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Birnbacher L, Braunagel M, Willner M, Marschner M, De Marco F, Viermetz M, Auweter S, Notohamiprodjo S, Hellbach K, Notohamiprodjo M, Staehler M, Pfeiffer D, Reiser MF, Pfeiffer F, Herzen J. Quantitative differentiation of minimal-fat angiomyolipomas from renal cell carcinomas using grating-based x-ray phase-contrast computed tomography: An ex vivo study. PLoS One 2023; 18:e0279323. [PMID: 37058505 PMCID: PMC10104346 DOI: 10.1371/journal.pone.0279323] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2022] [Accepted: 04/03/2023] [Indexed: 04/15/2023] Open
Abstract
BACKGROUND The differentiation of minimal-fat-or low-fat-angiomyolipomas from other renal lesions is clinically challenging in conventional computed tomography. In this work, we have assessed the potential of grating-based x-ray phase-contrast computed tomography (GBPC-CT) for visualization and quantitative differentiation of minimal-fat angiomyolipomas (mfAMLs) and oncocytomas from renal cell carcinomas (RCCs) on ex vivo renal samples. MATERIALS AND METHODS Laboratory GBPC-CT was performed at 40 kVp on 28 ex vivo kidney specimens including five angiomyolipomas with three minimal-fat (mfAMLs) and two high-fat (hfAMLs) subtypes as well as three oncocytomas and 20 RCCs with eight clear cell (ccRCCs), seven papillary (pRCCs) and five chromophobe RCC (chrRCC) subtypes. Quantitative values of conventional Hounsfield units (HU) and phase-contrast Hounsfield units (HUp) were determined and histogram analysis was performed on GBPC-CT and grating-based attenuation-contrast computed tomography (GBAC-CT) slices for each specimen. For comparison, the same specimens were imaged at a 3T magnetic resonance imaging (MRI) scanner. RESULTS We have successfully matched GBPC-CT images with clinical MRI and histology, as GBPC-CT presented with increased soft tissue contrast compared to absorption-based images. GBPC-CT images revealed a qualitative and quantitative difference between mfAML samples (58±4 HUp) and oncocytomas (44±10 HUp, p = 0.057) and RCCs (ccRCCs: 40±12 HUp, p = 0.012; pRCCs: 43±9 HUp, p = 0.017; chrRCCs: 40±7 HUp, p = 0.057) in contrast to corresponding laboratory attenuation-contrast CT and clinical MRI, although not all differences were statistically significant. Due to the heterogeneity and lower signal of oncocytomas, quantitative differentiation of the samples based on HUp or in combination with HUs was not possible. CONCLUSIONS GBPC-CT allows quantitative differentiation of minimal-fat angiomyolipomas from pRCCs and ccRCCs in contrast to absorption-based imaging and clinical MRI.
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Affiliation(s)
- Lorenz Birnbacher
- Chair of Biomedical Physics, School of Natural Sciences & Department of Physics, Munich Institute of Biomedical Engineering, Technical University of Munich, München, Germany
- Institute of Diagnostic and Interventional Radiology, School of Medicine & Klinikum rechts der Isar, Technical University of Munich, München, Germany
| | - Margarita Braunagel
- Institute of Clinical Radiology, Ludwig-Maximilians-University Hospital Munich, München, Germany
| | - Marian Willner
- Chair of Biomedical Physics, School of Natural Sciences & Department of Physics, Munich Institute of Biomedical Engineering, Technical University of Munich, München, Germany
| | - Mathias Marschner
- Chair of Biomedical Physics, School of Natural Sciences & Department of Physics, Munich Institute of Biomedical Engineering, Technical University of Munich, München, Germany
| | - Fabio De Marco
- Chair of Biomedical Physics, School of Natural Sciences & Department of Physics, Munich Institute of Biomedical Engineering, Technical University of Munich, München, Germany
- Department of Physics, University of Trieste, Trieste TS, Italy
| | - Manuel Viermetz
- Chair of Biomedical Physics, School of Natural Sciences & Department of Physics, Munich Institute of Biomedical Engineering, Technical University of Munich, München, Germany
| | - Sigrid Auweter
- Institute of Clinical Radiology, Ludwig-Maximilians-University Hospital Munich, München, Germany
| | - Susan Notohamiprodjo
- Institute of Clinical Radiology, Ludwig-Maximilians-University Hospital Munich, München, Germany
- Department of Nuclear Medicine, School of Medicine & Klinikum rechts der Isar, Technical University of Munich, München, Germany
| | - Katharina Hellbach
- Institute of Clinical Radiology, Ludwig-Maximilians-University Hospital Munich, München, Germany
- Department of Diagnostic and Interventional Radiology, University Hospital of Heidelberg, Ruprecht-Karls-University Heidelberg, München, Germany
| | - Mike Notohamiprodjo
- Institute of Clinical Radiology, Ludwig-Maximilians-University Hospital Munich, München, Germany
| | - Michael Staehler
- Institute of Urology, Ludwig-Maximilians-University Hospital Munich, München, Germany
| | - Daniela Pfeiffer
- Institute of Diagnostic and Interventional Radiology, School of Medicine & Klinikum rechts der Isar, Technical University of Munich, München, Germany
- Institute of Advanced Study, Technical University of Munich, München, Germany
| | - Maximilian F Reiser
- Institute of Clinical Radiology, Ludwig-Maximilians-University Hospital Munich, München, Germany
| | - Franz Pfeiffer
- Chair of Biomedical Physics, School of Natural Sciences & Department of Physics, Munich Institute of Biomedical Engineering, Technical University of Munich, München, Germany
- Institute of Diagnostic and Interventional Radiology, School of Medicine & Klinikum rechts der Isar, Technical University of Munich, München, Germany
- Institute of Advanced Study, Technical University of Munich, München, Germany
| | - Julia Herzen
- Chair of Biomedical Physics, School of Natural Sciences & Department of Physics, Munich Institute of Biomedical Engineering, Technical University of Munich, München, Germany
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Seibold S, Müller J, Allner S, Willner M, Baldrian P, Ulyshen MD, Brandl R, Bässler C, Hagge J, Mitesser O. Quantifying wood decomposition by insects and fungi using computed tomography scanning and machine learning. Sci Rep 2022; 12:16150. [PMID: 36168033 PMCID: PMC9515192 DOI: 10.1038/s41598-022-20377-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2022] [Accepted: 09/13/2022] [Indexed: 11/18/2022] Open
Abstract
Wood decomposition is a central process contributing to global carbon and nutrient cycling. Quantifying the role of the major biotic agents of wood decomposition, i.e. insects and fungi, is thus important for a better understanding of this process. Methods to quantify wood decomposition, such as dry mass loss, suffer from several shortcomings, such as destructive sampling or subsampling. We developed and tested a new approach based on computed tomography (CT) scanning and semi-automatic image analysis of logs from a field experiment with manipulated beetle communities. We quantified the volume of beetle tunnels in wood and bark and the relative wood volume showing signs of fungal decay and compared both measures to classic approaches. The volume of beetle tunnels was correlated with dry mass loss and clearly reflected the differences between beetle functional groups. Fungal decay was identified with high accuracy and strongly correlated with ergosterol content. Our data show that this is a powerful approach to quantify wood decomposition by insects and fungi. In contrast to other methods, it is non-destructive, covers entire deadwood objects and provides spatially explicit information opening a wide range of research options. For the development of general models, we urge researchers to publish training data.
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Affiliation(s)
- Sebastian Seibold
- Ecosystem Dynamics and Forest Management Group, Technical University of Munich, 85354, Freising, Germany. .,Berchtesgaden National Park, Doktorberg 6, 83471, Berchtesgaden, Germany. .,Terrestrial Ecology Research Group, Technical University of Munich, 85354, Freising, Germany.
| | - Jörg Müller
- Field Station Fabrikschleichach, Animal Ecology and Tropical Biology, Biocenter, University of Würzburg, Glashüttenstrasse 5, 96181, Rauhenebrach, Germany.,Bavarian Forest National Park, Freyungerstrasse 2, 94481, Grafenau, Germany
| | | | - Marian Willner
- MITOS GmbH, Lichtenbergstrasse 8, 85748, Garching, Germany
| | - Petr Baldrian
- Laboratory of Environmental Microbiology, Institute of Microbiology of the Czech Academy of Sciences, Videnska 1083, 14220, Praha 4, Czech Republic
| | | | - Roland Brandl
- Faculty of Biology, Department of Ecology, Animal Ecology, Philipps-Universität Marburg, Karl-Von-Frisch Strasse 8, 35032, Marburg, Germany
| | - Claus Bässler
- Bavarian Forest National Park, Freyungerstrasse 2, 94481, Grafenau, Germany.,Faculty of Biological Sciences, Institute for Ecology, Evolution and Diversity, Goethe University Frankfurt, 60438, Frankfurt am Main, Germany
| | - Jonas Hagge
- Forest Nature Conservation, Northwest German Forest Research Institute NW-FVA, 34346, Hann. Münden, Germany.,Forest Nature Conservation, Georg-August-University Göttingen, 37077, Göttingen, Germany
| | - Oliver Mitesser
- Field Station Fabrikschleichach, Animal Ecology and Tropical Biology, Biocenter, University of Würzburg, Glashüttenstrasse 5, 96181, Rauhenebrach, Germany
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Braig EM, Pfeiffer D, Willner M, Sellerer T, Taphorn K, Petrich C, Scholz J, Petzold L, Birnbacher L, Dierolf M, Pfeiffer F, Herzen J. Single spectrum three-material decomposition with grating-based x-ray phase-contrast CT. Phys Med Biol 2020; 65:185011. [PMID: 32460250 DOI: 10.1088/1361-6560/ab9704] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Grating-based x-ray phase-contrast imaging provides three simultaneous image channels originating from a single image acquisition. While the phase signal provides direct access to the electron density in tomography, there is additional information on sub-resolutional structural information which is called dark-field signal in analogy to optical microscopy. The additional availability of the conventional attenuation image qualifies the method for implementation into existing diagnostic routines. The simultaneous access to the attenuation coefficient and the electron density allows for quantitative two-material discrimination as demonstrated lately for measurements at a quasi-monochromatic compact synchrotron source. Here, we investigate the transfer of the method to conventional polychromatic x-ray sources and the additional inclusion of the dark-field signal for three-material decomposition. We evaluate the future potential of grating-based x-ray phase-contrast CT for quantitative three-material discrimination for the specific case of early stroke diagnosis at conventional polychromatic x-ray sources. Compared to conventional CT, the method has the potential to discriminate coagulated blood directly from contrast agent extravasation within a single CT acquisition. Additionally, the dark-field information allows for the clear identification of hydroxyapatite clusters due to their micro-structure despite a similar attenuation as the applied contrast agent. This information on materials with sub-resolutional microstructures is considered to comprise advantages relevant for various pathologies.
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Affiliation(s)
- Eva-Maria Braig
- Chair of Biomedical Physics, Department of Physics and Munich School of BioEngineering, Technical University of Munich, 85748 Garching, Germany
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Kimm MA, Willner M, Drecoll E, Herzen J, Noël PB, Rummeny EJ, Pfeiffer F, Fingerle AA. Grating-based phase-contrast CT (PCCT): histopathological correlation of human liver cirrhosis and hepatocellular carcinoma specimen. J Clin Pathol 2020; 73:483-487. [PMID: 31941652 DOI: 10.1136/jclinpath-2019-206380] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2019] [Revised: 12/16/2019] [Accepted: 12/17/2019] [Indexed: 01/24/2023]
Abstract
AIMS To correlate signal intensities in grating-based phase-contrast CT (PCCT) images obtained at a synchrotron light source and a conventional X-ray source with tissue components in human liver cirrhosis and hepatocellular carcinoma (HCC) specimen. METHODS Study approval was obtained by the institutional review board. Human specimen of liver cirrhosis and HCC were imaged at experimental grating-based PCCT setups using either a synchrotron radiation source or a conventional X-ray tube. Tissue samples were sectioned and processed for H&E and Elastica van Gieson staining. PCCT and histological images were manually correlated. Depending on morphology and staining characteristics tissue components like fibrosis, HCC, inflammation, connective tissue and necrosis were differentiated and visually correlated with signal intensity in PCCT images using a 5-point Likert scale with normal liver parenchyma as a reference. RESULTS Grating-based PCCT images of human cirrhotic liver and HCC specimen showed high soft-tissue contrast allowing correlation with histopathological sections. Signal intensities were similar in both setups independent of the nature of the radiation source. Connective tissue and areas of haemorrhage displayed the highest signal intensities, fibrotic liver tissue the lowest. CONCLUSIONS Grating-based PCCT provides comparable results for the characterisation of human specimen of liver cirrhosis and HCC using either a synchrotron light source or a conventional X-ray tube. Due to its high soft-tissue contrast and its applicability to conventional X-ray tubes grating-based PCCT holds potential for preclinical research and virtual histology applications.
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Affiliation(s)
- Melanie A Kimm
- Department of Diagnostic and Interventional Radiology, School of Medicine & Klinikum rechts der Isar, Technical University of Munich, Munich, Germany
| | - Marian Willner
- Chair of Biomedical Physics, Department of Physics and Munich School of Bioengineering, Technical University of Munich, Garching, Germany
| | - Enken Drecoll
- Department of Pathology, School of Medicine & Technical University of Munich, Munich, Germany
| | - Julia Herzen
- Chair of Biomedical Physics, Department of Physics and Munich School of Bioengineering, Technical University of Munich, Garching, Germany
| | - Peter B Noël
- Department of Diagnostic and Interventional Radiology, School of Medicine & Klinikum rechts der Isar, Technical University of Munich, Munich, Germany
- Department of Radiology, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Ernst J Rummeny
- Department of Diagnostic and Interventional Radiology, School of Medicine & Klinikum rechts der Isar, Technical University of Munich, Munich, Germany
| | - Franz Pfeiffer
- Chair of Biomedical Physics, Department of Physics and Munich School of Bioengineering, Technical University of Munich, Garching, Germany
| | - Alexander A Fingerle
- Department of Diagnostic and Interventional Radiology, School of Medicine & Klinikum rechts der Isar, Technical University of Munich, Munich, Germany
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Hellerhoff K, Birnbacher L, Sztrókay-Gaul A, Grandl S, Auweter S, Willner M, Marschner M, Mayr D, Reiser MF, Pfeiffer F, Herzen J. Assessment of intraductal carcinoma in situ (DCIS) using grating-based X-ray phase-contrast CT at conventional X-ray sources: An experimental ex-vivo study. PLoS One 2019; 14:e0210291. [PMID: 30625220 PMCID: PMC6326478 DOI: 10.1371/journal.pone.0210291] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2018] [Accepted: 11/08/2018] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND The extent of intraductal carcinoma in situ (DCIS) is commonly underestimated due to the discontinuous growth and lack of microcalcifications. Specimen radiography has been established to reduce the rate of re-excision. However, the predictive value for margin assessment with conventional specimen radiography for DCIS is low. In this study we assessed the potential of grating-based phase-contrast computed tomography (GBPC-CT) at conventional X-ray sources for specimen tomography of DCIS containing samples. MATERIALS AND METHODS GBPC-CT was performed on four ex-vivo breast specimens containing DCIS and invasive carcinoma of non-specific type. Phase-contrast and absorption-based datasets were manually matched with corresponding histological slices as the standard of reference. RESULTS Matching of CT images and histology was successful. GBPC-CT showed an improved soft tissue contrast compared to absorption-based images revealing more histological details in the same sections. Non-calcifying DCIS exceeding the invasive tumor could be correlated to areas of dilated bright ducts around the tumor. CONCLUSIONS GBPC-CT imaging at conventional X-ray sources offers improved depiction quality for the imaging of breast tissue samples compared to absorption-based imaging, allows the identification of diagnostically relevant tissue details, and provides full three-dimensional assessment of sample margins.
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MESH Headings
- Breast Neoplasms/diagnostic imaging
- Breast Neoplasms/pathology
- Breast Neoplasms/surgery
- Calcinosis/diagnostic imaging
- Calcinosis/pathology
- Carcinoma, Ductal, Breast/diagnostic imaging
- Carcinoma, Ductal, Breast/pathology
- Carcinoma, Intraductal, Noninfiltrating/diagnostic imaging
- Carcinoma, Intraductal, Noninfiltrating/pathology
- Carcinoma, Intraductal, Noninfiltrating/surgery
- Female
- Humans
- In Vitro Techniques
- Mammography/methods
- Microscopy, Phase-Contrast/methods
- Prospective Studies
- Tomography, X-Ray Computed/methods
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Affiliation(s)
- Karin Hellerhoff
- Institute for Clinical Radiology, Ludwig-Maximilians-University Hospital Munich, Munich, Germany
- Abteilung für Diagnostische Radiologie, Rotkreuzklinikum München, Munich, Germany
| | - Lorenz Birnbacher
- Chair of Biomedical Physics, Department of Physics & Munich School of BioEngineering, Technical University of Munich, Garching, Germany
- * E-mail:
| | - Anikó Sztrókay-Gaul
- Institute for Clinical Radiology, Ludwig-Maximilians-University Hospital Munich, Munich, Germany
- Abteilung für Diagnostische Radiologie, Rotkreuzklinikum München, Munich, Germany
| | - Susanne Grandl
- Institute for Clinical Radiology, Ludwig-Maximilians-University Hospital Munich, Munich, Germany
- Abteilung für Diagnostische Radiologie, Rotkreuzklinikum München, Munich, Germany
| | - Sigrid Auweter
- Institute for Clinical Radiology, Ludwig-Maximilians-University Hospital Munich, Munich, Germany
| | - Marian Willner
- Chair of Biomedical Physics, Department of Physics & Munich School of BioEngineering, Technical University of Munich, Garching, Germany
| | - Mathias Marschner
- Chair of Biomedical Physics, Department of Physics & Munich School of BioEngineering, Technical University of Munich, Garching, Germany
| | - Doris Mayr
- Institute of Pathology, Ludwig-Maximilians-University Hospital Munich, Munich, Germany
| | - Maximilian F. Reiser
- Institute for Clinical Radiology, Ludwig-Maximilians-University Hospital Munich, Munich, Germany
| | - Franz Pfeiffer
- Chair of Biomedical Physics, Department of Physics & Munich School of BioEngineering, Technical University of Munich, Garching, Germany
- Institute of Diagnostic and Interventional Radiology, Klinikum rechts der Isar, Technical University of Munich, Munich, Germany
| | - Julia Herzen
- Chair of Biomedical Physics, Department of Physics & Munich School of BioEngineering, Technical University of Munich, Garching, Germany
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Birnbacher L, Willner M, Marschner M, Pfeiffer D, Pfeiffer F, Herzen J. Accurate effective atomic number determination with polychromatic grating-based phase-contrast computed tomography. Opt Express 2018; 26:15153-15166. [PMID: 30114766 DOI: 10.1364/oe.26.015153] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/19/2018] [Accepted: 04/30/2018] [Indexed: 06/08/2023]
Abstract
The demand for quantitative medical imaging is increasing in the ongoing digitalization. Conventional computed tomography (CT) is energy-dependent and therefore of limited comparability. In contrast, dual-energy CT (DECT) allows for the determination of absolute image contrast quantities, namely the electron density and the effective atomic number, and is already established in clinical radiology and radiation therapy. Grating-based phase-contrast computed tomography (GBPC-CT) is an experimental X-ray technique that also allows for the measurement of the electron density and the effective atomic number. However, the determination of both quantities is challenging when dealing with polychromatic GBPC-CT setups. In this paper, we present how to calculate the effective atomic numbers with a polychromatic, laboratory GBPC-CT setup operating between 35 and 50\,kVp. First, we investigated the accuracy of the measurement of the attenuation coefficients and electron densities. For this, we performed a calibration using the concept of effective energy. With the reliable experimental quantitative values, we were able to evaluate the effective atomic numbers of the investigated materials using a method previously shown with monochromatic X-ray radiation. In detail, we first calculated the ratio of the electron density and attenuation coefficient, which were experimentally determined with our polychromatic GBPC-CT setup. Second, we compared this ratio with tabulated total attenuation cross sections from literature values to determine the effective atomic numbers. Thus, we were able to calculate two physical absolute quantities -- the electron density and effective atomic number -- that are in general independent of the specific experimental conditions like the X-ray beam spectrum or the setup design.
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Marschner M, Birnbacher L, Willner M, Chabior M, Herzen J, Noël PB, Pfeiffer F. Revising the lower statistical limit of x-ray grating-based phase-contrast computed tomography. PLoS One 2017; 12:e0184217. [PMID: 28877253 PMCID: PMC5587302 DOI: 10.1371/journal.pone.0184217] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2016] [Accepted: 08/21/2017] [Indexed: 11/18/2022] Open
Abstract
Phase-contrast x-ray computed tomography (PCCT) is currently investigated as an interesting extension of conventional CT, providing high soft-tissue contrast even if examining weakly absorbing specimen. Until now, the potential for dose reduction was thought to be limited compared to attenuation CT, since meaningful phase retrieval fails for scans with very low photon counts when using the conventional phase retrieval method via phase stepping. In this work, we examine the statistical behaviour of the reverse projection method, an alternative phase retrieval approach and compare the results to the conventional phase retrieval technique. We investigate the noise levels in the projections as well as the image quality and quantitative accuracy of the reconstructed tomographic volumes. The results of our study show that this method performs better in a low-dose scenario than the conventional phase retrieval approach, resulting in lower noise levels, enhanced image quality and more accurate quantitative values. Overall, we demonstrate that the lower statistical limit of the phase stepping procedure as proposed by recent literature does not apply to this alternative phase retrieval technique. However, further development is necessary to overcome experimental challenges posed by this method which would enable mainstream or even clinical application of PCCT.
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Affiliation(s)
- Mathias Marschner
- Chair of Biomedical Physics, Department of Physics and Munich School of BioEngineering, Technical University of Munich, 85748 Garching, Germany
- * E-mail:
| | - Lorenz Birnbacher
- Chair of Biomedical Physics, Department of Physics and Munich School of BioEngineering, Technical University of Munich, 85748 Garching, Germany
| | - Marian Willner
- 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, Klinikum rechts der Isar, Technical University of Munich, 81675 München, Germany
| | - Michael Chabior
- Chair of Biomedical Physics, Department of Physics and Munich School of BioEngineering, Technical University of Munich, 85748 Garching, Germany
| | - Julia Herzen
- 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, Klinikum rechts der Isar, Technical University of Munich, 81675 München, Germany
| | - Peter B. Noël
- 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, Klinikum rechts der Isar, Technical University of Munich, 81675 München, Germany
| | - Franz Pfeiffer
- 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, Klinikum rechts der Isar, Technical University of Munich, 81675 München, Germany
- Institute for Advanced Study, Technical University of Munich, 85748 Garching, Germany
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Hetterich H, Webber N, Willner M, Herzen J, Birnbacher L, Auweter S, Schüller U, Bamberg F, Notohamiprodjo S, Bartsch H, Wolf J, Marschner M, Pfeiffer F, Reiser M, Saam T. Dark-field imaging in coronary atherosclerosis. Eur J Radiol 2017; 94:38-45. [PMID: 28941758 DOI: 10.1016/j.ejrad.2017.07.018] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2017] [Accepted: 07/21/2017] [Indexed: 02/01/2023]
Abstract
OBJECTIVES Dark-field imaging based on small angle X-ray scattering has been shown to be highly sensitive for microcalcifications, e.g. in breast tissue. We hypothesized (i) that high signal areas in dark-field imaging of atherosclerotic plaque are associated with microcalcifications and (ii) that dark-field imaging is more sensitive for microcalcifications than attenuation-based imaging. METHODS Fifteen coronary artery specimens were examined at an experimental set-up consisting of X-ray tube (40kV), grating-interferometer and detector. Tomographic dark-field-, attenuation-, and phase-contrast data were simultaneously acquired. Histopathology served as standard of reference. To explore the potential of dark field imaging in a full-body CT system, simulations were carried out with spherical calcifications of different sizes to simulate small and intermediate microcalcifications. RESULTS Microcalcifications were present in 10/10 (100%) cross-sections with high dark-field signal and without evidence of calcifications in attenuation- or phase contrast. In positive controls with high signal areas in all three modalities, 10/10 (100%) cross-sections showed macrocalcifications. In negative controls without high signal areas, no calcifications were detected. Simulations showed that the microcalcifications generate substantially higher dark-field than attenuation signal. CONCLUSIONS Dark-field imaging is highly sensitive for microcalcifications in coronary atherosclerotic plaque and might provide complementary information in the assessment of plaque instability.
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Affiliation(s)
- Holger Hetterich
- Institute of Clinical Radiology, Ludwig-Maximilians-University Hospital, Munich, Germany.
| | - Nicole Webber
- Institute of Clinical Radiology, Ludwig-Maximilians-University Hospital, Munich, Germany
| | - Marian Willner
- Physics Department & Institute for Medical Engineering, Technical University Munich, Garching, Germany
| | - Julia Herzen
- Physics Department & Institute for Medical Engineering, Technical University Munich, Garching, Germany
| | - Lorenz Birnbacher
- Physics Department & Institute for Medical Engineering, Technical University Munich, Garching, Germany
| | - Sigrid Auweter
- Institute of Clinical Radiology, Ludwig-Maximilians-University Hospital, Munich, Germany
| | - Ulrich Schüller
- Center for Neuropathology, Ludwig-Maximilians-University Hospital, Munich, Germany; Institute for Neuropathology, University Medical Center Hamburg, Germany; Department for Pediatric Hematology and Oncology, University Medical Center Hamburg, Germany
| | - Fabian Bamberg
- Institute of Clinical Radiology, Ludwig-Maximilians-University Hospital, Munich, Germany
| | - Susan Notohamiprodjo
- Institute of Clinical Radiology, Ludwig-Maximilians-University Hospital, Munich, Germany
| | - Harald Bartsch
- Institute of Pathology, Ludwig-Maximilians-University Hospital, Munich, Germany
| | - Johannes Wolf
- Physics Department & Institute for Medical Engineering, Technical University Munich, Garching, Germany
| | - Mathias Marschner
- Physics Department & Institute for Medical Engineering, Technical University Munich, Garching, Germany
| | - Franz Pfeiffer
- Physics Department & Institute for Medical Engineering, Technical University Munich, Garching, Germany
| | - Maximilian Reiser
- Institute of Clinical Radiology, Ludwig-Maximilians-University Hospital, Munich, Germany
| | - Tobias Saam
- Institute of Clinical Radiology, Ludwig-Maximilians-University Hospital, Munich, Germany
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Bidola P, Morgan K, Willner M, Fehringer A, Allner S, Prade F, Pfeiffer F, Achterhold K. Application of sensitive, high-resolution imaging at a commercial lab-based X-ray micro-CT system using propagation-based phase retrieval. J Microsc 2017; 266:211-220. [PMID: 28181677 DOI: 10.1111/jmi.12530] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2016] [Revised: 01/09/2017] [Accepted: 01/14/2017] [Indexed: 01/13/2023]
Abstract
Several dedicated commercial lab-based micro-computed tomography (μCT) systems exist, which provide high-resolution images of samples, with the capability to also deliver in-line phase contrast. X-ray phase contrast is particularly beneficial when visualizing very small features and weakly absorbing samples. The raw measured projections will include both phase and absorption effects. Extending our previous work that addressed the optimization of experimental conditions at the commercial ZEISS Xradia 500 Versa system, single-distance phase-contrast imaging is demonstrated on complex biological and material samples. From data captured at this system, we demonstrate extraction of the phase signal or the correction of the mixed image for the phase shift, and show how this procedure increases the contrast and removes artefacts. These high-quality images, measured without the use of a synchrotron X-ray source, demonstrate that highly sensitive, micrometre-resolution imaging of 3D volumes is widely accessible using commercially advanced laboratory devices.
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Affiliation(s)
- P Bidola
- Chair of Biomedical Physics, Department of Physics & Munich School of Bioengineering, Technical University of Munich, Garching, Germany
| | - K Morgan
- Chair of Biomedical Physics, Department of Physics & Munich School of Bioengineering, Technical University of Munich, Garching, Germany.,School of Physics and Astronomy, Monash University, Victoria, Australia
| | - M Willner
- Chair of Biomedical Physics, Department of Physics & Munich School of Bioengineering, Technical University of Munich, Garching, Germany.,MITOS GmbH, Garching, Germany
| | - A Fehringer
- Chair of Biomedical Physics, Department of Physics & Munich School of Bioengineering, Technical University of Munich, Garching, Germany
| | - S Allner
- Chair of Biomedical Physics, Department of Physics & Munich School of Bioengineering, Technical University of Munich, Garching, Germany
| | - F Prade
- Chair of Biomedical Physics, Department of Physics & Munich School of Bioengineering, Technical University of Munich, Garching, Germany
| | - F Pfeiffer
- Chair of Biomedical Physics, Department of Physics & Munich School of Bioengineering, Technical University of Munich, Garching, Germany.,Institute for Advanced Study, Technical University of Munich, Garching, Germany.,Department of Diagnostic and Interventional Radiology, Klinikum rechts der Isar, Technical University of Munich, 81675, München, Germany
| | - K Achterhold
- Chair of Biomedical Physics, Department of Physics & Munich School of Bioengineering, Technical University of Munich, Garching, Germany
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10
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Marschner M, Birnbacher L, Mechlem K, Noichl W, Fehringer A, Willner M, Scherer K, Herzen J, Noël PB, Pfeiffer F. Two-shot X-ray dark-field imaging. Opt Express 2016; 24:27032-27045. [PMID: 27857430 DOI: 10.1364/oe.24.027032] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
In this article, we report on a novel acquisition scheme for time- and dose-saving retrieval of dark-field data in grating-based phase-contrast imaging. In comparison to currently available techniques, the proposed approach only requires two phase steps. More importantly, our method is capable of accurately retrieving the dark-field signal where conventional approaches fail, for instance in the case of very low photon statistics. Finally, we successfully extend two-shot dark-field imaging to tomographic investigations, by implementing an iterative reconstruction with appropriate weights. Our results indicate an important progression towards the clinical feasibility of dark-field tomography.
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11
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Allner S, Koehler T, Fehringer A, Birnbacher L, Willner M, Pfeiffer F, Noël PB. Bilateral filtering using the full noise covariance matrix applied to x-ray phase-contrast computed tomography. Phys Med Biol 2016; 61:3867-56. [PMID: 27100408 DOI: 10.1088/0031-9155/61/10/3867] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
The purpose of this work is to develop an image-based de-noising algorithm that exploits complementary information and noise statistics from multi-modal images, as they emerge in x-ray tomography techniques, for instance grating-based phase-contrast CT and spectral CT. Among the noise reduction methods, image-based de-noising is one popular approach and the so-called bilateral filter is a well known algorithm for edge-preserving filtering. We developed a generalization of the bilateral filter for the case where the imaging system provides two or more perfectly aligned images. The proposed generalization is statistically motivated and takes the full second order noise statistics of these images into account. In particular, it includes a noise correlation between the images and spatial noise correlation within the same image. The novel generalized three-dimensional bilateral filter is applied to the attenuation and phase images created with filtered backprojection reconstructions from grating-based phase-contrast tomography. In comparison to established bilateral filters, we obtain improved noise reduction and at the same time a better preservation of edges in the images on the examples of a simulated soft-tissue phantom, a human cerebellum and a human artery sample. The applied full noise covariance is determined via cross-correlation of the image noise. The filter results yield an improved feature recovery based on enhanced noise suppression and edge preservation as shown here on the example of attenuation and phase images captured with grating-based phase-contrast computed tomography. This is supported by quantitative image analysis. Without being bound to phase-contrast imaging, this generalized filter is applicable to any kind of noise-afflicted image data with or without noise correlation. Therefore, it can be utilized in various imaging applications and fields.
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Affiliation(s)
- S Allner
- Department of Physics and Institute of Medical Engineering, Technische Universität München, Garching, Germany
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12
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Marschner M, Willner M, Potdevin G, Fehringer A, Noël PB, Pfeiffer F, Herzen J. Helical X-ray phase-contrast computed tomography without phase stepping. Sci Rep 2016; 6:23953. [PMID: 27052368 PMCID: PMC4823776 DOI: 10.1038/srep23953] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2014] [Accepted: 03/17/2016] [Indexed: 01/15/2023] Open
Abstract
X-ray phase-contrast computed tomography (PCCT) using grating interferometry provides enhanced soft-tissue contrast. The possibility to use standard polychromatic laboratory sources enables an implementation into a clinical setting. Thus, PCCT has gained significant attention in recent years. However, phase-contrast CT scans still require significantly increased measurement times in comparison to conventional attenuation-based CT imaging. This is mainly due to a time-consuming stepping of a grating, which is necessary for an accurate retrieval of the phase information. In this paper, we demonstrate a novel scan technique, which directly allows the determination of the phase signal without a phase-stepping procedure. The presented work is based on moiré fringe scanning, which allows fast data acquisition in radiographic applications such as mammography or in-line product analysis. Here, we demonstrate its extension to tomography enabling a continuous helical sample rotation as routinely performed in clinical CT systems. Compared to standard phase-stepping techniques, the proposed helical fringe-scanning procedure enables faster measurements, an extended field of view and relaxes the stability requirements of the system, since the gratings remain stationary. Finally, our approach exceeds previously introduced methods by not relying on spatial interpolation to acquire the phase-contrast signal.
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Affiliation(s)
- M Marschner
- Lehrstuhl für Biomedizinische Physik, Physik-Department &Institut für Medizintechnik, Technische Universität München, 85748 Garching, Germany
| | - M Willner
- Lehrstuhl für Biomedizinische Physik, Physik-Department &Institut für Medizintechnik, Technische Universität München, 85748 Garching, Germany
| | - G Potdevin
- Lehrstuhl für Biomedizinische Physik, Physik-Department &Institut für Medizintechnik, Technische Universität München, 85748 Garching, Germany
| | - A Fehringer
- Lehrstuhl für Biomedizinische Physik, Physik-Department &Institut für Medizintechnik, Technische Universität München, 85748 Garching, Germany
| | - P B Noël
- Lehrstuhl für Biomedizinische Physik, Physik-Department &Institut für Medizintechnik, Technische Universität München, 85748 Garching, Germany.,Institut für diagnostische und interventionelle Radiologie, Klinikum rechts der Isar, Technische Universität München, 81675 München, Germany
| | - F Pfeiffer
- Lehrstuhl für Biomedizinische Physik, Physik-Department &Institut für Medizintechnik, Technische Universität München, 85748 Garching, Germany.,Institut für diagnostische und interventionelle Radiologie, Klinikum rechts der Isar, Technische Universität München, 81675 München, Germany
| | - J Herzen
- Lehrstuhl für Biomedizinische Physik, Physik-Department &Institut für Medizintechnik, Technische Universität München, 85748 Garching, Germany
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13
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Willner M, Viermetz M, Marschner M, Scherer K, Braun C, Fingerle A, Noël P, Rummeny E, Pfeiffer F, Herzen J. Quantitative Three-Dimensional Imaging of Lipid, Protein, and Water Contents via X-Ray Phase-Contrast Tomography. PLoS One 2016; 11:e0151889. [PMID: 27003308 PMCID: PMC4803315 DOI: 10.1371/journal.pone.0151889] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2015] [Accepted: 03/04/2016] [Indexed: 02/07/2023] Open
Abstract
X-ray phase-contrast computed tomography is an emerging imaging technology with powerful capabilities for three-dimensional (3D) visualization of weakly absorbing objects such as biological soft tissues. This technique is an extension of existing X-ray applications because conventional attenuation-contrast images are simultaneously acquired. The complementary information provided by both the contrast modalities suggests that enhanced material characterization is possible when performing combined data analysis. In this study, we describe how protein, lipid, and water concentrations in each 3D voxel can be quantified by vector decomposition. Experimental results of dairy products, porcine fat and rind, and different human soft tissue types are presented. The results demonstrate the potential of phase-contrast imaging as a new analysis tool. The 3D representations of protein, lipid, and water contents open up new opportunities in the fields of biology, medicine, and food science.
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Affiliation(s)
- Marian Willner
- Department of Physics and Institute of Medical Engineering, Technische Universität München, Garching, Germany
- Department of Diagnostic and Interventional Radiology, Technische Universität München, Munich, Germany
- * E-mail:
| | - Manuel Viermetz
- Department of Physics and Institute of Medical Engineering, Technische Universität München, Garching, Germany
| | - Mathias Marschner
- Department of Physics and Institute of Medical Engineering, Technische Universität München, Garching, Germany
| | - Kai Scherer
- Department of Physics and Institute of Medical Engineering, Technische Universität München, Garching, Germany
| | - Christian Braun
- Institute of Forensic Medicine, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Alexander Fingerle
- Department of Diagnostic and Interventional Radiology, Technische Universität München, Munich, Germany
| | - Peter Noël
- Department of Diagnostic and Interventional Radiology, Technische Universität München, Munich, Germany
| | - Ernst Rummeny
- Department of Diagnostic and Interventional Radiology, Technische Universität München, Munich, Germany
| | - Franz Pfeiffer
- Department of Physics and Institute of Medical Engineering, Technische Universität München, Garching, Germany
| | - Julia Herzen
- Department of Physics and Institute of Medical Engineering, Technische Universität München, Garching, Germany
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14
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Meiser J, Willner M, Schröter T, Hofmann A, Rieger J, Koch F, Birnbacher L, Schüttler M, Kunka D, Meyer P, Faisal A, Amberger M, Duttenhofer T, Weber T, Hipp A, Ehn S, Walter M, Herzen J, Schulz J, Pfeiffer F, Mohr J. Increasing the field of view in grating based X-ray phase contrast imaging using stitched gratings. J Xray Sci Technol 2016; 24:379-388. [PMID: 27257876 DOI: 10.3233/xst-160552] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Grating based X-ray differential phase contrast imaging (DPCI) allows for high contrast imaging of materials with similar absorption characteristics. In the last years' publications, small animals or parts of the human body like breast, hand, joints or blood vessels have been studied. Larger objects could not be investigated due to the restricted field of view limited by the available grating area. In this paper, we report on a new stitching method to increase the grating area significantly: individual gratings are merged on a carrier substrate. Whereas the grating fabrication process is based on the LIGA technology (X-ray lithography and electroplating) different cutting and joining methods have been evaluated. First imaging results using a 2×2 stitched analyzer grating in a Talbot-Lau interferometer have been generated using a conventional polychromatic X-ray source. The image quality and analysis confirm the high potential of the stitching method to increase the field of view considerably.
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Affiliation(s)
- J Meiser
- Institute of Microstructure Technology, Karlsruhe Institute of Technology Eggenstein-Leopoldshafen, Germany
| | - M Willner
- Department of Physics and Institute of Medical Engineering, Technische Universität München, Garching, Germany
| | - T Schröter
- Institute of Microstructure Technology, Karlsruhe Institute of Technology Eggenstein-Leopoldshafen, Germany
| | - A Hofmann
- Institute for Applied Computer Science, Karlsruhe Institute of Technology, Karlsruhe, Germany
| | - J Rieger
- Erlangen Center for Astroparticle Physics, Friedrich - Alexander - Universität Erlangen - Nürnberg, Erlangen, Germany
| | - F Koch
- Institute of Microstructure Technology, Karlsruhe Institute of Technology Eggenstein-Leopoldshafen, Germany
| | - L Birnbacher
- Department of Physics and Institute of Medical Engineering, Technische Universität München, Garching, Germany
| | - M Schüttler
- Institute of Microstructure Technology, Karlsruhe Institute of Technology Eggenstein-Leopoldshafen, Germany
- Department of Physics and Institute of Medical Engineering, Technische Universität München, Garching, Germany
| | - D Kunka
- Institute of Microstructure Technology, Karlsruhe Institute of Technology Eggenstein-Leopoldshafen, Germany
| | - P Meyer
- Institute of Microstructure Technology, Karlsruhe Institute of Technology Eggenstein-Leopoldshafen, Germany
| | - A Faisal
- Institute of Microstructure Technology, Karlsruhe Institute of Technology Eggenstein-Leopoldshafen, Germany
| | - M Amberger
- Institute of Microstructure Technology, Karlsruhe Institute of Technology Eggenstein-Leopoldshafen, Germany
| | | | - T Weber
- Erlangen Center for Astroparticle Physics, Friedrich - Alexander - Universität Erlangen - Nürnberg, Erlangen, Germany
| | - A Hipp
- Department of Physics and Institute of Medical Engineering, Technische Universität München, Garching, Germany
- Institute of Materials Research, Helmholtz-Zentrum Geesthacht, Geesthacht, Germany
| | - S Ehn
- Department of Physics and Institute of Medical Engineering, Technische Universität München, Garching, Germany
| | - M Walter
- Microworks GmbH, Karlsruhe, Germany
| | - J Herzen
- Department of Physics and Institute of Medical Engineering, Technische Universität München, Garching, Germany
| | - J Schulz
- Microworks GmbH, Karlsruhe, Germany
| | - F Pfeiffer
- Department of Physics and Institute of Medical Engineering, Technische Universität München, Garching, Germany
| | - J Mohr
- Institute of Microstructure Technology, Karlsruhe Institute of Technology Eggenstein-Leopoldshafen, Germany
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15
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Gromann LB, Bequé D, Scherer K, Willer K, Birnbacher L, Willner M, Herzen J, Grandl S, Hellerhoff K, Sperl JI, Pfeiffer F, Cozzini C. Low-dose, phase-contrast mammography with high signal-to-noise ratio. Biomed Opt Express 2016; 7:381-391. [PMID: 26977347 PMCID: PMC4771456 DOI: 10.1364/boe.7.000381] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/28/2015] [Revised: 12/19/2015] [Accepted: 12/20/2015] [Indexed: 06/05/2023]
Abstract
Differential phase-contrast X-ray imaging using a Talbot-Lau interferometer has recently shown promising results for applications in medical imaging. However, reducing the applied radiation dose remains a major challenge. In this study, we consider the realization of a Talbot-Lau interferometer in a high Talbot order to increase the signal-to-noise ratio for low-dose applications. The quantitative performance of π and π/2 systems at high Talbot orders is analyzed through simulations, and the design energy and X-ray spectrum are optimized for mammography. It is found that operation even at very high Talbot orders is feasible and beneficial for image quality. As long as the X-ray spectrum is matched to the visibility spectrum, the SNR continuously increases with the Talbot order for π-systems. We find that the optimal X-ray spectra and design energies are almost independent of the Talbot order and that the overall imaging performance is robust against small variations in these parameters. Discontinuous spectra, such as that from molybdenum, are less robust because the characteristic lines may coincide with minima in the visibility spectra; however, they may offer slightly better performance. We verify this hypothesis by realizing a prototype system with a mean fringe visibility of above 40% at the seventh Talbot order. With this prototype, a proof-of-principle measurement of a freshly dissected breast at reasonable compression to 4 cm is conducted with a mean glandular dose of only 3 mGy but with a high SNR.
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Affiliation(s)
- Lukas B. Gromann
- Lehrstuhl für Biomedizinische Physik, Physik-Department & Institut für Medizintechnik, Technische Universität München, 85748 Garching,
Germany
- GE Global Research, 85748 Garching,
Germany
| | - Dirk Bequé
- GE Global Research, 85748 Garching,
Germany
| | - Kai Scherer
- Lehrstuhl für Biomedizinische Physik, Physik-Department & Institut für Medizintechnik, Technische Universität München, 85748 Garching,
Germany
| | - Konstantin Willer
- Lehrstuhl für Biomedizinische Physik, Physik-Department & Institut für Medizintechnik, Technische Universität München, 85748 Garching,
Germany
| | - Lorenz Birnbacher
- Lehrstuhl für Biomedizinische Physik, Physik-Department & Institut für Medizintechnik, Technische Universität München, 85748 Garching,
Germany
| | - Marian Willner
- Lehrstuhl für Biomedizinische Physik, Physik-Department & Institut für Medizintechnik, Technische Universität München, 85748 Garching,
Germany
| | - Julia Herzen
- Lehrstuhl für Biomedizinische Physik, Physik-Department & Institut für Medizintechnik, Technische Universität München, 85748 Garching,
Germany
| | - Susanne Grandl
- Institute of Clinical Radiology, Ludwig-Maximilians-University Hospital Munich,
Germany
| | - Karin Hellerhoff
- Institute of Clinical Radiology, Ludwig-Maximilians-University Hospital Munich,
Germany
| | | | - Franz Pfeiffer
- Lehrstuhl für Biomedizinische Physik, Physik-Department & Institut für Medizintechnik, Technische Universität München, 85748 Garching,
Germany
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16
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Willner M, Fior G, Marschner M, Birnbacher L, Schock J, Braun C, Fingerle AA, Noël PB, Rummeny EJ, Pfeiffer F, Herzen J. Phase-Contrast Hounsfield Units of Fixated and Non-Fixated Soft-Tissue Samples. PLoS One 2015; 10:e0137016. [PMID: 26322638 PMCID: PMC4556454 DOI: 10.1371/journal.pone.0137016] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2015] [Accepted: 08/10/2015] [Indexed: 11/25/2022] Open
Abstract
X-ray phase-contrast imaging is a novel technology that achieves high soft-tissue contrast. Although its clinical impact is still under investigation, the technique may potentially improve clinical diagnostics. In conventional attenuation-based X-ray computed tomography, radiological diagnostics are quantified by Hounsfield units. Corresponding Hounsfield units for phase-contrast imaging have been recently introduced, enabling a setup-independent comparison and standardized interpretation of imaging results. Thus far, the experimental values of few tissue types have been reported; these values have been determined from fixated tissue samples. This study presents phase-contrast Hounsfield units for various types of non-fixated human soft tissues. A large variety of tissue specimens ranging from adipose, muscle and connective tissues to liver, kidney and pancreas tissues were imaged by a grating interferometer with a rotating-anode X-ray tube and a photon-counting detector. Furthermore, we investigated the effects of formalin fixation on the quantitative phase-contrast imaging results.
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Affiliation(s)
- Marian Willner
- Department of Physics & Institute of Medical Engineering, Technische Universität München, Garching, Germany
- * E-mail:
| | - Gabriel Fior
- Department of Physics & Institute of Medical Engineering, Technische Universität München, Garching, Germany
| | - Mathias Marschner
- Department of Physics & Institute of Medical Engineering, Technische Universität München, Garching, Germany
| | - Lorenz Birnbacher
- Department of Physics & Institute of Medical Engineering, Technische Universität München, Garching, Germany
| | - Jonathan Schock
- Department of Physics & Institute of Medical Engineering, Technische Universität München, Garching, Germany
| | - Christian Braun
- Institute of Forensic Medicine, Ludwig-Maximilians-Universität, Munich, Germany
| | - Alexander A. Fingerle
- Department of Diagnostic and Interventional Radiology, Technische Universität München, Munich, Germany
| | - Peter B. Noël
- Department of Diagnostic and Interventional Radiology, Technische Universität München, Munich, Germany
| | - Ernst J. Rummeny
- Department of Diagnostic and Interventional Radiology, Technische Universität München, Munich, Germany
| | - Franz Pfeiffer
- Department of Physics & Institute of Medical Engineering, Technische Universität München, Garching, Germany
| | - Julia Herzen
- Department of Physics & Institute of Medical Engineering, Technische Universität München, Garching, Germany
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17
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Hetterich H, Webber N, Willner M, Herzen J, Birnbacher L, Hipp A, Bamberg F, Pfeiffer F, Saam T. Klassifikation atherosklerotischer Plaques mittels gitterbasierter Phasenkontrast-Computertomografie. ROFO-FORTSCHR RONTG 2015. [DOI: 10.1055/s-0035-1550859] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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18
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Braunagel M, Birnbacher L, Willner M, Herzen J, Notohamiprodjo S, Mai V, Pfeiffer F, Reiser M, Notohamiprodjo M. Gitter-basierte Phasenkontrast-Röntgenbildgebung: Eine neue Methode zur Differenzierung von Nierentumoren ex vivo. ROFO-FORTSCHR RONTG 2015. [DOI: 10.1055/s-0035-1551451] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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19
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Sarapata A, Willner M, Walter M, Duttenhofer T, Kaiser K, Meyer P, Braun C, Fingerle A, Noël PB, Pfeiffer F, Herzen J. Quantitative imaging using high-energy X-ray phase-contrast CT with a 70 kVp polychromatic X-ray spectrum. Opt Express 2015; 23:523-535. [PMID: 25835698 DOI: 10.1364/oe.23.000523] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Imaging of large and dense objects with grating-based X-ray phase-contrast computed tomography requires high X-ray photon energy and large fields of view. It has become increasingly possible due to the improvements in the grating manufacturing processes. Using a high-energy X-ray phase-contrast CT setup with a large (10 cm in diameter) analyzer grating and operated at an acceleration tube voltage of 70 kVp, we investigate the complementarity of both attenuation and phase contrast modalities with materials of various atomic numbers (Z). We confirm experimentally that for low-Z materials, phase contrast yields no additional information content over attenuation images, yet it provides increased contrast-to-noise ratios (CNRs). The complementarity of both signals can be seen again with increasing Z of the materials and a more comprehensive material characterization is thus possible. Imaging of a part of a human cervical spine with intervertebral discs surrounded by bones and various soft tissue types showcases the benefit of high-energy X-ray phase-contrast system. Phase-contrast reconstruction reveals the internal structure of the discs and makes the boundary between the disc annulus and nucleus pulposus visible. Despite the fact that it still remains challenging to develop a high-energy grating interferometer with a broad polychromatic source with satisfactory optical performance, improved image quality for phase contrast as compared to attenuation contrast can be obtained and new exciting applications foreseen.
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20
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Burger K, Koehler T, Chabior M, Allner S, Marschner M, Fehringer A, Willner M, Pfeiffer F, Noël P. Regularized iterative integration combined with non-linear diffusion filtering for phase-contrast x-ray computed tomography. Opt Express 2014; 22:32107-32118. [PMID: 25607176 DOI: 10.1364/oe.22.032107] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Phase-contrast x-ray computed tomography has a high potential to become clinically implemented because of its complementarity to conventional absorption-contrast.In this study, we investigate noise-reducing but resolution-preserving analytical reconstruction methods to improve differential phase-contrast imaging. We apply the non-linear Perona-Malik filter on phase-contrast data prior or post filtered backprojected reconstruction. Secondly, the Hilbert kernel is replaced by regularized iterative integration followed by ramp filtered backprojection as used for absorption-contrast imaging. Combining the Perona-Malik filter with this integration algorithm allows to successfully reveal relevant sample features, quantitatively confirmed by significantly increased structural similarity indices and contrast-to-noise ratios. With this concept, phase-contrast imaging can be performed at considerably lower dose.
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21
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Hipp A, Willner M, Herzen J, Auweter S, Chabior M, Meiser J, Achterhold K, Mohr J, Pfeiffer F. Energy-resolved visibility analysis of grating interferometers operated at polychromatic X-ray sources. Opt Express 2014; 22:30394-30409. [PMID: 25606986 DOI: 10.1364/oe.22.030394] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Grating interferometry has been successfully adapted at standard X-ray tubes and is a promising candidate for a broad use of phase-contrast imaging in medical diagnostics or industrial testing. The achievable image quality using this technique is mainly dependent on the interferometer performance with the interferometric visibility as crucial parameter. The presented study deals with experimental investigations of the spectral dependence of the visibility in order to understand the interaction between the single contributing energies. Especially for the choice which type of setup has to be preferred using a polychromatic source, this knowledge is highly relevant. Our results affirm previous findings from theoretical investigations but also show that measurements of the spectral contributions to the visibility are necessary to fully characterize and optimize a grating interferometer and cannot be replaced by only relying on simulated data up to now.
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22
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Fingerle AA, Willner M, Herzen J, Münzel D, Hahn D, Rummeny EJ, Noël PB, Pfeiffer F. Simulated Cystic Renal Lesions: Quantitative X-ray Phase-Contrast CT—An in Vitro Phantom Study. Radiology 2014; 272:739-48. [DOI: 10.1148/radiol.14130876] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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23
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Mohajerani P, Hipp A, Willner M, Marschner M, Trajkovic-Arsic M, Ma X, Burton NC, Klemm U, Radrich K, Ermolayev V, Tzoumas S, Siveke JT, Bech M, Pfeiffer F, Ntziachristos V. FMT-PCCT: hybrid fluorescence molecular tomography-x-ray phase-contrast CT imaging of mouse models. IEEE Trans Med Imaging 2014; 33:1434-46. [PMID: 24686244 DOI: 10.1109/tmi.2014.2313405] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
The implementation of hybrid fluorescence molecular tomography (FMT) and X-ray computed tomography (CT) has been shown to be a necessary development, not only for combining anatomical with functional and molecular contrast, but also for generating optical images of high accuracy. FMT affords highly sensitive 3-D imaging of fluorescence bio-distribution, but in stand-alone form it offers images of low resolution. It was shown that FMT accuracy significantly improves by considering anatomical priors from CT. Conversely, CT generally suffers from low soft tissue contrast. Therefore utilization of CT data as prior information in FMT inversion is challenging when different internal organs are not clearly differentiated. Instead, we combined herein FMT with emerging X-ray phase-contrast CT (PCCT). PCCT relies on phase shift differences in tissue to achieve soft tissue contrast superior to conventional CT. We demonstrate for the first time FMT-PCCT imaging of different animal models, where FMT and PCCT scans were performed in vivo and ex vivo, respectively. The results show that FMT-PCCT expands the potential of FMT in imaging lesions with otherwise low or no CT contrast, while retaining the cost benefits of CT and simplicity of hybrid device realizations. The results point to the most accurate FMT performance to date.
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Grandl S, Willner M, Herzen J, Sztrókay-Gaul A, Mayr D, Auweter SD, Hipp A, Birnbacher L, Marschner M, Chabior M, Reiser M, Pfeiffer F, Bamberg F, Hellerhoff K. Visualizing typical features of breast fibroadenomas using phase-contrast CT: an ex-vivo study. PLoS One 2014; 9:e97101. [PMID: 24824169 PMCID: PMC4019647 DOI: 10.1371/journal.pone.0097101] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2014] [Accepted: 04/15/2014] [Indexed: 11/29/2022] Open
Abstract
Background Fibroadenoma is the most common benign solid breast lesion type and a very common cause for histologic assessment. To justify a conservative therapy, a highly specific discrimination between fibroadenomas and other breast lesions is crucial. Phase-contrast imaging offers improved soft-tissue contrast and differentiability of fine structures combined with the potential of 3-dimensional imaging. In this study we assessed the potential of grating-based phase-contrast CT imaging for visualizing diagnostically relevant features of fibroadenomas. Materials and Methods Grating-based phase-contrast CT was performed on six ex-vivo formalin-fixed breast specimens containing a fibroadenoma and three samples containing benign changes that resemble fibroadenomas using Talbot Lau interferometry and a polychromatic X-ray source. Phase-contrast and simultaneously acquired absorption-based 3D-datasets were manually matched with corresponding histological slices. The visibility of diagnostically valuable features was assessed in comparison with histology as the gold-standard. Results In all cases, matching of grating-based phase-contrast CT images and histology was successfully completed. Grating-based phase-contrast CT showed greatly improved differentiation of fine structures and provided accurate depiction of strands of fibrous tissue within the fibroadenomas as well as of the diagnostically valuable dilated, branched ductuli of the fibroadenomas. A clear demarcation of tumor boundaries in all cases was provided by phase- but not absorption-contrast CT. Conclusions Pending successful translation of the technology to a clinical setting and considerable reduction of the required dose, the data presented here suggest that grating-based phase-contrast CT may be used as a supplementary non-invasive diagnostic tool in breast diagnostics. Phase-contrast CT may thus contribute to the reduction of false positive findings and reduce the recall and core biopsy rate in population-based screening. Phase-contrast CT may further be used to assist during histopathological workup, offering a 3D view of the tumor and helping to identify diagnostically valuable tissue sections within large tumors.
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Affiliation(s)
- Susanne Grandl
- Institute for Clinical Radiology, Ludwig-Maximilians-University Hospital, Munich, Germany
- * E-mail:
| | - Marian Willner
- Department of Physics and Institute of Medical Engineering, Technical University of Munich, Munich, Germany
| | - Julia Herzen
- Department of Physics and Institute of Medical Engineering, Technical University of Munich, Munich, Germany
- Institute for Materials Research, Helmholtz-Zentrum Geesthacht, Geesthacht, Germany
| | - Anikó Sztrókay-Gaul
- Institute for Clinical Radiology, Ludwig-Maximilians-University Hospital, Munich, Germany
| | - Doris Mayr
- Institute of Pathology, Ludwig-Maximilians-University Hospital Munich, Munich, Germany
| | - Sigrid D. Auweter
- Institute for Clinical Radiology, Ludwig-Maximilians-University Hospital, Munich, Germany
| | - Alexander Hipp
- Institute for Materials Research, Helmholtz-Zentrum Geesthacht, Geesthacht, Germany
| | - Lorenz Birnbacher
- Department of Physics and Institute of Medical Engineering, Technical University of Munich, Munich, Germany
| | - Mathias Marschner
- Department of Physics and Institute of Medical Engineering, Technical University of Munich, Munich, Germany
| | - Michael Chabior
- Department of Physics and Institute of Medical Engineering, Technical University of Munich, Munich, Germany
| | - Maximilian Reiser
- Institute for Clinical Radiology, Ludwig-Maximilians-University Hospital, Munich, Germany
| | - Franz Pfeiffer
- Department of Physics and Institute of Medical Engineering, Technical University of Munich, Munich, Germany
| | - Fabian Bamberg
- Institute for Clinical Radiology, Ludwig-Maximilians-University Hospital, Munich, Germany
| | - Karin Hellerhoff
- Institute for Clinical Radiology, Ludwig-Maximilians-University Hospital, Munich, Germany
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Saam T, Willner M, Fill S, Herzen J, Webber N, Hipp A, Reiser M, Pfeiffer F, Bamberg F, Hetterich H. Gewebecharakterisierung atherosklerotischer Plaque-Komponenten von Carotiden mittels quantitativer Phasenkontrast-Hounsfield-Einheiten. ROFO-FORTSCHR RONTG 2014. [DOI: 10.1055/s-0034-1372791] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Hetterich H, Habbel C, Willner M, Herzen J, Saam T, Hipp A, Marschner M, Reiser M, Pfeiffer F, Bamberg F. Charakterisierung der koronaren Atherosklerose mittels röntgenbasierter Phasenkontrast-Computertomografie. ROFO-FORTSCHR RONTG 2014. [DOI: 10.1055/s-0034-1372792] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Willner M, Herzen J, Grandl S, Auweter S, Mayr D, Hipp A, Chabior M, Sarapata A, Achterhold K, Zanette I, Weitkamp T, Sztrókay A, Hellerhoff K, Reiser M, Pfeiffer F. Quantitative breast tissue characterization using grating-based x-ray phase-contrast imaging. Phys Med Biol 2014; 59:1557-71. [PMID: 24614413 DOI: 10.1088/0031-9155/59/7/1557] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
X-ray phase-contrast imaging has received growing interest in recent years due to its high capability in visualizing soft tissue. Breast imaging became the focus of particular attention as it is considered the most promising candidate for a first clinical application of this contrast modality. In this study, we investigate quantitative breast tissue characterization using grating-based phase-contrast computed tomography (CT) at conventional polychromatic x-ray sources. Different breast specimens have been scanned at a laboratory phase-contrast imaging setup and were correlated to histopathology. Ascertained tumor types include phylloides tumor, fibroadenoma and infiltrating lobular carcinoma. Identified tissue types comprising adipose, fibroglandular and tumor tissue have been analyzed in terms of phase-contrast Hounsfield units and are compared to high-quality, high-resolution data obtained with monochromatic synchrotron radiation, as well as calculated values based on tabulated tissue properties. The results give a good impression of the method's prospects and limitations for potential tumor detection and the associated demands on such a phase-contrast breast CT system. Furthermore, the evaluated quantitative tissue values serve as a reference for simulations and the design of dedicated phantoms for phase-contrast mammography.
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Affiliation(s)
- M Willner
- Department of Physics and Institute of Medical Engineering, Technische Universität München, James-Franck-Straße 1, D-85748 Garching, Germany
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Auweter SD, Herzen J, Willner M, Grandl S, Scherer K, Bamberg F, Reiser MF, Pfeiffer F, Hellerhoff K. X-ray phase-contrast imaging of the breast--advances towards clinical implementation. Br J Radiol 2014; 87:20130606. [PMID: 24452106 DOI: 10.1259/bjr.20130606] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
Breast cancer constitutes about one-quarter of all cancers and is the leading cause of cancer death in women. To reduce breast cancer mortality, mammographic screening programmes have been implemented in many Western countries. However, these programmes remain controversial because of the associated radiation exposure and the need for improvement in terms of diagnostic accuracy. Phase-contrast imaging is a new X-ray-based technology that has been shown to provide enhanced soft-tissue contrast and improved visualization of cancerous structures. Furthermore, there is some indication that these improvements of image quality can be maintained at reduced radiation doses. Thus, X-ray phase-contrast mammography may significantly contribute to advancements in early breast cancer diagnosis. Feasibility studies of X-ray phase-contrast breast CT have provided images that allow resolution of the fine structure of tissue that can otherwise only be obtained by histology. This implies that X-ray phase-contrast imaging may also lead to the development of entirely new (micro-) radiological applications. This review provides a brief overview of the physical characteristics of this new technology and describes recent developments towards clinical implementation of X-ray phase-contrast imaging of the breast.
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Affiliation(s)
- S D Auweter
- Department of Clinical Radiology, Ludwig-Maximilians-Universität München, Munich, Germany
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Hetterich H, Willner M, Fill S, Herzen J, Bamberg F, Hipp A, Schüller U, Adam-Neumair S, Wirth S, Reiser M, Pfeiffer F, Saam T. Phase-contrast CT: qualitative and quantitative evaluation of atherosclerotic carotid artery plaque. Radiology 2014; 271:870-8. [PMID: 24588675 DOI: 10.1148/radiol.14131554] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
PURPOSE To evaluate the potential of phase-contrast computed tomography (CT) for atherosclerotic plaque imaging in human carotid arteries in an experimental ex vivo study. MATERIALS AND METHODS The study was approved by the institutional review board, and informed consent was obtained from the patients' relatives. Seven postmortem human carotid artery specimens were imaged at a laboratory setup by using a conventional x-ray tube and grating interferometer. After histologic processing, phase-contrast imaging and histopathologic data were matched. Characteristics of the necrotic core (NC) covered by a fibrous cap (FC), intraplaque hemorrhage (IPH), and calcifications (CAs) were established, and sensitivity, specificity, and accuracy of phase-contrast CT for plaque detection and the potential for accurate quantification were assessed. The Cohen κ and Pearson correlation coefficient R were used to determine the agreement between phase-contrast imaging and histopathologic findings for plaque characterization and correlation of quantitative plaque measurements, respectively. A difference with a P value of less than .05 was considered significant. RESULTS Characteristic criteria were found in all analyzed plaque components. Applying these criteria, phase-contrast CT had a good sensitivity for the detection of the FC and NC, IPH, and CAs (all, >80%) and excellent specificity and accuracy (all, >90%), with good interreader agreement (κ ≥ 0.72, P < .0001). There were excellent correlations for quantitative measurements of FC, NC, and CAs between phase-contrast imaging and histopathologic findings (R ≥ 0.92). Interreader reproducibility was excellent, with an intraclass correlation coefficient of 0.98 or higher for all measurements. CONCLUSION The results of this study indicate that ex vivo phase-contrast CT can help identify and quantify atherosclerotic plaque components, with excellent correlation to histopathologic findings. Although not yet applicable in vivo, phase-contrast CT may become a valuable tool to monitor atherosclerotic disease process noninvasively.
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Affiliation(s)
- Holger Hetterich
- From the Institute of Clinical Radiology (H.H., S.F., F.B., S.A., S.W., M.R., T.S.), Center for Neuropathology (U.S.), and Institute of Anatomy (S.A.), Ludwig-Maximilians-University Hospital, Pettenkoferstrasse 8a, 80336 Munich, Germany; {Department of Physics and Institute for Technical Medicine}, Technische Universität München, Garching, Germany (M.W., J.H., A.H., F.P.); and Institute of Materials Research, Helmholtz-Zentrum, Geesthacht, Germany (J.H.)
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Fu J, Willner M, Chen L, Tan R, Achterhold K, Bech M, Herzen J, Kunka D, Mohr J, Pfeiffer F. Helical differential X-ray phase-contrast computed tomography. Phys Med 2014; 30:374-9. [PMID: 24518822 DOI: 10.1016/j.ejmp.2014.01.005] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/17/2013] [Revised: 01/09/2014] [Accepted: 01/11/2014] [Indexed: 10/25/2022] Open
Abstract
We report on the first experimental results of helical differential phase-contrast computed tomography (helical DPC-CT) with a laboratory X-ray tube source and a Talbot-Lau grating interferometer. The results experimentally verify the feasibility of helical data acquisition and reconstruction in phase-contrast imaging, in analogy to its use in clinical CT systems. This allows fast and continuous volumetric scans for long objects with lengths exceeding the dimension of the detector. Since helical CT revolutionized the field of medical CT several years ago, we anticipate that this method will bring the same significant impact on the future medical and industrial applications of X-ray DPC-CT.
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Affiliation(s)
- Jian Fu
- Beijing University of Aeronautics and Astronautics, 100191 Beijing, China.
| | | | - Liyuan Chen
- Beijing University of Aeronautics and Astronautics, 100191 Beijing, China
| | - Renbo Tan
- Beijing University of Aeronautics and Astronautics, 100191 Beijing, China
| | | | - Martin Bech
- Technische Universität München, 85748 Garching, Germany; Lund University, Department for Medical Radiation Physics, 22185 Lund, Sweden.
| | - Julia Herzen
- Institute of Materials Research, Helmholtz-Zentrum Geesthacht, 22607 Hamburg, Germany
| | - Danays Kunka
- Karlsruhe Institute of Technology, Institute for Microstructure Technology, 76344 Eggenstein-Leopoldshafen, Germany
| | - Juergen Mohr
- Karlsruhe Institute of Technology, Institute for Microstructure Technology, 76344 Eggenstein-Leopoldshafen, Germany
| | - Franz Pfeiffer
- Technische Universität München, 85748 Garching, Germany.
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Saam T, Herzen J, Hetterich H, Fill S, Willner M, Stockmar M, Achterhold K, Zanette I, Weitkamp T, Schüller U, Auweter S, Adam-Neumair S, Nikolaou K, Reiser MF, Pfeiffer F, Bamberg F. Translation of atherosclerotic plaque phase-contrast CT imaging from synchrotron radiation to a conventional lab-based X-ray source. PLoS One 2013; 8:e73513. [PMID: 24039969 PMCID: PMC3767700 DOI: 10.1371/journal.pone.0073513] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2013] [Accepted: 07/21/2013] [Indexed: 11/26/2022] Open
Abstract
Objectives Phase-contrast imaging is a novel X-ray based technique that provides enhanced soft tissue contrast. The aim of this study was to evaluate the feasibility of visualizing human carotid arteries by grating-based phase-contrast tomography (PC-CT) at two different experimental set-ups: (i) applying synchrotron radiation and (ii) using a conventional X-ray tube. Materials and Methods Five ex-vivo carotid artery specimens were examined with PC-CT either at the European Synchrotron Radiation Facility using a monochromatic X-ray beam (2 specimens; 23 keV; pixel size 5.4 µm), or at a laboratory set-up on a conventional X-ray tube (3 specimens; 35-40 kVp; 70 mA; pixel size 100 µm). Tomographic images were reconstructed and compared to histopathology. Two independent readers determined vessel dimensions and one reader determined signal-to-noise ratios (SNR) between PC-CT and absorption images. Results In total, 51 sections were included in the analysis. Images from both set-ups provided sufficient contrast to differentiate individual vessel layers. All PCI-based measurements strongly predicted but significantly overestimated lumen, intima and vessel wall area for both the synchrotron and the laboratory-based measurements as compared with histology (all p<0.001 with slope >0.53 per mm2, 95%-CI: 0.35 to 0.70). Although synchrotron-based images were characterized by higher SNRs than laboratory-based images; both PC-CT set-ups had superior SNRs compared to corresponding conventional absorption-based images (p<0.001). Inter-reader reproducibility was excellent (ICCs >0.98 and >0.84 for synchrotron and for laboratory-based measurements; respectively). Conclusion Experimental PC-CT of carotid specimens is feasible with both synchrotron and conventional X-ray sources, producing high-resolution images suitable for vessel characterization and atherosclerosis research.
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Affiliation(s)
- Tobias Saam
- Institute of Clinical Radiology, Ludwig-Maximilians-University Hospital, Munich, Germany
- * E-mail:
| | - Julia Herzen
- Chair of Biomedical Physics, Technical University of Munich, Munich, Germany
- Institute of Materials Research, Helmholtz-Zentrum Geesthacht, Geesthacht, Germany
| | - Holger Hetterich
- Institute of Clinical Radiology, Ludwig-Maximilians-University Hospital, Munich, Germany
| | - Sandra Fill
- Institute of Clinical Radiology, Ludwig-Maximilians-University Hospital, Munich, Germany
| | - Marian Willner
- Chair of Biomedical Physics, Technical University of Munich, Munich, Germany
| | - Marco Stockmar
- Chair of Biomedical Physics, Technical University of Munich, Munich, Germany
| | - Klaus Achterhold
- Chair of Biomedical Physics, Technical University of Munich, Munich, Germany
| | - Irene Zanette
- European Synchrotron Radiation Facility (ESRF), Grenoble, France
| | | | - Ulrich Schüller
- Center for Neuropathology, Ludwig-Maximilians-University Hospital, Munich, Germany
| | - Sigrid Auweter
- Institute of Clinical Radiology, Ludwig-Maximilians-University Hospital, Munich, Germany
| | | | - Konstantin Nikolaou
- Institute of Clinical Radiology, Ludwig-Maximilians-University Hospital, Munich, Germany
| | - Maximilian F. Reiser
- Institute of Clinical Radiology, Ludwig-Maximilians-University Hospital, Munich, Germany
| | - Franz Pfeiffer
- Chair of Biomedical Physics, Technical University of Munich, Munich, Germany
| | - Fabian Bamberg
- Institute of Clinical Radiology, Ludwig-Maximilians-University Hospital, Munich, Germany
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Noël PB, Herzen J, Fingerle AA, Willner M, Stockmar MK, Hahn D, Settles M, Drecoll E, Zanette I, Weitkamp T, Rummeny EJ, Pfeiffer F. Evaluation of the potential of phase-contrast computed tomography for improved visualization of cancerous human liver tissue. Z Med Phys 2013; 23:204-11. [PMID: 23570951 DOI: 10.1016/j.zemedi.2013.02.006] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2012] [Revised: 02/17/2013] [Accepted: 02/27/2013] [Indexed: 02/01/2023]
Abstract
PURPOSE Phase-contrast X-ray computed tomography (PCCT) is currently investigated and developed as a potentially very interesting extension of conventional CT, and can offer several advantages for specific indications in diagnostic imaging. Current absorption-based computed tomography (CT) without the application of contrast material is limited in the detection of minor density differences in soft-tissue. The purpose of this study is to test whether PCCT can improve soft tissue contrast in healthy and tumorous human liver specimens. MATERIALS AND METHODS Two specimens of human liver (one healthy and one metastasized liver sample) were imaged with brilliant X-ray beam at the synchrotron radiation source ESRF in Grenoble, France. For correlation the same specimens were imaged with a magnetic resonance imaging system at 1.5 T. The histopathology confirmed our findings in the corresponding sections of the specimens. RESULTS In the phase-contrast CT images we observed a significantly enhanced soft-tissue contrast when compared to simultaneously recorded standard absorption CT measurements. Further, we found that the pathological and morphological information in the PCCT reconstructions show significant improvement when compared to those performed on MRI. Based on matching of prominent features, a good correlation between PCCT and the histological section is demonstrated; especially the tumor capsule and the surrounding vascular structures are visible in PCCT. In addition, our study revealed the ability of PCCT to visualize the blood vessels structure in the tumorous liver without the need of any contrast agents. CONCLUSION Grating-based PCCT significantly improves the soft-tissue contrast in ex-vivo liver specimens and holds the potential to overcome the need of contrast materials for visualization of the tumor vascularization.
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Affiliation(s)
- Peter B Noël
- Department of Radiology, Technische Universität München, Munich, Germany.
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Grandl S, Willner M, Herzen J, Mayr D, Auweter SD, Hipp A, Pfeiffer F, Reiser M, Hellerhoff K. Evaluation of phase-contrast CT of breast tissue at conventional X-ray sources - presentation of selected findings. Z Med Phys 2013; 23:212-21. [PMID: 23489931 DOI: 10.1016/j.zemedi.2013.02.005] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2012] [Revised: 02/14/2013] [Accepted: 02/18/2013] [Indexed: 12/20/2022]
Abstract
BACKGROUND Grating-based phase contrast computed tomography (PC-CT) at synchrotron radiation sources has been shown to provide improved visualization of breast tumors. However, broad clinical application of phase-contrast imaging will likely depend on transferring the technology to standard polychromatic X-ray sources. On the basis of selected findings, we demonstrate the potential of grating-based PC-CT using a conventional X-ray source. MATERIALS AND METHODS Grating-based PC-CT of two ex-vivo formalin fixed breast specimens containing lobular carcinoma was conducted using a Talbot Lau interferometer run at a polychromatic X-ray source of 40kVp. Phase-contrast and absorption-based 3D-datasets of both specimens were simultaneously recorded. Radiological images were manually matched with corresponding histological sections. The visualization of selected histological findings in phase contrast was compared to absorption contrast. RESULTS Grating-based PC-CT was able to depict the 3-dimensional structure of dilated ducts and high phase contrast was found as a correlate to thickened fibrous ductal walls. Differences in contrast between fibrous and less fibrous breast tissue were observed in phase- but not in absorption-contrast images. Furthermore, regions of low phase contrast correlated with the extension of compact tumor components. CONCLUSIONS On the basis of selected findings, we show that grating-based PC-CT at a polychromatic X-ray source provides complementary information to conventional absorption contrast; albeit at lower spatial resolution than synchrotron-based imaging.
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Affiliation(s)
- Susanne Grandl
- Department of Clinical Radiology, Ludwig-Maximilians-Universität München, Marchioninistrasse 15, 81377 Munich, Germany.
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Tapfer A, Braren R, Bech M, Willner M, Zanette I, Weitkamp T, Trajkovic-Arsic M, Siveke JT, Settles M, Aichler M, Walch A, Pfeiffer F. X-ray phase-contrast CT of a pancreatic ductal adenocarcinoma mouse model. PLoS One 2013; 8:e58439. [PMID: 23536795 PMCID: PMC3594292 DOI: 10.1371/journal.pone.0058439] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2012] [Accepted: 02/04/2013] [Indexed: 12/20/2022] Open
Abstract
To explore the potential of grating-based x-ray phase-contrast computed tomography (CT) for preclinical research, a genetically engineered mouse model of pancreatic ductal adenocarcinoma (PDAC) was investigated. One ex-vivo mouse specimen was scanned with different grating-based phase-contrast CT imaging setups covering two different settings: i) high-resolution synchrotron radiation (SR) imaging and ii) dose-reduced imaging using either synchrotron radiation or a conventional x-ray tube source. These experimental settings were chosen to assess the potential of phase-contrast imaging for two different types of application: i) high-performance imaging for virtual microscopy applications and ii) biomedical imaging with increased soft-tissue contrast for in-vivo applications. For validation and as a reference, histological slicing and magnetic resonance imaging (MRI) were performed on the same mouse specimen. For each x-ray imaging setup, attenuation and phase-contrast images were compared visually with regard to contrast in general, and specifically concerning the recognizability of lesions and cancerous tissue. To quantitatively assess contrast, the contrast-to-noise ratios (CNR) of selected regions of interest (ROI) in the attenuation images and the phase images were analyzed and compared. It was found that both for virtual microscopy and for in-vivo applications, there is great potential for phase-contrast imaging: in the SR-based benchmarking data, fine details about tissue composition are accessible in the phase images and the visibility of solid tumor tissue under dose-reduced conditions is markedly superior in the phase images. The present study hence demonstrates improved diagnostic value with phase-contrast CT in a mouse model of a complex endogenous cancer, promoting the use and further development of grating-based phase-contrast CT for biomedical imaging applications.
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Affiliation(s)
- Arne Tapfer
- Department of Physics and Institute of Medical Engineering, Technische Universität München, Garching, Germany.
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Pfeiffer F, Herzen J, Willner M, Chabior M, Auweter S, Reiser M, Bamberg F. Grating-based X-ray phase contrast for biomedical imaging applications. Z Med Phys 2013; 23:176-85. [PMID: 23453793 DOI: 10.1016/j.zemedi.2013.02.002] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2012] [Revised: 01/31/2013] [Accepted: 02/05/2013] [Indexed: 02/01/2023]
Abstract
In this review article we describe the development of grating-based X-ray phase-contrast imaging, with particular emphasis on potential biomedical applications of the technology. We review the basics of image formation in grating-based phase-contrast and dark-field radiography and present some exemplary multimodal radiography results obtained with laboratory X-ray sources. Furthermore, we discuss the theoretical concepts to extend grating-based multimodal radiography to quantitative transmission, phase-contrast, and dark-field scattering computed tomography.
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Affiliation(s)
- Franz Pfeiffer
- Department of Physics, Technical University Munich, 85748 Garching, Germany.
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Willner M, Bech M, Herzen J, Zanette I, Hahn D, Kenntner J, Mohr J, Rack A, Weitkamp T, Pfeiffer F. Quantitative X-ray phase-contrast computed tomography at 82 keV. Opt Express 2013; 21:4155-4166. [PMID: 23481949 DOI: 10.1364/oe.21.004155] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Potential applications of grating-based X-ray phase-contrast imaging are investigated in various fields due to its compatibility with laboratory X-ray sources. So far the method was mainly restricted to X-ray energies below 40 keV, which is too low to examine dense or thick objects, but a routine operation at higher energies is on the brink of realisation. In this study, imaging results obtained at 82 keV are presented. These comprise a test object consisting of well-defined materials for a quantitative analysis and a tooth to translate the findings to a biomedical sample. Measured linear attenuation coefficients ? and electron densities ?e are in good agreement with theoretical values. Improved contrast-to-noise ratios were found in phase contrast compared to attenuation contrast. The combination of both contrast modalities further enables to simultaneously assess information on density and composition of materials with effective atomic numbers Z? > 8. In our biomedical example, we demonstrate the possibility to detect differences in mass density and calcium concentration within teeth.
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Affiliation(s)
- Marian Willner
- Biomedical Physics, TU Munchen, 85748 Garching, Germany.
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Liebhardt S, Willner M, Herzen J, Mayr D, Auweter SD, Reiser M, Hellerhoff K. Fortschritte in der Brustdiagnostik mittels gitterbasierter Phasenkontrastbildgebung. ROFO-FORTSCHR RONTG 2012. [DOI: 10.1055/s-0032-1329777] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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Noël P, Herzen J, Fingerle A, Hahn D, Willner M, Settels M, Drecoll E, Zanette I, Weitkamp T, Rummeny E, Pfeiffer F. TH-E-110-01: Phase-Contrast Computed Tomography for Detection of Liver Cancer: Initial Results. Med Phys 2011. [DOI: 10.1118/1.3613585] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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39
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Herzen J, Willner M, Hahn D, Schleede S, Bech M, Noël P, Sztrókay A, Bamberg F, Zanette I, Weitkamp T, Pfeiffer F. SU-E-I-162: Quantitative Analysis of Human Soft Tissue Using Grating-Based X- Ray Phase Contrast. Med Phys 2011. [DOI: 10.1118/1.3611736] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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40
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Gesslein M, Willner M. [The family physician must also know it: the basic hernia multiplication table]. MMW Fortschr Med 2005; 147:56-7. [PMID: 16392404] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
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41
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Nachamkin I, MacGregor RR, Staneck JL, Tsang AY, Denner JC, Willner M, Barbagallo S. Niacin-positive Mycobacterium kansasii isolated from immunocompromised patients. J Clin Microbiol 1992; 30:1344-6. [PMID: 1583146 PMCID: PMC265283 DOI: 10.1128/jcm.30.5.1344-1346.1992] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Niacin-positive Mycobacterium kansasii was isolated from three patients, two with respiratory infections and one with a perirectal abscess. The isolates were phenotypically similar to other strains of M. kansasii, differing only in their ability to produce niacin. This phenotype has been reported only twice in the literature, during the 1960s.
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Affiliation(s)
- I Nachamkin
- Department of Pathology and Laboratory Medicine, University of Pennsylvania School of Medicine, Philadelphia 19104
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Willner M. Individual and group psychotherapy with the depressed geriatric patient: a rewarding approach. Long Term Care Health Serv Adm Q 1978; 2:308-31. [PMID: 10240181] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/12/2023]
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Abstract
A review is presented of the status of geriatric psychotherapy with the depressed elderly community resident, over the past 20 years. Feelings of helplessness and hopelessness accompanying or following a significant loss are often chief features of the depressive syndrome in elderly persons who seek help. The experiences of those involved in treating this disorder in the elderly can be most rewarding to both therapist and patient.
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