
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Affiliation(s)
- Zhijun Chi
- Department of Engineering Physics, Tsinghua University, Beijing 100084, People's Republic of China
| | - Yingchao Du
- Department of Engineering Physics, Tsinghua University, Beijing 100084, People's Republic of China
| | - Lixin Yan
- Department of Engineering Physics, Tsinghua University, Beijing 100084, People's Republic of China
| | - Dong Wang
- Department of Engineering Physics, Tsinghua University, Beijing 100084, People's Republic of China
| | - Hongze Zhang
- Department of Engineering Physics, Tsinghua University, Beijing 100084, People's Republic of China
| | - Wenhui Huang
- Department of Engineering Physics, Tsinghua University, Beijing 100084, People's Republic of China
| | - Chuanxiang Tang
- Department of Engineering Physics, Tsinghua University, Beijing 100084, People's Republic of China
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21
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Windt DL. Monochromatic mammography using scanning multilayer X-ray mirrors. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2018; 89:083702. [PMID: 30184654 PMCID: PMC6095706 DOI: 10.1063/1.5041799] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/26/2018] [Accepted: 07/21/2018] [Indexed: 06/08/2023]
Abstract
A prototype system for breast imaging using monochromatic X-rays has been developed using a scanning multilayer X-ray mirror in combination with a conventional mammography tube and an imaging detector. The X-ray mirror produces a monochromatic fan beam tuned near 19 keV, with an energy bandpass of approximately 1.5 keV. Rotating the mirror about the tube's focal spot in synchronization with the X-ray generator and detector enables the acquisition of monochromatic X-ray images over large areas. The X-ray mirror also can be rotated completely out of the beam so that conventional polychromatic images can be acquired using a K-edge filter, facilitating direct comparison between the two modes of operation. The system was used to image synthetic, tissue-equivalent breast phantoms in order to experimentally quantify the improvements in image quality and dose that can be realized using monochromatic radiation. Nine custom phantoms spanning a range of thicknesses and glandular/adipose ratios, each containing both glandular- and calcification-equivalent features, were used to measure contrast and signal-difference-to-noise ratio (SDNR). Mean glandular dose (MGD) was computed from measured entrance exposure, and a figure-of-merit (FOM) was computed as FOM = SDNR2/MGD in each case. Monochromatic MGD ranges from 0.606 to 0.134 of polychromatic MGD for images having comparable glandular SDNR, depending on breast thickness and glandularity; relative monochromatic dose decreases with increasing glandularity for all thicknesses. Monochromatic FOM values are higher than the corresponding polychromatic FOM values in all but one case. Additionally, the monochromatic contrast for glandular features is higher than the polychromatic contrast in all but one case as well. These results represent important steps toward the realization of clinically practical monochromatic X-ray breast imaging systems having lower dose and better image quality, including those for digital mammography, digital breast tomosynthesis, contrast-enhanced spectral mammography and other modalities, for safer, more accurate breast cancer detection, diagnosis and staging.
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Affiliation(s)
- David L Windt
- Reflective X-ray Optics LLC, 425 Riverside Dr., New York, New York 10025, USA
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22
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In vivo Dynamic Phase-Contrast X-ray Imaging using a Compact Light Source. Sci Rep 2018; 8:6788. [PMID: 29717143 PMCID: PMC5931574 DOI: 10.1038/s41598-018-24763-8] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2017] [Accepted: 04/05/2018] [Indexed: 12/14/2022] Open
Abstract
We describe the first dynamic and the first in vivo X-ray imaging studies successfully performed at a laser-undulator-based compact synchrotron light source. The X-ray properties of this source enable time-sequence propagation-based X-ray phase-contrast imaging. We focus here on non-invasive imaging for respiratory treatment development and physiological understanding. In small animals, we capture the regional delivery of respiratory treatment, and two measures of respiratory health that can reveal the effectiveness of a treatment; lung motion and mucociliary clearance. The results demonstrate the ability of this set-up to perform laboratory-based dynamic imaging, specifically in small animal models, and with the possibility of longitudinal studies.
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23
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Töpperwien M, Gradl R, Keppeler D, Vassholz M, Meyer A, Hessler R, Achterhold K, Gleich B, Dierolf M, Pfeiffer F, Moser T, Salditt T. Propagation-based phase-contrast x-ray tomography of cochlea using a compact synchrotron source. Sci Rep 2018; 8:4922. [PMID: 29563553 PMCID: PMC5862924 DOI: 10.1038/s41598-018-23144-5] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2017] [Accepted: 03/06/2018] [Indexed: 11/23/2022] Open
Abstract
We demonstrate that phase retrieval and tomographic imaging at the organ level of small animals can be advantageously carried out using the monochromatic radiation emitted by a compact x-ray light source, without further optical elements apart from source and detector. This approach allows to carry out microtomography experiments which - due to the large performance gap with respect to conventional laboratory instruments - so far were usually limited to synchrotron sources. We demonstrate the potential by mapping the functional soft tissue within the guinea pig and marmoset cochlea, including in the latter case an electrical cochlear implant. We show how 3d microanatomical studies without dissection or microscopic imaging can enhance future research on cochlear implants.
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Affiliation(s)
- Mareike Töpperwien
- Institute for X-Ray Physics, University of Göttingen, Göttingen, Germany.,Center for Nanoscopy and Molecular Physiology of the Brain, Göttingen, Germany
| | - Regine Gradl
- Chair of Biomedical Physics, Department of Physics, Technical University of Munich, Garching, Germany.,Institute for Advanced Study, Technical University of Munich, Garching, Germany.,Munich School of BioEngineering, Technical University of Munich, Garching, Germany
| | - Daniel Keppeler
- Institute for Auditory Neuroscience and InnerEarLab, University Medical Center Göttingen, Göttingen, Germany
| | - Malte Vassholz
- Institute for X-Ray Physics, University of Göttingen, Göttingen, Germany
| | - Alexander Meyer
- InnerEarLab, Department of Otolaryngology, University Medical Center Göttingen, Göttingen, Germany
| | | | - Klaus Achterhold
- Chair of Biomedical Physics, Department of Physics, Technical University of Munich, Garching, Germany.,Munich School of BioEngineering, Technical University of Munich, Garching, Germany
| | - Bernhard Gleich
- Munich School of BioEngineering, Technical University of Munich, Garching, Germany
| | - Martin Dierolf
- Chair of Biomedical Physics, Department of Physics, Technical University of Munich, Garching, Germany.,Munich School of BioEngineering, Technical University of Munich, Garching, Germany
| | - Franz Pfeiffer
- Chair of Biomedical Physics, Department of Physics, Technical University of Munich, Garching, Germany.,Institute for Advanced Study, Technical University of Munich, Garching, Germany.,Munich School of BioEngineering, Technical University of Munich, Garching, Germany.,Department of Diagnostic and Interventional Radiology, Klinikum rechts der Isar, Technical University of Munich, München, Germany
| | - Tobias Moser
- Center for Nanoscopy and Molecular Physiology of the Brain, Göttingen, Germany.,Institute for Auditory Neuroscience and InnerEarLab, University Medical Center Göttingen, Göttingen, Germany.,Bernstein Focus for Neurotechnology, University of Göttingen, Göttingen, Germany
| | - Tim Salditt
- Institute for X-Ray Physics, University of Göttingen, Göttingen, Germany. .,Center for Nanoscopy and Molecular Physiology of the Brain, Göttingen, Germany.
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24
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Making spectral shape measurements in inverse Compton scattering a tool for advanced diagnostic applications. Sci Rep 2018; 8:1398. [PMID: 29362472 PMCID: PMC5780516 DOI: 10.1038/s41598-018-19546-0] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2017] [Accepted: 12/29/2017] [Indexed: 11/27/2022] Open
Abstract
Interaction of relativistic electron beams with high power lasers can both serve as a secondary light source and as a novel diagnostic tool for various beam parameters. For both applications, it is important to understand the dynamics of the inverse Compton scattering mechanism and the dependence of the scattered light’s spectral properties on the interacting laser and electron beam parameters. Measurements are easily misinterpreted due to the complex interplay of the interaction parameters. Here we report the potential of inverse Compton scattering as an advanced diagnostic tool by investigating two of the most influential interaction parameters, namely the laser intensity and the electron beam emittance. Established scaling laws for the spectral bandwidth and redshift of the mean scattered photon energy are refined. This allows for a quantitatively well matching prediction of the spectral shape. Driving the interaction to a nonlinear regime, we spectrally resolve the rise of higher harmonic radiation with increasing laser intensity. Unprecedented agreement with 3D radiation simulations is found, showing the good control and characterization of the interaction. The findings advance the interpretation of inverse Compton scattering measurements into a diagnostic tool for electron beams from laser plasma acceleration.
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25
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Abstract
Unlike conventional x-ray attenuation one of the advantages of phase contrast x-ray imaging is its capability of extracting useful physical properties of the sample. In particular the possibility to obtain information from small angle scattering about unresolvable structures with sub-pixel resolution sensitivity has drawn attention for both medical and material science applications. We report on a novel algorithm for the analyzer based x-ray phase contrast imaging modality, which allows the robust separation of absorption, refraction and scattering effects from three measured x-ray images. This analytical approach is based on a simple Gaussian description of the analyzer transmission function and this method is capable of retrieving refraction and small angle scattering angles in the full angular range typical of biological samples. After a validation of the algorithm with a simulation code, which demonstrated the potential of this highly sensitive method, we have applied this theoretical framework to experimental data on a phantom and biological tissues obtained with synchrotron radiation. Owing to its extended angular acceptance range the algorithm allows precise assessment of local scattering distributions at biocompatible radiation doses, which in turn might yield a quantitative characterization tool with sufficient structural sensitivity on a submicron length scale.
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26
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Trabecular bone anisotropy imaging with a compact laser-undulator synchrotron x-ray source. Sci Rep 2017; 7:14477. [PMID: 29101369 PMCID: PMC5670213 DOI: 10.1038/s41598-017-14830-x] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2017] [Accepted: 10/18/2017] [Indexed: 02/01/2023] Open
Abstract
Conventional x-ray radiography is a well-established standard in diagnostic imaging of human bones. It reveals typical bony anatomy with a strong surrounding cortical bone and trabecular structure of the inner part. However, due to limited spatial resolution, x-ray radiography cannot provide information on the microstructure of the trabecular bone. Thus, microfractures without dislocation are often missed in initial radiographs, resulting in a lack or delay of adequate therapy. Here we show that x-ray vector radiography (XVR) can overcome this limitation and allows for a deeper insight into the microstructure with a radiation exposure comparable to standard radiography. XVR senses x-ray ultrasmall-angle scattering in addition to the attenuation contrast and thereby reveals the mean scattering strength, its degree of anisotropy and the orientation of scattering structures. Corresponding to the structural characteristics of bones, there is a homogenous mean scattering signal of the trabecular bone but the degree of anisotropy is strongly affected by variations in the trabecular structure providing more detailed information on the bone microstructure. The measurements were performed at the Munich Compact Light Source, a novel type of x-ray source based on inverse Compton scattering. This laboratory-sized source produces highly brilliant quasi-monochromatic x-rays with a tunable energy.
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27
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Gradl R, Dierolf M, Hehn L, Günther B, Yildirim AÖ, Gleich B, Achterhold K, Pfeiffer F, Morgan KS. Propagation-based Phase-Contrast X-ray Imaging at a Compact Light Source. Sci Rep 2017; 7:4908. [PMID: 28687726 PMCID: PMC5501835 DOI: 10.1038/s41598-017-04739-w] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2017] [Accepted: 05/18/2017] [Indexed: 11/09/2022] Open
Abstract
We demonstrate the applicability of propagation-based X-ray phase-contrast imaging at a laser-assisted compact light source with known phantoms and the lungs and airways of a mouse. The Munich Compact Light Source provides a quasi-monochromatic beam with partial spatial coherence, and high flux relative to other non-synchrotron sources (up to 1010 ph/s). In our study we observe significant edge-enhancement and quantitative phase-retrieval is successfully performed on the known phantom. Furthermore the images of a small animal show the potential for live bio-imaging research studies that capture biological function using short exposures.
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Affiliation(s)
- Regine Gradl
- Chair of Biomedical Physics, Department of Physics, Technical University of Munich, James-Franck-Str. 1, 85748, Garching, Germany. .,Munich School of BioEngineering, Technical University of Munich, Boltzmannstr. 11, 85748, Garching, Germany. .,Institute for Advanced Studies, Technical University of Munich, Lichtenbergstrasse 2 a, 85748, Garching, Germany.
| | - Martin Dierolf
- Chair of Biomedical Physics, Department of Physics, Technical University of Munich, James-Franck-Str. 1, 85748, Garching, Germany.,Munich School of BioEngineering, Technical University of Munich, Boltzmannstr. 11, 85748, Garching, Germany
| | - Lorenz Hehn
- Chair of Biomedical Physics, Department of Physics, Technical University of Munich, James-Franck-Str. 1, 85748, Garching, Germany.,Department of Diagnostic and Interventional Radiology, Klinikum rechts der Isar, Technical University of Munich, Ismaninger Str. 22, 81675, München, Germany
| | - Benedikt Günther
- Chair of Biomedical Physics, Department of Physics, Technical University of Munich, James-Franck-Str. 1, 85748, Garching, Germany.,Munich School of BioEngineering, Technical University of Munich, Boltzmannstr. 11, 85748, Garching, Germany.,Max-Plank-Institute for Quantum Optics, Hans-Kopfermannstr. 1, 85748, Garching, Germany
| | - Ali Önder Yildirim
- Comprehensive Pneumologie Center (CPC), Institute of Lung Biology and Disease, Helmholtz Zentrum München, Member of the German Lung Center for Lung Research (DZL), Ingolstädter Landstr. 1, 85764, Neuherberg, Germany
| | - Bernhard Gleich
- Munich School of BioEngineering, Technical University of Munich, Boltzmannstr. 11, 85748, Garching, Germany
| | - Klaus Achterhold
- Chair of Biomedical Physics, Department of Physics, Technical University of Munich, James-Franck-Str. 1, 85748, Garching, Germany.,Munich School of BioEngineering, Technical University of Munich, Boltzmannstr. 11, 85748, Garching, Germany
| | - Franz Pfeiffer
- Chair of Biomedical Physics, Department of Physics, Technical University of Munich, James-Franck-Str. 1, 85748, Garching, Germany.,Munich School of BioEngineering, Technical University of Munich, Boltzmannstr. 11, 85748, Garching, Germany.,Institute for Advanced Studies, Technical University of Munich, Lichtenbergstrasse 2 a, 85748, Garching, Germany.,Department of Diagnostic and Interventional Radiology, Klinikum rechts der Isar, Technical University of Munich, Ismaninger Str. 22, 81675, München, Germany
| | - Kaye Susannah Morgan
- Chair of Biomedical Physics, Department of Physics, Technical University of Munich, James-Franck-Str. 1, 85748, Garching, Germany.,Institute for Advanced Studies, Technical University of Munich, Lichtenbergstrasse 2 a, 85748, Garching, Germany.,School of Physics and Astronomy, Monash University, Clayton, Victoria, 3800, Australia
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28
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High-resolution short-exposure small-animal laboratory x-ray phase-contrast tomography. Sci Rep 2016; 6:39074. [PMID: 27958376 PMCID: PMC5153650 DOI: 10.1038/srep39074] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2016] [Accepted: 11/17/2016] [Indexed: 01/06/2023] Open
Abstract
X-ray computed tomography of small animals and their organs is an essential tool in basic and preclinical biomedical research. In both phase-contrast and absorption tomography high spatial resolution and short exposure times are of key importance. However, the observable spatial resolutions and achievable exposure times are presently limited by system parameters rather than more fundamental constraints like, e.g., dose. Here we demonstrate laboratory tomography with few-ten μm spatial resolution and few-minute exposure time at an acceptable dose for small-animal imaging, both with absorption contrast and phase contrast. The method relies on a magnifying imaging scheme in combination with a high-power small-spot liquid-metal-jet electron-impact source. The tomographic imaging is demonstrated on intact mouse, phantoms and excised lungs, both healthy and with pulmonary emphysema.
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29
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Potential of compact Compton sources in the medical field. Phys Med 2016; 32:1790-1794. [DOI: 10.1016/j.ejmp.2016.11.003] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/07/2016] [Revised: 08/02/2016] [Accepted: 11/01/2016] [Indexed: 11/21/2022] Open
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30
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Eggl E, Dierolf M, Achterhold K, Jud C, Günther B, Braig E, Gleich B, Pfeiffer F. The Munich Compact Light Source: initial performance measures. JOURNAL OF SYNCHROTRON RADIATION 2016; 23:1137-42. [PMID: 27577768 DOI: 10.1107/s160057751600967x] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/22/2016] [Accepted: 06/15/2016] [Indexed: 05/20/2023]
Abstract
While large-scale synchrotron sources provide a highly brilliant monochromatic X-ray beam, these X-ray sources are expensive in terms of installation and maintenance, and require large amounts of space due to the size of storage rings for GeV electrons. On the other hand, laboratory X-ray tube sources can easily be implemented in laboratories or hospitals with comparatively little cost, but their performance features a lower brilliance and a polychromatic spectrum creates problems with beam hardening artifacts for imaging experiments. Over the last decade, compact synchrotron sources based on inverse Compton scattering have evolved as one of the most promising types of laboratory-scale X-ray sources: they provide a performance and brilliance that lie in between those of large-scale synchrotron sources and X-ray tube sources, with significantly reduced financial and spatial requirements. These sources produce X-rays through the collision of relativistic electrons with infrared laser photons. In this study, an analysis of the performance, such as X-ray flux, source size and spectra, of the first commercially sold compact light source, the Munich Compact Light Source, is presented.
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Affiliation(s)
- Elena Eggl
- Physik-Department und Institut für Medizintechnik, Technische Universität München, James-Franck-Straße 1, 85748 Garching, Germany
| | - Martin Dierolf
- Physik-Department und Institut für Medizintechnik, Technische Universität München, James-Franck-Straße 1, 85748 Garching, Germany
| | - Klaus Achterhold
- Physik-Department und Institut für Medizintechnik, Technische Universität München, James-Franck-Straße 1, 85748 Garching, Germany
| | - Christoph Jud
- Physik-Department und Institut für Medizintechnik, Technische Universität München, James-Franck-Straße 1, 85748 Garching, Germany
| | - Benedikt Günther
- Physik-Department und Institut für Medizintechnik, Technische Universität München, James-Franck-Straße 1, 85748 Garching, Germany
| | - Eva Braig
- Physik-Department und Institut für Medizintechnik, Technische Universität München, James-Franck-Straße 1, 85748 Garching, Germany
| | - Bernhard Gleich
- Institut für Medizintechnik, Technische Universität München, Boltzmannstraße 11, 85748 Garching, Germany
| | - Franz Pfeiffer
- Physik-Department und Institut für Medizintechnik, Technische Universität München, James-Franck-Straße 1, 85748 Garching, Germany
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31
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Radiation therapy at compact Compton sources. Phys Med 2015; 31:596-600. [DOI: 10.1016/j.ejmp.2015.02.010] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/20/2014] [Revised: 01/27/2015] [Accepted: 02/16/2015] [Indexed: 11/21/2022] Open
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32
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X-ray phase-contrast tomography with a compact laser-driven synchrotron source. Proc Natl Acad Sci U S A 2015; 112:5567-72. [PMID: 25902493 DOI: 10.1073/pnas.1500938112] [Citation(s) in RCA: 74] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
Between X-ray tubes and large-scale synchrotron sources, a large gap in performance exists with respect to the monochromaticity and brilliance of the X-ray beam. However, due to their size and cost, large-scale synchrotrons are not available for more routine applications in small and medium-sized academic or industrial laboratories. This gap could be closed by laser-driven compact synchrotron light sources (CLS), which use an infrared (IR) laser cavity in combination with a small electron storage ring. Hard X-rays are produced through the process of inverse Compton scattering upon the intersection of the electron bunch with the focused laser beam. The produced X-ray beam is intrinsically monochromatic and highly collimated. This makes a CLS well-suited for applications of more advanced--and more challenging--X-ray imaging approaches, such as X-ray multimodal tomography. Here we present, to our knowledge, the first results of a first successful demonstration experiment in which a monochromatic X-ray beam from a CLS was used for multimodal, i.e., phase-, dark-field, and attenuation-contrast, X-ray tomography. We show results from a fluid phantom with different liquids and a biomedical application example in the form of a multimodal CT scan of a small animal (mouse, ex vivo). The results highlight particularly that quantitative multimodal CT has become feasible with laser-driven CLS, and that the results outperform more conventional approaches.
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33
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Li JX, Hatsagortsyan KZ, Keitel CH. Robust signatures of quantum radiation reaction in focused ultrashort laser pulses. PHYSICAL REVIEW LETTERS 2014; 113:044801. [PMID: 25105623 DOI: 10.1103/physrevlett.113.044801] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/15/2014] [Indexed: 06/03/2023]
Abstract
Radiation-reaction effects in the interaction of an electron bunch with a superstrong focused ultrashort laser pulse are investigated in the quantum radiation-dominated regime. The angle-resolved Compton scattering spectra are calculated in laser pulses of variable duration using a semiclassical description for the radiation-dominated dynamics and a full quantum treatment for the emitted radiation. In dependence of the laser-pulse duration we find signatures of quantum radiation reaction in the radiation spectra, which are characteristic for the focused laser beam and visible in the qualitative behavior of both the angular spread and the spectral bandwidth of the radiation spectra. The signatures are robust with respect to the variation of the electron and laser-beam parameters in a large range. Qualitatively, they differ fully from those in the classical radiation-reaction regime and are measurable with presently available laser technology.
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Affiliation(s)
- Jian-Xing Li
- Max-Planck-Institut für Kernphysik, Saupfercheckweg 1, 69029 Heidelberg, Germany
| | | | - Christoph H Keitel
- Max-Planck-Institut für Kernphysik, Saupfercheckweg 1, 69029 Heidelberg, Germany
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34
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Cunningham JA, Rahman IA, Lautenschlager S, Rayfield EJ, Donoghue PCJ. A virtual world of paleontology. Trends Ecol Evol 2014; 29:347-57. [PMID: 24821516 DOI: 10.1016/j.tree.2014.04.004] [Citation(s) in RCA: 151] [Impact Index Per Article: 15.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2013] [Revised: 03/26/2014] [Accepted: 04/08/2014] [Indexed: 11/28/2022]
Abstract
Computer-aided visualization and analysis of fossils has revolutionized the study of extinct organisms. Novel techniques allow fossils to be characterized in three dimensions and in unprecedented detail. This has enabled paleontologists to gain important insights into their anatomy, development, and preservation. New protocols allow more objective reconstructions of fossil organisms, including soft tissues, from incomplete remains. The resulting digital reconstructions can be used in functional analyses, rigorously testing long-standing hypotheses regarding the paleobiology of extinct organisms. These approaches are transforming our understanding of long-studied fossil groups, and of the narratives of organismal and ecological evolution that have been built upon them.
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Affiliation(s)
- John A Cunningham
- School of Earth Sciences, University of Bristol, Wills Memorial Building, Queen's Road, Bristol BS8 1RJ, UK
| | - Imran A Rahman
- School of Earth Sciences, University of Bristol, Wills Memorial Building, Queen's Road, Bristol BS8 1RJ, UK
| | - Stephan Lautenschlager
- School of Earth Sciences, University of Bristol, Wills Memorial Building, Queen's Road, Bristol BS8 1RJ, UK
| | - Emily J Rayfield
- School of Earth Sciences, University of Bristol, Wills Memorial Building, Queen's Road, Bristol BS8 1RJ, UK.
| | - Philip C J Donoghue
- School of Earth Sciences, University of Bristol, Wills Memorial Building, Queen's Road, Bristol BS8 1RJ, UK.
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35
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Terzić B, Deitrick K, Hofler AS, Krafft GA. Narrow-band emission in Thomson sources operating in the high-field regime. PHYSICAL REVIEW LETTERS 2014; 112:074801. [PMID: 24579606 DOI: 10.1103/physrevlett.112.074801] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/24/2013] [Indexed: 06/03/2023]
Abstract
We present a novel and quite general analysis of the interaction of a high-field chirped laser pulse and a relativistic electron, in which exquisite control of the spectral brilliance of the up-shifted Thomson-scattered photon is shown to be possible. Normally, when Thomson scattering occurs at high field strengths, there is ponderomotive line broadening in the scattered radiation. This effect makes the bandwidth too large for some applications and reduces the spectral brilliance. We show that such broadening can be corrected and eliminated by suitable frequency modulation of the incident laser pulse. Furthermore, we suggest a practical realization of this compensation idea in terms of a chirped-beam-driven free electron laser oscillator configuration and show that significant compensation can occur, even with the imperfect matching to be expected in these conditions.
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Affiliation(s)
| | - Kirsten Deitrick
- Center for Accelerator Science, Old Dominion University, Norfolk, Virginia 23539, USA
| | | | - Geoffrey A Krafft
- Jefferson Lab, Newport News, Virginia 23606, USA and Center for Accelerator Science, Old Dominion University, Norfolk, Virginia 23539, USA
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