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Galli S, Naito Y, Karlsson J, He W, Miyamoto I, Xue Y, Andersson M, Mustafa K, Wennerberg A, Jimbo R. Local release of magnesium from mesoporous TiO2 coatings stimulates the peri-implant expression of osteogenic markers and improves osteoconductivity in vivo. Acta Biomater 2014; 10:5193-5201. [PMID: 25153781 DOI: 10.1016/j.actbio.2014.08.011] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2014] [Revised: 08/03/2014] [Accepted: 08/10/2014] [Indexed: 11/17/2022]
Abstract
Local release of Mg ions from titanium implant surfaces has been shown to enhance implant retention and integration. To clarify the biological events that lead to this positive outcome, threaded implants coated with mesoporous TiO2 thin films were loaded with Mg-ions and placed in the tibia of rabbits for 3weeks, after surface characterization. Non-loaded mesoporous coated implants were used as controls. Peri-implant gene expression of a set of osteogenic and inflammatory assays was quantified by means of real-time quantitative polymerase chain reaction. The expression of three osteogenic markers (OC, RUNX-2 and IGF-1) was significantly more pronounced in the test specimens, suggesting that the release of Mg ions directly at the implant sites may stimulate an osteogenic environment. Furthermore, bone healing around implants was evaluated on histological slides and by diffraction-enhanced imaging (DEI), using synchrotron radiation. The histological analysis demonstrated new bone formation around all implants, without negative responses, with a significant increase in the number of threads filled with new bone for test surfaces. DEI analysis attested the high mineral content of the newly formed bone. Improved surface osteoconductivity and increased expression of genes involved in the bone regeneration were found for magnesium-incorporation of mesoporous TiO2 coatings.
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Affiliation(s)
- Silvia Galli
- Department of Prosthodontics, Faculty of Odontology, Malmö University, 205 06 Malmö, Sweden.
| | - Yoshihito Naito
- Oral Implant Center, Tokushima University Hospital, Tokushima, Japan
| | - Johan Karlsson
- Department of Chemical and Biological Engineering, Applied Surface Chemistry, Chalmers University of Technology, 412 96 Gothenburg, Sweden
| | - Wenxiao He
- Department of Chemical and Biological Engineering, Applied Surface Chemistry, Chalmers University of Technology, 412 96 Gothenburg, Sweden
| | - Ikuya Miyamoto
- Division of Oral Medicine, Kyushu Dental University, Fukuoka, Japan
| | - Ying Xue
- Department of Clinical Dentistry, Center for Clinical Dental Research, University of Bergen, Norway
| | - Martin Andersson
- Department of Chemical and Biological Engineering, Applied Surface Chemistry, Chalmers University of Technology, 412 96 Gothenburg, Sweden
| | - Kamal Mustafa
- Department of Clinical Dentistry, Center for Clinical Dental Research, University of Bergen, Norway
| | - Ann Wennerberg
- Department of Prosthodontics, Faculty of Odontology, Malmö University, 205 06 Malmö, Sweden
| | - Ryo Jimbo
- Department of Prosthodontics, Faculty of Odontology, Malmö University, 205 06 Malmö, Sweden; Department of Applied Prosthodontics, Graduate School of Biomedical Sciences, Nagasaki University, Nagasaki, Japan
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Olubamiji AD, Izadifar Z, Chen DX. Synchrotron Imaging Techniques for Bone and Cartilage Tissue Engineering: Potential, Current Trends, and Future Directions. TISSUE ENGINEERING PART B-REVIEWS 2014; 20:503-22. [DOI: 10.1089/ten.teb.2013.0493] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Affiliation(s)
| | - Zohreh Izadifar
- Division of Biomedical Engineering, University of Saskatchewan, Saskatoon, Canada
| | - Daniel Xiongbiao Chen
- Division of Biomedical Engineering, University of Saskatchewan, Saskatoon, Canada
- Department of Mechanical Engineering, University of Saskatchewan, Saskatoon, Canada
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Roth TD, Buckwalter KA, Choplin RH. Musculoskeletal computed tomography: current technology and clinical applications. Semin Roentgenol 2013; 48:126-39. [PMID: 23452460 DOI: 10.1053/j.ro.2012.11.009] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Trenton D Roth
- Department of Radiology and Imaging Sciences, Indiana University School of Medicine, Indianapolis, IN, USA.
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Synchrotron-based non-destructive diffraction-enhanced imaging systems to image walnut at 20 keV. JOURNAL OF FOOD MEASUREMENT AND CHARACTERIZATION 2013. [DOI: 10.1007/s11694-012-9134-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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Rao DV, Swapna M, Cesareo R, Brunetti A, Akatsuka T, Yuasa T, Zhong Z, Takeda T, Gigante GE. Synchrotron-based DEI for bio-imaging and DEI-CT to image phantoms with contrast agents. Appl Radiat Isot 2012; 70:1570-8. [DOI: 10.1016/j.apradiso.2012.05.002] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2012] [Revised: 05/04/2012] [Accepted: 05/04/2012] [Indexed: 11/28/2022]
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Connor DM, Zhong Z, Foda HD, Wiebe S, Parham CA, Dilmanian FA, Cole EB, Pisano ED. Diffraction enhanced imaging of a rat model of gastric acid aspiration pneumonitis. Acad Radiol 2011; 18:1515-21. [PMID: 21958600 DOI: 10.1016/j.acra.2011.08.005] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2011] [Revised: 08/09/2011] [Accepted: 08/09/2011] [Indexed: 11/28/2022]
Abstract
RATIONALE AND OBJECTIVES Diffraction-enhanced imaging (DEI) is a type of phase contrast x-ray imaging that has improved image contrast at a lower dose than conventional radiography for many imaging applications, but no studies have been done to determine if DEI might be useful for diagnosing lung injury. The goals of this study were to determine if DEI could differentiate between healthy and injured lungs for a rat model of gastric aspiration and to compare diffraction-enhanced images with chest radiographs. MATERIALS AND METHODS Radiographs and diffraction-enhanced chest images of adult Sprague Dawley rats were obtained before and 4 hours after the aspiration of 0.4 mL/kg of 0.1 mol/L hydrochloric acid. Lung damage was confirmed with histopathology. RESULTS The radiographs and diffraction-enhanced peak images revealed regions of atelectasis in the injured rat lung. The diffraction-enhanced peak images revealed the full extent of the lung with improved clarity relative to the chest radiographs, especially in the portion of the lower lobe that extended behind the diaphragm on the anteroposterior projection. CONCLUSIONS For a rat model of gastric acid aspiration, DEI is capable of distinguishing between a healthy and an injured lung and more clearly than radiography reveals the full extent of the lung and the lung damage.
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Affiliation(s)
- Dean M Connor
- Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC 29425, USA.
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Ignatyev K, Munro PRT, Speller RD, Olivo A. Effects of signal diffusion on x-ray phase contrast images. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2011; 82:073702. [PMID: 21806184 DOI: 10.1063/1.3606442] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
We discuss the problem of signal diffusion among neighbouring pixels in x-ray phase contrast imaging (XPCi) specifically for coded-aperture (CA) XPCi, but many of the discussed observations are directly transferable to other XPCi modalities. CA XPCi exploits the principle of pixel edge illumination by means of two CA masks. The first mask, placed in contact with the detector, creates insensitive regions between adjacent pixels; the second one, placed immediately before the sample, creates individual beams impinging on the boundaries between sensitive and insensitive regions on the detector, as created by the detector mask. In this way, edge illumination is achieved for all pixels of an area detector illuminated by a divergent and polychromatic beam generated by a conventional source. As the detector mask redefines the resolution properties of the detector, sample dithering can be used to effectively increase the system spatial resolution, without having to apply any post-processing procedure (e.g., deconvolution). This however creates artifacts in the form of secondary fringes (which have nothing to do with phase-related secondary fringes) if there is signal diffusion between adjacent pixels. In non-dithered images, signal diffusion between adjacent pixels causes a reduction in image contrast. This effect is investigated both theoretically and experimentally, and its direct implications on image quality are discussed. The interplay with the sample positioning with respect to the detector pixel matrix, which also has an effect on the obtained image contrast, is also discussed.
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Affiliation(s)
- K Ignatyev
- Department of Medical Physics and Bioengineering, UCL, Malet Place, Gower Street, London WC1E 6BT, United Kingdom
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Abstract
In nerve tissue engineering, scaffolds act as carriers for cells and biochemical factors and as constructs providing appropriate mechanical conditions. During nerve regeneration, new tissue grows into the scaffolds, which degrade gradually. To optimize this process, researchers must study and analyze various morphological and structural features of the scaffolds, the ingrowth of nerve tissue, and scaffold degradation. Therefore, visualization of the scaffolds as well as the generated nerve tissue is essential, yet challenging Visualization techniques currently used in nerve tissue engineering include electron microscopy, confocal laser scanning microscopy (CLSM), and micro-computed tomography (micro-CT or μCT). Synchrotron-based micro-CT (SRμCT) is an emerging and promising technique, drawing considerable recent attention. Here, we review typical applications of these visualization techniques in nerve tissue engineering. The promise, feasibility, and challenges of SRμCT as a visualization technique applied to nerve tissue engineering are also discussed.
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Use of synchrotron-based diffraction-enhanced imaging for visualization of soft tissues in invertebrates. Appl Radiat Isot 2010; 68:1687-93. [DOI: 10.1016/j.apradiso.2010.04.001] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2008] [Revised: 04/04/2010] [Accepted: 04/04/2010] [Indexed: 11/19/2022]
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Cooper DML, Bewer B, Wiebe S, Wysokinski TW, Chapman D. Diffraction enhanced X-ray imaging of the distal radius: a novel approach for visualization of trabecular bone architecture. Can Assoc Radiol J 2010; 62:251-5. [PMID: 20591611 DOI: 10.1016/j.carj.2010.04.015] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2010] [Revised: 04/27/2010] [Accepted: 04/29/2010] [Indexed: 10/19/2022] Open
Affiliation(s)
- David M L Cooper
- Department of Anatomy and Cell Biology, University of Saskatchewan, Saskatoon, Saskatchewan, Canada.
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Connor DM, Hallen HD, Lalush DS, Sumner DR, Zhong Z. Comparison of diffraction-enhanced computed tomography and monochromatic synchrotron radiation computed tomography of human trabecular bone. Phys Med Biol 2009; 54:6123-33. [PMID: 19779219 DOI: 10.1088/0031-9155/54/20/006] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Diffraction-enhanced imaging (DEI) is an x-ray-based medical imaging modality that, when used in tomography mode (DECT), can generate a three-dimensional map of both the apparent absorption coefficient and the out-of-plane gradient of the index of refraction of the sample. DECT is known to have contrast gains over monochromatic synchrotron radiation CT (SRCT) for soft tissue structures. The goal of this experiment was to compare contrast-to-noise ratio (CNR) and resolution in images of human trabecular bone acquired using SRCT with images acquired using DECT. All images were acquired at the National Synchrotron Light Source (Upton, NY, USA) at beamline X15 A at an x-ray energy of 40 keV and the silicon [3 3 3] reflection. SRCT, apparent absorption DECT and refraction DECT slice images of the trabecular bone were created. The apparent absorption DECT images have significantly higher spatial resolution and CNR than the corresponding SRCT images. Thus, DECT will prove to be a useful tool for imaging applications in which high contrast and high spatial resolution are required for both soft tissue features and bone.
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Affiliation(s)
- D M Connor
- Department of Biomedical Engineering, Biomedical Research Imaging Center, University of North Carolina at Chapel Hill, 4030 Bondurant Hall, CB 7000, Chapel Hill, NC 27599, USA.
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Nesch I, Fogarty DP, Tzvetkov T, Reinhart B, Walus AC, Khelashvili G, Muehleman C, Chapman D. The design and application of an in-laboratory diffraction-enhanced x-ray imaging instrument. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2009; 80:093702. [PMID: 19791939 DOI: 10.1063/1.3213621] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
We describe the design and application of a new in-laboratory diffraction-enhanced x-ray imaging (DEXI) instrument that uses a nonsynchrotron, conventional x-ray source to image the internal structure of an object. In the work presented here, a human cadaveric thumb is used as a test-sample to demonstrate the imaging capability of our instrument. A 22 keV monochromatic x-ray beam is prepared using a mismatched, two-crystal monochromator; a silicon analyzer crystal is placed in a parallel crystal geometry with the monochromator allowing both diffraction-enhanced imaging and multiple-imaging radiography to be performed. The DEXI instrument was found to have an experimentally determined spatial resolution of 160+/-7 mum in the horizontal direction and 153+/-7 mum in the vertical direction. As applied to biomedical imaging, the DEXI instrument can detect soft tissues, such as tendons and other connective tissues, that are normally difficult or impossible to image via conventional x-ray techniques.
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Affiliation(s)
- Ivan Nesch
- Nesch, LLC 9800 Connecticut Drive, Crown Point, Indiana 46307, USA
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Kao T, Connor D, Dilmanian FA, Faulconer L, Liu T, Parham C, Pisano ED, Zhong Z. Characterization of diffraction-enhanced imaging contrast in breast cancer. Phys Med Biol 2009; 54:3247-56. [PMID: 19420420 DOI: 10.1088/0031-9155/54/10/019] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Diffraction-enhanced imaging (DEI) is a new x-ray imaging modality that has been shown to enhance contrast between normal and cancerous breast tissues. In this study, diffraction-enhanced imaging in computed tomography (DEI-CT) mode was used to quantitatively characterize the refraction contrasts of the organized structures associated with invasive human breast cancer. Using a high-sensitivity Si (3 3 3) reflection, the individual features of breast cancer, including masses, calcifications and spiculations, were observed. DEI-CT yields 14, 5 and 7 times higher CT numbers and 10, 9 and 6 times higher signal-to-noise ratios (SNR) for masses, calcifications and spiculations, respectively, as compared to conventional CT of the same specimen performed using the same detector, x-ray energy and dose. Furthermore, DEI-CT at ten times lower dose yields better SNR than conventional CT. In light of the recent development of a compact DEI prototype using an x-ray tube as its source, these results, acquired at a clinically relevant x-ray energy for which a pre-clinical DEI prototype currently exists, suggest the potential of clinical implementation of mammography with DEI-CT to provide high-contrast, high-resolution images of breast cancer (Parham 2006 PhD Dissertation University of North Carolina at Chapel Hill).
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Affiliation(s)
- T Kao
- National Synchrotron Light Source, Medical Department, Brookhaven National Laboratory, Upton, NY 11973, USA
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Kelly ME, Beavis RC, Fiorella D, Schültke E, Allen LA, Juurlink BH, Zhong Z, Chapman LD. Analyzer-based imaging of spinal fusion in an animal model. Phys Med Biol 2008; 53:2607-16. [PMID: 18441411 DOI: 10.1088/0031-9155/53/10/011] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Analyzer-based imaging (ABI) utilizes synchrotron radiation sources to create collimated monochromatic x-rays. In addition to x-ray absorption, this technique uses refraction and scatter rejection to create images. ABI provides dramatically improved contrast over standard imaging techniques. Twenty-one adult male Wistar rats were divided into four experimental groups to undergo the following interventions: (1) non-injured control, (2) decortication alone, (3) decortication with iliac crest bone grafting and (4) decortication with iliac crest bone grafting and interspinous wiring. Surgical procedures were performed at the L5-6 level. Animals were killed at 2, 4 and 6 weeks after the intervention and the spine muscle blocks were excised. Specimens were assessed for the presence of fusion by (1) manual testing, (2) conventional absorption radiography and (3) ABI. ABI showed no evidence of bone fusion in groups 1 and 2 and showed solid or possibly solid fusion in subjects from groups 3 and 4 at 6 weeks. Metal artifacts were not present in any of the ABI images. Conventional absorption radiographs did not provide diagnostic quality imaging of either the graft material or fusion masses in any of the specimens in any of the groups. Synchrotron-based ABI represents a novel imaging technique which can be used to assess spinal fusion in a small animal model. ABI produces superior image quality when compared to conventional radiographs.
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Affiliation(s)
- M E Kelly
- Division of Neurosurgery, Royal University Hospital, University of Saskatchewan, Saskatoon, SK, Canada.
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