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Paternò G, Cardarelli P, Fantoni S, Masoumi F, Mettivier G, Cialdi S, Taibi A. Effect of the local energy distribution of x-ray beams generated through inverse Compton scattering in dual-energy imaging applications. APPLIED OPTICS 2023; 62:4399-4408. [PMID: 37707130 DOI: 10.1364/ao.489239] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/09/2023] [Accepted: 05/07/2023] [Indexed: 09/15/2023]
Abstract
X-ray sources based on the inverse Compton interaction between a laser and a relativistic electron beam are emerging as a promising compact alternative to synchrotron for the production of intense monochromatic and tunable radiation. The emission characteristics enable several innovative imaging techniques, including dual-energy K-edge subtraction (KES) imaging. The performance of these techniques is optimal in the case of perfectly monochromatic x-ray beams, and the implementation of KES was proven to be very effective with synchrotron radiation. Nonetheless, the features of inverse Compton scattering (ICS) sources make them good candidates for a more compact implementation of KES techniques. The energy and intensity distribution of the emitted radiation is related to the emission direction, which means different beam qualities in different spatial positions. In fact, as the polar angle increases, the average energy decreases, while the local energy bandwidth increases and the emission intensity decreases. The scope of this work is to describe the impact of the local energy distribution variations on KES imaging performance. By means of analytical simulations, the reconstructed signal, signal-to-noise ratio, and background contamination were evaluated as a function of the position of each detector pixel. The results show that KES imaging is possible with ICS x-ray beams, even if the image quality slightly degrades at the detector borders for a fixed collimation angle and, in general, as the beam divergence increases. Finally, an approach for the optimization of specific imaging tasks is proposed by considering the characteristics of a given source.
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2
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A High-Energy and High-Intensity Inverse Compton Scattering Source Based on CompactLight Technology. PHOTONICS 2022. [DOI: 10.3390/photonics9050308] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
An inverse Compton scattering source based on the CompactLight injector and capable of producing MeV gamma-rays with a brilliance several orders of magnitude larger than existing sources is proposed. The CompactLight injector can operate at a bunch repetition rate of 1 kHz, with trains of 50 bunches and a bunch spacing of 5 ns, giving a maximum total flux of 8.62 × 1011 photons/s. For a normalised emittance of 0.3 mm mrad, an average brilliance of 1.85 × 1014 photons/(s mm2 mrad2 0.1%BW) could be obtained. A 1 kW colliding laser was considered, corresponding to a laser pulse energy of 50 mJ. Given the electron beam energy up to 300 MeV provided by the CompactLight photoinjector, a maximum photon energy of 2 MeV is obtained. Simulations of inverse Compton scattering were performed using the RF-Track particle tracking software. Parametric scans were used to derive the electron and laser spot sizes maximising the total flux. The accelerator optic components were also determined from the final focus design, which was optimised for a micrometer-level electron beam size at the interaction point. Given a maximum total flux in the order of 1012 photons/s and a maximum output photon energy in the MeV range, the proposed source could be used for various applications, including X-ray imaging.
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Effarah HH, Reutershan T, Lagzda A, Hwang Y, Hartemann FV, Barty CPJ. Computational method for the optimization of quasimonoenergetic laser Compton x-ray sources for imaging applications. APPLIED OPTICS 2022; 61:C143-C153. [PMID: 35201039 PMCID: PMC10619704 DOI: 10.1364/ao.444307] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/18/2021] [Accepted: 02/03/2022] [Indexed: 06/14/2023]
Abstract
The development of compact quasimonoenergetic x-ray radiation sources based on laser Compton scattering (LCS) offers opportunities for novel approaches to medical imaging. However, careful experimental design is required to fully utilize the angle-correlated x-ray spectra produced by LCS sources. Direct simulations of LCS x-ray spectra are computationally expensive and difficult to employ in experimental optimization. In this manuscript, we present a computational method that fully characterizes angle-correlated LCS x-ray spectra at any end point energy within a range defined by three direct simulations. With this approach, subsequent LCS x-ray spectra can be generated with up to 200 times less computational overhead.
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Affiliation(s)
- Haytham H. Effarah
- Department of Physics and Astronomy, University of California – Irvine, Irvine, CA, 92617, USA
- Beckman Laser Institute and Medical Clinic, University of California – Irvine, Irvine, CA 92612, USA
| | - Trevor Reutershan
- Department of Physics and Astronomy, University of California – Irvine, Irvine, CA, 92617, USA
- Beckman Laser Institute and Medical Clinic, University of California – Irvine, Irvine, CA 92612, USA
| | - Agnese Lagzda
- Lumitron Technologies, Inc., 5201 California Ave, Suite 100, Irvine, CA, 92617, USA
| | - Yoonwoo Hwang
- Lumitron Technologies, Inc., 5201 California Ave, Suite 100, Irvine, CA, 92617, USA
| | - Fred V. Hartemann
- Lumitron Technologies, Inc., 5201 California Ave, Suite 100, Irvine, CA, 92617, USA
| | - C. P. J. Barty
- Department of Physics and Astronomy, University of California – Irvine, Irvine, CA, 92617, USA
- Beckman Laser Institute and Medical Clinic, University of California – Irvine, Irvine, CA 92612, USA
- Lumitron Technologies, Inc., 5201 California Ave, Suite 100, Irvine, CA, 92617, USA
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4
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Reutershan T, Effarah HH, Lagzda A, Barty CPJ. Numerical evaluation of high-energy, laser-Compton x-ray sources for contrast enhancement and dose reduction in clinical imaging via gadolinium-based K-edge subtraction. APPLIED OPTICS 2022; 61:C162-C178. [PMID: 35201049 PMCID: PMC10619702 DOI: 10.1364/ao.446189] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/18/2021] [Accepted: 02/03/2022] [Indexed: 06/14/2023]
Abstract
Conventional x-ray sources for medical imaging utilize bremsstrahlung radiation. These sources generate large bandwidth (BW) x-ray spectra with large fractions of photons that impart a dose, but do not contribute to image production. X-ray sources based on laser-Compton scattering can have inherently small energy BWs and can be tuned to low dose-imparting energies, allowing them to take advantage of atomic K-edge contrast enhancement. This paper investigates the use of gadolinium-based K-edge subtraction imaging in the context of mammography using a laser-Compton source through simulations quantifying contrast and dose in such imaging systems as a function of laser-Compton source parameters. Our simulations indicate that a K-edge subtraction image generated with a 0.5% BW (FWHM) laser-Compton x-ray source can obtain an equal contrast to a bremsstrahlung image with only 3% of the dose.
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Affiliation(s)
- Trevor Reutershan
- Department of Physics and Astronomy, University of California – Irvine, CA, 92617
- Beckman Laser Institute and Medical Clinic, University of California – Irvine, CA, 92697
| | - Haytham H. Effarah
- Department of Physics and Astronomy, University of California – Irvine, CA, 92617
- Beckman Laser Institute and Medical Clinic, University of California – Irvine, CA, 92697
| | - Agnese Lagzda
- Lumitron Technologies, Inc., 5201 California Ave, Suite 100, Irvine, CA, 92617, USA
| | - C. P. J. Barty
- Department of Physics and Astronomy, University of California – Irvine, CA, 92617
- Beckman Laser Institute and Medical Clinic, University of California – Irvine, CA, 92697
- Lumitron Technologies, Inc., 5201 California Ave, Suite 100, Irvine, CA, 92617, USA
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5
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Sung JH, Chang JH. Mechanically Rotating Intravascular Ultrasound (IVUS) Transducer: A Review. SENSORS (BASEL, SWITZERLAND) 2021; 21:3907. [PMID: 34198822 PMCID: PMC8201242 DOI: 10.3390/s21113907] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/30/2021] [Revised: 05/31/2021] [Accepted: 06/03/2021] [Indexed: 12/30/2022]
Abstract
Intravascular ultrasound (IVUS) is a valuable imaging modality for the diagnosis of atherosclerosis. It provides useful clinical information, such as lumen size, vessel wall thickness, and plaque composition, by providing a cross-sectional vascular image. For several decades, IVUS has made remarkable progress in improving the accuracy of diagnosing cardiovascular disease that remains the leading cause of death globally. As the quality of IVUS images mainly depends on the performance of the IVUS transducer, various IVUS transducers have been developed. Therefore, in this review, recently developed mechanically rotating IVUS transducers, especially ones exploiting piezoelectric ceramics or single crystals, are discussed. In addition, this review addresses the history and technical challenges in the development of IVUS transducers and the prospects of next-generation IVUS transducers.
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Affiliation(s)
| | - Jin-Ho Chang
- Department of Information and Communication Engineering, Deagu Gyeongbuk Institute of Science and Technology, Daegu 42988, Korea;
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6
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Silver EH, Shulman SD, Rehani MM. Innovative monochromatic x-ray source for high-quality and low-dose medical imaging. Med Phys 2021; 48:1064-1078. [PMID: 33368354 DOI: 10.1002/mp.14677] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2020] [Revised: 12/14/2020] [Accepted: 12/14/2020] [Indexed: 02/02/2023] Open
Abstract
PURPOSE An estimated 377 million diagnostic and interventional radiological exams are performed annually in the United States and approximately 4 to 5 billion globally. All use x-ray tubes that emit x-rays over a broad energy band, a technology that is more than a century old. Only a small fraction of the radiation is useful for imaging while the remaining fraction either increases the radiation dose received by the patient or degrades the image. Monochromatic x-rays can provide lower dose images in many of these radiological applications while maintaining or improving image quality. We report the development of the first monochromatic x-ray source suitable for low-dose, high-quality imaging in the clinic and demonstrate its first application and performance with mammography phantoms. METHODS X-ray fluorescence was used to generate monochromatic x-rays with selectable energies from 18 to 60 keV. This patented technology was incorporated into a laboratory prototype of a monochromatic x-ray mammography system. Image quality was evaluated as a function of radiation dose in standard breast phantoms using the signal-to-noise ratio (SNR) measured for high and low contrast masses and microcalcifications. Spatial imaging properties were assessed from these images as well as from modulation transfer function (MTF) analysis. Measurements using an iodine contrast agent were also performed. The results were compared to those obtained using a commercially available, conventional x-ray mammography system. RESULTS Our prototype system reduced radiation dose by factors of five to ten times for the same SNRs as obtained from the conventional system. This performance was demonstrated in phantoms simulating a wide range of lesion sizes and microcalcifications in a variety of breast thicknesses. The high SNRs for very thick breast phantoms provide evidence that screening with less breast compression is possible while maintaining image quality. Contrast-enhanced digital mammography (CEDM) with monochromatic x-rays was shown to provide a simpler and more effective technique at substantially lower radiation dose. The MTF value at 20% was 9 lp/mm. CONCLUSIONS The monochromatic x-ray system is more sensitive for imaging a wide range of breast sizes and compositions than conventional broadband mammography. High image quality and lower dose are its hallmarks. It also makes CEDM much more effective than current methods developed for use with conventional broadband mammography systems.
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Affiliation(s)
- Eric H Silver
- Imagine Scientific, Inc., 90 Kerry Place, Norwood, MA, 02062, USA
| | - Seth D Shulman
- Imagine Scientific, Inc., 90 Kerry Place, Norwood, MA, 02062, USA
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7
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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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8
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Functional lung imaging with synchrotron radiation: Methods and preclinical applications. Phys Med 2020; 79:22-35. [PMID: 33070047 DOI: 10.1016/j.ejmp.2020.10.001] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/09/2020] [Revised: 09/30/2020] [Accepted: 10/03/2020] [Indexed: 01/05/2023] Open
Abstract
Many lung disease processes are characterized by structural and functional heterogeneity that is not directly appreciable with traditional physiological measurements. Experimental methods and lung function modeling to study regional lung function are crucial for better understanding of disease mechanisms and for targeting treatment. Synchrotron radiation offers useful properties to this end: coherence, utilized in phase-contrast imaging, and high flux and a wide energy spectrum which allow the selection of very narrow energy bands of radiation, thus allowing imaging at very specific energies. K-edge subtraction imaging (KES) has thus been developed at synchrotrons for both human and small animal imaging. The unique properties of synchrotron radiation extend X-ray computed tomography (CT) capabilities to quantitatively assess lung morphology, and also to map regional lung ventilation, perfusion, inflammation and biomechanical properties, with microscopic spatial resolution. Four-dimensional imaging, allows the investigation of the dynamics of regional lung functional parameters simultaneously with structural deformation of the lung as a function of time. This review summarizes synchrotron radiation imaging methods and overviews examples of its application in the study of disease mechanisms in preclinical animal models, as well as the potential for clinical translation both through the knowledge gained using these techniques and transfer of imaging technology to laboratory X-ray sources.
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9
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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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10
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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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Kulpe S, Dierolf M, Günther B, Brantl J, Busse M, Achterhold K, Gleich B, Pfeiffer F, Pfeiffer D. Dynamic K-edge Subtraction Fluoroscopy at a Compact Inverse-Compton Synchrotron X-ray Source. Sci Rep 2020; 10:9612. [PMID: 32541788 PMCID: PMC7295988 DOI: 10.1038/s41598-020-66414-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2020] [Accepted: 05/20/2020] [Indexed: 11/09/2022] Open
Abstract
X-ray fluoroscopy is a commonly applied diagnostic tool for morphological and functional evaluation of the intestine in clinical routine. Acquisition of repetitive X-ray images following oral or rectal application of iodine contrast agent visualizes the time dependent distribution of the contrast medium, and helps to detect for example leakages, tumors or functional disorders. However, movements of the intestine and air trapped inside usually prevent temporal subtraction imaging to be applied to fluoroscopy of the gastrointestinal tract. K-edge subtraction (KES) imaging would enable subtraction fluoroscopy because it allows for imaging of moving organs with little artefacts. Although KES imaging is a well established technique at synchrotron sources, this imaging method is not applied in clinical routine as it relies on brilliant synchrotron radiation. Recently emerging compact synchrotron X-ray sources could provide a quasi-monochromatic, high-flux X-ray beam and allow for the application of KES in a laboratory environment. Here, we present a filter-based dynamic KES approach at the Munich Compact Light Source (MuCLS), the first user-dedicated installation of a compact synchrotron X-ray source worldwide. Compared to conventional temporal subtraction X-ray radiography, our approach increases the contrast while reducing the generated image artefacts.
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Affiliation(s)
- Stephanie Kulpe
- 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.
| | - 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
| | - 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
| | - Johannes Brantl
- 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
| | - Madleen Busse
- 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
| | - 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
| | - Bernhard Gleich
- 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.,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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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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Brun F, Di Trapani V, Albers J, Sacco P, Dreossi D, Brombal L, Rigon L, Longo R, Mittone A, Dullin C, Bravin A, Delogu P. Single-shot K-edge subtraction x-ray discrete computed tomography with a polychromatic source and the Pixie-III detector. Phys Med Biol 2020; 65:055016. [PMID: 31995530 DOI: 10.1088/1361-6560/ab7105] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
K-edge subtraction (KES) imaging is a technique able to map a specific element such as e.g. a contrast agent within the tissues, by exploiting the sharp rise of its absorption coefficient at the K-edge energy. Whereas mainly explored at synchrotron radiation sources, the energy discrimination properties of modern x-ray photon counting detectors (XPCDs) pave the way for an implementation of single-shot KES imaging with conventional polychromatic sources. In this work we present an x-ray CT imaging system based on the innovative Pixie-III detector and discrete reconstruction. The results reported here show that a reliable automatic localization of Barium (above a certain concentration) is possible with a few dozens of tomographic projections for a volume having an axial slice of 512 [Formula: see text] 512 pixels. The final application is a routine high-fidelity 3D mapping of a specific element ready for further morphological quantification by means of x-ray CT with potential promising applications in vivo.
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Affiliation(s)
- Francesco Brun
- Department of Engineering and Architecture, University of Trieste, Trieste, Italy. National Institute for Nuclear Physics (INFN), Trieste Division, Italy
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14
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Heck L, Dierolf M, Jud C, Eggl E, Sellerer T, Mechlem K, Günther B, Achterhold K, Gleich B, Metz S, Pfeiffer D, Kröninger K, Herzen J. Contrast-enhanced spectral mammography with a compact synchrotron source. PLoS One 2019; 14:e0222816. [PMID: 31600236 PMCID: PMC6786764 DOI: 10.1371/journal.pone.0222816] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2019] [Accepted: 09/06/2019] [Indexed: 11/18/2022] Open
Abstract
For early breast cancer detection, mammography is nowadays the commonly used standard imaging approach, offering a valuable clinical tool for visualization of suspicious findings like microcalcifications and tumors within the breast. However, due to the superposition of anatomical structures, the sensitivity of mammography screening is limited. Within the last couple of years, the implementation of contrast-enhanced spectral mammography (CESM) based on K-edge subtraction (KES) imaging helped to improve the identification and classification of uncertain findings. In this study, we introduce another approach for CESM based on a two-material decomposition, with which we expect fundamental improvements compared to the clinical procedure. We demonstrate the potential of our proposed method using the quasi-monochromatic radiation of a compact synchrotron source-the Munich Compact Light Source (MuCLS)-and a modified mammographic accreditation phantom. For direct comparison with the clinical CESM approach, we also performed a standard dual-energy KES at the MuCLS, which outperformed the clinical CESM images in terms of contrast-to-noise ratio (CNR) and spatial resolution. However, the dual-energy-based two-material decomposition approach achieved even higher CNR values. Our experimental results with quasi-monochromatic radiation show a significant improvement of the image quality at lower mean glandular dose (MGD) than the clinical CESM. At the same time, our study indicates the great potential for the material-decomposition instead of clinically used KES to improve the quantitative outcome of CESM.
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Affiliation(s)
- Lisa Heck
- Chair of Biomedical Physics, Department of Physics and Munich School of BioEngineering, Technical University of Munich, 85748 Garching, Germany
- Chair for Experimental Physics IV, TU Dortmund University, 44221 Dortmund, Germany
- * E-mail:
| | - Martin Dierolf
- Chair of Biomedical Physics, Department of Physics and Munich School of BioEngineering, Technical University of Munich, 85748 Garching, Germany
| | - Christoph Jud
- Chair of Biomedical Physics, Department of Physics and Munich School of BioEngineering, Technical University of Munich, 85748 Garching, Germany
| | - Elena Eggl
- Chair of Biomedical Physics, Department of Physics and Munich School of BioEngineering, Technical University of Munich, 85748 Garching, Germany
| | - Thorsten Sellerer
- Chair of Biomedical Physics, Department of Physics and Munich School of BioEngineering, Technical University of Munich, 85748 Garching, Germany
| | - Korbinian Mechlem
- Chair of Biomedical Physics, Department of Physics and Munich School of BioEngineering, Technical University of Munich, 85748 Garching, Germany
- Department of Diagnostic and Interventional Radiology, School of Medicine & Klinikum rechts der Isar, Technical University of Munich, 81675 München, Germany
| | - Benedikt Günther
- Chair of Biomedical Physics, Department of Physics and Munich School of BioEngineering, Technical University of Munich, 85748 Garching, Germany
| | - Klaus Achterhold
- Chair of Biomedical Physics, Department of Physics and Munich School of BioEngineering, Technical University of Munich, 85748 Garching, Germany
| | - Bernhard Gleich
- Chair of Biomedical Physics, Department of Physics and Munich School of BioEngineering, Technical University of Munich, 85748 Garching, Germany
| | - Stephan Metz
- Department of Diagnostic and Interventional Radiology, School of Medicine & Klinikum rechts der Isar, Technical University of Munich, 81675 München, Germany
| | - Daniela Pfeiffer
- Department of Diagnostic and Interventional Radiology, School of Medicine & Klinikum rechts der Isar, Technical University of Munich, 81675 München, Germany
| | - Kevin Kröninger
- Chair for Experimental Physics IV, TU Dortmund University, 44221 Dortmund, Germany
| | - Julia Herzen
- Chair of Biomedical Physics, Department of Physics and Munich School of BioEngineering, Technical University of Munich, 85748 Garching, Germany
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15
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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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Paternò G, Cardarelli P, Gambaccini M, Serafini L, Petrillo V, Drebot I, Taibi A. Inverse Compton radiation: a novel x-ray source for K-edge subtraction angiography? Phys Med Biol 2019; 64:185002. [PMID: 31307026 DOI: 10.1088/1361-6560/ab325c] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Coronary angiography is clinically used worldwide to diagnose diseases of coronary arteries. Despite its effectiveness, this technique is quite invasive and it is associated with significant risks due to the arterial catheterisation needed to inject the contrast agent. A valid alternative is using the K-edge subtraction (KES) method, which is based on the subtraction of two images acquired at energies bracketing the K-edge of the contrast element. The enhanced sensitivity of KES allows the intravenous injection of the contrast agent, thus reducing the risks of catheterisation. This technique can be effectively implemented by using intense and quasi-monochromatic x-ray beams. Synchrotron radiation has been proven to work well for this purpose, but its cost and size prevent a widespread clinical application. Inverse Compton sources are among the most promising innovative sources of intense and quasi-monochromatic x-rays. These sources are intrinsically more compact than those based on synchrotron radiation. In this work, the potential application of inverse Compton radiation to KES angiography is investigated. To this purpose, after a short review of the physics behind the inverse Compton process, an analytical framework is described. The proposed model is based on the application of the KES algorithm to calculate the SNR of details inside a suitable mathematical phantom. That allowed us to identify the characteristics of an inverse Compton source required for KES imaging. In particular, it was estimated that a photon fluence of 108 ph mm-2 is necessary to detect signals of clinical interest. Novel sources based on inverse Compton promise to achieve this requirement with an acquisition time of few hundreds of ms. This feature, together with compactness, broad two-dimensional radiation field, absence of harmonic contamination and the ability to deliver high photon fluxes also at high energies, makes this kind of sources promising for KES angiography and other diagnostic applications.
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Affiliation(s)
- G Paternò
- Dipartimento di Fisica e Scienze della Terra, Università di Ferrara, Via G. Saragat 1, 44122 Ferrara, Italy. INFN-Sez. Ferrara, Via G. Saragat 1, 44122 Ferrara, Italy
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