1
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Khorshidi A, Ashoor M. Quantitative assessment of full-width at half-maximum and detector energy threshold in X-ray imaging systems. Eur J Radiol 2024; 176:111537. [PMID: 38823162 DOI: 10.1016/j.ejrad.2024.111537] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2024] [Revised: 04/25/2024] [Accepted: 05/28/2024] [Indexed: 06/03/2024]
Abstract
BACKGROUND The response function of imaging systems is regularly considered to improve the qualified maps in various fields. More the accuracy of this function, the higher the quality of the images. METHODS In this study, a distinct analytical relationship between full-width at half-maximum (FWHM) value and detector energy thresholds at distinct tube peak voltage of 100 kV has been addressed in X-ray imaging. The outcomes indicate that the behavior of the function is exponential. The relevant cut-off frequency and summation of point spread function S(PSF) were assessed at large and detailed energy ranges. RESULTS A compromise must be made between cut-off frequency and FWHM to determine the optimal model. By detailed energy range, the minimum and maximum of S(PSF) values were revealed at 20 keV and 48 keV, respectively, by 2979 and 3073. Although the maximum value of FWHM occurred at the energy of 48 keV by 224 mm, its minimum value was revealed at 62 keV by 217 mm. Generally, FWHM value converged to 220 mm and S(PSF) to 3026 with small fluctuations. Consequently, there is no need to increase the voltage of the X-ray tube after the energy threshold of 20 keV. CONCLUSION The proposed FWHM function may be used in designing the setup of the imaging parameters in order to reduce the absorbed dose and obtain the final accurate maps using the related mathematical suggestions.
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Affiliation(s)
- Abdollah Khorshidi
- Radiation Applications Research School, Nuclear Science and Technology Research Institute, Tehran, Iran.
| | - Mansour Ashoor
- Radiation Applications Research School, Nuclear Science and Technology Research Institute, Tehran, Iran
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2
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Bairagi S, Abdollahifar MA, Atake OJ, Dust W, Wiebe S, Belev G, Chapman LD, Webb MA, Zhu N, Cooper DML, Eames BF. MRI overestimates articular cartilage thickness and volume compared to synchrotron radiation phase-contrast imaging. PLoS One 2023; 18:e0291757. [PMID: 37788257 PMCID: PMC10547194 DOI: 10.1371/journal.pone.0291757] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2022] [Accepted: 09/05/2023] [Indexed: 10/05/2023] Open
Abstract
Accurate evaluation of morphological changes in articular cartilage are necessary for early detection of osteoarthritis (OA). 3T magnetic resonance imaging (MRI) has highly sensitive contrast resolution and is widely used clinically to detect OA. However, synchrotron radiation phase-contrast imaging computed tomography (SR-PCI) can also provide contrast to tissue interfaces that do not have sufficient absorption differences, with the added benefit of very high spatial resolution. Here, MRI was compared with SR-PCI for quantitative evaluation of human articular cartilage. Medial tibial condyles were harvested from non-OA donors and from OA patients receiving knee replacement surgery. Both imaging methods revealed that average cartilage thickness and cartilage volume were significantly reduced in the OA group, compared to the non-OA group. When comparing modalities, the superior resolution of SR-PCI enabled more precise mapping of the cartilage surface relative to MRI. As a result, MRI showed significantly higher average cartilage thickness and cartilage volume, compared to SR-PCI. These data highlight the potential for high-resolution imaging of articular cartilage using SR-PCI as a solution for early OA diagnosis. Recognizing current limitations of using a synchrotron for clinical imaging, we discuss its nascent utility for preclinical models, particularly longitudinal studies of live animal models of OA.
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Affiliation(s)
- Suranjan Bairagi
- Department of Anatomy, Physiology, and Pharmacology, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
| | - Mohammad-Amin Abdollahifar
- Department of Anatomy, Physiology, and Pharmacology, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
| | - Oghenevwogaga J. Atake
- Department of Anatomy, Physiology, and Pharmacology, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
| | - William Dust
- Department of Surgery, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
| | - Sheldon Wiebe
- Department of Medical Imaging, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
| | - George Belev
- Canadian Light Source Inc., Saskatoon, Saskatchewan, Canada
| | - L. Dean Chapman
- Department of Anatomy, Physiology, and Pharmacology, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
| | - M. Adam Webb
- Canadian Light Source Inc., Saskatoon, Saskatchewan, Canada
| | - Ning Zhu
- Canadian Light Source Inc., Saskatoon, Saskatchewan, Canada
| | - David M. L. Cooper
- Department of Anatomy, Physiology, and Pharmacology, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
| | - B. Frank Eames
- Department of Anatomy, Physiology, and Pharmacology, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
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3
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Ylitalo T, Finnilä MA, Gahunia HK, Karhula SS, Suhonen H, Valkealahti M, Lehenkari P, Hæggström E, Pritzker KP, Saarakkala S, Nieminen HJ. Quantifying Complex Micro-Topography of Degenerated Articular Cartilage Surface by Contrast-Enhanced Micro-Computed Tomography and Parametric Analyses. J Orthop Res 2019; 37:855-866. [PMID: 30737811 PMCID: PMC6518937 DOI: 10.1002/jor.24245] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/03/2018] [Accepted: 01/29/2019] [Indexed: 02/04/2023]
Abstract
One of the earliest changes in osteoarthritis (OA) is a surface discontinuity of the articular cartilage (AC), and these surface changes become gradually more complex with OA progression. We recently developed a contrast enhanced micro-computed tomography (μCT) method for visualizing AC surface in detail. The present study aims to introduce a μCT analysis technique to parameterize these complex AC surface features and to demonstrate the feasibility of using these parameters to quantify degenerated AC surface. Osteochondral plugs (n = 35) extracted from 19 patients undergoing joint surgery were stained with phosphotungstic acid and imaged using μCT. The surface micro-topography of AC was analyzed with developed method. Standard root mean square roughness (Rq ) was calculated as a reference, and the Area Under Curve (AUC) for receiver operating characteristic analysis was used to compare the acquired quantitative parameters with semi-quantitative visual grading of μCT image stacks. The parameters quantifying the complex micro-topography of AC surface exhibited good sensitivity and specificity in identifying surface continuity (AUC: 0.93, [0.80 0.99]), fissures (AUC: 0.94, [0.83 0.99]) and fibrillation (AUC: 0.98, [0.88 1.0]). Standard Rq was significantly smaller compared with the complex roughness (CRq ) already with mild surface changes with all surface reference parameters - continuity, fibrillation, and fissure sum. Furthermore, only CRq showed a significant difference when comparing the intact surface with lowest fissure sum score. These results indicate that the presented method for evaluating complex AC surfaces exhibit potential to identify early OA changes in superficial AC and is dynamic throughout OA progression. © 2019 The Authors. Journal of Orthopaedic Research® Published by Wiley Periodicals, Inc. on behalf of the Orthopaedic Research Society. Society. 9999:1-12, 2019.
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Affiliation(s)
- Tuomo Ylitalo
- Research Unit of Medical Imaging, Physics and Technology, Faculty of MedicineUniversity of OuluOuluFinland,Department of PhysicsUniversity of HelsinkiHelsinkiFinland
| | - Mikko A.J. Finnilä
- Research Unit of Medical Imaging, Physics and Technology, Faculty of MedicineUniversity of OuluOuluFinland,Department of Applied Physics University of Eastern FinlandKuopioFinland,Medical Research Center OuluOulu University Hospital and University of OuluOuluFinland
| | | | - Sakari S. Karhula
- Research Unit of Medical Imaging, Physics and Technology, Faculty of MedicineUniversity of OuluOuluFinland,Infotech OuluUniversity of OuluOuluFinland
| | - Heikki Suhonen
- Department of PhysicsUniversity of HelsinkiHelsinkiFinland
| | - Maarit Valkealahti
- Department of Surgery and Intensive CareUniversity of Oulu and Oulu University HospitalOuluFinland
| | - Petri Lehenkari
- Medical Research Center OuluOulu University Hospital and University of OuluOuluFinland,Department of Surgery and Intensive CareUniversity of Oulu and Oulu University HospitalOuluFinland,Institute of Cancer Research and Translational Medicine, Department of Anatomy and Cell Biology, Faculty of MedicineUniversity of OuluOuluFinland
| | | | - Kenneth P.H. Pritzker
- Department of Laboratory Medicine and PathobiologyUniversity of TorontoTorontoCanada,Mount Sinai HospitalTorontoCanada
| | - Simo Saarakkala
- Research Unit of Medical Imaging, Physics and Technology, Faculty of MedicineUniversity of OuluOuluFinland,Infotech OuluUniversity of OuluOuluFinland,Department of Diagnostic RadiologyOulu University HospitalOuluFinland
| | - Heikki J. Nieminen
- Research Unit of Medical Imaging, Physics and Technology, Faculty of MedicineUniversity of OuluOuluFinland,Department of PhysicsUniversity of HelsinkiHelsinkiFinland,Department of Laboratory Medicine and PathobiologyUniversity of TorontoTorontoCanada,Department of Neuroscience and Biomedical EngineeringAalto UniversityEspooFinland
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4
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Abidin AZ, Deng B, DSouza AM, Nagarajan MB, Coan P, Wismüller A. Deep transfer learning for characterizing chondrocyte patterns in phase contrast X-Ray computed tomography images of the human patellar cartilage. Comput Biol Med 2018; 95:24-33. [PMID: 29433038 PMCID: PMC5869140 DOI: 10.1016/j.compbiomed.2018.01.008] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2017] [Revised: 01/22/2018] [Accepted: 01/23/2018] [Indexed: 10/18/2022]
Abstract
Phase contrast X-ray computed tomography (PCI-CT) has been demonstrated to be effective for visualization of the human cartilage matrix at micrometer resolution, thereby capturing osteoarthritis induced changes to chondrocyte organization. This study aims to systematically assess the efficacy of deep transfer learning methods for classifying between healthy and diseased tissue patterns. We extracted features from two different convolutional neural network architectures, CaffeNet and Inception-v3 for characterizing such patterns. These features were quantitatively evaluated in a classification task measured by the area (AUC) under the Receiver Operating Characteristic (ROC) curve as well as qualitative visualization through a dimension reduction approach t-Distributed Stochastic Neighbor Embedding (t-SNE). The best classification performance, for CaffeNet, was observed when using features from the last convolutional layer and the last fully connected layer (AUCs >0.91). Meanwhile, off-the-shelf features from Inception-v3 produced similar classification performance (AUC >0.95). Visualization of features from these layers further confirmed adequate characterization of chondrocyte patterns for reliably distinguishing between healthy and osteoarthritic tissue classes. Such techniques, can be potentially used for detecting the presence of osteoarthritis related changes in the human patellar cartilage.
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Affiliation(s)
- Anas Z Abidin
- Department of Biomedical Engineering, University of Rochester Medical Center, Rochester, NY, USA.
| | - Botao Deng
- Department of Electrical Engineering, University of Rochester Medical Center, Rochester, NY, USA
| | - Adora M DSouza
- Department of Electrical Engineering, University of Rochester Medical Center, Rochester, NY, USA
| | - Mahesh B Nagarajan
- Department of Radiological Sciences, University of California Los Angeles, Los Angeles, USA
| | - Paola Coan
- European Synchrotron Radiation Facility, Grenoble, France; Faculty of Medicine and Institute of Clinical Radiology, Ludwig Maximilians University, Munich Germany
| | - Axel Wismüller
- Department of Biomedical Engineering, University of Rochester Medical Center, Rochester, NY, USA; Department of Imaging Sciences, University of Rochester Medical Center, Rochester, NY, USA; Department of Electrical Engineering, University of Rochester Medical Center, Rochester, NY, USA; Faculty of Medicine and Institute of Clinical Radiology, Ludwig Maximilians University, Munich Germany
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5
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Khimchenko A, Schulz G, Thalmann P, Müller B. Implementation of a double-grating interferometer for phase-contrast computed tomography in a conventional system nanotom ® m. APL Bioeng 2018; 2:016106. [PMID: 31069291 PMCID: PMC6481705 DOI: 10.1063/1.5022184] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2017] [Accepted: 12/26/2017] [Indexed: 02/07/2023] Open
Abstract
Visualizing the internal architecture of large soft tissue specimens within the laboratory environment in a label-free manner is challenging, as the conventional absorption-contrast tomography yields a poor contrast. In this communication, we present the integration of an X-ray double-grating interferometer (XDGI) into an advanced, commercially available micro computed tomography system nanotom® m with a transmission X-ray source and a micrometer-sized focal spot. The performance of the interferometer is demonstrated by comparing the registered three-dimensional images of a human knee joint sample in phase- and conventional absorption-contrast modes. XDGI provides enough contrast (1.094 ± 0.152) to identify the cartilage layer, which is not recognized in the conventional mode (0.287 ± 0.003). Consequently, the two modes are complementary, as the present XDGI set-up only reaches a spatial resolution of (73 ± 6) μm, whereas the true micrometer resolution in the absorption-contrast mode has been proven. By providing complimentary information, XDGI is especially a supportive quantitative method for imaging soft tissues and visualizing weak X-ray absorbing species in the direct neighborhood of stronger absorbing components at the microscopic level.
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Affiliation(s)
- Anna Khimchenko
- Biomaterials Science Center, University of Basel, 4123 Allschwil, Switzerland
| | - Georg Schulz
- Biomaterials Science Center, University of Basel, 4123 Allschwil, Switzerland
| | - Peter Thalmann
- Biomaterials Science Center, University of Basel, 4123 Allschwil, Switzerland
| | - Bert Müller
- Biomaterials Science Center, University of Basel, 4123 Allschwil, Switzerland
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6
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Gasilov S, Mittone A, Horng A, Geith T, Bravin A, Baumbach T, Coan P. Hard X-ray index of refraction tomography of a whole rabbit knee joint: A feasibility study. Phys Med 2016; 32:1785-1789. [PMID: 27793538 DOI: 10.1016/j.ejmp.2016.10.001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/29/2016] [Revised: 09/30/2016] [Accepted: 10/01/2016] [Indexed: 10/20/2022] Open
Abstract
We report results of the computed tomography reconstruction of the index of refraction in a whole rabbit knee joint examined at the photon energy of 51keV. Refraction based images make it possible to delineate the bone, cartilage, and soft tissues without adjusting the contrast window width and level. Density variations, which are related to tissue composition and are not visible in absorption X-ray images, are detected in the obtained refraction based images. We discuss why refraction-based images provide better detectability of low contrast features than absorption images.
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Affiliation(s)
- S Gasilov
- Institute for Beam Physics and Technology, Karlsruhe Institute for Technology, Eggenstein 76344, Germany; Department of Physics, Ludwig Maximilians University, Garching 85748, Germany.
| | - A Mittone
- European Synchrotron Radiation Facility, Grenoble 38043, France; Department of Physics, Ludwig Maximilians University, Garching 85748, Germany
| | - A Horng
- Institute for Clinical Radiology, Ludwig-Maximilians-University, Munich 81377, Germany
| | - T Geith
- Institute for Clinical Radiology, Ludwig-Maximilians-University, Munich 81377, Germany
| | - A Bravin
- European Synchrotron Radiation Facility, Grenoble 38043, France
| | - T Baumbach
- Institute for Photon Science and Synchrotron Radiation, Karlsruhe Institute for Technology, Eggenstein 76344, Germany; Laboratory for Application of Synchrotron Radiation, Karlsruhe Institute for Technology, Eggenstein 76344, Germany
| | - P Coan
- Institute for Clinical Radiology, Ludwig-Maximilians-University, Munich 81377, Germany; Department of Physics, Ludwig Maximilians University, Garching 85748, Germany
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7
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Sun W, Zhang Y, Gao F, Li Z, Li G, Pan L. Phase-contrast imaging with synchrotron hard X-ray of micro lesions of the cartilage of the femoral head in rabbits. Int J Clin Exp Med 2015; 8:20086-20091. [PMID: 26884921 PMCID: PMC4723766] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2015] [Accepted: 10/25/2015] [Indexed: 06/05/2023]
Abstract
BACKGROUND To observe micro lesions on the cartilage of the rabbit femoral head using phase-contrast imaging with synchrotron hard X-ray and to prove that this method can be useful in the study of the degeneration of cartilage. METHODS New Zealand white rabbits were used in a micro lesion model of rabbit femoral head cartilage. Bilateral femoral heads were excised from rabbits, and micro lesions were made on one side with a specially made knife with a blade 20 μm in width. The other femur was left intact to serve as the control. Phase-contrast imaging with synchrotron hard X-ray and conventional X-ray imaging were used to observe the cartilage. Histological changes were investigated using modified Golden tri-color staining. RESULTS Phase-contrast imaging with synchrotron hard X-ray clearly showed the 20 μm lesions on the cartilage on the heads of rabbit femurs. These lesions were not visible with conventional X-ray imaging. Histological observation confirmed the presence of the microscopic lesions. CONCLUSION Phase-contrast imaging with synchrotron hard X-ray can detect microscopic lesions on cartilage that cannot be detected by conventional absorption-contrast X-ray. This provides an unequivocal, non-invasive alternative to histological examination in the diagnosis of joint disease. It should be considered a new tool in osteoarthritis and cartilage research.
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Affiliation(s)
- Wei Sun
- Centre for Osteonecrosis and Joint-Preserving & Reconstruction, China-Japan Friendship HospitalBeijing 100029, China
| | - Yong Zhang
- Department of Cardiovascular Surgery, Jinan Command General Hospital of PLAJinan 250031, China
| | - Fuqiang Gao
- Centre for Osteonecrosis and Joint-Preserving & Reconstruction, China-Japan Friendship HospitalBeijing 100029, China
| | - Zirong Li
- Centre for Osteonecrosis and Joint-Preserving & Reconstruction, China-Japan Friendship HospitalBeijing 100029, China
| | - Gang Li
- Beijing Synchrotron Radiation Facility, Institute of High Energy PhysicsBeijing 100039, China
| | - Lin Pan
- China-Japan Friendship Institute of Clinical Medical ScienceBeijing 100029, China
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8
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Nagarajan MB, Coan P, Huber MB, Diemoz PC, Wismüller A. Volumetric quantitative characterization of human patellar cartilage with topological and geometrical features on phase-contrast X-ray computed tomography. Med Biol Eng Comput 2015; 53:1211-20. [PMID: 26142112 PMCID: PMC4630098 DOI: 10.1007/s11517-015-1340-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2014] [Accepted: 06/22/2015] [Indexed: 01/19/2023]
Abstract
Phase-contrast X-ray computed tomography (PCI-CT) has attracted significant interest in recent years for its ability to provide significantly improved image contrast in low absorbing materials such as soft biological tissue. In the research context of cartilage imaging, previous studies have demonstrated the ability of PCI-CT to visualize structural details of human patellar cartilage matrix and capture changes to chondrocyte organization induced by osteoarthritis. This study evaluates the use of geometrical and topological features for volumetric characterization of such chondrocyte patterns in the presence (or absence) of osteoarthritic damage. Geometrical features derived from the scaling index method (SIM) and topological features derived from Minkowski Functionals were extracted from 1392 volumes of interest (VOI) annotated on PCI-CT images of ex vivo human patellar cartilage specimens. These features were subsequently used in a machine learning task with support vector regression to classify VOIs as healthy or osteoarthritic; classification performance was evaluated using the area under the receiver operating characteristic curve (AUC). Our results show that the classification performance of SIM-derived geometrical features (AUC: 0.90 ± 0.09) is significantly better than Minkowski Functionals volume (AUC: 0.54 ± 0.02), surface (AUC: 0.72 ± 0.06), mean breadth (AUC: 0.74 ± 0.06) and Euler characteristic (AUC: 0.78 ± 0.04) (p < 10(-4)). These results suggest that such geometrical features can provide a detailed characterization of the chondrocyte organization in the cartilage matrix in an automated manner, while also enabling classification of cartilage as healthy or osteoarthritic with high accuracy. Such features could potentially serve as diagnostic imaging markers for evaluating osteoarthritis progression and its response to different therapeutic intervention strategies.
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Affiliation(s)
- Mahesh B Nagarajan
- Departments of Imaging Sciences and Biomedical Engineering, University of Rochester, Rochester, NY, USA.
| | - Paola Coan
- Faculty of Medicine & Institute of Clinical Radiology, Ludwig Maximilians University, 80336, Munich, Germany
- Department of Physics, Ludwig Maximilians University, 85748, Munich, Germany
- European Synchrotron Radiation Facility, 38000, Grenoble, France
| | - Markus B Huber
- Departments of Imaging Sciences and Biomedical Engineering, University of Rochester, Rochester, NY, USA
| | - Paul C Diemoz
- Department of Physics, Ludwig Maximilians University, 85748, Munich, Germany
- European Synchrotron Radiation Facility, 38000, Grenoble, France
| | - Axel Wismüller
- Departments of Imaging Sciences and Biomedical Engineering, University of Rochester, Rochester, NY, USA
- Faculty of Medicine & Institute of Clinical Radiology, Ludwig Maximilians University, 80336, Munich, Germany
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9
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Sunaguchi N, Yuasa T, Sun F, Gupta R, Ando M. Limited view reconstruction for differential phase-contrast computed tomography. OPTICS EXPRESS 2015; 23:9717-9729. [PMID: 25969010 DOI: 10.1364/oe.23.009717] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
This paper describes an algebraic reconstruction algorithm that uses total variation (TV) regularization for differential phase contrast computed tomography (DPC-CT) using a limited number of views. In order to overcome over-flattening inherent in TV regularization, a two-step reconstruction process is used: we first reconstruct tomographic images of gradient refractive index from differential projections with TV regularization; these images are then used to compute tomographic images of refractive index by solving the Poisson equation. We incorporate TV regularization in the reconstruction process because the distribution of gradient refractive index is much more flattened than the refractive index. Simulations of the proposed method demonstrate that it can achieve satisfactory image quality from a much smaller number of projections than is required by the Nyquist sampling theorem. We experimentally prove the feasibility of the proposed method using dark field imaging optics at PF-14C beamline at the Photon Factory, KEK. The differential phase contrast projection data was experimentally acquired from a biological sample and DPC-CT images were reconstructed. We show that far fewer projections are needed when the proposed algorithm is used.
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10
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Nagarajan MB, Coan P, Huber MB, Diemoz PC, Glaser C, Wismüller A. Computer-aided diagnosis for phase-contrast X-ray computed tomography: quantitative characterization of human patellar cartilage with high-dimensional geometric features. J Digit Imaging 2014; 27:98-107. [PMID: 24043594 DOI: 10.1007/s10278-013-9634-3] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022] Open
Abstract
Phase-contrast computed tomography (PCI-CT) has shown tremendous potential as an imaging modality for visualizing human cartilage with high spatial resolution. Previous studies have demonstrated the ability of PCI-CT to visualize (1) structural details of the human patellar cartilage matrix and (2) changes to chondrocyte organization induced by osteoarthritis. This study investigates the use of high-dimensional geometric features in characterizing such chondrocyte patterns in the presence or absence of osteoarthritic damage. Geometrical features derived from the scaling index method (SIM) and statistical features derived from gray-level co-occurrence matrices were extracted from 842 regions of interest (ROI) annotated on PCI-CT images of ex vivo human patellar cartilage specimens. These features were subsequently used in a machine learning task with support vector regression to classify ROIs as healthy or osteoarthritic; classification performance was evaluated using the area under the receiver-operating characteristic curve (AUC). SIM-derived geometrical features exhibited the best classification performance (AUC, 0.95 ± 0.06) and were most robust to changes in ROI size. These results suggest that such geometrical features can provide a detailed characterization of the chondrocyte organization in the cartilage matrix in an automated and non-subjective manner, while also enabling classification of cartilage as healthy or osteoarthritic with high accuracy. Such features could potentially serve as imaging markers for evaluating osteoarthritis progression and its response to different therapeutic intervention strategies.
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Affiliation(s)
- Mahesh B Nagarajan
- Department of Biomedical Engineering, University of Rochester, 430 Elmwood Ave, Rochester, NY, 14627, USA,
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11
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Horng A, Brun E, Mittone A, Gasilov S, Weber L, Geith T, Adam-Neumair S, Auweter SD, Bravin A, Reiser MF, Coan P. Cartilage and Soft Tissue Imaging Using X-rays. Invest Radiol 2014; 49:627-34. [DOI: 10.1097/rli.0000000000000063] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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12
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13
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Ye D, Peramo A. Implementing tissue engineering and regenerative medicine solutions in medical implants. Br Med Bull 2014; 109:3-18. [PMID: 24357734 DOI: 10.1093/bmb/ldt036] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
BACKGROUND Surgical implants are widely used in the medical field but their long-term performance is limited due to failure of integration with tissues. This manuscript describes very well-known problems associated with implants and discusses novel solutions used in tissue engineering and regenerative medicine that can be implemented in this uncommonly discussed medical area. SOURCES OF DATA General and medical literature describing modifications of medical and surgical implants, biofunctionalization, tissue engineering and regenerative medicine. AREAS OF AGREEMENT Procedures for surgical implantation have grown substantially in the last few decades and provided improved quality of life for patients, regardless of area of implantation and device type and purpose. AREAS OF CONTROVERSY In general, implants fail because of lack of long-term integration with the surrounding tissues. Implant manufacturers have not addressed implant failure from the point of view of biointegration. In addition, some medical practitioners are inclined to treat implant failure by using anti-infection methods to prevent bacterial adhesion. However, both approaches are conceptually limited, as discussed in this manuscript. GROWING POINTS Implantation in the future will not be limited to medically needed procedures but also to a growing number of cosmetic body transformation procedures, which may include perceived 'improved implant functions' over natural tissues or organs. An additional trend is that implant procedures are being progressively performed in younger individuals. AREAS TIMELY FOR DEVELOPING RESEARCH Current implants generally do not allow the physician to have controlled long-term access to internal tissues in contact with the implants, for example to release specific compounds when medically needed to the problem area.
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Affiliation(s)
- Dongxia Ye
- Shanghai Ninth People's Hospital Affiliated to Medical School of Shanghai Jiaotong University, Shanghai, China
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14
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Nagarajan MB, Coan P, Huber MB, Diemoz PC, Glaser C, Wismuller A. Computer-aided diagnosis in phase contrast imaging X-ray computed tomography for quantitative characterization of ex vivo human patellar cartilage. IEEE Trans Biomed Eng 2013; 60:2896-903. [PMID: 23744660 DOI: 10.1109/tbme.2013.2266325] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Visualization of ex vivo human patellar cartilage matrix through the phase contrast imaging X-ray computed tomography (PCI-CT) has been previously demonstrated. Such studies revealed osteoarthritis-induced changes to chondrocyte organization in the radial zone. This study investigates the application of texture analysis to characterizing such chondrocyte patterns in the presence and absence of osteoarthritic damage. Texture features derived from Minkowski functionals (MF) and gray-level co-occurrence matrices (GLCM) were extracted from 842 regions of interest (ROI) annotated on PCI-CT images of ex vivo human patellar cartilage specimens. These texture features were subsequently used in a machine learning task with support vector regression to classify ROIs as healthy or osteoarthritic; classification performance was evaluated using the area under the receiver operating characteristic curve (AUC). The best classification performance was observed with the MF features perimeter (AUC: 0.94 ±0.08 ) and "Euler characteristic" (AUC: 0.94 ±0.07 ), and GLCM-derived feature "Correlation" (AUC: 0.93 ±0.07). These results suggest that such texture features can provide a detailed characterization of the chondrocyte organization in the cartilage matrix, enabling classification of cartilage as healthy or osteoarthritic with high accuracy.
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15
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Bravin A, Coan P, Suortti P. X-ray phase-contrast imaging: from pre-clinical applications towards clinics. Phys Med Biol 2012; 58:R1-35. [PMID: 23220766 DOI: 10.1088/0031-9155/58/1/r1] [Citation(s) in RCA: 379] [Impact Index Per Article: 31.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Phase-contrast x-ray imaging (PCI) is an innovative method that is sensitive to the refraction of the x-rays in matter. PCI is particularly adapted to visualize weakly absorbing details like those often encountered in biology and medicine. In past years, PCI has become one of the most used imaging methods in laboratory and preclinical studies: its unique characteristics allow high contrast 3D visualization of thick and complex samples even at high spatial resolution. Applications have covered a wide range of pathologies and organs, and are more and more often performed in vivo. Several techniques are now available to exploit and visualize the phase-contrast: propagation- and analyzer-based, crystal and grating interferometry and non-interferometric methods like the coded aperture. In this review, covering the last five years, we will give an overview of the main theoretical and experimental developments and of the important steps performed towards the clinical implementation of PCI.
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Affiliation(s)
- Alberto Bravin
- European Synchrotron Radiation Facility, 6 rue Horowitz, 38043 Grenoble Cedex, France.
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Sztrókay A, Diemoz PC, Schlossbauer T, Brun E, Bamberg F, Mayr D, Reiser MF, Bravin A, Coan P. High-resolution breast tomography at high energy: a feasibility study of phase contrast imaging on a whole breast. Phys Med Biol 2012; 57:2931-42. [PMID: 22516937 DOI: 10.1088/0031-9155/57/10/2931] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Previous studies on phase contrast imaging (PCI) mammography have demonstrated an enhancement of breast morphology and cancerous tissue visualization compared to conventional imaging. We show here the first results of the PCI analyser-based imaging (ABI) in computed tomography (CT) mode on whole and large (>12 cm) tumour-bearing breast tissues. We demonstrate in this work the capability of the technique of working at high x-ray energies and producing high-contrast images of large and complex specimens. One entire breast of an 80-year-old woman with invasive ductal cancer was imaged using ABI-CT with monochromatic 70 keV x-rays and an area detector of 92×92 µm² pixel size. Sagittal slices were reconstructed from the acquired data, and compared to corresponding histological sections. Comparison with conventional absorption-based CT was also performed. Five blinded radiologists quantitatively evaluated the visual aspects of the ABI-CT images with respect to sharpness, soft tissue contrast, tissue boundaries and the discrimination of different structures/tissues. ABI-CT excellently depicted the entire 3D architecture of the breast volume by providing high-resolution and high-contrast images of the normal and cancerous breast tissues. These results are an important step in the evolution of PCI-CT towards its clinical implementation.
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Affiliation(s)
- A Sztrókay
- Institute of Clinical Radiology, Ludwig-Maximilians University, Munich, Germany
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Appel A, Anastasio MA, Brey EM. Potential for imaging engineered tissues with X-ray phase contrast. TISSUE ENGINEERING. PART B, REVIEWS 2011; 17:321-30. [PMID: 21682604 PMCID: PMC3179620 DOI: 10.1089/ten.teb.2011.0230] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/21/2011] [Accepted: 06/15/2011] [Indexed: 11/12/2022]
Abstract
As the field of tissue engineering advances, it is crucial to develop imaging methods capable of providing detailed three-dimensional information on tissue structure. X-ray imaging techniques based on phase-contrast (PC) have great potential for a number of biomedical applications due to their ability to provide information about soft tissue structure without exogenous contrast agents. X-ray PC techniques retain the excellent spatial resolution, tissue penetration, and calcified tissue contrast of conventional X-ray techniques while providing drastically improved imaging of soft tissue and biomaterials. This suggests that X-ray PC techniques are very promising for evaluation of engineered tissues. In this review, four different implementations of X-ray PC imaging are described and applications to tissues of relevance to tissue engineering reviewed. In addition, recent applications of X-ray PC to the evaluation of biomaterial scaffolds and engineered tissues are presented and areas for further development and application of these techniques are discussed. Imaging techniques based on X-ray PC have significant potential for improving our ability to image and characterize engineered tissues, and their continued development and optimization could have significant impact on the field of tissue engineering.
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Affiliation(s)
- Alyssa Appel
- Department of Biomedical Engineering and Pritzker Institute of Biomedical Science and Engineering, Illinois Institute of Technology, Chicago, Illinois
- Research Service, Hines Veterans Administration Hospital, Hines, Illinois
| | - Mark A. Anastasio
- Department of Biomedical Engineering, Washington University in St. Louis, St. Louis, Missouri
| | - Eric M. Brey
- Department of Biomedical Engineering and Pritzker Institute of Biomedical Science and Engineering, Illinois Institute of Technology, Chicago, Illinois
- Research Service, Hines Veterans Administration Hospital, Hines, Illinois
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Fogarty DP, Reinhart B, Tzvetkov T, Nesch I, Williams C. In-Laboratory Diffraction-Enhanced X-Ray Imaging of an Equine Hoof. J Equine Vet Sci 2011. [DOI: 10.1016/j.jevs.2011.03.015] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Coan P, Wagner A, Bravin A, Diemoz PC, Keyriläinen J, Mollenhauer J. In vivo x-ray phase contrast analyzer-based imaging for longitudinal osteoarthritis studies in guinea pigs. Phys Med Biol 2010; 55:7649-62. [PMID: 21113092 DOI: 10.1088/0031-9155/55/24/017] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Over the last two decades phase contrast x-ray imaging techniques have been extensively studied for applications in the biomedical field. Published results demonstrate the high capability of these imaging modalities of improving the image contrast of biological samples with respect to standard absorption-based radiography and routinely used clinical imaging techniques. A clear depiction of the anatomic structures and a more accurate disease diagnosis may be provided by using radiation doses comparable to or lower than those used in current clinical methods. In the literature many works show images of phantoms and excised biological samples proving the high sensitivity of the phase contrast imaging methods for in vitro investigations. In this scenario, the applications of the so-called analyzer-based x-ray imaging (ABI) phase contrast technique are particularly noteworthy. The objective of this work is to demonstrate the feasibility of in vivo x-ray ABI phase contrast imaging for biomedical applications and in particular with respect to joint anatomic depiction and osteoarthritis detection. ABI in planar and tomographic modes was performed in vivo on articular joints of guinea pigs in order to investigate the animals with respect to osteoarthritis by using highly monochromatic x-rays of 52 keV and a low noise detector with a pixel size of 47 × 47 µm(2). Images give strong evidence of the ability of ABI in depicting both anatomic structures in complex systems as living organisms and all known signs of osteoarthritis with high contrast, high spatial resolution and with an acceptable radiation dose. This paper presents the first proof of principle study of in vivo application of ABI. The technical challenges encountered when imaging an animal in vivo are discussed. This experimental study is an important step toward the study of clinical applications of phase contrast x-ray imaging techniques.
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Affiliation(s)
- Paola Coan
- Faculty of Medicine and Institute of Clinical Radiology, Ludwig-Maximilians University, Munich, Germany.
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Stutman D, Finkenthal M, Moldovan N. Development of microperiodic mirrors for hard x-ray phase-contrast imaging. APPLIED OPTICS 2010; 49:4677-4686. [PMID: 20820208 DOI: 10.1364/ao.49.004677] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Differential phase-contrast imaging with hard x rays can have important applications in medicine, material sciences, and energy research. Phase-contrast methods based on microperiodic optics, such as shearing interferometry, are particularly attractive because they allow the use of conventional x-ray tubes. To enable shearing interferometry with x rays up to 100?keV, we propose using grazing-incidence microperiodic mirrors. In addition, a simple lithographic method is proposed for the production of the microperiodic x-ray mirrors, based on the difference in grazing-incidence reflectivity between a low-Z substrate and a high-Z film. Using this method, we produced prototype mirrors with 5-100?mum periods and 90?mm active length. Experimental tests with x rays up to 60?keV indicate good microperiodic mirror reflectivity and high-contrast fringe patterns, encouraging further development of the proposed imaging concept.
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Affiliation(s)
- Dan Stutman
- Department of Physics and Astronomy, Johns Hopkins University, Baltimore, Maryland 21030, USA.
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Characterization of Osteoarthritic and Normal Human Patella Cartilage by Computed Tomography X-ray Phase-Contrast Imaging. Invest Radiol 2010; 45:437-44. [DOI: 10.1097/rli.0b013e3181e193bd] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Morelhão SL, Coelho PG, Hönnicke MG. Synchrotron X-ray imaging via ultra-small-angle scattering: principles of quantitative analysis and application in studying bone integration to synthetic grafting materials. EUROPEAN BIOPHYSICS JOURNAL: EBJ 2009; 39:861-5. [PMID: 19784835 DOI: 10.1007/s00249-009-0541-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/06/2009] [Revised: 07/02/2009] [Accepted: 09/08/2009] [Indexed: 11/29/2022]
Abstract
Optimized experimental conditions for extracting accurate information at subpixel length scales from analyzer-based X-ray imaging were obtained and applied to investigate bone regeneration by means of synthetic beta-TCP grafting materials in a rat calvaria model. The results showed a 30% growth in the particulate size due to bone ongrowth/ingrowth within the critical size defect over a 1-month healing period.
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Affiliation(s)
- Sérgio L Morelhão
- Instituto de Física, Universidade de São Paulo, São Paulo, SP, Brazil.
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Li J, Zhong Z, Connor D, Mollenhauer J, Muehleman C. Phase-sensitive X-ray imaging of synovial joints. Osteoarthritis Cartilage 2009; 17:1193-6. [PMID: 19328880 PMCID: PMC2730993 DOI: 10.1016/j.joca.2009.03.005] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/22/2008] [Revised: 02/02/2009] [Accepted: 03/06/2009] [Indexed: 02/02/2023]
Abstract
OBJECTIVE To test the efficacy of phase-sensitive X-ray imaging for intact synovial joints, whereby refraction effects, along with the attenuation of conventional radiography, can be exploited. DESIGN Intact cadaveric human knee joints were imaged, in the computed tomographic mode, using an analyzer-based X-ray system at the National Synchrotron Light Source, Brookhaven National Laboratory. A collimated fan beam of 51 keV X-rays was prepared by a silicon [1,1,1 reflection] double-crystal monochromator. The X-ray beam transmitted through the specimen was imaged after diffraction in the vertical plane by means of the analyzer crystal with the analyzer crystal tuned to its half-reflectivity point (6.5 microrad). A two-dimensional filtered backprojection (FBP) algorithm was used for reconstructing transverse slices of images. RESULTS The resulting images demonstrate simultaneous soft tissue and bone contrast at a level that has not been achieved previously. Identifiable structures include articular cartilage, cruciate ligaments, loose connective tissue, menisci, and chondrocalcinosis. CONCLUSION Phase-sensitive X-ray imaging using an analyzer-based system renders exceptionally high quality images of soft and hard tissues within synovial joints, with high contrast and resolution, and thus holds promise for the eventual clinical utility.
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Affiliation(s)
- Jun Li
- Department of Biochemistry, Rush University Medical Center, Chicago, IL
| | - Zhong Zhong
- National Synchrotron Light Source, Brookhaven National Laboratory, Upton, NY
| | - Dean Connor
- National Synchrotron Light Source, Brookhaven National Laboratory, Upton, NY
| | - Jorgen Mollenhauer
- Natural Science and Medicine Institute at Tübingen University, Reutlingen, Germany
| | - Carol Muehleman
- Department of Biochemistry, Rush University Medical Center, Chicago, IL,Department of Orthopedic Surgery, Rush University Medical Center, Chicago, IL,Correspondence should be addressed to CM ()
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Brunner A, Honigmann P, Treumann T, Babst R. The impact of stereo-visualisation of three-dimensional CT datasets on the inter- and intraobserver reliability of the AO/OTA and Neer classifications in the assessment of fractures of the proximal humerus. ACTA ACUST UNITED AC 2009; 91:766-71. [PMID: 19483230 DOI: 10.1302/0301-620x.91b6.22109] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
We evaluated the impact of stereo-visualisation of three-dimensional volume-rendering CT datasets on the inter- and intraobserver reliability assessed by kappa values on the AO/OTA and Neer classifications in the assessment of proximal humeral fractures. Four independent observers classified 40 fractures according to the AO/OTA and Neer classifications using plain radiographs, two-dimensional CT scans and with stereo-visualised three-dimensional volume-rendering reconstructions. Both classification systems showed moderate interobserver reliability with plain radiographs and two-dimensional CT scans. Three-dimensional volume-rendered CT scans improved the interobserver reliability of both systems to good. Intraobserver reliability was moderate for both classifications when assessed by plain radiographs. Stereo visualisation of three-dimensional volume rendering improved intraobserver reliability to good for the AO/OTA method and to excellent for the Neer classification. These data support our opinion that stereo visualisation of three-dimensional volume-rendering datasets is of value when analysing and classifying complex fractures of the proximal humerus.
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Affiliation(s)
- A Brunner
- Department of Trauma Surgery, Cantonal Hospital, Lucerne, Switzerland.
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