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Brombal L, Arfelli F, Brun F, Di Trapani V, Endrizzi M, Menk RH, Perion P, Rigon L, Saccomano M, Tromba G, Olivo A. Edge-illumination spectral phase-contrast tomography. Phys Med Biol 2024; 69:075027. [PMID: 38471186 PMCID: PMC10991267 DOI: 10.1088/1361-6560/ad3328] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2023] [Revised: 02/23/2024] [Accepted: 03/12/2024] [Indexed: 03/14/2024]
Abstract
Following the rapid, but independent, diffusion of x-ray spectral and phase-contrast systems, this work demonstrates the first combination of spectral and phase-contrast computed tomography (CT) obtained by using the edge-illumination technique and a CdTe small-pixel (62μm) spectral detector. A theoretical model is introduced, starting from a standard attenuation-based spectral decomposition and leading to spectral phase-contrast material decomposition. Each step of the model is followed by quantification of accuracy and sensitivity on experimental data of a test phantom containing different solutions with known concentrations. An example of a micro CT application (20μm voxel size) on an iodine-perfusedex vivomurine model is reported. The work demonstrates that spectral-phase contrast combines the advantages of spectral imaging, i.e. high-Zmaterial discrimination capability, and phase-contrast imaging, i.e. soft tissue sensitivity, yielding simultaneously mass density maps of water, calcium, and iodine with an accuracy of 1.1%, 3.5%, and 1.9% (root mean square errors), respectively. Results also show a 9-fold increase in the signal-to-noise ratio of the water channel when compared to standard spectral decomposition. The application to the murine model revealed the potential of the technique in the simultaneous 3D visualization of soft tissue, bone, and vasculature. While being implemented by using a broad spectrum (pink beam) at a synchrotron radiation facility (Elettra, Trieste, Italy), the proposed experimental setup can be readily translated to compact laboratory systems including conventional x-ray tubes.
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Affiliation(s)
- Luca Brombal
- Department of Physics, University of Trieste, Via A. Valerio 2, I-34127 Trieste, Italy
- INFN Division of Trieste, Via A. Valerio 2, I-34127 Trieste, Italy
| | - Fulvia Arfelli
- Department of Physics, University of Trieste, Via A. Valerio 2, I-34127 Trieste, Italy
- INFN Division of Trieste, Via A. Valerio 2, I-34127 Trieste, Italy
| | - Francesco Brun
- INFN Division of Trieste, Via A. Valerio 2, I-34127 Trieste, Italy
- Department of Engineering and Architecture, University of Trieste, Via A. Valerio 10, I-34127 Trieste, Italy
| | - Vittorio Di Trapani
- Department of Physics, University of Trieste, Via A. Valerio 2, I-34127 Trieste, Italy
| | - Marco Endrizzi
- Department of Medical Physics and Biomedical Engineering, University College London, Gower Street, GWC1E 6BT, London, United Kingdom
| | - Ralf H Menk
- INFN Division of Trieste, Via A. Valerio 2, I-34127 Trieste, Italy
- Elettra-Sincrotrone Trieste S.C.p.A, I-34149 Basovizza Trieste, Italy
- Department of Computer and Electrical Engineering, Midsweden University, Holmgatan 10, Sundsvall, Sweden
| | - Paola Perion
- Department of Physics, University of Trieste, Via A. Valerio 2, I-34127 Trieste, Italy
- INFN Division of Trieste, Via A. Valerio 2, I-34127 Trieste, Italy
| | - Luigi Rigon
- Department of Physics, University of Trieste, Via A. Valerio 2, I-34127 Trieste, Italy
- INFN Division of Trieste, Via A. Valerio 2, I-34127 Trieste, Italy
| | - Mara Saccomano
- Helmholtz Zentrum München, Helmholtz Pioneer Campus, Ingolstädter Landstraße 1, D-85764 Neuherberg, Germany
| | - Giuliana Tromba
- Elettra-Sincrotrone Trieste S.C.p.A, I-34149 Basovizza Trieste, Italy
| | - Alessandro Olivo
- Department of Medical Physics and Biomedical Engineering, University College London, Gower Street, GWC1E 6BT, London, United Kingdom
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Cai X, Tan Y, Zhang X, Yang J, Xu J, Zheng H, Liang D, Ge Y. Energy resolving dark-field imaging with dual phase grating interferometer. OPTICS EXPRESS 2023; 31:44273-44282. [PMID: 38178502 DOI: 10.1364/oe.503843] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/21/2023] [Accepted: 11/14/2023] [Indexed: 01/06/2024]
Abstract
X-ray dark-filed imaging is a powerful approach to quantify the dimension of micro-structures of the object. Often, a series of dark-filed signals have to be measured under various correlation lengths. For instance, this is often achieved by adjusting the sample positions by multiple times in Talbot-Lau interferometer. Moreover, such multiple measurements can also be collected via adjustments of the inter-space between the phase gratings in dual phase grating interferometer. In this study, the energy resolving capability of the dual phase grating interferometer is explored with the aim to accelerate the data acquisition speed of dark-filed imaging. To do so, both theoretical analyses and numerical simulations are investigated. Specifically, the responses of the dual phase grating interferometer at varied X-ray beam energies are studied. Compared with the mechanical position translation approach, the combination of such energy resolving capability helps to greatly shorten the total dark-field imaging time in dual phase grating interferometer.
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Navarrete-León C, Doherty A, Savvidis S, Gerli MFM, Piredda G, Astolfo A, Bate D, Cipiccia S, Hagen CK, Olivo A, Endrizzi M. X-ray phase-contrast microtomography of soft tissues using a compact laboratory system with two-directional sensitivity. OPTICA 2023; 10:880-887. [PMID: 37841216 PMCID: PMC10575607 DOI: 10.1364/optica.487270] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/07/2023] [Revised: 05/18/2023] [Accepted: 06/01/2023] [Indexed: 10/17/2023]
Abstract
X-ray microtomography is a nondestructive, three-dimensional inspection technique applied across a vast range of fields and disciplines, ranging from research to industrial, encompassing engineering, biology, and medical research. Phase-contrast imaging extends the domain of application of x-ray microtomography to classes of samples that exhibit weak attenuation, thus appearing with poor contrast in standard x-ray imaging. Notable examples are low-atomic-number materials, like carbon-fiber composites, soft matter, and biological soft tissues. We report on a compact and cost-effective system for x-ray phase-contrast microtomography. The system features high sensitivity to phase gradients and high resolution, requires a low-power sealed x-ray tube, a single optical element, and fits in a small footprint. It is compatible with standard x-ray detector technologies: in our experiments, we have observed that single-photon counting offered higher angular sensitivity, whereas flat panels provided a larger field of view. The system is benchmarked against known-material phantoms, and its potential for soft-tissue three-dimensional imaging is demonstrated on small-animal organs: a piglet esophagus and a rat heart. We believe that the simplicity of the setup we are proposing, combined with its robustness and sensitivity, will facilitate accessing quantitative x-ray phase-contrast microtomography as a research tool across disciplines, including tissue engineering, materials science, and nondestructive testing in general.
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Affiliation(s)
- Carlos Navarrete-León
- Department of Medical Physics and Biomedical Engineering, University College London, Gower Street, London, WC1E 6BT, UK
| | - Adam Doherty
- Department of Medical Physics and Biomedical Engineering, University College London, Gower Street, London, WC1E 6BT, UK
| | - Savvas Savvidis
- Department of Medical Physics and Biomedical Engineering, University College London, Gower Street, London, WC1E 6BT, UK
| | - Mattia F. M. Gerli
- UCL Division of Surgery and Interventional Science, Royal Free Hospital, Rowland Hill Street, London, NW3 2PF, UK
- Stem Cell and Regenerative Medicine Section, Great Ormond Street Institute of Child Health, University College London, London, WC1N 1EH, UK
| | - Giovanni Piredda
- Research Center for Microtechnology, Vorarlberg University of Applied Sciences, Hochschulstr. 1, 6850, Dornbirn, Austria
| | - Alberto Astolfo
- Department of Medical Physics and Biomedical Engineering, University College London, Gower Street, London, WC1E 6BT, UK
| | - David Bate
- Department of Medical Physics and Biomedical Engineering, University College London, Gower Street, London, WC1E 6BT, UK
- Nikon X-Tek Systems Ltd, Tring, Herts, HP23 4JX, UK
| | - Silvia Cipiccia
- Department of Medical Physics and Biomedical Engineering, University College London, Gower Street, London, WC1E 6BT, UK
| | - Charlotte K. Hagen
- Department of Medical Physics and Biomedical Engineering, University College London, Gower Street, London, WC1E 6BT, UK
| | - Alessandro Olivo
- Department of Medical Physics and Biomedical Engineering, University College London, Gower Street, London, WC1E 6BT, UK
| | - Marco Endrizzi
- Department of Medical Physics and Biomedical Engineering, University College London, Gower Street, London, WC1E 6BT, UK
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Brombal L, Arfelli F, Menk RH, Rigon L, Brun F. PEPI Lab: a flexible compact multi-modal setup for X-ray phase-contrast and spectral imaging. Sci Rep 2023; 13:4206. [PMID: 36918574 PMCID: PMC10014955 DOI: 10.1038/s41598-023-30316-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2022] [Accepted: 02/21/2023] [Indexed: 03/15/2023] Open
Abstract
This paper presents a new flexible compact multi-modal imaging setup referred to as PEPI (Photon-counting Edge-illumination Phase-contrast imaging) Lab, which is based on the edge-illumination (EI) technique and a chromatic detector. The system enables both X-ray phase-contrast (XPCI) and spectral (XSI) imaging of samples on the centimeter scale. This work conceptually follows all the stages in its realization, from the design to the first imaging results. The setup can be operated in four different modes, i.e. photon-counting/conventional, spectral, double-mask EI, and single-mask EI, whereby the switch to any modality is fast, software controlled, and does not require any hardware modification or lengthy re-alignment procedures. The system specifications, ranging from the X-ray tube features to the mask material and aspect ratio, have been quantitatively studied and optimized through a dedicated Geant4 simulation platform, guiding the choice of the instrumentation. The realization of the imaging setup, both in terms of hardware and control software, is detailed and discussed with a focus on practical/experimental aspects. Flexibility and compactness (66 cm source-to-detector distance in EI) are ensured by dedicated motion stages, whereas spectral capabilities are enabled by the Pixirad-1/Pixie-III detector in combination with a tungsten anode X-ray source operating in the range 40-100 kVp. The stability of the system, when operated in EI, has been verified, and drifts leading to mask misalignment of less than 1 [Formula: see text]m have been measured over a period of 54 h. The first imaging results, one for each modality, demonstrate that the system fulfills its design requirements. Specifically, XSI tomographic images of an iodine-based phantom demonstrate the system's quantitativeness and sensibility to concentrations in the order of a few mg/ml. Planar XPCI images of a carpenter bee specimen, both in single and double-mask modes, demonstrate that refraction sensitivity (below 0.6 [Formula: see text]rad in double-mask mode) is comparable with other XPCI systems based on microfocus sources. Phase CT capabilities have also been tested on a dedicated plastic phantom, where the phase channel yielded a 15-fold higher signal-to-noise ratio with respect to attenuation.
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Affiliation(s)
- Luca Brombal
- Department of Physics, University of Trieste, 34127, Trieste, Italy.,Division of Trieste, National Institute for Nuclear Physics (INFN), 34127, Trieste, Italy
| | - Fulvia Arfelli
- Department of Physics, University of Trieste, 34127, Trieste, Italy.,Division of Trieste, National Institute for Nuclear Physics (INFN), 34127, Trieste, Italy
| | - Ralf Hendrik Menk
- Division of Trieste, National Institute for Nuclear Physics (INFN), 34127, Trieste, Italy. .,Elettra Sincrotrone Trieste S.C.p.A., 34149, Basovizza, TS, Italy.
| | - Luigi Rigon
- Department of Physics, University of Trieste, 34127, Trieste, Italy.,Division of Trieste, National Institute for Nuclear Physics (INFN), 34127, Trieste, Italy
| | - Francesco Brun
- Division of Trieste, National Institute for Nuclear Physics (INFN), 34127, Trieste, Italy.,Department of Engineering and Architecture, University of Trieste, 34127, Trieste, Italy
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Zhang X, Su T, Yang J, Zhu J, Xia D, Zheng H, Liang D, Ge Y. Performance evaluation of dual-energy CT and differential phase contrast CT in quantitative imaging applications. Med Phys 2021; 49:1123-1138. [PMID: 34951037 DOI: 10.1002/mp.15417] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2021] [Revised: 11/29/2021] [Accepted: 11/29/2021] [Indexed: 11/05/2022] Open
Abstract
PURPOSE The purpose of this study is to evaluate and compare the quantitative material decomposition performance of the dual-energy CT (DECT) and differential phase contrast CT (DPCT) via numerical observer studies. METHODS The electron density (ρe ) and the effective atomic number (Zeff ) are selected as the decomposition bases. The image domain based decomposition algorithms with certain noise suppression are used to extract the ρe and Zeff information under three different spatial resolutions (0.3 mm, 0.1 mm, and 0.03 mm). The contrast-to-noise-ratio (CNR) and the numerical human observer model which is sensitive to the noise textures are investigated to compare the quantitative imaging performance of DECT and DPCT under varied radiation dose levels. RESULTS The model observer results show that the DECT is superior to DPCT at 0.3 mm spatial resolution (300 mm object size); the DECT and DPCT show similar quantitative imaging performance at 0.1 mm spatial resolution (100 mm object size); and the DPCT outperforms the DECT by approximately 1.5 times for the 0.3 mm sized imaging target at 0.03 mm spatial resolution (30 mm object size). CONCLUSIONS In conclusion, the DECT would be recommended to obtain ρe and Zeff for the low spatial resolution quantitative imaging applications such as the diagnostic CT imaging. Whereas, the DPCT would be recommended for ultra high spatial resolution imaging tasks of small objects such as the micro-CT imaging. This study provides a reference to determine the most appropriate quantitative X-ray CT imaging method for a certain radiation dose level. This article is protected by copyright. All rights reserved.
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Affiliation(s)
- Xin Zhang
- Key Laboratory of Low-grade Energy Utilization Technologies and Systems of Ministry of Education of China, College of Power Engineering, Chongqing University, Chongqing, 400044, China.,Research Center for Medical Artificial Intelligence, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, 518055, China
| | - Ting Su
- Research Center for Medical Artificial Intelligence, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, 518055, China
| | - Jiecheng Yang
- Research Center for Medical Artificial Intelligence, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, 518055, China
| | - Jiongtao Zhu
- Research Center for Medical Artificial Intelligence, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, 518055, China
| | - Dongmei Xia
- Key Laboratory of Low-grade Energy Utilization Technologies and Systems of Ministry of Education of China, College of Power Engineering, Chongqing University, Chongqing, 400044, China
| | - Hairong Zheng
- Paul C Lauterbur Research Center for Biomedical Imaging, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, 518055, China
| | - Dong Liang
- Research Center for Medical Artificial Intelligence, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, 518055, China.,Paul C Lauterbur Research Center for Biomedical Imaging, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, 518055, China
| | - Yongshuai Ge
- Research Center for Medical Artificial Intelligence, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, 518055, China.,Paul C Lauterbur Research Center for Biomedical Imaging, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, 518055, China
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Birnbacher L, Braig EM, Pfeiffer D, Pfeiffer F, Herzen J. Quantitative X-ray phase contrast computed tomography with grating interferometry : Biomedical applications of quantitative X-ray grating-based phase contrast computed tomography. Eur J Nucl Med Mol Imaging 2021; 48:4171-4188. [PMID: 33846846 PMCID: PMC8566444 DOI: 10.1007/s00259-021-05259-6] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2020] [Accepted: 02/11/2021] [Indexed: 11/25/2022]
Abstract
The ability of biomedical imaging data to be of quantitative nature is getting increasingly important with the ongoing developments in data science. In contrast to conventional attenuation-based X-ray imaging, grating-based phase contrast computed tomography (GBPC-CT) is a phase contrast micro-CT imaging technique that can provide high soft tissue contrast at high spatial resolution. While there is a variety of different phase contrast imaging techniques, GBPC-CT can be applied with laboratory X-ray sources and enables quantitative determination of electron density and effective atomic number. In this review article, we present quantitative GBPC-CT with the focus on biomedical applications.
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Affiliation(s)
- Lorenz Birnbacher
- Physics Department, Munich School of Bioengineering, Technical University of Munich, Munich, Germany
- Department of Diagnostic and Interventional Radiology, School of Medicine, Klinikum rechts der Isar, Technical University of Munich, Munich, Germany
| | - Eva-Maria Braig
- Physics Department, Munich School of Bioengineering, Technical University of Munich, Munich, Germany
| | - Daniela Pfeiffer
- Department of Diagnostic and Interventional Radiology, School of Medicine, Klinikum rechts der Isar, Technical University of Munich, Munich, Germany
| | - Franz Pfeiffer
- Physics Department, Munich School of Bioengineering, Technical University of Munich, Munich, Germany
- Department of Diagnostic and Interventional Radiology, School of Medicine, Klinikum rechts der Isar, Technical University of Munich, Munich, Germany
| | - Julia Herzen
- Physics Department, Munich School of Bioengineering, Technical University of Munich, Munich, Germany.
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Tang R, Li Y, Qin L, Yan F, Yang GY, Chen KM. Phase retrieval-based phase-contrast CT for vascular imaging with microbubble contrast agent. Med Phys 2021; 48:3459-3469. [PMID: 33657645 DOI: 10.1002/mp.14819] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2020] [Revised: 02/15/2021] [Accepted: 02/23/2021] [Indexed: 11/11/2022] Open
Abstract
PURPOSE The introduction of microbubble contrast agent into tissues can create significant phase shifts. Phase retrieval (PR)-based phase-contrast computed tomography (PCCT) is an imaging method for retrieving and reconstructing the phase shifts within an object. This study aimed to evaluate the feasibility of PR-based PCCT with microbubble contrast agent for vascular imaging. METHODS Projection phase-contrast images of individual microbubbles and a cluster of microbubbles were captured and compared. Contrast enhancement from microbubbles was evaluated by comparing to the gold standard iodine-based contrast agent in vitro. The arterial systems of 14 Sprague-Dawley rats were perfused with microbubbles or saline. The rat hearts and the arterial systems were excised and imaged ex vivo. CT imaging was performed at the energy of 22 keV. PR was performed using the phase-attenuation duality (PAD) method with different δ/β values (PAD property). The contrast-to-noise ratio (CNR) was used for quantitatively assessing the contrast enhancement. RESULTS Individual microbubbles functioned as a lens to focus the x rays, whereas, a cluster of microbubbles scattered the x rays. In the in vitro experiment, the contrast enhancement from iodine was significantly greater than that from microbubbles (P < 0.05). In the heart samples, the CNRs for microbubbles on PR-based PCCT were significantly greater than those on absorption-contrast CT (ACCT) and PR-free PCCT (both P < 0.001). The CNRs for microbubbles were also significantly greater than those for saline on PR-based PCCT in the samples (P < 0.001). Although they provided weaker contrast enhancement than that from iodine, microbubbles could still provide sufficient contrast enhancement to clearly show the 3D architecture of rat aortas and their main branches. CONCLUSION The imaging modality can currently be used as a complement or alternative to absorption-based microCT for imaging vessels in biological samples.
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Affiliation(s)
- Rongbiao Tang
- Department of Radiology, Rui Jin Hospital, Shanghai Jiao Tong University, and School of Medicine, Shanghai, China
| | - Yongfang Li
- Department of Neurology, Rui Jin Hospital, Shanghai Jiao Tong University, and School of Medicine, Shanghai, China
| | - Le Qin
- Department of Radiology, Rui Jin Hospital, Shanghai Jiao Tong University, and School of Medicine, Shanghai, China
| | - Fuhua Yan
- Department of Radiology, Rui Jin Hospital, Shanghai Jiao Tong University, and School of Medicine, Shanghai, China
| | - Guo-Yuan Yang
- Med-X Research Institute and School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai, China
| | - Ke-Min Chen
- Department of Radiology, Rui Jin Hospital, Shanghai Jiao Tong University, and School of Medicine, Shanghai, China
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