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Li G, Cong W, Michaelson JS, Liu H, Gjesteby L, Wang G. Novel Detection Scheme for X-ray Small-Angle Scattering. IEEE TRANSACTIONS ON RADIATION AND PLASMA MEDICAL SCIENCES 2019; 2:315-325. [PMID: 30854499 DOI: 10.1109/trpms.2018.2839066] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
X-ray imaging techniques, including x-ray radiography and computed tomography, have been in use for decades and proven effective and indispensable in diagnosis and therapy due to their fine resolution and fast acquisition speed. However, the innate disadvantage of x-ray is the poor soft tissue contrast. Small-angle scattering signals were shown to provide unique information about the abnormality of soft tissues that is complementary to the traditional attenuation image. Currently, there is no effective small-angle scattering detection system. In this paper, we propose a new "collimation" design dedicated to capture a small-angle scattering radiographic image directly, which carries critical pathological information for differentiation between normal and abnormal tissues. Our design consists of two interlaced gratings so that both the primary flux and Compton scattering photons are effectively blocked to leave the apertures mainly open to small-angle scattering photons. Theoretical analysis and Monte Carlo simulations demonstrate that small-angle scattering radiography is feasible with our proposed technology.
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Affiliation(s)
- Guang Li
- Biomedical Imaging Center, BME/CBIS, Rensselaer Polytechnic Institute, New York, USA
| | - Wenxiang Cong
- Biomedical Imaging Center, BME/CBIS, Rensselaer Polytechnic Institute, New York, USA
| | | | - Hong Liu
- Center for advanced medical imaging, University of Oklahoma, USA
| | - Lars Gjesteby
- Biomedical Imaging Center, BME/CBIS, Rensselaer Polytechnic Institute, New York, USA
| | - Ge Wang
- Biomedical Imaging Center, BME/CBIS, Rensselaer Polytechnic Institute, New York, USA
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2
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Vedantham S, Karellas A. Emerging Breast Imaging Technologies on the Horizon. Semin Ultrasound CT MR 2018; 39:114-121. [PMID: 29317033 DOI: 10.1053/j.sult.2017.09.004] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Early detection of breast cancers by mammography in conjunction with adjuvant therapy has contributed to reduction in breast cancer mortality. Mammography remains the "gold-standard" for breast cancer screening but is limited by tissue superposition. Digital breast tomosynthesis and more recently, dedicated breast computed tomography have been developed to alleviate the tissue superposition problem. However, all of these modalities rely upon x-ray attenuation contrast to provide anatomical images, and there are ongoing efforts to develop and clinically translate alternative modalities. These emerging modalities could provide for new contrast mechanisms and may potentially improve lesion detection and diagnosis. In this article, several of these emerging modalities are discussed with a focus on technologies that have advanced to the stage of in vivo clinical evaluation.
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Affiliation(s)
- Srinivasan Vedantham
- Department of Medical Imaging, University of Arizona College of Medicine, Banner University Medical Center, Tucson, AZ.
| | - Andrew Karellas
- Department of Medical Imaging, University of Arizona College of Medicine, Banner University Medical Center, Tucson, AZ
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3
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Yashiro W, Noda D, Kajiwara K. Effect of insufficient temporal coherence on visibility contrast in X-ray grating interferometry. OPTICS EXPRESS 2018; 26:1012-1027. [PMID: 29401974 DOI: 10.1364/oe.26.001012] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/23/2017] [Accepted: 01/04/2018] [Indexed: 06/07/2023]
Abstract
X-ray grating interferometry, which has been spotlighted in the last decade as a multi-modal X-ray imaging technique, can provide three independent images, i.e., absorption, differential-phase, and visibility-contrast images. We report on a cause of the visibility contrast, an effect of insufficient temporal coherence, that can be observed when continuous-spectrum X-rays are used. This effect occurs even for a sample without unresolvable random structures, which are known as the main causes of visibility contrast. We performed an experiment using an acrylic cylinder and quantitatively explained the visibility contrast due to this effect.
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Bao Y, Shao Q, Hu R, Wang S, Gao K, Wang Y, Tian Y, Zhu P. Effect of particle-size selectivity on quantitative X-ray dark-field computed tomography using a grating interferometer. Radiat Phys Chem Oxf Engl 1993 2017. [DOI: 10.1016/j.radphyschem.2016.01.022] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Sharma Y, Schaff F, Wieczorek M, Pfeiffer F, Lasser T. Design of Acquisition Schemes and Setup Geometry for Anisotropic X-ray Dark-Field Tomography (AXDT). Sci Rep 2017; 7:3195. [PMID: 28600544 PMCID: PMC5466688 DOI: 10.1038/s41598-017-03329-0] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2017] [Accepted: 04/26/2017] [Indexed: 11/23/2022] Open
Abstract
Anisotropic X-ray Dark-field Tomography (AXDT) is a new imaging technique for reconstructing the three-dimensional scattering profile within a sample using the dark-field signal measured in an X-ray grating interferometry setup. As in any tomographic measurement, the acquisition geometry plays a key role in the accurate reconstruction of the scattering information. More- over, the anisotropic nature of the dark-field signal poses additional challenges for designing the acquisition protocols. In this work, we present an efficient approach to measure scattering orientations spread over the unit sphere and prove its efficacy using the knowledge from conventional tomography. In addition, we conclude (using analytical and experimental results) that placing the gratings such that the grating bars make an angle of 45 degrees with respect to the vertical direction is the optimal setup configuration for AXDT.
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Affiliation(s)
- Y Sharma
- Chair of Biomedical Physics, Department of Physics and School of BioEngineering, Technical University of Munich, 85748, Garching, Germany.
- Computer Aided Medical Procedures, Technical University of Munich, 85748, Garching, Germany.
| | - F Schaff
- Chair of Biomedical Physics, Department of Physics and School of BioEngineering, Technical University of Munich, 85748, Garching, Germany
| | - M Wieczorek
- Computer Aided Medical Procedures, Technical University of Munich, 85748, Garching, Germany
| | - F Pfeiffer
- Chair of Biomedical Physics, Department of Physics and School of BioEngineering, Technical University of Munich, 85748, Garching, Germany
- Department of Diagnostic and Interventional Radiology, Klinikum rechts der Isar, Technical University of Munich, 81675, München, Germany
- Institute for Advanced Study, Technical University of Munich, 85748, Garching, Germany
| | - T Lasser
- Computer Aided Medical Procedures, Technical University of Munich, 85748, Garching, Germany
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Gkoumas S, Villanueva-Perez P, Wang Z, Romano L, Abis M, Stampanoni M. A generalized quantitative interpretation of dark-field contrast for highly concentrated microsphere suspensions. Sci Rep 2016; 6:35259. [PMID: 27734931 PMCID: PMC5062466 DOI: 10.1038/srep35259] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2016] [Accepted: 09/26/2016] [Indexed: 02/01/2023] Open
Abstract
In X-ray grating interferometry, dark-field contrast arises due to partial extinction of the detected interference fringes. This is also called visibility reduction and is attributed to small-angle scattering from unresolved structures in the imaged object. In recent years, analytical quantitative frameworks of dark-field contrast have been developed for highly diluted monodisperse microsphere suspensions with maximum 6% volume fraction. These frameworks assume that scattering particles are separated by large enough distances, which make any interparticle scattering interference negligible. In this paper, we start from the small-angle scattering intensity equation and, by linking Fourier and real-space, we introduce the structure factor and thus extend the analytical and experimental quantitative interpretation of dark-field contrast, for a range of suspensions with volume fractions reaching 40%. The structure factor accounts for interparticle scattering interference. Without introducing any additional fitting parameters, we successfully predict the experimental values measured at the TOMCAT beamline, Swiss Light Source. Finally, we apply this theoretical framework to an experiment probing a range of system correlation lengths by acquiring dark-field images at different energies. This proposed method has the potential to be applied in single-shot-mode using a polychromatic X-ray tube setup and a single-photon-counting energy-resolving detector.
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Affiliation(s)
- Spyridon Gkoumas
- Swiss Light Source, Paul Scherrer Institute, 5232 Villigen, Switzerland
| | | | - Zhentian Wang
- Swiss Light Source, Paul Scherrer Institute, 5232 Villigen, Switzerland.,Institute for Biomedical Engineering University and ETH Zürich, 8092 Zürich, Switzerland
| | - Lucia Romano
- Swiss Light Source, Paul Scherrer Institute, 5232 Villigen, Switzerland.,Institute for Biomedical Engineering University and ETH Zürich, 8092 Zürich, Switzerland.,Department of Physics and IMM-CNR, University of Catania, 64 via S. Sofia, I-95123 Catania, Italy
| | - Matteo Abis
- Swiss Light Source, Paul Scherrer Institute, 5232 Villigen, Switzerland.,Institute for Biomedical Engineering University and ETH Zürich, 8092 Zürich, Switzerland
| | - Marco Stampanoni
- Swiss Light Source, Paul Scherrer Institute, 5232 Villigen, Switzerland.,Institute for Biomedical Engineering University and ETH Zürich, 8092 Zürich, Switzerland
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Weber T, Pelzer G, Rieger J, Ritter A, Anton G. Report of improved performance in Talbot-Lau phase-contrast computed tomography. Med Phys 2016; 42:2892-6. [PMID: 26127042 DOI: 10.1118/1.4921022] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
PURPOSE Many expectations have been raised since the use of conventional x-ray tubes on grating-based x-ray phase-contrast imaging. Despite a reported increase in contrast-to-noise ratio (CNR) in many publications, there is doubt on whether phase-contrast computed tomography (CT) is advantageous in clinical CT scanners in vivo. The aim of this paper is to contribute to this discussion by analyzing the performance of a phase-contrast CT laboratory setup. METHODS A phase-contrast CT performance analysis was done. Projection images of a phantom were recorded, and image slices were reconstructed using standard filtered back projection methods. The resulting image slices were analyzed by determining the CNRs in the attenuation and phase image. These results were compared to analytically calculated expectations according to the already published phase-contrast CT performance analysis by Raupach and Flohr [Med. Phys. 39, 4761-4774 (2012)]. There, a severe mistake was found leading to wrong predictions of the performance of phase-contrast CT. The error was corrected and with the new formulae, the experimentally obtained results matched the analytical calculations. RESULTS The squared ratios of the phase-contrast CNR and the attenuation CNR obtained in the authors' experiment are five- to ten-fold higher than predicted by Raupach and Flohr [Med. Phys. 39, 4761-4774 (2012)]. The effective lateral spatial coherence length deduced outnumbers the already optimistic assumption of Raupach and Flohr [Med. Phys. 39, 4761-4774 (2012)] by a factor of 3. CONCLUSIONS The authors' results indicate that the assumptions made in former performance analyses are pessimistic. The break-even point, when phase-contrast CT outperforms attenuation CT, is within reach even with realistic, nonperfect gratings. Further improvements to state-of-the-art clinical CT scanners, like increasing the spatial resolution, could change the balance in favor of phase-contrast computed tomography even more. This could be done by, e.g., quantum-counting pixel detectors with four-fold smaller pixel pitches.
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Affiliation(s)
- Thomas Weber
- Friedrich-Alexander Universität Erlangen-Nürnberg, Erlangen Centre for Astroparticle Physics (ECAP), Radiation and Detector Physics Group, Erwin-Rommel-Str. 1, 91058 Erlangen, Germany
| | - Georg Pelzer
- Friedrich-Alexander Universität Erlangen-Nürnberg, Erlangen Centre for Astroparticle Physics (ECAP), Radiation and Detector Physics Group, Erwin-Rommel-Str. 1, 91058 Erlangen, Germany
| | - Jens Rieger
- Friedrich-Alexander Universität Erlangen-Nürnberg, Erlangen Centre for Astroparticle Physics (ECAP), Radiation and Detector Physics Group, Erwin-Rommel-Str. 1, 91058 Erlangen, Germany
| | - André Ritter
- Friedrich-Alexander Universität Erlangen-Nürnberg, Erlangen Centre for Astroparticle Physics (ECAP), Radiation and Detector Physics Group, Erwin-Rommel-Str. 1, 91058 Erlangen, Germany
| | - Gisela Anton
- Friedrich-Alexander Universität Erlangen-Nürnberg, Erlangen Centre for Astroparticle Physics (ECAP), Radiation and Detector Physics Group, Erwin-Rommel-Str. 1, 91058 Erlangen, Germany
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Yashiro W, Momose A. Effects of unresolvable edges in grating-based X-ray differential phase imaging. OPTICS EXPRESS 2015; 23:9233-9251. [PMID: 25968757 DOI: 10.1364/oe.23.009233] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
We investigated effects of unresolvable sharp edges on images obtained in a grating-based X-ray differential phase imaging technique. Results of numerical calculations for monochromatic X-rays show that an unresolvable sharp edge generates not only differential-phase contrast but also visibility contrast. The latter shows that the visibility contrast has another major origin other than ultra-small-angle X-ray scattering (USAXS) from randomly distributed unresolvable microstructures, which has been considered the main origin for the contrast. The effects were experimentally confirmed using a synchrotron X-ray source.
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Peter S, Modregger P, Fix MK, Volken W, Frei D, Manser P, Stampanoni M. Combining Monte Carlo methods with coherent wave optics for the simulation of phase-sensitive X-ray imaging. JOURNAL OF SYNCHROTRON RADIATION 2014; 21:613-22. [PMID: 24763652 PMCID: PMC3998816 DOI: 10.1107/s1600577514000952] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/20/2013] [Accepted: 01/14/2014] [Indexed: 05/14/2023]
Abstract
Phase-sensitive X-ray imaging shows a high sensitivity towards electron density variations, making it well suited for imaging of soft tissue matter. However, there are still open questions about the details of the image formation process. Here, a framework for numerical simulations of phase-sensitive X-ray imaging is presented, which takes both particle- and wave-like properties of X-rays into consideration. A split approach is presented where we combine a Monte Carlo method (MC) based sample part with a wave optics simulation based propagation part, leading to a framework that takes both particle- and wave-like properties into account. The framework can be adapted to different phase-sensitive imaging methods and has been validated through comparisons with experiments for grating interferometry and propagation-based imaging. The validation of the framework shows that the combination of wave optics and MC has been successfully implemented and yields good agreement between measurements and simulations. This demonstrates that the physical processes relevant for developing a deeper understanding of scattering in the context of phase-sensitive imaging are modelled in a sufficiently accurate manner. The framework can be used for the simulation of phase-sensitive X-ray imaging, for instance for the simulation of grating interferometry or propagation-based imaging.
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Affiliation(s)
- Silvia Peter
- Swiss Light Source, Paul Scherrer Institut, CH-5232 Villigen, Switzerland
- Institute for Biomedical Engineering, Eidgenössische Technische Hochschule Zürich, CH-8092 Zürich, Switzerland
- Correspondence e-mail:
| | - Peter Modregger
- Swiss Light Source, Paul Scherrer Institut, CH-5232 Villigen, Switzerland
- Centre d’Imagerie BioMedicale, Ecole Polytechnique Federale de Lausanne, CH-1015 Lausanne, Switzerland
| | - Michael K. Fix
- Division of Medical Radiation Physics and Department of Radiation Oncology, Inselspital, University Hospital Bern and University of Bern, CH-3010 Bern, Switzerland
| | - Werner Volken
- Division of Medical Radiation Physics and Department of Radiation Oncology, Inselspital, University Hospital Bern and University of Bern, CH-3010 Bern, Switzerland
| | - Daniel Frei
- Division of Medical Radiation Physics and Department of Radiation Oncology, Inselspital, University Hospital Bern and University of Bern, CH-3010 Bern, Switzerland
| | - Peter Manser
- Division of Medical Radiation Physics and Department of Radiation Oncology, Inselspital, University Hospital Bern and University of Bern, CH-3010 Bern, Switzerland
| | - Marco Stampanoni
- Swiss Light Source, Paul Scherrer Institut, CH-5232 Villigen, Switzerland
- Institute for Biomedical Engineering, Eidgenössische Technische Hochschule Zürich, CH-8092 Zürich, Switzerland
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Michel T, Rieger J, Anton G, Bayer F, Beckmann MW, Durst J, Fasching PA, Haas W, Hartmann A, Pelzer G, Radicke M, Rauh C, Ritter A, Sievers P, Schulz-Wendtland R, Uder M, Wachter DL, Weber T, Wenkel E, Zang A. On a dark-field signal generated by micrometer-sized calcifications in phase-contrast mammography. Phys Med Biol 2013; 58:2713-32. [PMID: 23552903 DOI: 10.1088/0031-9155/58/8/2713] [Citation(s) in RCA: 81] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
We show that a distribution of micrometer-sized calcifications in the human breast which are not visible in clinical x-ray mammography at diagnostic dose levels can produce a significant dark-field signal in a grating-based x-ray phase-contrast imaging setup with a tungsten anode x-ray tube operated at 40 kVp. A breast specimen with invasive ductal carcinoma was investigated immediately after surgery by Talbot-Lau x-ray interferometry with a design energy of 25 keV. The sample contained two tumors which were visible in ultrasound and contrast-agent enhanced MRI but invisible in clinical x-ray mammography, in specimen radiography and in the attenuation images obtained with the Talbot-Lau interferometer. One of the tumors produced significant dark-field contrast with an exposure of 0.85 mGy air-kerma. Staining of histological slices revealed sparsely distributed grains of calcium phosphate with sizes varying between 1 and 40 μm in the region of this tumor. By combining the histological investigations with an x-ray wave-field simulation we demonstrate that a corresponding distribution of grains of calcium phosphate in the form of hydroxylapatite has the ability to produce a dark-field signal which would-to a substantial degree-explain the measured dark-field image. Thus we have found the appearance of new information (compared to attenuation and differential phase images) in the dark-field image. The second tumor in the same sample did not contain a significant fraction of these very fine calcification grains and was invisible in the dark-field image. We conclude that some tumors which are invisible in x-ray absorption mammography might be detected in the x-ray dark-field image at tolerable dose levels.
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Affiliation(s)
- Thilo Michel
- Erlangen Centre for Astroparticle Physics (ECAP), Friedrich-Alexander-Universität Erlangen-Nürnberg, Erwin-Rommel-Str 1, D-91058 Erlangen, Germany.
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Towards omni-tomography--grand fusion of multiple modalities for simultaneous interior tomography. PLoS One 2012; 7:e39700. [PMID: 22768108 PMCID: PMC3387257 DOI: 10.1371/journal.pone.0039700] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2012] [Accepted: 05/24/2012] [Indexed: 12/01/2022] Open
Abstract
We recently elevated interior tomography from its origin in computed tomography (CT) to a general tomographic principle, and proved its validity for other tomographic modalities including SPECT, MRI, and others. Here we propose “omni-tomography”, a novel concept for the grand fusion of multiple tomographic modalities for simultaneous data acquisition in a region of interest (ROI). Omni-tomography can be instrumental when physiological processes under investigation are multi-dimensional, multi-scale, multi-temporal and multi-parametric. Both preclinical and clinical studies now depend on in vivo tomography, often requiring separate evaluations by different imaging modalities. Over the past decade, two approaches have been used for multimodality fusion: Software based image registration and hybrid scanners such as PET-CT, PET-MRI, and SPECT-CT among others. While there are intrinsic limitations with both approaches, the main obstacle to the seamless fusion of multiple imaging modalities has been the bulkiness of each individual imager and the conflict of their physical (especially spatial) requirements. To address this challenge, omni-tomography is now unveiled as an emerging direction for biomedical imaging and systems biomedicine.
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