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Tielemans B, Dekoster K, Verleden SE, Sawall S, Leszczyński B, Laperre K, Vanstapel A, Verschakelen J, Kachelriess M, Verbeken E, Swoger J, Vande Velde G. From Mouse to Man and Back: Closing the Correlation Gap between Imaging and Histopathology for Lung Diseases. Diagnostics (Basel) 2020; 10:E636. [PMID: 32859103 PMCID: PMC7554749 DOI: 10.3390/diagnostics10090636] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2020] [Revised: 08/21/2020] [Accepted: 08/24/2020] [Indexed: 02/07/2023] Open
Abstract
Lung diseases such as fibrosis, asthma, cystic fibrosis, infection and cancer are life-threatening conditions that slowly deteriorate quality of life and for which our diagnostic power is high, but our knowledge on etiology and/or effective treatment options still contains important gaps. In the context of day-to-day practice, clinical and preclinical studies, clinicians and basic researchers team up and continuously strive to increase insights into lung disease progression, diagnostic and treatment options. To unravel disease processes and to test novel therapeutic approaches, investigators typically rely on end-stage procedures such as serum analysis, cyto-/chemokine profiles and selective tissue histology from animal models. These techniques are useful but provide only a snapshot of disease processes that are essentially dynamic in time and space. Technology allowing evaluation of live animals repeatedly is indispensable to gain a better insight into the dynamics of lung disease progression and treatment effects. Computed tomography (CT) is a clinical diagnostic imaging technique that can have enormous benefits in a research context too. Yet, the implementation of imaging techniques in laboratories lags behind. In this review we want to showcase the integrated approaches and novel developments in imaging, lung functional testing and pathological techniques that are used to assess, diagnose, quantify and treat lung disease and that may be employed in research on patients and animals. Imaging approaches result in often novel anatomical and functional biomarkers, resulting in many advantages, such as better insight in disease progression and a reduction in the numbers of animals necessary. We here showcase integrated assessment of lung disease with imaging and histopathological technologies, applied to the example of lung fibrosis. Better integration of clinical and preclinical imaging technologies with pathology will ultimately result in improved clinical translation of (therapy) study results.
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Affiliation(s)
- Birger Tielemans
- Department of Imaging and Pathology, KU Leuven, University of Leuven, 3000 Leuven, Belgium; (B.T.); (K.D.); (J.V.); (E.V.)
| | - Kaat Dekoster
- Department of Imaging and Pathology, KU Leuven, University of Leuven, 3000 Leuven, Belgium; (B.T.); (K.D.); (J.V.); (E.V.)
| | - Stijn E. Verleden
- Department of CHROMETA, BREATHE lab, KU Leuven, 3000 Leuven, Belgium; (S.E.V.); (A.V.)
| | - Stefan Sawall
- German Cancer Research Center (DKFZ), X-Ray Imaging and CT, Heidelberg University, 69117 Heidelberg, Germany; (S.S.); (M.K.)
| | - Bartosz Leszczyński
- Department of Medical Physics, M. Smoluchowski Institute of Physics, Faculty of Physics, Astronomy and Applied Computer Science, Jagiellonian University, 31-007 Kraków, Poland;
| | | | - Arno Vanstapel
- Department of CHROMETA, BREATHE lab, KU Leuven, 3000 Leuven, Belgium; (S.E.V.); (A.V.)
| | - Johny Verschakelen
- Department of Imaging and Pathology, KU Leuven, University of Leuven, 3000 Leuven, Belgium; (B.T.); (K.D.); (J.V.); (E.V.)
| | - Marc Kachelriess
- German Cancer Research Center (DKFZ), X-Ray Imaging and CT, Heidelberg University, 69117 Heidelberg, Germany; (S.S.); (M.K.)
| | - Erik Verbeken
- Department of Imaging and Pathology, KU Leuven, University of Leuven, 3000 Leuven, Belgium; (B.T.); (K.D.); (J.V.); (E.V.)
| | - Jim Swoger
- European Molecular Biology Laboratory (EMBL) Barcelona, 08003 Barcelona, Spain;
| | - Greetje Vande Velde
- Department of Imaging and Pathology, KU Leuven, University of Leuven, 3000 Leuven, Belgium; (B.T.); (K.D.); (J.V.); (E.V.)
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Gunnell ET, Franceschi DK, Inscoe CR, Hartman A, Goralski JL, Ceppe A, Handly B, Sams C, Fordham LA, Lu J, Zhou O, Lee YZ. Initial clinical evaluation of stationary digital chest tomosynthesis in adult patients with cystic fibrosis. Eur Radiol 2019; 29:1665-1673. [PMID: 30255248 PMCID: PMC6896210 DOI: 10.1007/s00330-018-5703-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2018] [Revised: 07/19/2018] [Accepted: 07/31/2018] [Indexed: 01/26/2023]
Abstract
OBJECTIVE The imaging evaluation of cystic fibrosis currently relies on chest radiography or computed tomography. Recently, digital chest tomosynthesis has been proposed as an alternative. We have developed a stationary digital chest tomosynthesis (s-DCT) system based on a carbon nanotube (CNT) linear x-ray source array. This system enables tomographic imaging without movement of the x-ray tube and allows for physiological gating. The goal of this study was to evaluate the feasibility of clinical CF imaging with the s-DCT system. MATERIALS AND METHODS CF patients undergoing clinically indicated chest radiography were recruited for the study and imaged on the s-DCT system. Three board-certified radiologists reviewed both the CXR and s-DCT images for image quality relevant to CF. CF disease severity was assessed by Brasfield score on CXR and chest tomosynthesis score on s-DCT. Disease severity measures were also evaluated against subject pulmonary function tests. RESULTS Fourteen patients underwent s-DCT imaging within 72 h of their chest radiograph imaging. Readers scored the visualization of proximal bronchi, small airways and vascular pattern higher on s-DCT than CXR. Correlation between the averaged Brasfield score and averaged tomosynthesis disease severity score for CF was -0.73, p = 0.0033. The CF disease severity score system for tomosynthesis had high correlation with FEV1 (r = -0.685) and FEF 25-75% (r = -0.719) as well as good correlation with FVC (r = -0.582). CONCLUSION We demonstrate the potential of CNT x-ray-based s-DCT for use in the evaluation of cystic fibrosis disease status in the first clinical study of s-DCT. KEY POINTS • Carbon nanotube-based linear array x-ray tomosynthesis systems have the potential to provide diagnostically relevant information for patients with cystic fibrosis without the need for a moving gantry. • Despite the short angular span in this prototype system, lung features such as the proximal bronchi, small airways and pulmonary vasculature have improved visualization on s-DCT compared with CXR. Further improvements are anticipated with longer linear x-ray array tubes. • Evaluation of disease severity in CF patients is possible with s-DCT, yielding improved visualization of important lung features and high correlation with pulmonary function tests at a relatively low dose.
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Affiliation(s)
- Elias Taylor Gunnell
- School of Medicine, The University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA.
| | - Dora K Franceschi
- School of Medicine, The University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA
| | - Christina R Inscoe
- Department of Physics and Astronomy, The University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA
| | - Allison Hartman
- Department of Physics and Astronomy, The University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA
| | - Jennifer L Goralski
- Marsico Lung Institute, The University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA
- Division of Pulmonary and Critical Care Medicine, The University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA
- Division of Pediatric Pulmonology, The University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA
| | - Agathe Ceppe
- Marsico Lung Institute, The University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA
| | - Brian Handly
- Department of Radiology, The University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA
| | - Cassandra Sams
- Department of Radiology, The University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA
| | - Lynn Ansley Fordham
- Department of Radiology, The University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA
| | - Jianping Lu
- Department of Physics and Astronomy, The University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA
| | - Otto Zhou
- Department of Physics and Astronomy, The University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA
| | - Yueh Z Lee
- Department of Physics and Astronomy, The University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA
- Marsico Lung Institute, The University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA
- Department of Radiology, The University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA
- Lineberger Comprehensive Cancer Center, The University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA
- Biomedical Research Imaging Center, The University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA
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Affiliation(s)
- Guohua Cao
- Virginia Tech-Wake Forest University School of Biomedical Engineering and Sciences, Virginia Polytechnic Institute and State University (Virginia Tech), Blacksburg, VA 24061, USA
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Augustine S, Singh J, Srivastava M, Sharma M, Das A, Malhotra BD. Recent advances in carbon based nanosystems for cancer theranostics. Biomater Sci 2017; 5:901-952. [DOI: 10.1039/c7bm00008a] [Citation(s) in RCA: 143] [Impact Index Per Article: 20.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
This review deals with four different types of carbon allotrope based nanosystems and summarizes the results of recent studies that are likely to have applications in cancer theranostics. We discuss the applications of these nanosystems for cancer imaging, drug delivery, hyperthermia, and PDT/TA/PA.
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Affiliation(s)
- Shine Augustine
- NanoBioelectronics Laboratory
- Department of Biotechnology
- Delhi Technological University
- Delhi 110042
- India
| | - Jay Singh
- Department of Applied Chemistry & Polymer Technology
- Delhi Technological University
- Delhi 110042
- India
| | - Manish Srivastava
- Department of Physics & Astrophysics
- University of Delhi
- Delhi 110007
- India
| | - Monica Sharma
- NanoBioelectronics Laboratory
- Department of Biotechnology
- Delhi Technological University
- Delhi 110042
- India
| | - Asmita Das
- NanoBioelectronics Laboratory
- Department of Biotechnology
- Delhi Technological University
- Delhi 110042
- India
| | - Bansi D. Malhotra
- NanoBioelectronics Laboratory
- Department of Biotechnology
- Delhi Technological University
- Delhi 110042
- India
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Chtcheprov P, Burk L, Yuan H, Inscoe C, Ger R, Hadsell M, Lu J, Zhang L, Chang S, Zhou O. Physiologically gated microbeam radiation using a field emission x-ray source array. Med Phys 2015; 41:081705. [PMID: 25086515 DOI: 10.1118/1.4886015] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
PURPOSE Microbeam radiation therapy (MRT) uses narrow planes of high dose radiation beams to treat cancerous tumors. This experimental therapy method based on synchrotron radiation has been shown to spare normal tissue at up to 1000 Gy of peak entrance dose while still being effective in tumor eradication and extending the lifetime of tumor-bearing small animal models. Motion during treatment can lead to significant movement of microbeam positions resulting in broader beam width and lower peak to valley dose ratio (PVDR), which reduces the effectiveness of MRT. Recently, the authors have demonstrated the feasibility of generating microbeam radiation for small animal treatment using a carbon nanotube (CNT) x-ray source array. The purpose of this study is to incorporate physiological gating to the CNT microbeam irradiator to minimize motion-induced microbeam blurring. METHODS The CNT field emission x-ray source array with a narrow line focal track was operated at 160 kVp. The x-ray radiation was collimated to a single 280 μm wide microbeam at entrance. The microbeam beam pattern was recorded using EBT2 Gafchromic(©) films. For the feasibility study, a strip of EBT2 film was attached to an oscillating mechanical phantom mimicking mouse chest respiratory motion. The servo arm was put against a pressure sensor to monitor the motion. The film was irradiated with three microbeams under gated and nongated conditions and the full width at half maximums and PVDRs were compared. An in vivo study was also performed with adult male athymic mice. The liver was chosen as the target organ for proof of concept due to its large motion during respiration compared to other organs. The mouse was immobilized in a specialized mouse bed and anesthetized using isoflurane. A pressure sensor was attached to a mouse's chest to monitor its respiration. The output signal triggered the electron extraction voltage of the field emission source such that x-ray was generated only during a portion of the mouse respiratory cycle when there was minimum motion. Parallel planes of microbeams with 12.4 Gy/plane dose and 900 μm pitch were delivered. The microbeam profiles with and without gating were analyzed using γ-H2Ax immunofluorescence staining. RESULTS The phantom study showed that the respiratory motion caused a 50% drop in PVDR from 11.5 when there is no motion to 5.4, whereas there was only a 5.5% decrease in PVDR for gated irradiation compared to the no motion case. In the in vivo study, the histology result showed gating increased PVDR by a factor of 2.4 compared to the nongated case, similar to the result from the phantom study. The full width at tenth maximum of the microbeam decreased by 40% in gating in vivo and close to 38% with phantom studies. CONCLUSIONS The CNT field emission x-ray source array can be synchronized to physiological signals for gated delivery of x-ray radiation to minimize motion-induced beam blurring. Gated MRT reduces valley dose between lines during long-time radiation of a moving object. The technique allows for more precise MRT treatments and makes the CNT MRT device practical for extended treatment.
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Affiliation(s)
- Pavel Chtcheprov
- Department of Biomedical Engineering, University of North Carolina, 152 MacNider Hall, Campus Box 7575, Chapel Hill, North Carolina 27599
| | - Laurel Burk
- Department of Physics and Astronomy, University of North Carolina, Phillips Hall, CB #3255, 120 East Cameron Avenue, Chapel Hill, North Carolina 27599
| | - Hong Yuan
- Department of Radiology, University of North Carolina, 2006 Old Clinic, CB #7510, Chapel Hill, North Carolina 27599
| | - Christina Inscoe
- Department of Physics and Astronomy, University of North Carolina, Phillips Hall, CB #3255, 120 East Cameron Avenue, Chapel Hill, North Carolina 27599
| | - Rachel Ger
- Department of Physics and Astronomy, University of North Carolina, Phillips Hall, CB #3255, 120 East Cameron Avenue, Chapel Hill, North Carolina 27599
| | - Michael Hadsell
- Department of Physics and Astronomy, University of North Carolina, Phillips Hall, CB #3255, 120 East Cameron Avenue, Chapel Hill, North Carolina 27599
| | - Jianping Lu
- Department of Physics and Astronomy, University of North Carolina, Phillips Hall, CB #3255, 120 East Cameron Avenue, Chapel Hill, North Carolina 27599
| | - Lei Zhang
- Department of Applied Physical Sciences, University of North Carolina, Chapman Hall, CB#3216, Chapel Hill, North Carolina 27599
| | - Sha Chang
- Department of Radiation Oncology, University of North Carolina, 101 Manning Drive, Chapel Hill, North Carolina 27514 and UNC Lineberger Comprehensive Cancer Center, University of North Carolina, 101 Manning Drive, Chapel Hill, North Carolina 27514
| | - Otto Zhou
- Department of Physics and Astronomy, University of North Carolina, Phillips Hall, CB #3255, 120 East Cameron Avenue, Chapel Hill, North Carolina 27599 and UNC Lineberger Comprehensive Cancer Center, University of North Carolina, 101 Manning Drive, Chapel Hill, North Carolina 27514
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Hadsell M, Cao G, Zhang J, Burk L, Schreiber T, Schreiber E, Chang S, Lu J, Zhou O. Pilot study for compact microbeam radiation therapy using a carbon nanotube field emission micro-CT scanner. Med Phys 2014; 41:061710. [PMID: 24877805 PMCID: PMC4032446 DOI: 10.1118/1.4873683] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2013] [Revised: 04/02/2014] [Accepted: 04/14/2014] [Indexed: 11/07/2022] Open
Abstract
PURPOSE Microbeam radiation therapy (MRT) is defined as the use of parallel, microplanar x-ray beams with an energy spectrum between 50 and 300 keV for cancer treatment and brain radiosurgery. Up until now, the possibilities of MRT have mainly been studied using synchrotron sources due to their high flux (100s Gy/s) and approximately parallel x-ray paths. The authors have proposed a compact x-ray based MRT system capable of delivering MRT dose distributions at a high dose rate. This system would employ carbon nanotube (CNT) field emission technology to create an x-ray source array that surrounds the target of irradiation. Using such a geometry, multiple collimators would shape the irradiation from this array into multiple microbeams that would then overlap or interlace in the target region. This pilot study demonstrates the feasibility of attaining a high dose rate and parallel microbeam beams using such a system. METHODS The microbeam dose distribution was generated by our CNT micro-CT scanner (100 μm focal spot) and a custom-made microbeam collimator. An alignment assembly was fabricated and attached to the scanner in order to collimate and superimpose beams coming from different gantry positions. The MRT dose distribution was measured using two orthogonal radiochromic films embedded inside a cylindrical phantom. This target was irradiated with microbeams incident from 44 different gantry angles to simulate an array of x-ray sources as in the proposed compact CNT-based MRT system. Finally, phantom translation in a direction perpendicular to the microplanar beams was used to simulate the use of multiple parallel microbeams. RESULTS Microbeams delivered from 44 gantry angles were superimposed to form a single microbeam dose distribution in the phantom with a FWHM of 300 μm (calculated value was 290 μm). Also, during the multiple beam simulation, a peak to valley dose ratio of ~10 was found when the phantom translation distance was roughly 4x the beam width. The first prototype CNT-based x-ray tube dedicated to the development of compact MRT technology development was proposed and planned based on the preliminary experimental results presented here and the previous corresponding Monte Carlo simulations. CONCLUSIONS The authors have demonstrated the feasibility of creating microbeam dose distributions at a high dose rate using a proposed compact MRT system. The flexibility of CNT field emission x-ray sources could possibly bring compact and low cost MRT devices to the larger research community and assist in the translational research of this promising new approach to radiation therapy.
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Affiliation(s)
- Mike Hadsell
- Department of Physics and Astronomy, University of North Carolina, Chapel Hill, North Carolina 27599
| | - Guohua Cao
- Department of Physics and Astronomy, University of North Carolina, Chapel Hill, North Carolina 27599
| | - Jian Zhang
- Department of Physics and Astronomy, University of North Carolina, Chapel Hill, North Carolina 27599
| | - Laurel Burk
- Department of Physics and Astronomy, University of North Carolina, Chapel Hill, North Carolina 27599
| | - Torsten Schreiber
- Department of Physics and Astronomy, University of North Carolina, Chapel Hill, North Carolina 27599
| | - Eric Schreiber
- Department of Radiation Oncology, University of North Carolina, Chapel Hill, North Carolina 27599
| | - Sha Chang
- Department of Radiation Oncology, University of North Carolina, Chapel Hill, North Carolina 27599
| | - Jianping Lu
- Department of Physics and Astronomy, University of North Carolina, Chapel Hill, North Carolina 27599
| | - Otto Zhou
- Department of Physics and Astronomy, University of North Carolina, Chapel Hill, North Carolina 27599
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Chtcheprov P, Hadsell M, Burk L, Ger R, Zhang L, Yuan H, Lee YZ, Chang S, Lu J, Zhou O. Physiologically gated micro-beam radiation therapy using electronically controlled field emission x-ray source array. PROCEEDINGS OF SPIE--THE INTERNATIONAL SOCIETY FOR OPTICAL ENGINEERING 2013; 8671. [PMID: 27158179 DOI: 10.1117/12.2007998] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
Micro-beam radiation therapy (MRT) uses parallel planes of high dose narrow (10-100 um in width) radiation beams separated by a fraction of a millimeter to treat cancerous tumors. This experimental therapy method based on synchrotron radiation has been shown to spare normal tissue at up to 1000Gy of entrance dose while still being effective in tumor eradication and extending the lifetime of tumor-bearing small animal models. Motion during the treatment can result in significant movement of micro beam positions resulting in broader beam width and lower peak to valley dose ratio (PVDR), and thus can reduce the effectiveness of the MRT. Recently we have developed the first bench-top image guided MRT system for small animal treatment using a high powered carbon nanotube (CNT) x-ray source array. The CNT field emission x-ray source can be electronically synchronized to an external triggering signal to enable physiologically gated firing of x-ray radiation to minimize motion blurring. Here we report the results of phantom study of respiratory gated MRT. A simulation of mouse breathing was performed using a servo motor. Preliminary results show that without gating the micro beam full width at tenth maximum (FWTM) can increase by 70% and PVDR can decrease up to 50%. But with proper gating, both the beam width and PVDR changes can be negligible. Future experiments will involve irradiation of mouse models and comparing histology stains between the controls and the gated irradiation.
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Affiliation(s)
- Pavel Chtcheprov
- University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Michael Hadsell
- University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Laurel Burk
- University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Rachel Ger
- University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Lei Zhang
- University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Hong Yuan
- University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Yueh Z Lee
- University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Sha Chang
- University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Jianping Lu
- University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Otto Zhou
- University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
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Wait JMS, Tomita H, Burk LM, Lu J, Zhou OZ, Maeda N, Lee YZ. Detection of aortic arch calcification in apolipoprotein E-null mice using carbon nanotube-based micro-CT system. J Am Heart Assoc 2013; 2:e003358. [PMID: 23525427 PMCID: PMC3603263 DOI: 10.1161/jaha.112.003358] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Background We performed in vivo micro‐computed tomography (micro‐CT) imaging using a novel carbon nanotube (CNT)–based x‐ray source to detect calcification in the aortic arch of apolipoprotein E (apoE)–null mice. Methods and Results We measured calcification volume of aortic arch plaques using CNT‐based micro‐CT in 16‐ to 18‐month‐old males on 129S6/SvEvTac and C57BL/6J genetic backgrounds (129‐apoE KO and B6‐apoE KO). Cardiac and respiratory gated images were acquired in each mouse under anesthesia. Images obtained using a CNT micro‐CT had less motion blur and better spatial resolution for aortic calcification than those using conventional micro‐CT, evaluated by edge sharpness (slope of the normalized attenuation units, 1.6±0.3 versus 0.8±0.2) and contrast‐to‐noise ratio of the calcifications (118±34 versus 10±2); both P<0.05, n=6. Calcification volume in the arch inner curvature was 4 times bigger in the 129‐apoE KO than in the B6‐apoE KO mice (0.90±0.18 versus 0.22±0.10 mm3, P<0.01, n=7 and 5, respectively), whereas plaque areas in the inner curvature measured in dissected aorta were only twice as great in the 129‐apoE KO than in the B6‐apoE KO mice (6.1±0.6 versus 3.7±0.4 mm2, P<0.05). Consistent with this, histological calcification area in the plaques was significantly higher in the 129‐apoE KO than in the B6‐apoE KO mice (16.9±2.0 versus 9.6±0.8%, P<0.05, 3 animals for each). Conclusions A novel CNT‐based micro‐CT is a useful tool to evaluate vascular calcifications in living mice. Quantification from acquired images suggests higher susceptibility to calcification of the aortic arch plaques in 129‐apoE KO than in B6‐apoE KO mice.
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Affiliation(s)
- John M S Wait
- Department of Physics and Astronomy, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599-7510, USA
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Rodt T, Luepke M, Boehm C, Hueper K, Halter R, Glage S, Hoy L, Wacker F, Borlak J, von Falck C. Combined micro-PET/micro-CT imaging of lung tumours in SPC-raf and SPC-myc transgenic mice. PLoS One 2012; 7:e44427. [PMID: 23028537 PMCID: PMC3448619 DOI: 10.1371/journal.pone.0044427] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2012] [Accepted: 08/02/2012] [Indexed: 01/21/2023] Open
Abstract
Introduction SPC-raf and SPC-myc transgenic mice develop disseminated and circumscribed lung adenocarcinoma respectively, allowing for assessment of carcinogenesis and treatment strategies. The purpose of this study was to investigate the technical feasibility, the correlation of initial findings to histology and the administered radiation dose of combined micro-PET/micro-CT in these animal models. Material and Methods 14 C57BL/6 mice (4 nontransgenic, 4 SPC-raf transgenic, 6 SPC-myc transgenic) were examined using micro-CT and 18F-Fluoro-deoxyglucose micro-PET in-vivo. Micro-PET data was corrected for random events and scatter prior to reconstruction with a 3D-FORE/2D-OSEM iterative algorithm. Rigid micro-PET/micro-CT registration was performed. Tumour-to-non-tumour ratios were calculated for different lung regions and focal lesions. Diffuse tumour growth was quantified using a semiautomated micro-CT segmentation routine reported earlier. Regional histologic tumour load was assessed using a 4-point rating scale. Gamma radiation dose was determined using thermoluminescence dosimeters. Results Micro-CT allowed visualisation of diffuse and circumscribed tumours in SPC-raf and SPC-myc transgenic animals along with morphology, while micro-PET provided information on metabolism, but lacked morphologic detail. Mean tumour-to-non-tumour ratio was 2.47 for circumscribed lesions. No significant correlation could be shown between histological tumour load and tumour-to-nontumour ratio for diffuse tumours in SPC-raf transgenic animals. Calculation of the expected dose based on gamma dosimetry yielded approximately 140 mGy/micro-PET examination additional to approximately 200 mGy due to micro-CT. Conclusions Combined micro-PET/micro-CT imaging allows for in-vivo assessment of lung tumours in SPC-raf and SPC-myc transgenic mice. The technique has potential for the evaluation of carcinogenesis and treatment strategies in circumscribed lung tumours.
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Affiliation(s)
- Thomas Rodt
- Department of Diagnostic and Interventional Radiology, Hannover Medical School, Hannover, Germany.
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Schreiber EC, Chang SX. Monte Carlo simulation of a compact microbeam radiotherapy system based on carbon nanotube field emission technology. Med Phys 2012; 39:4669-78. [PMID: 22894391 DOI: 10.1118/1.4728220] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
PURPOSE Microbeam radiation therapy (MRT) is an experimental radiotherapy technique that has shown potent antitumor effects with minimal damage to normal tissue in animal studies. This unique form of radiation is currently only produced in a few large synchrotron accelerator research facilities in the world. To promote widespread translational research on this promising treatment technology we have proposed and are in the initial development stages of a compact MRT system that is based on carbon nanotube field emission x-ray technology. We report on a Monte Carlo based feasibility study of the compact MRT system design. METHODS Monte Carlo calculations were performed using EGSnrc-based codes. The proposed small animal research MRT device design includes carbon nanotube cathodes shaped to match the corresponding MRT collimator apertures, a common reflection anode with filter, and a MRT collimator. Each collimator aperture is sized to deliver a beam width ranging from 30 to 200 μm at 18.6 cm source-to-axis distance. Design parameters studied with Monte Carlo include electron energy, cathode design, anode angle, filtration, and collimator design. Calculations were performed for single and multibeam configurations. RESULTS Increasing the energy from 100 kVp to 160 kVp increased the photon fluence through the collimator by a factor of 1.7. Both energies produced a largely uniform fluence along the long dimension of the microbeam, with 5% decreases in intensity near the edges. The isocentric dose rate for 160 kVp was calculated to be 700 Gy∕min∕A in the center of a 3 cm diameter target. Scatter contributions resulting from collimator size were found to produce only small (<7%) changes in the dose rate for field widths greater than 50 μm. Dose vs depth was weakly dependent on filtration material. The peak-to-valley ratio varied from 10 to 100 as the separation between adjacent microbeams varies from 150 to 1000 μm. CONCLUSIONS Monte Carlo simulations demonstrate that the proposed compact MRT system design is capable of delivering a sufficient dose rate and peak-to-valley ratio for small animal MRT studies.
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Affiliation(s)
- Eric C Schreiber
- Department of Radiation Oncology, University of North Carolina, Chapel Hill, North Carolina 27599, USA.
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Burk LM, Lee YZ, Wait JM, Lu J, Zhou OZ. Non-contact respiration monitoring for in-vivo murine micro computed tomography: characterization and imaging applications. Phys Med Biol 2012; 57:5749-63. [PMID: 22948192 DOI: 10.1088/0031-9155/57/18/5749] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
A cone beam micro-CT has previously been utilized along with a pressure-tracking respiration sensor to acquire prospectively gated images of both wild-type mice and various adult murine disease models. While the pressure applied to the abdomen of the subject by this sensor is small and is generally without physiological effect, certain disease models of interest, as well as very young animals, are prone to atelectasis with added pressure, or they generate too weak a respiration signal with this method to achieve optimal prospective gating. In this work we present a new fibre-optic displacement sensor which monitors respiratory motion of a subject without requiring physical contact. The sensor outputs an analogue signal which can be used for prospective respiration gating in micro-CT imaging. The device was characterized and compared against a pneumatic air chamber pressure sensor for the imaging of adult wild-type mice. The resulting images were found to be of similar quality with respect to physiological motion blur; the quality of the respiration signal trace obtained using the non-contact sensor was comparable to that of the pressure sensor and was superior for gating purposes due to its better signal-to-noise ratio. The non-contact sensor was then used to acquire in-vivo micro-CT images of a murine model for congenital diaphragmatic hernia and of 11-day-old mouse pups. In both cases, quality CT images were successfully acquired using this new respiration sensor. Despite the presence of beam hardening artefacts arising from the presence of a fibre-optic cable in the imaging field, we believe this new technique for respiration monitoring and gating presents an opportunity for in-vivo imaging of disease models which were previously considered too delicate for established animal handling methods.
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Affiliation(s)
- Laurel M Burk
- Department of Physics and Astronomy, University of North Carolina, Chapel Hill, NC 27599, USA.
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