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Goossens E, Deblock L, Caboor L, Eynden DVD, Josipovic I, Isaacura PR, Maksimova E, Van Impe M, Bonnin A, Segers P, Cornillie P, Boone MN, Van Driessche I, De Spiegelaere W, De Roo J, Sips P, De Buysser K. From Corrosion Casting to Virtual Dissection: Contrast-Enhanced Vascular Imaging using Hafnium Oxide Nanocrystals. SMALL METHODS 2024; 8:e2301499. [PMID: 38200600 DOI: 10.1002/smtd.202301499] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/28/2023] [Indexed: 01/12/2024]
Abstract
Vascular corrosion casting is a method used to visualize the three dimensional (3D) anatomy and branching pattern of blood vessels. A polymer resin is injected in the vascular system and, after curing, the surrounding tissue is removed. The latter often deforms or even fractures the fragile cast. Here, a method is proposed that does not require corrosion, and is based on in situ micro computed tomography (micro-CT) scans. To overcome the lack of CT contrast between the polymer cast and the animals' surrounding soft tissue, hafnium oxide nanocrystals (HfO2 NCs) are introduced as CT contrast agents into the resin. The NCs dramatically improve the overall CT contrast of the cast and allow for straightforward segmentation in the CT scans. Careful design of the NC surface chemistry ensures the colloidal stability of the NCs in the casting resin. Using only 5 m% of HfO2 NCs, high-quality cardiovascular casts of both zebrafish and mice can be automatically segmented using CT imaging software. This allows to differentiate even μ $\umu$ m-scale details without having to alter the current resin injection methods. This new method of virtual dissection by visualizing casts in situ using contrast-enhanced CT imaging greatly expands the application potential of the technique.
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Affiliation(s)
- Eline Goossens
- Department of Chemistry, Ghent University, Ghent, 9000, Belgium
- Department of Chemistry, University of Basel, Basel, 4058, Switzerland
| | - Loren Deblock
- Department of Chemistry, Ghent University, Ghent, 9000, Belgium
| | - Lisa Caboor
- Department of Biomolecular Medicine, Ghent University, Ghent, 9000, Belgium
| | - Dietger Van den Eynden
- Department of Chemistry, Ghent University, Ghent, 9000, Belgium
- Department of Chemistry, University of Basel, Basel, 4058, Switzerland
| | - Iván Josipovic
- Center for X-ray Tomography, Ghent University, Ghent, 9000, Belgium
| | - Pablo Reyes Isaacura
- Laboratory of Veterinary Morphology, Ghent University, Merelbeke, 9820, Belgium
- Centre for Polymer Material Technologies, Ghent University, Ghent, 9052, Belgium
- Laboratory for Chemical Technology, Ghent University, Ghent, 9052, Belgium
| | - Elizaveta Maksimova
- Department of Chemistry, University of Basel, Basel, 4058, Switzerland
- Swiss Light Source, Paul Scherrer Institut, Villigen PSI, 5232, Switzerland
- Swiss Nanoscience Institute, University of Basel, Basel, 4056, Switzerland
| | - Matthias Van Impe
- Institute of Biomedical Engineering and Technology, Ghent University, Ghent, 9000, Belgium
| | - Anne Bonnin
- Swiss Light Source, Paul Scherrer Institut, Villigen PSI, 5232, Switzerland
| | - Patrick Segers
- Institute of Biomedical Engineering and Technology, Ghent University, Ghent, 9000, Belgium
| | - Pieter Cornillie
- Laboratory of Veterinary Morphology, Ghent University, Merelbeke, 9820, Belgium
| | - Matthieu N Boone
- Center for X-ray Tomography, Ghent University, Ghent, 9000, Belgium
| | | | - Ward De Spiegelaere
- Laboratory of Veterinary Morphology, Ghent University, Merelbeke, 9820, Belgium
| | - Jonathan De Roo
- Department of Chemistry, University of Basel, Basel, 4058, Switzerland
| | - Patrick Sips
- Department of Biomolecular Medicine, Ghent University, Ghent, 9000, Belgium
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Safari A, Mahdavi M, Fardid R, Oveisi A, Jalli R, Haghani M. Evaluation of hafnium oxide nanoparticles imaging characteristics as a contrast agent in X-ray computed tomography. Radiol Phys Technol 2024; 17:441-450. [PMID: 38630390 DOI: 10.1007/s12194-024-00797-8] [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: 12/23/2023] [Revised: 03/18/2024] [Accepted: 03/19/2024] [Indexed: 05/27/2024]
Abstract
This research aimed to compare the quantitative imaging attributes of synthesized hafnium oxide nanoparticles (NPs) derived from UiO-66-NH2(Hf) and two gadolinium- and iodine-based clinical contrast agents (CAs) using cylindrical phantom. Aqueous solutions of the studied CAs, containing 2.5, 5, and 10 mg/mL of HfO2NPs, gadolinium, and iodine, were prepared. Constructed within a cylindrical phantom, 15 cc small tubes were filled with CAs. Maintaining constant mAs, the phantom underwent scanning at tube voltage variations from 80 to 140 kVp. The CT numbers were quantified in Hounsfield units (HU), and the contrast-to-noise ratios (CNR) were calculated within delineated regions of interest (ROI) for all CAs. The HfO2NPs at 140 kVp and concentration of 2.5 mg/ml exhibited 2.3- and 1.3-times higher CT numbers than iodine and gadolinium, respectively. Notably, gadolinium consistently displayed higher CT numbers than iodine across all exposure techniques and concentrations. At the highest tube potential, the maximum amount of the CAs CT numbers was attained, and at 140 kVp and concentration of 2.5 mg/ml of HfO2NPs the CNR surpassed iodine by 114%, and gadolinium by 30%, respectively. HfO2NPs, as a contrast agent, demonstrated superior image quality in terms of contrast and noise in comparison to iodine- and gadolinium-based contrast media, particularly at higher energies of X-ray in computed tomography. Thus, its utilization is highly recommended in CT.
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Affiliation(s)
- Arash Safari
- Ionizing and Non-Ionizing Radiation Protection Research Center (INIRPRC), School of Paramedical Sciences, Shiraz University of Medical Sciences, Shiraz, Iran.
- Department of Radiology, School of Paramedical Sciences, Shiraz University of Medical Sciences, Shiraz, Iran.
| | - Maziyar Mahdavi
- Ionizing and Non-Ionizing Radiation Protection Research Center (INIRPRC), School of Paramedical Sciences, Shiraz University of Medical Sciences, Shiraz, Iran
- Department of Radiology, School of Paramedical Sciences, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Reza Fardid
- Ionizing and Non-Ionizing Radiation Protection Research Center (INIRPRC), School of Paramedical Sciences, Shiraz University of Medical Sciences, Shiraz, Iran
- Department of Radiology, School of Paramedical Sciences, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Alireza Oveisi
- Department of Chemistry, Faculty of Sciences, University of Zabol, P.O. Box: 98615-538, Zabol, Iran.
| | - Reza Jalli
- Department of Radiology, Medical Imaging Research Center, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Masoud Haghani
- Ionizing and Non-Ionizing Radiation Protection Research Center (INIRPRC), School of Paramedical Sciences, Shiraz University of Medical Sciences, Shiraz, Iran.
- Department of Radiology, School of Paramedical Sciences, Shiraz University of Medical Sciences, Shiraz, Iran.
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Skrodzki D, Molinaro M, Brown R, Moitra P, Pan D. Synthesis and Bioapplication of Emerging Nanomaterials of Hafnium. ACS NANO 2024; 18:1289-1324. [PMID: 38166377 DOI: 10.1021/acsnano.3c08917] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/04/2024]
Abstract
A significant amount of progress in nanotechnology has been made due to the development of engineered nanoparticles. The use of metallic nanoparticles for various biomedical applications has been extensively investigated. Biomedical research is highly focused on them because of their inert nature, nanoscale structure, and similar size to many biological molecules. The intrinsic characteristics of these particles, including electronic, optical, physicochemical, and surface plasmon resonance, that can be altered by altering their size, shape, environment, aspect ratio, ease of synthesis, and functionalization properties, have led to numerous biomedical applications. Targeted drug delivery, sensing, photothermal and photodynamic therapy, and imaging are some of these. The promising clinical results of NBTXR3, a high-Z radiosensitizing nanomaterial derived from hafnium, have demonstrated translational potential of this metal. This radiosensitization approach leverages the dependence of energy attenuation on atomic number to enhance energy-matter interactions conducive to radiation therapy. High-Z nanoparticle localization in tumor issue differentially increases the effect of ionizing radiation on cancer cells versus nearby healthy ones and mitigates adverse effects by reducing the overall radiation burden. This principle enables material multifunctionality as contrast agents in X-ray-based imaging. The physiochemical properties of hafnium (Z = 72) are particularly advantageous for these applications. A well-placed K-edge absorption energy and high mass attenuation coefficient compared to elements in human tissue across clinical energy ranges leads to significant attenuation. Chemical reactivity allows for variety in nanoparticle synthesis, composition, and functionalization. Nanoparticles such as hafnium oxide exhibit excellent biocompatibility due to physiochemical inertness prior to incidence with ionizing radiation. Additionally, the optical and electronic properties are applicable in biosensing, optical component coatings, and semiconductors. The wide interest has prompted extensive research in design and synthesis to facilitate property fine-tuning. This review summarizes synthetic methods for hafnium-based nanomaterials and applications in therapy, imaging, and biosensing with a mechanistic focus. A discussion and future perspective section highlights clinical progress and elaborates on current challenges. By focusing on factors impacting applicational effectiveness and examining limitations this review aims to support researchers and expedite clinical translation of future hafnium-based nanomedicine.
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Affiliation(s)
- David Skrodzki
- Department of Materials Science and Engineering, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
| | - Matthew Molinaro
- Department of Engineering Science and Mechanics, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
| | - Richard Brown
- Department of Nuclear Engineering, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
| | - Parikshit Moitra
- Department of Nuclear Engineering, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
| | - Dipanjan Pan
- Department of Materials Science and Engineering, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
- Department of Nuclear Engineering, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
- Huck Institutes of the Life Sciences, 101 Huck Life Sciences Building, University Park, Pennsylvania 16802, United States
- Department of Biomedical Engineering, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
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Jost G, McDermott M, Gutjahr R, Nowak T, Schmidt B, Pietsch H. New Contrast Media for K-Edge Imaging With Photon-Counting Detector CT. Invest Radiol 2023; 58:515-522. [PMID: 37068840 PMCID: PMC10259215 DOI: 10.1097/rli.0000000000000978] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2023] [Accepted: 03/01/2023] [Indexed: 04/19/2023]
Abstract
ABSTRACT The recent technological developments in photon-counting detector computed tomography (PCD-CT) and the introduction of the first commercially available clinical PCD-CT unit open up new exciting opportunities for contrast media research. With PCD-CT, the efficacy of available iodine-based contrast media improves, allowing for a reduction of iodine dosage or, on the other hand, an improvement of image quality in low contrast indications. Virtual monoenergetic image reconstructions are routinely available and enable the virtual monoenergetic image energy to be adapted to the diagnostic task.A key property of PCD-CT is the ability of spectral separation in combination with improved material decomposition. Thus, the discrimination of contrast media from intrinsic or pathological tissues and the discrimination of 2 or more contrasting elements that characterize different tissues are attractive fields for contrast media research. For these approaches, K-edge imaging in combination with high atomic number elements such as the lanthanides, tungsten, tantalum, or bismuth plays a central role.The purpose of this article is to present an overview of innovative contrast media concepts that use high atomic number elements. The emphasis is on improving contrast enhancement for cardiovascular plaque imaging, stent visualization, and exploring new approaches using 2 contrasting elements. Along with the published research, new experimental findings with a contrast medium that incorporates tungsten are included.Both the literature review and the new experimental data demonstrate the great potential and feasibility for new contrast media to significantly increase diagnostic performance and to enable new clinical fields and indications in combination with PCD-CT.
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Affiliation(s)
- Gregor Jost
- From the MR and CT Contrast Media Research, Bayer AG, Berlin, Germany
| | - Michael McDermott
- From the MR and CT Contrast Media Research, Bayer AG, Berlin, Germany
- Department of Radiology and Nuclear Medicine, Maastricht University Medical Center, Maastricht, the Netherlands
| | - Ralf Gutjahr
- Computed Tomography, Siemens Healthineers, Forchheim, Germany
| | - Tristan Nowak
- Computed Tomography, Siemens Healthineers, Forchheim, Germany
| | | | - Hubertus Pietsch
- From the MR and CT Contrast Media Research, Bayer AG, Berlin, Germany
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5
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Enhancing the radiographic imaging of void defects in grouts by attenuation coefficient modification of grouting materials. Radiat Phys Chem Oxf Engl 1993 2023. [DOI: 10.1016/j.radphyschem.2023.110886] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/06/2023]
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Liu S, Heshmat A, Andrew J, Barreto I, Rinaldi-Ramos CM. Dual imaging agent for magnetic particle imaging and computed tomography. NANOSCALE ADVANCES 2023; 5:3018-3032. [PMID: 37260489 PMCID: PMC10228371 DOI: 10.1039/d3na00105a] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/16/2023] [Accepted: 04/30/2023] [Indexed: 06/02/2023]
Abstract
Magnetic particle imaging (MPI) is a novel biomedical imaging modality that allows non-invasive, tomographic, and quantitative tracking of the distribution of superparamagnetic iron oxide nanoparticle (SPION) tracers. While MPI possesses high sensitivity, detecting nanograms of iron, it does not provide anatomical information. Computed tomography (CT) is a widely used biomedical imaging modality that yields anatomical information at high resolution. A multimodal imaging agent combining the benefits of MPI and CT imaging would be of interest. Here we combine MPI-tailored SPIONs with CT-contrast hafnium oxide (hafnia) nanoparticles using flash nanoprecipitation to obtain dual-imaging MPI/CT agents. Co-encapsulation of iron oxide and hafnia in the composite nanoparticles was confirmed via transmission electron microscopy and elemental mapping. Equilibrium and dynamic magnetic characterization show a reduction in effective magnetic diameter and changes in dynamic magnetic susceptibility spectra at high oscillating field frequencies, suggesting magnetic interactions within the composite dual imaging tracers. The MPI performance of the dual imaging agent was evaluated and compared to the commercial tracer ferucarbotran. The dual-imaging agent has MPI sensitivity that is ∼3× better than this commercial tracer. However, worsening of MPI resolution was observed in the composite tracer when compared to individually coated SPIONs. This worsening resolution could result from magnetic dipolar interactions within the composite dual imaging tracer. The CT performance of the dual imaging agent was evaluated in a pre-clinical animal scanner and a clinical scanner, revealing better contrast compared to a commercial iodine-based contrast agent. We demonstrate that the dual imaging agent can be differentiated from the commercial iodine contrast agent using dual energy CT (DECT) imaging. Furthermore, the dual imaging agent displayed energy-dependent CT contrast arising from the combination of SPION and hafnia, making it potentially suitable for virtual monochromatic imaging of the contrast agent distribution using DECT.
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Affiliation(s)
- Sitong Liu
- Department of Chemical Engineering, University of Florida Gainesville FL 32611 USA
| | - Anahita Heshmat
- Department of Radiology, University of Florida Gainesville FL 32610-0374 USA
| | - Jennifer Andrew
- Department of Material Science and Engineering, University of Florida Gainesville FL 32603 USA
| | - Izabella Barreto
- Department of Radiology, University of Florida Gainesville FL 32610-0374 USA
| | - Carlos M Rinaldi-Ramos
- Department of Chemical Engineering, University of Florida Gainesville FL 32611 USA
- J. Crayton Pruitt Family Department of Biomedical Engineering, University of Florida Gainesville FL 32611-6131 USA
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Haubold J, Zensen S, Hosch R, Schaarschmidt BM, Bos D, Schmidt B, Flohr T, Li Y, Forsting M, Pietsch H, Nensa F, Jost G. Individualized scan protocols for CT angiography: an animal study for contrast media or radiation dose optimization. Eur Radiol Exp 2023; 7:24. [PMID: 37185930 PMCID: PMC10130261 DOI: 10.1186/s41747-023-00332-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2022] [Accepted: 02/16/2023] [Indexed: 05/17/2023] Open
Abstract
BACKGROUND We investigated about optimization of contrast media (CM) dose or radiation dose in thoracoabdominal computed tomography angiography (CTA) by automated tube voltage selection (ATVS) system configuration and CM protocol adaption. METHODS In six minipigs, CTA-optimized protocols were evaluated regarding objective (contrast-to-noise ratio, CNR) and subjective (6 criteria assessed by Likert scale) image quality. Scan parameters were automatically adapted by the ATVS system operating at 90-kV semi-mode and configured for standard, CM saving, or radiation dose saving (image task, quality settings). Injection protocols (dose, flow rate) were adapted manually. This approach was tested for normal and simulated obese conditions. RESULTS Radiation exposure (volume-weighted CT dose index) for normal (obese) conditions was 2.4 ± 0.7 (5.0 ± 0.7) mGy (standard), 4.3 ± 1.1 (9.0 ± 1.3) mGy (CM reduced), and 1.7 ± 0.5 (3.5 ± 0.5) mGy (radiation reduced). The respective CM doses for normal (obese) settings were 210 (240) mgI/kg, 155 (177) mgI/kg, and 252 (288) mgI/kg. No significant differences in CNR (normal; obese) were observed between standard (17.8 ± 3.0; 19.2 ± 4.0), CM-reduced (18.2 ± 3.3; 20.5 ± 4.9), and radiation-saving CTAs (16.0 ± 3.4; 18.4 ± 4.1). Subjective analysis showed similar values for optimized and standard CTAs. Only the parameter diagnostic acceptability was significantly lower for radiation-saving CTA compared to the standard CTA. CONCLUSIONS The CM dose (-26%) or radiation dose (-30%) for thoracoabdominal CTA can be reduced while maintaining objective and subjective image quality, demonstrating the feasibility of the personalization of CTA scan protocols. KEY POINTS • Computed tomography angiography protocols could be adapted to individual patient requirements using an automated tube voltage selection system combined with adjusted contrast media injection. • Using an adapted automated tube voltage selection system, a contrast media dose reduction (-26%) or radiation dose reduction (-30%) could be possible.
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Affiliation(s)
- Johannes Haubold
- Department of Diagnostic and Interventional Radiology and Neuroradiology, University Hospital Essen, 45147, Essen, Germany.
| | - Sebastian Zensen
- Department of Diagnostic and Interventional Radiology and Neuroradiology, University Hospital Essen, 45147, Essen, Germany
| | - René Hosch
- Department of Diagnostic and Interventional Radiology and Neuroradiology, University Hospital Essen, 45147, Essen, Germany
- Institute of Artificial Intelligence in Medicine, University Hospital Essen, Essen, Germany
| | - Benedikt Michael Schaarschmidt
- Department of Diagnostic and Interventional Radiology and Neuroradiology, University Hospital Essen, 45147, Essen, Germany
| | - Denise Bos
- Department of Diagnostic and Interventional Radiology and Neuroradiology, University Hospital Essen, 45147, Essen, Germany
| | | | | | - Yan Li
- Department of Diagnostic and Interventional Radiology and Neuroradiology, University Hospital Essen, 45147, Essen, Germany
| | - Michael Forsting
- Department of Diagnostic and Interventional Radiology and Neuroradiology, University Hospital Essen, 45147, Essen, Germany
| | | | - Felix Nensa
- Department of Diagnostic and Interventional Radiology and Neuroradiology, University Hospital Essen, 45147, Essen, Germany
- Institute of Artificial Intelligence in Medicine, University Hospital Essen, Essen, Germany
| | - Gregor Jost
- MR and CT Contrast Media Research, Bayer AG, Berlin, Germany
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Sawall S. [New contrast agents for photon-counting computed tomography]. RADIOLOGIE (HEIDELBERG, GERMANY) 2023:10.1007/s00117-023-01135-6. [PMID: 37069237 DOI: 10.1007/s00117-023-01135-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 03/03/2023] [Indexed: 04/19/2023]
Abstract
BACKGROUND The introduction of energy-selective photon-counting detectors into clinical practice represents the next milestone in computed tomography (CT). In addition to significantly higher resolution, these detectors allow the implicit acquisition of dual or multispectral data in a single measurement through the use of typically freely selectable thresholds. This capability reignited the interest in new contrast agents based on heavy elements, so-called high‑z elements, for clinical CT. OBJECTIVE The present article aims to investigate the potential suitability of different chemical elements as contrast agents and to discuss possible clinical applications, for example, K‑edge imaging or simultaneous application of different contrast agents. CONCLUSION First preclinical experiments as well as experiments in large animals could demonstrate potential advantages of contrast agents based on heavy elements. For example, such contrast agents promise a significant increase in image contrast compared to conventional iodine-based agents.
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Affiliation(s)
- Stefan Sawall
- Röntgenbildgebung und CT (E025), Deutsches Krebsforschungszentrum (DKFZ), Heidelberg, Deutschland.
- Medizinische Fakultät, Universität Heidelberg, Heidelberg, Deutschland.
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9
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Gu C, Wang Z, Pan Y, Zhu S, Gu Z. Tungsten-based Nanomaterials in the Biomedical Field: A Bibliometric Analysis of Research Progress and Prospects. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2023; 35:e2204397. [PMID: 35906814 DOI: 10.1002/adma.202204397] [Citation(s) in RCA: 11] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/16/2022] [Revised: 07/17/2022] [Indexed: 06/15/2023]
Abstract
Tungsten-based nanomaterials (TNMs) with diverse nanostructures and unique physicochemical properties have been widely applied in the biomedical field. Although various reviews have described the application of TNMs in specific biomedical fields, there are still no comprehensive studies that summarize and analyze research trends of the field as a whole. To identify and further promote the development of biomedical TNMs, a bibliometric analysis method is used to analyze all relevant literature on this topic. First, general bibliometric distributions of the dataset by year, country, institute, referenced source, and research hotspots are recognized. Next, a comprehensive review of the subjectively recognized research hotspots in various biomedical fields, including biological sensing, anticancer treatments, antibacterials, and toxicity evaluation, is provided. Finally, the prospects and challenges of TNMs are discussed to provide a new perspective for further promoting their development in biomedical research.
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Affiliation(s)
- Chenglu Gu
- CAS Key Laboratory for Biomedical Effects of Nanomaterials and Nanosafety, Institute of High Energy Physics, Beijing, 100049, China
- Center of Materials Science and Optoelectronics Engineering, College of Materials Science and Optoelectronic Technology, University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Zhiqiang Wang
- School of Science, China University of Geosciences, Beijing, 100049, China
| | - Yawen Pan
- School of Science, China University of Geosciences, Beijing, 100049, China
| | - Shuang Zhu
- CAS Key Laboratory for Biomedical Effects of Nanomaterials and Nanosafety, Institute of High Energy Physics, Beijing, 100049, China
- Center of Materials Science and Optoelectronics Engineering, College of Materials Science and Optoelectronic Technology, University of Chinese Academy of Sciences, Beijing, 100049, China
- CAS Center for Excellence in Nanoscience, National Center for Nanoscience and Technology of China, Chinese Academy of Sciences, Beijing, 100049, China
| | - Zhanjun Gu
- CAS Key Laboratory for Biomedical Effects of Nanomaterials and Nanosafety, Institute of High Energy Physics, Beijing, 100049, China
- Center of Materials Science and Optoelectronics Engineering, College of Materials Science and Optoelectronic Technology, University of Chinese Academy of Sciences, Beijing, 100049, China
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10
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Suslova EV, Kozlov AP, Shashurin DA, Rozhkov VA, Sotenskii RV, Maximov SV, Savilov SV, Medvedev OS, Chelkov GA. New Composite Contrast Agents Based on Ln and Graphene Matrix for Multi-Energy Computed Tomography. NANOMATERIALS (BASEL, SWITZERLAND) 2022; 12:4110. [PMID: 36500733 PMCID: PMC9737213 DOI: 10.3390/nano12234110] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/12/2022] [Revised: 11/11/2022] [Accepted: 11/17/2022] [Indexed: 06/17/2023]
Abstract
The subject of the current research study is aimed at the development of novel types of contrast agents (CAs) for multi-energy computed tomography (CT) based on Ln-graphene composites, which include Ln (Ln = La, Nd, and Gd) nanoparticles with a size of 2-3 nm, acting as key contrasting elements, and graphene nanoflakes (GNFs) acting as the matrix. The synthesis and surface modifications of the GNFs and the properties of the new CAs are presented herein. The samples have had their characteristics determined using X-ray photoelectron spectroscopy, X-Ray diffraction, transmission electron microscopy, thermogravimetric analysis, and Raman spectroscopy. Multi-energy CT images of the La-, Nd-, and Gd-based CAs demonstrating their visualization and discriminative properties, as well as the possibility of a quantitative analysis, are presented.
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Affiliation(s)
- Evgeniya V. Suslova
- Department of Chemistry, Lomonosov Moscow State University, 119991 Moscow, Russia
| | - Alexei P. Kozlov
- Department of Chemistry, Lomonosov Moscow State University, 119991 Moscow, Russia
| | - Denis A. Shashurin
- Department of Chemistry, Lomonosov Moscow State University, 119991 Moscow, Russia
- Faculty of Medicine, Lomonosov Moscow State University, 119991 Moscow, Russia
| | | | | | - Sergei V. Maximov
- Department of Chemistry, Lomonosov Moscow State University, 119991 Moscow, Russia
| | - Serguei V. Savilov
- Department of Chemistry, Lomonosov Moscow State University, 119991 Moscow, Russia
| | - Oleg S. Medvedev
- Faculty of Medicine, Lomonosov Moscow State University, 119991 Moscow, Russia
- Laboratory of Experimental Pharmacology, Institute of Experimental Cardiology, National Medical Research Center of Cardiology Named after Academician E.I. Chazov, 121552 Moscow, Russia
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11
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Li Y, Younis MH, Wang H, Zhang J, Cai W, Ni D. Spectral computed tomography with inorganic nanomaterials: State-of-the-art. Adv Drug Deliv Rev 2022; 189:114524. [PMID: 36058350 PMCID: PMC9664656 DOI: 10.1016/j.addr.2022.114524] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2022] [Revised: 08/09/2022] [Accepted: 08/27/2022] [Indexed: 01/24/2023]
Abstract
Recently, spectral computed tomography (CT) technology has received great interest in the field of radiology. Spectral CT imaging utilizes the distinct, energy-dependent X-ray absorption properties of substances in order to provide additional imaging information. Dual-energy CT and multi-energy CT (Spectral CT) are capable of constructing monochromatic energy images, material separation images, energy spectrum curves, constructing effective atomic number maps, and more. However, poor contrast, due to neighboring X-ray attenuation of organs and tissues, is still a challenge to spectral CT. Hence, contrast agents (CAs) are applied for better differentiation of a given region of interest (ROI). Currently, many different kinds of inorganic nanoparticulate CAs for spectral CT have been developed due to the limitations of clinical iodine (I)-based contrast media, leading to the conclusion that inorganic nanomedicine applied to spectral CT will be a powerful collaboration both in basic research and in clinics. In this review, the underlying principles and types of spectral CT techniques are discussed, and some evolving clinical diagnosis applications of spectral CT techniques are introduced. In particular, recent developments in inorganic CAs used for spectral CT are summarized. Finally, the challenges and future developments of inorganic nanomedicine in spectral CT are briefly discussed.
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Affiliation(s)
- Yuhan Li
- School of Medicine, Shanghai University, No. 99 Shangda Rd, Shanghai 200444, PR China
| | - Muhsin H Younis
- Departments of Radiology and Medical Physics, University of Wisconsin-Madison, WI 53705, United States
| | - Han Wang
- Department of Orthopaedics, Shanghai Key Laboratory for Prevention and Treatment of Bone and Joint Diseases, Shanghai Institute of Traumatology and Orthopaedics, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, No. 197, Ruijin 2nd Rd, Shanghai 200025, PR China
| | - Jian Zhang
- School of Medicine, Shanghai University, No. 99 Shangda Rd, Shanghai 200444, PR China; Shanghai Universal Medical Imaging Diagnostic Center, Bldg 8, No. 406 Guilin Rd, Shanghai 200233, PR China.
| | - Weibo Cai
- Departments of Radiology and Medical Physics, University of Wisconsin-Madison, WI 53705, United States.
| | - Dalong Ni
- Department of Orthopaedics, Shanghai Key Laboratory for Prevention and Treatment of Bone and Joint Diseases, Shanghai Institute of Traumatology and Orthopaedics, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, No. 197, Ruijin 2nd Rd, Shanghai 200025, PR China.
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12
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Varbanov HP, Glasnov T, Belaj F, Herbert S, Brumby T, Mösch-Zanetti NC. New strategies towards advanced CT contrast agents. Development of neutral and monoanionic sulfur-bridged W(V) dimeric complexes. Dalton Trans 2022; 51:11086-11097. [PMID: 35796232 DOI: 10.1039/d2dt01470j] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Multinuclear tungsten complexes are intriguing candidates for new contrast media that can provide substantial improvements in CT imaging diagnostics. Herein, we present a ligand strategy, based on amino acids, and mono- and disubstituted EDTA derivatives, that enables the development of stable complexes with high tungsten content and reasonably low osmolality. Accordingly, a series of neutral and monoanionic di-μ-sulfido W(V) dimers have been synthesized via a convenient procedure utilizing microwave heating in combination with ion-pair HPLC reaction monitoring. The compounds were characterized in detail by various techniques, including ESI-HRMS, NMR spectroscopy, HPLC, elemental analysis, and X-ray crystallography. The aqueous stability of the complexes under physiologically relevant conditions, and during heat sterilization was also examined as an initial assessment of their potential applicability as radiocontrast agents. Monoanionic complexes featuring monosubstituted EDTA derivatives have demonstrated high stability, while producing a lower number of ions in solution (resulting in lower osmolality) in comparison to their bis-anionic EDTA counterparts. Nevertheless, they exhibited insufficient water solubility for application as intravascular contrast agents. However, our study showed that aqueous solubility of this type of complexes can be tuned by small modifications in the ligand structure.
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Affiliation(s)
- Hristo P Varbanov
- Institute of Chemistry - Inorganic Chemistry, University of Graz, Schubertstraße 1/III, 8010 Graz, Austria.
| | - Toma Glasnov
- Institute of Chemistry - Medicinal Chemistry, University of Graz, Schubertstraße 1/IV, 8010 Graz, Austria
| | - Ferdinand Belaj
- Institute of Chemistry - Inorganic Chemistry, University of Graz, Schubertstraße 1/III, 8010 Graz, Austria.
| | - Simon Herbert
- Research & Development, Pharmaceuticals Laboratory, Bayer AG, 13342 Berlin, Germany
| | - Thomas Brumby
- Research & Development, Pharmaceuticals Laboratory, Bayer AG, 13342 Berlin, Germany
| | - Nadia C Mösch-Zanetti
- Institute of Chemistry - Inorganic Chemistry, University of Graz, Schubertstraße 1/III, 8010 Graz, Austria.
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13
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Rebelo N, Sanders L, Li K, Chow J. Learning the Treatment Process in Radiotherapy: An Al-assisted Chatbot (Preprint). JMIR Form Res 2022; 6:e39443. [DOI: 10.2196/39443] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2022] [Revised: 09/29/2022] [Accepted: 10/11/2022] [Indexed: 11/06/2022] Open
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14
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Sartoretti T, Eberhard M, Nowak T, Gutjahr R, Jost G, Pietsch H, Schmidt B, Flohr T, Alkadhi H, Euler A. Photon-Counting Multienergy Computed Tomography With Spectrally Optimized Contrast Media for Plaque Removal and Stenosis Assessment. Invest Radiol 2021; 56:563-570. [PMID: 33660630 DOI: 10.1097/rli.0000000000000773] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
PURPOSE The aim of this study was to systematically evaluate the potential to combine investigational contrast media with spectrally optimized energy-thresholding of photon-counting detector computed tomography (PCCT) for subtraction of calcified plaques in a coronary artery stenosis phantom. METHODS A small vessel phantom containing 3 fillable tubes (diameter, 3 mm each) with calcified plaques was placed into an anthropomorphic chest phantom. The plaques had incremental thicknesses ranging from 0.3 to 2.7 mm, simulating vessel stenoses ranging from 10% to 90% of the lumen diameter. The phantom was filled with 5 different investigational contrast media (iodine, bismuth, hafnium, holmium, and tungsten) at equal mass concentrations (15 mg/mL) and was imaged on a prototype PCCT at 140 kVp using optimized, contrast media-dependent energy thresholds. Contrast maps (CMs) were reconstructed for each contrast medium by applying a linear 2-material decomposition algorithm. Image noise magnitude and noise texture of CM were compared among the contrast media using the noise power spectrum. Two blinded readers independently rated the vessel lumen visualization on short-axis and the overall subjective image quality on long-axis CM relative to iodine as the reference standard. Four readers determined the highest degree of stenosis that could be assessed with high diagnostic confidence on long-axis CM. RESULTS Average image noise on CM was lower for tungsten (49 HU) and hafnium (62 HU) and higher for bismuth (81 HU) and holmium (165 HU) compared with iodine (78 HU). Noise texture of CM was similar among the contrast media. Interreader agreement for vessel lumen visualization on short-axis CM ranged from moderate to excellent (k = 0.567-0.814). Compared with iodine, lumen visualization of each reader was improved using tungsten (P < 0.001 for both readers), similar to improved using hafnium (P = 0.008, P = 0.29), similar using bismuth (P = 0.38, P = 0.69), and decreased using holmium (both, P < 0.001). Overall subjective image quality was similar for holmium and superior for tungsten, hafnium, and bismuth as compared with iodine. Higher-degree stenoses were evaluable with high confidence using tungsten (mean, 70%; interquartile range, 70%-70%), bismuth (70%; 60%-70%), and hafnium (75%; 70%-80%) compared with iodine (50%; 50%-60%) and holmium (50%; 50%-60%). CONCLUSIONS Spectral optimization in PCCT combined with investigational contrast media can improve calcium subtraction and stenosis assessment in small vessels. Contrast maps of tungsten and, to a lesser extent, hafnium as contrast media yielded superior image noise properties and improved vessel lumen visualization, along with a higher subjective image quality compared with the reference standard iodine.
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Affiliation(s)
- Thomas Sartoretti
- From the Institute of Diagnostic and Interventional Radiology, University Hospital Zurich, University of Zurich, Zurich, Switzerland
| | - Matthias Eberhard
- From the Institute of Diagnostic and Interventional Radiology, University Hospital Zurich, University of Zurich, Zurich, Switzerland
| | | | | | | | | | | | | | - Hatem Alkadhi
- From the Institute of Diagnostic and Interventional Radiology, University Hospital Zurich, University of Zurich, Zurich, Switzerland
| | - André Euler
- From the Institute of Diagnostic and Interventional Radiology, University Hospital Zurich, University of Zurich, Zurich, Switzerland
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15
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Sawall S, Amato C, Klein L, Wehrse E, Maier J, Kachelrieß M. Toward molecular imaging using spectral photon-counting computed tomography? Curr Opin Chem Biol 2021; 63:163-170. [PMID: 34051510 DOI: 10.1016/j.cbpa.2021.04.002] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2021] [Accepted: 04/07/2021] [Indexed: 12/22/2022]
Abstract
Molecular imaging is a valuable tool in drug discovery and development, early screening and diagnosis of diseases, and therapy assessment among others. Although many different imaging modalities are in use today, molecular imaging with computed tomography (CT) is still challenging owing to its low sensitivity and soft tissue contrast compared with other modalities. Recent technical advances, particularly the introduction of spectral photon-counting detectors, might allow overcoming these challenges. Herein, the fundamentals and recent advances in CT relevant to molecular imaging are reviewed and potential future preclinical and clinical applications are highlighted. The review concludes with a discussion of potential future advancements of CT for molecular imaging.
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Affiliation(s)
- Stefan Sawall
- Division of X-Ray Imaging and CT, German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, Heidelberg, 69120, Baden-Württemberg, Germany; Medical Faculty, Ruprecht-Karls-University Heidelberg, Im Neuenheimer Feld 672, Heidelberg, 69120, Baden-Württemberg, Germany.
| | - Carlo Amato
- Division of X-Ray Imaging and CT, German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, Heidelberg, 69120, Baden-Württemberg, Germany; Medical Faculty, Ruprecht-Karls-University Heidelberg, Im Neuenheimer Feld 672, Heidelberg, 69120, Baden-Württemberg, Germany
| | - Laura Klein
- Division of X-Ray Imaging and CT, German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, Heidelberg, 69120, Baden-Württemberg, Germany; Physical Faculty, Ruprecht-Karls-University Heidelberg, Im Neuenheimer Feld 226, Heidelberg, 69120, Baden-Württemberg, Germany
| | - Eckhard Wehrse
- Division of Radiology, German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, Heidelberg, 69120, Baden-Württemberg, Germany; Medical Faculty, Ruprecht-Karls-University Heidelberg, Im Neuenheimer Feld 672, Heidelberg, 69120, Baden-Württemberg, Germany
| | - Joscha Maier
- Division of X-Ray Imaging and CT, German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, Heidelberg, 69120, Baden-Württemberg, Germany
| | - Marc Kachelrieß
- Division of X-Ray Imaging and CT, German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, Heidelberg, 69120, Baden-Württemberg, Germany; Medical Faculty, Ruprecht-Karls-University Heidelberg, Im Neuenheimer Feld 672, Heidelberg, 69120, Baden-Württemberg, Germany
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16
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Damasco JA, Ravi S, Perez JD, Hagaman DE, Melancon MP. Understanding Nanoparticle Toxicity to Direct a Safe-by-Design Approach in Cancer Nanomedicine. NANOMATERIALS (BASEL, SWITZERLAND) 2020; 10:E2186. [PMID: 33147800 PMCID: PMC7692849 DOI: 10.3390/nano10112186] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/08/2020] [Revised: 10/26/2020] [Accepted: 10/28/2020] [Indexed: 12/22/2022]
Abstract
Nanomedicine is a rapidly growing field that uses nanomaterials for the diagnosis, treatment and prevention of various diseases, including cancer. Various biocompatible nanoplatforms with diversified capabilities for tumor targeting, imaging, and therapy have materialized to yield individualized therapy. However, due to their unique properties brought about by their small size, safety concerns have emerged as their physicochemical properties can lead to altered pharmacokinetics, with the potential to cross biological barriers. In addition, the intrinsic toxicity of some of the inorganic materials (i.e., heavy metals) and their ability to accumulate and persist in the human body has been a challenge to their translation. Successful clinical translation of these nanoparticles is heavily dependent on their stability, circulation time, access and bioavailability to disease sites, and their safety profile. This review covers preclinical and clinical inorganic-nanoparticle based nanomaterial utilized for cancer imaging and therapeutics. A special emphasis is put on the rational design to develop non-toxic/safe inorganic nanoparticle constructs to increase their viability as translatable nanomedicine for cancer therapies.
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Affiliation(s)
- Jossana A. Damasco
- Department of Interventional Radiology, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA; (J.A.D.); (J.D.P.); (D.E.H.)
| | - Saisree Ravi
- School of Medicine, University of Texas Rio Grande Valley, Edinburg, TX 78539, USA;
| | - Joy D. Perez
- Department of Interventional Radiology, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA; (J.A.D.); (J.D.P.); (D.E.H.)
| | - Daniel E. Hagaman
- Department of Interventional Radiology, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA; (J.A.D.); (J.D.P.); (D.E.H.)
| | - Marites P. Melancon
- Department of Interventional Radiology, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA; (J.A.D.); (J.D.P.); (D.E.H.)
- UT Health Graduate School of Biomedical Sciences, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
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17
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Amato C, Klein L, Wehrse E, Rotkopf LT, Sawall S, Maier J, Ziener CH, Schlemmer H, Kachelrieß M. Potential of contrast agents based on high‐Z elements for contrast‐enhanced photon‐counting computed tomography. Med Phys 2020; 47:6179-6190. [DOI: 10.1002/mp.14519] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2020] [Revised: 09/01/2020] [Accepted: 09/21/2020] [Indexed: 12/17/2022] Open
Affiliation(s)
- Carlo Amato
- Division of X‐Ray Imaging and Computed Tomography German Cancer Research Center (DKFZ) Heidelberg69120Germany
- Medical Faculty Ruprecht–Karls–University Heidelberg69120Germany
| | - Laura Klein
- Division of X‐Ray Imaging and Computed Tomography German Cancer Research Center (DKFZ) Heidelberg69120Germany
- Department of Physics and Astronomy Ruprecht–Karls–University Heidelberg69120Germany
| | - Eckhard Wehrse
- Medical Faculty Ruprecht–Karls–University Heidelberg69120Germany
- Division of Radiology German Cancer Research Center (DKFZ) Heidelberg69120Germany
| | - Lukas T. Rotkopf
- Division of Radiology German Cancer Research Center (DKFZ) Heidelberg69120Germany
| | - Stefan Sawall
- Division of X‐Ray Imaging and Computed Tomography German Cancer Research Center (DKFZ) Heidelberg69120Germany
- Medical Faculty Ruprecht–Karls–University Heidelberg69120Germany
| | - Joscha Maier
- Division of X‐Ray Imaging and Computed Tomography German Cancer Research Center (DKFZ) Heidelberg69120Germany
| | - Christian H. Ziener
- Division of Radiology German Cancer Research Center (DKFZ) Heidelberg69120Germany
| | | | - Marc Kachelrieß
- Division of X‐Ray Imaging and Computed Tomography German Cancer Research Center (DKFZ) Heidelberg69120Germany
- Medical Faculty Ruprecht–Karls–University Heidelberg69120Germany
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18
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Sartoretti T, Eberhard M, Rüschoff JH, Pietsch H, Jost G, Nowak T, Schmidt B, Flohr T, Euler A, Alkadhi H. Photon-counting CT with tungsten as contrast medium: Experimental evidence of vessel lumen and plaque visualization. Atherosclerosis 2020; 310:11-16. [PMID: 32861961 DOI: 10.1016/j.atherosclerosis.2020.07.023] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/26/2020] [Revised: 06/30/2020] [Accepted: 07/23/2020] [Indexed: 01/26/2023]
Abstract
BACKGROUND AND AIMS We aimed to investigate the potential of a preclinical photon-counting detector CT (PCT) scanner with an experimental tungsten-based contrast medium for carotid artery imaging. METHODS A carotid artery specimen was imaged on a PCT system using the multi-energy bin option (pixel size 0.5 × 0.5 mm2; tube voltage 140 kVp, contrast media-dependent energy thresholds: iodine 20, 75 keV; tungsten 20, 68 keV) at two radiation doses (CTDIvol of 100 mGy and 10 mGy) with iodine and tungsten as contrast media at equal mass-concentrations. Standard CT, virtual non-calcium (VNCa) and calcium-only images were reconstructed. Subjective image quality (4-point Likert scale) was rated using histology as reference. Noise and attenuation measurements were performed. Simulations were conducted to assess the material-decomposition efficiency for different object diameters. RESULTS Image quality on VNCa images was significantly higher for tungsten at lower dose (reader 1/reader 2: 2, [2,2]/2, [2,2] vs 1.5, [2,1]/1, [1,1.75], p < 0.05). Noise was significantly lower at both dose levels for tungsten VNCa images as compared to iodine images (higher dose: tungsten 24 vs iodine 31; lower dose: tungsten 60 vs iodine 82; both p < 0.01). Simulations indicated improved material-decomposition efficiency for tungsten than for iodine pronounced at smaller object diameters. CONCLUSIONS PCT employing the multi-energy bin option in combination with tungsten as contrast media enables improved carotid artery imaging with respect to lumen and plaque visualization and image noise.
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Affiliation(s)
- Thomas Sartoretti
- Institute of Diagnostic and Interventional Radiology, University Hospital Zurich, University of Zurich, Switzerland
| | - Matthias Eberhard
- Institute of Diagnostic and Interventional Radiology, University Hospital Zurich, University of Zurich, Switzerland
| | - Jan Hendrik Rüschoff
- Department of Pathology, University Hospital Zurich, University of Zurich, Switzerland
| | | | | | | | | | | | - André Euler
- Institute of Diagnostic and Interventional Radiology, University Hospital Zurich, University of Zurich, Switzerland
| | - Hatem Alkadhi
- Institute of Diagnostic and Interventional Radiology, University Hospital Zurich, University of Zurich, Switzerland.
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19
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Schöckel L, Jost G, Seidensticker P, Lengsfeld P, Palkowitsch P, Pietsch H. Developments in X-Ray Contrast Media and the Potential Impact on Computed Tomography. Invest Radiol 2020; 55:592-597. [DOI: 10.1097/rli.0000000000000696] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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20
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Hsu JC, Nieves LM, Betzer O, Sadan T, Noël PB, Popovtzer R, Cormode DP. Nanoparticle contrast agents for X-ray imaging applications. WILEY INTERDISCIPLINARY REVIEWS-NANOMEDICINE AND NANOBIOTECHNOLOGY 2020; 12:e1642. [PMID: 32441050 DOI: 10.1002/wnan.1642] [Citation(s) in RCA: 51] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/03/2020] [Revised: 04/13/2020] [Accepted: 04/14/2020] [Indexed: 12/12/2022]
Abstract
X-ray imaging is the most widely used diagnostic imaging method in modern medicine and several advanced forms of this technology have recently emerged. Iodinated molecules and barium sulfate suspensions are clinically approved X-ray contrast agents and are widely used. However, these existing contrast agents provide limited information, are suboptimal for new X-ray imaging techniques and are developing safety concerns. Thus, over the past 15 years, there has been a rapid growth in the development of nanoparticles as X-ray contrast agents. Nanoparticles have several desirable features such as high contrast payloads, the potential for long circulation times, and tunable physicochemical properties. Nanoparticles have also been used in a range of biomedical applications such as disease treatment, targeted imaging, and cell tracking. In this review, we discuss the principles behind X-ray contrast generation and introduce new types of X-ray imaging modalities, as well as potential elements and chemical compositions that are suitable for novel contrast agent development. We focus on the progress in nanoparticle X-ray contrast agents developed to be renally clearable, long circulating, theranostic, targeted, or for cell tracking. We feature agents that are used in conjunction with the newly developed multi-energy computed tomography and mammographic imaging technologies. Finally, we offer perspectives on current limitations and emerging research topics as well as expectations for the future development of the field. This article is categorized under: Diagnostic Tools > in vivo Nanodiagnostics and Imaging Nanotechnology Approaches to Biology > Nanoscale Systems in Biology.
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Affiliation(s)
- Jessica C Hsu
- Department of Radiology, Perelman School of Medicine of the University of Pennsylvania, Philadelphia, Pennsylvania, USA.,Department of Bioengineering, School of Engineering and Applied Science of the University of Pennsylvania, Pennsylvania, USA
| | - Lenitza M Nieves
- Department of Radiology, Perelman School of Medicine of the University of Pennsylvania, Philadelphia, Pennsylvania, USA.,Department of Biochemistry and Molecular Biophysics, Perelman School of Medicine of the University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Oshra Betzer
- Faculty of Engineering and the Institute of Nanotechnology and Advanced Materials, Bar-Ilan University, Ramat Gan, Israel
| | - Tamar Sadan
- Faculty of Engineering and the Institute of Nanotechnology and Advanced Materials, Bar-Ilan University, Ramat Gan, Israel
| | - Peter B Noël
- Department of Radiology, Perelman School of Medicine of the University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Rachela Popovtzer
- Faculty of Engineering and the Institute of Nanotechnology and Advanced Materials, Bar-Ilan University, Ramat Gan, Israel
| | - David P Cormode
- Department of Radiology, Perelman School of Medicine of the University of Pennsylvania, Philadelphia, Pennsylvania, USA.,Department of Bioengineering, School of Engineering and Applied Science of the University of Pennsylvania, Pennsylvania, USA.,Department of Biochemistry and Molecular Biophysics, Perelman School of Medicine of the University of Pennsylvania, Philadelphia, Pennsylvania, USA
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21
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C Bakker R, Bastiaannet R, van Nimwegen SA, D Barten-van Rijbroek A, Van Es RJJ, Rosenberg AJWP, de Jong HWAM, Lam MGEH, Nijsen JFW. Feasibility of CT quantification of intratumoural 166Ho-microspheres. Eur Radiol Exp 2020; 4:29. [PMID: 32390070 PMCID: PMC7211782 DOI: 10.1186/s41747-020-00157-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2019] [Accepted: 03/26/2020] [Indexed: 12/13/2022] Open
Abstract
Background Microspheres loaded with radioactive 166Ho (166Ho-MS) are novel particles for radioembolisation and intratumoural treatment. Because of the limited penetration of β radiation, quantitative imaging of microsphere distribution is crucial for optimal intratumoural treatment. Computed tomography (CT) may provide high-resolution and fast imaging of the distribution of these microspheres, with lower costs and widespread availability in comparison with current standard single-photon emission tomography (SPECT) and magnetic resonance imaging. This phantom study investigated the feasibility of CT quantification of 166Ho-MS. Methods CT quantification was performed on a phantom with various concentrations of HoCl and Ho-MS to investigate the CT sensitivity and calibrate the CT recovery. 166Ho-MS were injected into ex vivo tissues, in VX-2 cancer-bearing rabbits, and in patients with head-neck cancer, to demonstrate sensitivity and clinical visibility. The amount of Ho-MS was determined by CT scanning, using a density-based threshold method and compared with a validated 166Ho SPECT quantification method. Results In the phantom, a near perfect linearity (least squares R2 > 0.99) between HU values and concentration of 166Ho was found. Ex vivo tissue experiments showed an excellent correlation (r = 0.99, p < 0.01) between the dose calibrator, SPECT, and CT imaging. CT recovery was on average 86.4% ex vivo, 76.0% in rabbits, and 99.1% in humans. Conclusion This study showed that CT-based quantification of Ho microspheres is feasible and is a high-resolution alternative to SPECT-based determination of their local distribution.
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Affiliation(s)
- R C Bakker
- Department of Radiology and Nuclear Medicine, University Medical Center Utrecht, Utrecht, The Netherlands.,Department of Oral and Maxillofacial Surgery, University Medical Center Utrecht, Utrecht, The Netherlands
| | - R Bastiaannet
- Department of Radiology and Nuclear Medicine, University Medical Center Utrecht, Utrecht, The Netherlands
| | - S A van Nimwegen
- Department of Clinical Sciences of Companion Animals, Faculty of Veterinary Medicine, Utrecht University, Utrecht, The Netherlands
| | - A D Barten-van Rijbroek
- Department of Radiology and Nuclear Medicine, University Medical Center Utrecht, Utrecht, The Netherlands
| | - R J J Van Es
- Department of Oral and Maxillofacial Surgery, University Medical Center Utrecht, Utrecht, The Netherlands.,Department of Head and Neck Surgical Oncology, UMC Utrecht Cancer Center, Utrecht, The Netherlands
| | - A J W P Rosenberg
- Department of Oral and Maxillofacial Surgery, University Medical Center Utrecht, Utrecht, The Netherlands
| | - H W A M de Jong
- Department of Radiology and Nuclear Medicine, University Medical Center Utrecht, Utrecht, The Netherlands
| | - M G E H Lam
- Department of Radiology and Nuclear Medicine, University Medical Center Utrecht, Utrecht, The Netherlands
| | - J F W Nijsen
- Department of Radiology, Nuclear Medicine and Anatomy, Radboudumc, Nijmegen, The Netherlands
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22
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Sivasubramanian M, Chuang YC, Chen NT, Lo LW. Seeing Better and Going Deeper in Cancer Nanotheranostics. Int J Mol Sci 2019; 20:E3490. [PMID: 31315232 PMCID: PMC6678689 DOI: 10.3390/ijms20143490] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2019] [Revised: 07/12/2019] [Accepted: 07/12/2019] [Indexed: 02/07/2023] Open
Abstract
Biomedical imaging modalities in clinical practice have revolutionized oncology for several decades. State-of-the-art biomedical techniques allow visualizing both normal physiological and pathological architectures of the human body. The use of nanoparticles (NP) as contrast agents enabled visualization of refined contrast images with superior resolution, which assists clinicians in more accurate diagnoses and in planning appropriate therapy. These desirable features are due to the ability of NPs to carry high payloads (contrast agents or drugs), increased in vivo half-life, and disease-specific accumulation. We review the various NP-based interventions for treatments of deep-seated tumors, involving "seeing better" to precisely visualize early diagnosis and "going deeper" to activate selective therapeutics in situ.
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Affiliation(s)
- Maharajan Sivasubramanian
- Institute of Biomedical Engineering and Nanomedicine, National Health Research Institutes, Zhunan 350, Taiwan
| | - Yao Chen Chuang
- Institute of Biomedical Engineering and Nanomedicine, National Health Research Institutes, Zhunan 350, Taiwan
| | - Nai-Tzu Chen
- Department of Cosmeceutics, China Medical University, Taichung 40402, Taiwan.
- Department of Biological Science and Technology, China Medical University, Taichung 40402, Taiwan.
| | - Leu-Wei Lo
- Institute of Biomedical Engineering and Nanomedicine, National Health Research Institutes, Zhunan 350, Taiwan.
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Liu M, Wang L, Zheng X, Liu S, Xie Z. Hypoxia-Triggered Nanoscale Metal-Organic Frameworks for Enhanced Anticancer Activity. ACS APPLIED MATERIALS & INTERFACES 2018; 10:24638-24647. [PMID: 29957930 DOI: 10.1021/acsami.8b07570] [Citation(s) in RCA: 59] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
The oxygen-dependent feature of most photosensitizers (PSs) and the aggravated hypoxia tumor microenvironment seriously impede the photodynamic therapy (PDT) effectiveness. However, this undesirable impediment can be utilized to further trigger the activation of hypoxia-sensitive prodrugs. Moreover, a combined therapy can be used by associating PDT with hypoxia-activated chemotherapy. Herein, a multifunctional Hf-porphyrin nanoscale metal-organic framework (NMOF) platform [Hf/tetra(4-carboxyphenyl)porphine (TCPP)] has been synthesized, with a high porphyrin loading capacity and a well-ordered coordination array preventing porphyrin self-quenching, thus greatly improving the generation efficiency of reactive oxygen species (ROS), which is helpful for PDT. As-synthesized Hf-TCPP nanoparticles possess more than 50 wt % of TCPP PS content, good crystallization, and a large Brunauer-Emmett-Teller surface for further loading the hypoxia-activated prodrug [tirapazamine (TPZ)] in a high-loading content. Additionally, subsequent surface modification with a dopamine-derived polymer (DOPA-PIMA-mPEG) significantly improves their dispersibility and structural stability, and the controlled release kinetics of TPZ. Such a nanoplatform can efficiently produce ROS for PDT upon irradiation, and also the depletion of the oxygen could further aggravate the hypoxic environment of tumors to induce the activation of TPZ for achieving an enhanced treatment efficacy. This work demonstrates the great advantages of an NMOF-based platform in antitumor therapies for combined PDT and hypoxia-activated chemotherapy.
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Affiliation(s)
- Ming Liu
- State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry , Chinese Academy of Sciences , Changchun , Jilin 130022 , P. R. China
- The University of Chinese Academy of Sciences , Beijing 100049 , P. R. China
| | - Lei Wang
- State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry , Chinese Academy of Sciences , Changchun , Jilin 130022 , P. R. China
| | - Xiaohua Zheng
- State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry , Chinese Academy of Sciences , Changchun , Jilin 130022 , P. R. China
- University of Science and Technology of China , Hefei 230026 , P. R. China
| | - Shi Liu
- State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry , Chinese Academy of Sciences , Changchun , Jilin 130022 , P. R. China
| | - Zhigang Xie
- State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry , Chinese Academy of Sciences , Changchun , Jilin 130022 , P. R. China
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Lambert JW, Sun Y, Stillson C, Li Z, Kumar R, Wang S, FitzGerald PF, Bonitatibus PJ, Colborn RE, Roberts JC, Edic PM, Marino M, Yeh BM. An Intravascular Tantalum Oxide-based CT Contrast Agent: Preclinical Evaluation Emulating Overweight and Obese Patient Size. Radiology 2018; 289:103-110. [PMID: 29969071 DOI: 10.1148/radiol.2018172381] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Purpose To compare the CT imaging performance of a carboxybetaine zwitterionic-coated tantalum oxide (TaCZ) nanoparticle CT contrast agent with that of a conventional iodinated contrast agent in a swine model meant to simulate overweight and obese patients. Materials and Methods Four swine were evaluated inside three different-sized adipose-equivalent encasements emulating abdominal girths of 102, 119, and 137 cm. Imaging was performed with a 64-detector row CT scanner at six scan delays after intravenous injection of 240 mg element (Ta or I) per kilogram of body weight of TaCZ or iopromide. For each time point, contrast enhancement of the aorta and liver were measured by using regions of interest. Two readers independently recorded the clarity of vasculature using a five-point Likert scale. Findings were compared by using paired t tests and Wilcoxon signed-rank tests. Results Mean peak enhancement was higher for TaCZ than for iopromide in the aorta (270 HU [σ = 24.5] vs 199 HU [σ = 10.2], P < .001) and liver (61.3 HU [σ = 11.7] vs 45.2 HU [σ = 8], P < .001). Vascular clarity was higher for TaCZ than for iopromide in 63% (132 of 208), 82% (170 of 208), and 86% (178 of 208) of the individual vessels at the 102-, 119-, and 137-cm girths, respectively (P < .01). Arterial clarity scores were higher for TaCZ than for iopromide in 62% (208 of 336) of vessels. Venous clarity scores were higher for TaCZ than for iopromide in 89% (128 of 144) of the veins in the venous phase and in 100% (144 of 144) of veins in the delayed phase (P < .01). No vessel showed higher clarity score with iopromide than with TaCZ. Conclusion An experimental tantalum nanoparticle-based contrast agent showed greater contrast enhancement compared with iopromide in swine models meant to simulate overweight and obese patients. © RSNA, 2018.
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Affiliation(s)
- Jack W Lambert
- From the Department of Radiology and Biomedical Imaging, University of California San Francisco, 505 Parnassus Ave, San Francisco, CA 94143-0628 (J.W.L., Y.S., C.S., Z.L., R.K., S.W., B.M.Y.); and Departments of Imaging (P.F.F., P.M.E.) and Biosciences (P.J.B., R.E.C., J.C.R., M.M.), GE Global Research, Niskayuna, NY
| | - Yuxin Sun
- From the Department of Radiology and Biomedical Imaging, University of California San Francisco, 505 Parnassus Ave, San Francisco, CA 94143-0628 (J.W.L., Y.S., C.S., Z.L., R.K., S.W., B.M.Y.); and Departments of Imaging (P.F.F., P.M.E.) and Biosciences (P.J.B., R.E.C., J.C.R., M.M.), GE Global Research, Niskayuna, NY
| | - Carol Stillson
- From the Department of Radiology and Biomedical Imaging, University of California San Francisco, 505 Parnassus Ave, San Francisco, CA 94143-0628 (J.W.L., Y.S., C.S., Z.L., R.K., S.W., B.M.Y.); and Departments of Imaging (P.F.F., P.M.E.) and Biosciences (P.J.B., R.E.C., J.C.R., M.M.), GE Global Research, Niskayuna, NY
| | - Zhixi Li
- From the Department of Radiology and Biomedical Imaging, University of California San Francisco, 505 Parnassus Ave, San Francisco, CA 94143-0628 (J.W.L., Y.S., C.S., Z.L., R.K., S.W., B.M.Y.); and Departments of Imaging (P.F.F., P.M.E.) and Biosciences (P.J.B., R.E.C., J.C.R., M.M.), GE Global Research, Niskayuna, NY
| | - Rahi Kumar
- From the Department of Radiology and Biomedical Imaging, University of California San Francisco, 505 Parnassus Ave, San Francisco, CA 94143-0628 (J.W.L., Y.S., C.S., Z.L., R.K., S.W., B.M.Y.); and Departments of Imaging (P.F.F., P.M.E.) and Biosciences (P.J.B., R.E.C., J.C.R., M.M.), GE Global Research, Niskayuna, NY
| | - Sizhe Wang
- From the Department of Radiology and Biomedical Imaging, University of California San Francisco, 505 Parnassus Ave, San Francisco, CA 94143-0628 (J.W.L., Y.S., C.S., Z.L., R.K., S.W., B.M.Y.); and Departments of Imaging (P.F.F., P.M.E.) and Biosciences (P.J.B., R.E.C., J.C.R., M.M.), GE Global Research, Niskayuna, NY
| | - Paul F FitzGerald
- From the Department of Radiology and Biomedical Imaging, University of California San Francisco, 505 Parnassus Ave, San Francisco, CA 94143-0628 (J.W.L., Y.S., C.S., Z.L., R.K., S.W., B.M.Y.); and Departments of Imaging (P.F.F., P.M.E.) and Biosciences (P.J.B., R.E.C., J.C.R., M.M.), GE Global Research, Niskayuna, NY
| | - Peter J Bonitatibus
- From the Department of Radiology and Biomedical Imaging, University of California San Francisco, 505 Parnassus Ave, San Francisco, CA 94143-0628 (J.W.L., Y.S., C.S., Z.L., R.K., S.W., B.M.Y.); and Departments of Imaging (P.F.F., P.M.E.) and Biosciences (P.J.B., R.E.C., J.C.R., M.M.), GE Global Research, Niskayuna, NY
| | - Robert E Colborn
- From the Department of Radiology and Biomedical Imaging, University of California San Francisco, 505 Parnassus Ave, San Francisco, CA 94143-0628 (J.W.L., Y.S., C.S., Z.L., R.K., S.W., B.M.Y.); and Departments of Imaging (P.F.F., P.M.E.) and Biosciences (P.J.B., R.E.C., J.C.R., M.M.), GE Global Research, Niskayuna, NY
| | - Jeannette C Roberts
- From the Department of Radiology and Biomedical Imaging, University of California San Francisco, 505 Parnassus Ave, San Francisco, CA 94143-0628 (J.W.L., Y.S., C.S., Z.L., R.K., S.W., B.M.Y.); and Departments of Imaging (P.F.F., P.M.E.) and Biosciences (P.J.B., R.E.C., J.C.R., M.M.), GE Global Research, Niskayuna, NY
| | - Peter M Edic
- From the Department of Radiology and Biomedical Imaging, University of California San Francisco, 505 Parnassus Ave, San Francisco, CA 94143-0628 (J.W.L., Y.S., C.S., Z.L., R.K., S.W., B.M.Y.); and Departments of Imaging (P.F.F., P.M.E.) and Biosciences (P.J.B., R.E.C., J.C.R., M.M.), GE Global Research, Niskayuna, NY
| | - Michael Marino
- From the Department of Radiology and Biomedical Imaging, University of California San Francisco, 505 Parnassus Ave, San Francisco, CA 94143-0628 (J.W.L., Y.S., C.S., Z.L., R.K., S.W., B.M.Y.); and Departments of Imaging (P.F.F., P.M.E.) and Biosciences (P.J.B., R.E.C., J.C.R., M.M.), GE Global Research, Niskayuna, NY
| | - Benjamin M Yeh
- From the Department of Radiology and Biomedical Imaging, University of California San Francisco, 505 Parnassus Ave, San Francisco, CA 94143-0628 (J.W.L., Y.S., C.S., Z.L., R.K., S.W., B.M.Y.); and Departments of Imaging (P.F.F., P.M.E.) and Biosciences (P.J.B., R.E.C., J.C.R., M.M.), GE Global Research, Niskayuna, NY
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Lambert JW, Sun Y, Ordovas KG, Gould RG, Wang S, Yeh BM. Improved Calcium Scoring at Dual-Energy Computed Tomography Angiography Using a High-Z Contrast Element and Novel Material Separation Technique. J Comput Assist Tomogr 2018; 42:459-466. [PMID: 28937491 PMCID: PMC5860919 DOI: 10.1097/rct.0000000000000676] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
OBJECTIVES The aim of this study was to compare the accuracy of existing dual-energy computed tomography (CT) angiography coronary artery calcium scoring methods to those obtained using an experimental tungsten-based contrast material and a recently described contrast material extraction process (CMEP). METHODS Phantom coronary arteries of varied diameters, with different densities and arcs of simulated calcified plaque, were sequentially filled with water, iodine, and tungsten contrast materials and scanned within a thorax phantom at rapid-kVp-switching dual-energy CT. Calcium and contrast density images were obtained by material decomposition (MD) and CMEP. Relative calcium scoring errors among the 4 reconstructed datasets were compared with a ground truth, 120-kVp dataset. RESULTS Compared with the 120-kVp dataset, tungsten CMEP showed a significantly lower mean absolute error in calcium score (6.2%, P < 0.001) than iodine CMEP, tungsten MD, and iodine MD (9.9%, 15.7%, and 40.8%, respectively). CONCLUSIONS Novel contrast elements and material separation techniques offer improved coronary artery calcium scoring accuracy and show potential to improve the use of dual-energy CT angiography in a clinical setting.
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Affiliation(s)
- Jack W Lambert
- From the University of California, San Francisco, San Francisco, CA
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Abstract
OBJECTIVES Conventional material decomposition techniques for dual-energy computed tomography (CT) assume mass or volume conservation, where the CT number of each voxel is fully assigned to predefined materials. We present an image-domain contrast material extraction process (CMEP) method that preferentially extracts contrast-producing materials while leaving the remaining image intact. MATERIALS AND METHODS Image processing freeware (Fiji) is used to perform consecutive arithmetic operations on a dual-energy ratio map to generate masks, which are then applied to the original images to generate material-specific images. First, a low-energy image is divided by a high-energy image to generate a ratio map. The ratio map is then split into material-specific masks. Ratio intervals known to correspond to particular materials (eg, iodine, calcium) are assigned a multiplier of 1, whereas ratio values in between these intervals are assigned linear gradients from 0 to 1. The masks are then multiplied by an original CT image to produce material-specific images. The method was tested quantitatively at dual-source CT and rapid kVp-switching CT (RSCT) with phantoms using pure and mixed formulations of tungsten, calcium, and iodine. Errors were evaluated by comparing the known material concentrations with those derived from the CMEP material-specific images. Further qualitative evaluation was performed in vivo at RSCT with a rabbit model using identical CMEP parameters to the phantom. Orally administered tungsten, vascularly administered iodine, and skeletal calcium were used as the 3 contrast materials. RESULTS All 5 material combinations-tungsten, iodine, and calcium, and mixtures of tungsten-calcium and iodine-calcium-showed distinct dual-energy ratios, largely independent of material concentration at both dual-source CT and RSCT. The CMEP was successful in both phantoms and in vivo. For pure contrast materials in the phantom, the maximum error between the known and CMEP-derived material concentrations was 0.9 mg/mL, 24.9 mg/mL, and 0.4 mg/mL for iodine, calcium, and tungsten respectively. Mixtures of iodine and calcium showed the highest discrepancies, which reflected the sensitivity of iodine to the image-type chosen for the extraction of the final material-specific image. The rabbit model was able to clearly show the 3 extracted material phases, vascular iodine, oral tungsten, and skeletal calcium. Some skeletal calcium was misassigned to the extracted iodine image; however, this did not impede the depiction of the vasculature. CONCLUSIONS The CMEP is a straightforward, image-domain approach to extract material signal at dual-energy CT. It has particular value for separation of experimental high-Z contrast elements from conventional iodine contrast or calcium, even when the exact attenuation coefficient profiles of desired contrast materials may be unknown. The CMEP is readily implemented in the image-domain within freeware, and can be adapted for use with images from multiple vendors.
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FitzGerald PF, Colborn RE, Edic PM, Lambert JW, Bonitatibus PJ, Yeh BM. Liquid tissue surrogates for X-ray and CT phantom studies. Med Phys 2017; 44:6251-6260. [PMID: 28986933 DOI: 10.1002/mp.12617] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2017] [Revised: 09/01/2017] [Accepted: 09/28/2017] [Indexed: 12/15/2022] Open
Abstract
PURPOSE To develop a simple method for producing liquid-tissue-surrogate (LTS) materials that accurately represent human soft tissues in terms of density and X-ray attenuation coefficient. METHODS AND MATERIALS We evaluated hypothetical mixtures of water, glycerol, butanol, methanol, sodium chloride, and potassium nitrate; these mixtures were intended to emulate human adipose, blood, brain, kidney, liver, muscle, pancreas, and skin. We compared the hypothetical densities, effective atomic numbers (Zeff ), and calculated discrete-energy CT attenuation [Hounsfield Units (HU)] of the proposed materials with those of human tissue elemental composition as specified in International Commission on Radiation Units (ICRU) Report 46. We then physically produced the proposed LTS materials for adipose, liver, and pancreas tissue, and we measured the polyenergetic CT attenuation (also expressed as HU) of these materials within a 32 cm phantom using a 64-slice clinical CT scanner at 80 kVp, 100 kVp, 120 kVp, and 140 kVp. RESULTS The predicted densities, Zeff , and calculated discrete-energy CT attenuation of our proposed formulations generally agreed with those of ICRU within < 1% or < 10 HU. For example, the densities of our hypothetical materials agreed precisely with ICRU's reported values and were 0.95 g/mL for adipose tissue, 1.04 g/mL for pancreatic tissue, and 1.06 g/mL for liver tissue; the discrete-energy CT attenuation at 60 keV of our hypothetical materials (and ICRU-specified compositions) were -107 HU (-113 HU) for adipose #3, -89 HU (-90 HU) for adipose #2, 56 HU (55 HU) for liver tissue, and 31 HU (31 HU) for pancreatic tissue. The densities of our physically produced materials (compared to ICRU-specified compositions) were 0.947 g/mL (0.0%) for adipose #2, 1.061 g/mL (+2.0%) for pancreatic tissue, and 1.074 g/mL (+1.3%) for liver tissue. The empirical polyenergetic CT attenuation measurements of our LTS materials (and the discrete-energy HU of the ICRU compositions at the mean energy of each spectrum) at 80 kVp were -104 HU (-113 HU) for adipose #3, -87 HU (-90 HU) for adipose #2, 59 HU (55 HU) for liver tissue, and 33 HU (31 HU) for pancreatic tissue; at 120 kVp, these were -83 HU (-83 HU) for adipose #3, -68 HU (-63 HU) for adipose #2, 55 HU (52 HU) for liver tissue, and 35 HU (33 HU) for pancreatic tissue. CONCLUSION Our method for formulating tissue surrogates allowed straightforward production of solutions with CT attenuation that closely matched the target tissues' expected CT attenuation values and trends with kVp. The LTSs' inexpensive and widely available constituent chemicals, combined with their liquid state, should enable rapid production and versatile use among different phantom and experiment types. Further study is warranted, such as the inclusion of contrast agents. These liquid tissue surrogates may potentially accelerate development and testing of advanced CT imaging techniques and technologies.
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Affiliation(s)
- Paul F FitzGerald
- Imaging, GE Global Research, 1 Research Circle, Niskayuna, NY, 12309, USA
| | - Robert E Colborn
- Imaging, GE Global Research, 1 Research Circle, Niskayuna, NY, 12309, USA
| | - Peter M Edic
- Imaging, GE Global Research, 1 Research Circle, Niskayuna, NY, 12309, USA
| | - Jack W Lambert
- Department of Radiology and Biomedical Imaging, University of California, San Francisco, CA, 94143, USA
| | | | - Benjamin M Yeh
- Department of Radiology and Biomedical Imaging, University of California, San Francisco, CA, 94143, USA
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The Effect of Patient Diameter on the Dual-Energy Ratio of Selected Contrast-Producing Elements. J Comput Assist Tomogr 2017; 41:505-510. [PMID: 27824676 DOI: 10.1097/rct.0000000000000557] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
OBJECTIVES The aim of this study was to assess whether the low- to high-kVp computed tomography (CT) number ratio at dual-energy CT is affected by changes in patient diameter. METHODS Seven contrast-producing elements were housed sequentially within an abdomen phantom. Fat rings enlarged the phantom diameter from 26 to 44 cm. The phantom was scanned using single-energy CT at tube potentials of 80 and 140 kVp and rapid-kVp-switching dual-energy CT. RESULTS CT numbers decreased proportionally (∼20% CT number reduction for smallest to largest phantom diameters) for low- and high-energy acquisitions but resulted in consistent dual-energy ratios for each contrast element. For 17 of 21 material pair combinations, the dual-energy ratio ranges of the two elements did not overlap, implying that discrimination should remain possible for these material pairs at all patient sizes. CONCLUSIONS The dual-energy ratio for different contrast materials is largely unaffected by changes in phantom diameter. This should allow for robust separation of most contrast material combinations irrespective of patient size.
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Bongers MN, Schabel C, Krauss B, Claussen CD, Nikolaou K, Thomas C. Potential of gadolinium as contrast material in second generation dual energy computed tomography – An ex vivo phantom study. Clin Imaging 2017; 43:74-79. [DOI: 10.1016/j.clinimag.2017.02.005] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2016] [Revised: 01/16/2017] [Accepted: 02/17/2017] [Indexed: 11/26/2022]
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Berger M, Bauser M, Frenzel T, Hilger CS, Jost G, Lauria S, Morgenstern B, Neis C, Pietsch H, Sülzle D, Hegetschweiler K. Hafnium-Based Contrast Agents for X-ray Computed Tomography. Inorg Chem 2017; 56:5757-5761. [PMID: 28430423 DOI: 10.1021/acs.inorgchem.7b00359] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Heavy-metal-based contrast agents (CAs) offer enhanced X-ray absorption for X-ray computed tomography (CT) compared to the currently used iodinated CAs. We report the discovery of new lanthanide and hafnium azainositol complexes and their optimization with respect to high water solubility and stability. Our efforts culminated in the synthesis of BAY-576, an uncharged hafnium complex with 3:2 stoichiometry and broken complex symmetry. The superior properties of this asymmetrically substituted hafnium CA were demonstrated by a CT angiography study in rabbits that revealed excellent signal contrast enhancement.
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Affiliation(s)
- Markus Berger
- Drug Discovery, Pharmaceuticals, Bayer AG , 13342 Berlin, Germany
| | - Marcus Bauser
- Drug Discovery, Pharmaceuticals, Bayer AG , 13342 Berlin, Germany
| | - Thomas Frenzel
- Drug Discovery, Pharmaceuticals, Bayer AG , 13342 Berlin, Germany
| | | | - Gregor Jost
- Drug Discovery, Pharmaceuticals, Bayer AG , 13342 Berlin, Germany
| | - Silvia Lauria
- Department of Inorganic Chemistry, Saarland University , Campus C4.1, 66123 Saarbrücken, Germany
| | - Bernd Morgenstern
- Department of Inorganic Chemistry, Saarland University , Campus C4.1, 66123 Saarbrücken, Germany
| | - Christian Neis
- Department of Inorganic Chemistry, Saarland University , Campus C4.1, 66123 Saarbrücken, Germany
| | - Hubertus Pietsch
- Drug Discovery, Pharmaceuticals, Bayer AG , 13342 Berlin, Germany
| | - Detlev Sülzle
- Drug Discovery, Pharmaceuticals, Bayer AG , 13342 Berlin, Germany
| | - Kaspar Hegetschweiler
- Department of Inorganic Chemistry, Saarland University , Campus C4.1, 66123 Saarbrücken, Germany
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Firouzi M, Poursalehi R, Delavari H H, Saba F, Oghabian MA. Chitosan coated tungsten trioxide nanoparticles as a contrast agent for X-ray computed tomography. Int J Biol Macromol 2017; 98:479-485. [PMID: 28174086 DOI: 10.1016/j.ijbiomac.2017.01.138] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2016] [Revised: 01/22/2017] [Accepted: 01/31/2017] [Indexed: 11/27/2022]
Abstract
Recent advances have shown that inorganic nanoparticles (NPs) based on heavy elements are highly appropriate for X-ray computed tomography (CT). In this contribution, tungsten trioxide NPs are prepared by the electrical arc discharge (EAD) method in DI water. The effect of chitosan (CTS) and glutaraldehyde (GTA) as coating and cross-linking agent, respectively, on the hydrodynamic size and zeta potential of prepared tungsten trioxide NPs is investigated. It is found that zeta potential increases by increasing the amounts of CTS. Meanwhile, by increasing the volume of glutaraldehyde (GTA), the final particle size increases whereas the zeta potential deceases. Chitosan coated tungsten trioxide demonstrated no significant cytotoxicity at concentration up to 5mg/mL after 24h. Finally, the X-ray attenuation of prepared chitosan coated tungsten trioxide NPs are higher than Iohexol as the commercially available iodinated contrasting agent at the same concentrations.
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Affiliation(s)
- Mehdi Firouzi
- Department of Materials Engineering, Tarbiat Modares University, P.O. Box 14115-143, Tehran, Iran
| | - Reza Poursalehi
- Department of Materials Engineering, Tarbiat Modares University, P.O. Box 14115-143, Tehran, Iran
| | - Hamid Delavari H
- Department of Materials Engineering, Tarbiat Modares University, P.O. Box 14115-143, Tehran, Iran.
| | - Fakhredin Saba
- Department of Laboratory Science, Kermanshah University of Medical Sciences, Kermanshah, Iran
| | - Mohammad A Oghabian
- Department of Medical Physics and Biomedical Engineering, Faculty of Medicine, Tehran University of Medical Sciences, Tehran, Iran
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Rui X, Jin Y, FitzGerald PF, Wu M, Alessio AM, Kinahan PE, De Man B. Fast analytical approach of application specific dose efficient spectrum selection for diagnostic CT imaging and PET attenuation correction. Phys Med Biol 2016; 61:7787-7811. [PMID: 27754977 DOI: 10.1088/0031-9155/61/21/7787] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Computed tomography (CT) has been used for a variety of applications, two of which include diagnostic imaging and attenuation correction for PET or SPECT imaging. Ideally, the x-ray tube spectrum should be optimized for the specific application to minimize the patient radiation dose while still providing the necessary information. In this study, we proposed a projection-based analytic approach for the analysis of contrast, noise, and bias. Dose normalized contrast to noise ratio (CNRD), inverse noise normalized by dose (IND) and bias are used as evaluation metrics to determine the optimal x-ray spectrum. Our simulation investigated the dose efficiency of the x-ray spectrum ranging from 40 kVp to 200 kVp. Water cylinders with diameters of 15 cm, 24 cm, and 35 cm were used in the simulation to cover a variety of patient sizes. The effects of electronic noise and pre-patient copper filtration were also evaluated. A customized 24 cm CTDI-like phantom with 13 mm diameter inserts filled with iodine (10 mg ml-1), tantalum (10 mg ml-1), water, and PMMA was measured with both standard (1.5 mGy) and ultra-low (0.2 mGy) dose to verify the simulation results at tube voltages of 80, 100, 120, and 140 kVp. For contrast-enhanced diagnostic imaging, the simulation results indicated that for high dose without filtration, the optimal kVp for water contrast is approximately 100 kVp for a 15 cm water cylinder. However, the 60 kVp spectrum produces the highest CNRD for bone and iodine. The optimal kVp for tantalum has two selections: approximately 50 and 100 kVp. The kVp that maximizes CNRD increases when the object size increases. The trend in the CTDI phantom measurements agrees with the simulation results, which also agrees with previous studies. Copper filtration improved the dose efficiency for water and tantalum, but reduced the iodine and bone dose efficiency in a clinically-relevant range (70-140 kVp). Our study also shows that for CT-based attenuation correction applications for PET or SPECT, a higher-kVp spectrum with copper filtration is preferable. This method is developed based on filter back projection and does not require image reconstruction or Monte Carlo dose estimates; thus, it could potentially be used for patient-specific and task-based on-the-fly protocol optimization.
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Affiliation(s)
- Xue Rui
- Image Reconstruction Laboratory, GE Global Research Center, Niskayuna, NY, USA
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McGinnity TL, Dominguez O, Curtis TE, Nallathamby PD, Hoffman AJ, Roeder RK. Hafnia (HfO2) nanoparticles as an X-ray contrast agent and mid-infrared biosensor. NANOSCALE 2016; 8:13627-37. [PMID: 27364973 DOI: 10.1039/c6nr03217f] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
The interaction of hafnium oxide (HfO2) nanoparticles (NPs) with X-ray and mid-infrared radiation was investigated to assess the potential as a multifunctional diagnostic probe for X-ray computed tomography (CT) and/or mid-infrared biosensing. HfO2 NPs of controlled size were prepared by a sol-gel process and surface functionalized with polyvinylpyrrolidone, resulting in relatively spherical and monodispersed NPs with a tunable mean diameter in the range of ∼7-31 nm. The X-ray attenuation of HfO2 NPs was measured over 0.5-50 mM concentration and compared with Au NPs and iodine, which are the most prominent X-ray contrast agents currently used in research and clinical diagnostic imaging, respectively. At clinical CT tube potentials >80 kVp, HfO2 NPs exhibited superior or similar X-ray contrast compared to Au NPs, while both exhibited significantly greater X-ray contrast compared to iodine, due to the favorable location of the k-shell absorption edge for hafnium and gold. Moreover, energy-dependent differences in X-ray attenuation enabled simultaneous quantitative molecular imaging of each agent using photon-counting spectral (multi-energy) CT. HfO2 NPs also exhibited a strong mid-infrared absorption in the Reststrahlen band from ∼250-800 cm(-1) and negative permittivity below 695 cm(-1), which can enable development of mid-infrared biosensors and contrast agents, leveraging surface enhanced mid-infrared and/or phonon polariton absorption.
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Affiliation(s)
- Tracie L McGinnity
- Department of Aerospace and Mechanical Engineering, Bioengineering Graduate Program, University of Notre Dame, Notre Dame, IN 46556, USA. and Harper Cancer Research Institute, University of Notre Dame, Notre Dame, IN 46556, USA
| | - Owen Dominguez
- Department of Electrical Engineering, University of Notre Dame, Notre Dame, IN 46556, USA and Notre Dame Center for Nanoscience and Nanotechnology (NDnano), University of Notre Dame, Notre Dame, IN 46556, USA
| | - Tyler E Curtis
- Department of Aerospace and Mechanical Engineering, Bioengineering Graduate Program, University of Notre Dame, Notre Dame, IN 46556, USA.
| | - Prakash D Nallathamby
- Department of Aerospace and Mechanical Engineering, Bioengineering Graduate Program, University of Notre Dame, Notre Dame, IN 46556, USA. and Harper Cancer Research Institute, University of Notre Dame, Notre Dame, IN 46556, USA
| | - Anthony J Hoffman
- Department of Electrical Engineering, University of Notre Dame, Notre Dame, IN 46556, USA and Notre Dame Center for Nanoscience and Nanotechnology (NDnano), University of Notre Dame, Notre Dame, IN 46556, USA
| | - Ryan K Roeder
- Department of Aerospace and Mechanical Engineering, Bioengineering Graduate Program, University of Notre Dame, Notre Dame, IN 46556, USA. and Department of Electrical Engineering, University of Notre Dame, Notre Dame, IN 46556, USA and Harper Cancer Research Institute, University of Notre Dame, Notre Dame, IN 46556, USA and Notre Dame Center for Nanoscience and Nanotechnology (NDnano), University of Notre Dame, Notre Dame, IN 46556, USA
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High Atomic Number Contrast Media Offer Potential for Radiation Dose Reduction in Contrast-Enhanced Computed Tomography. Invest Radiol 2016; 51:249-54. [DOI: 10.1097/rli.0000000000000232] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Zygmanski P, Sajo E. Nanoscale radiation transport and clinical beam modeling for gold nanoparticle dose enhanced radiotherapy (GNPT) using X-rays. Br J Radiol 2015; 89:20150200. [PMID: 26642305 PMCID: PMC4986475 DOI: 10.1259/bjr.20150200] [Citation(s) in RCA: 49] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2015] [Revised: 11/17/2015] [Accepted: 12/01/2015] [Indexed: 11/05/2022] Open
Abstract
We review radiation transport and clinical beam modelling for gold nanoparticle dose-enhanced radiotherapy using X-rays. We focus on the nanoscale radiation transport and its relation to macroscopic dosimetry for monoenergetic and clinical beams. Among other aspects, we discuss Monte Carlo and deterministic methods and their applications to predicting dose enhancement using various metrics.
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Affiliation(s)
- Piotr Zygmanski
- Department of Radiation Oncology, Brigham and Women's Hospital, Dana-Farber Cancer Institute, and Harvard Medical School, Boston, MA, USA
| | - Erno Sajo
- Department of Physics and Applied Physics, University of Massachusetts Lowell, Medical Physics Program, Lowell, MA, USA
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FitzGerald PF, Colborn RE, Edic PM, Lambert JW, Torres AS, Bonitatibus PJ, Yeh BM. CT Image Contrast of High-Z Elements: Phantom Imaging Studies and Clinical Implications. Radiology 2015; 278:723-33. [PMID: 26356064 DOI: 10.1148/radiol.2015150577] [Citation(s) in RCA: 56] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
PURPOSE To quantify the computed tomographic (CT) image contrast produced by potentially useful contrast material elements in clinically relevant imaging conditions. MATERIALS AND METHODS Equal mass concentrations (grams of active element per milliliter of solution) of seven radiodense elements, including iodine, barium, gadolinium, tantalum, ytterbium, gold, and bismuth, were formulated as compounds in aqueous solutions. The compounds were chosen such that the active element dominated the x-ray attenuation of the solution. The solutions were imaged within a modified 32-cm CT dose index phantom at 80, 100, 120, and 140 kVp at CT. To simulate larger body sizes, 0.2-, 0.5-, and 1.0-mm-thick copper filters were applied. CT image contrast was measured and corrected for measured concentrations and presence of chlorine in some compounds. RESULTS Each element tested provided higher image contrast than iodine at some tube potential levels. Over the range of tube potentials that are clinically practical for average-sized and larger adults-that is, 100 kVp and higher-barium, gadolinium, ytterbium, and tantalum provided consistently increased image contrast compared with iodine, respectively demonstrating 39%, 56%, 34%, and 24% increases at 100 kVp; 39%, 66%, 53%, and 46% increases at 120 kVp; and 40%, 72%, 65%, and 60% increases at 140 kVp, with no added x-ray filter. CONCLUSION The consistently high image contrast produced with 100-140 kVp by tantalum compared with bismuth and iodine at equal mass concentration suggests that tantalum could potentially be favorable for use as a clinical CT contrast agent.
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Affiliation(s)
- Paul F FitzGerald
- From the Radiation Systems Lab (P.F.F.), Emission Chemistry and Catalysis Lab (R.E.C., P.J.B.), Department of CT, X-ray and Functional Imaging (P.M.E.), and GE Ventures (A.S.T.), GE Global Research, One Research Circle, Niskayuna, NY 12309; and Department of Radiology and Biomedical Imaging, University of California-San Francisco, San Francisco, Calif (J.W.L., B.M.Y.)
| | - Robert E Colborn
- From the Radiation Systems Lab (P.F.F.), Emission Chemistry and Catalysis Lab (R.E.C., P.J.B.), Department of CT, X-ray and Functional Imaging (P.M.E.), and GE Ventures (A.S.T.), GE Global Research, One Research Circle, Niskayuna, NY 12309; and Department of Radiology and Biomedical Imaging, University of California-San Francisco, San Francisco, Calif (J.W.L., B.M.Y.)
| | - Peter M Edic
- From the Radiation Systems Lab (P.F.F.), Emission Chemistry and Catalysis Lab (R.E.C., P.J.B.), Department of CT, X-ray and Functional Imaging (P.M.E.), and GE Ventures (A.S.T.), GE Global Research, One Research Circle, Niskayuna, NY 12309; and Department of Radiology and Biomedical Imaging, University of California-San Francisco, San Francisco, Calif (J.W.L., B.M.Y.)
| | - Jack W Lambert
- From the Radiation Systems Lab (P.F.F.), Emission Chemistry and Catalysis Lab (R.E.C., P.J.B.), Department of CT, X-ray and Functional Imaging (P.M.E.), and GE Ventures (A.S.T.), GE Global Research, One Research Circle, Niskayuna, NY 12309; and Department of Radiology and Biomedical Imaging, University of California-San Francisco, San Francisco, Calif (J.W.L., B.M.Y.)
| | - Andrew S Torres
- From the Radiation Systems Lab (P.F.F.), Emission Chemistry and Catalysis Lab (R.E.C., P.J.B.), Department of CT, X-ray and Functional Imaging (P.M.E.), and GE Ventures (A.S.T.), GE Global Research, One Research Circle, Niskayuna, NY 12309; and Department of Radiology and Biomedical Imaging, University of California-San Francisco, San Francisco, Calif (J.W.L., B.M.Y.)
| | - Peter J Bonitatibus
- From the Radiation Systems Lab (P.F.F.), Emission Chemistry and Catalysis Lab (R.E.C., P.J.B.), Department of CT, X-ray and Functional Imaging (P.M.E.), and GE Ventures (A.S.T.), GE Global Research, One Research Circle, Niskayuna, NY 12309; and Department of Radiology and Biomedical Imaging, University of California-San Francisco, San Francisco, Calif (J.W.L., B.M.Y.)
| | - Benjamin M Yeh
- From the Radiation Systems Lab (P.F.F.), Emission Chemistry and Catalysis Lab (R.E.C., P.J.B.), Department of CT, X-ray and Functional Imaging (P.M.E.), and GE Ventures (A.S.T.), GE Global Research, One Research Circle, Niskayuna, NY 12309; and Department of Radiology and Biomedical Imaging, University of California-San Francisco, San Francisco, Calif (J.W.L., B.M.Y.)
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Material Decomposition in Dual-Energy Computed Tomography Separates High-Z Elements From Iodine, Identifying Potential Contrast Media Tailored for Dual Contrast Medium Examinations. J Comput Assist Tomogr 2015; 39:975-80. [DOI: 10.1097/rct.0000000000000298] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Ghadiri H, Ay MR, Shiran MB, Soltanian-Zadeh H, Zaidi H. K-edge ratio method for identification of multiple nanoparticulate contrast agents by spectral CT imaging. Br J Radiol 2013; 86:20130308. [PMID: 23934964 DOI: 10.1259/bjr.20130308] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
OBJECTIVE Recently introduced energy-sensitive X-ray CT makes it feasible to discriminate different nanoparticulate contrast materials. The purpose of this work is to present a K-edge ratio method for differentiating multiple simultaneous contrast agents using spectral CT. METHODS The ratio of two images relevant to energy bins straddling the K-edge of the materials is calculated using an analytic CT simulator. In the resulting parametric map, the selected contrast agent regions can be identified using a thresholding algorithm. The K-edge ratio algorithm is applied to spectral images of simulated phantoms to identify and differentiate up to four simultaneous and targeted CT contrast agents. RESULTS We show that different combinations of simultaneous CT contrast agents can be identified by the proposed K-edge ratio method when energy-sensitive CT is used. In the K-edge parametric maps, the pixel values for biological tissues and contrast agents reach a maximum of 0.95, whereas for the selected contrast agents, the pixel values are larger than 1.10. The number of contrast agents that can be discriminated is limited owing to photon starvation. For reliable material discrimination, minimum photon counts corresponding to 140 kVp, 100 mAs and 5-mm slice thickness must be used. CONCLUSION The proposed K-edge ratio method is a straightforward and fast method for identification and discrimination of multiple simultaneous CT contrast agents. ADVANCES IN KNOWLEDGE A new spectral CT-based algorithm is proposed which provides a new concept of molecular CT imaging by non-iteratively identifying multiple contrast agents when they are simultaneously targeting different organs.
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Affiliation(s)
- H Ghadiri
- Department of Medical Physics and Biomedical Engineering, Tehran University of Medical Sciences, Tehran, Iran
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Mongan J, Rathnayake S, Fu Y, Gao DW, Yeh BM. Extravasated contrast material in penetrating abdominopelvic trauma: dual-contrast dual-energy CT for improved diagnosis--preliminary results in an animal model. Radiology 2013; 268:738-42. [PMID: 23687174 DOI: 10.1148/radiol.13121267] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
PURPOSE To compare the diagnostic performance of dual-energy (DE) computed tomography (CT) with two simultaneously administered contrast agents (hereafter, dual contrast) with that of conventional CT in the evaluation of the presence and source of extravasation in penetrating abdominopelvic trauma. MATERIALS AND METHODS Institutional animal care and use committee approval was obtained, and the study was performed in accordance with National Institutes of Health guidelines for the care and use of laboratory animals. Five rabbits with bowel trauma, vascular penetrating trauma, or both were imaged with simultaneous iodinated intravenous and bismuth subsalicylate enteric contrast material at DE CT. Four attending radiologists and six radiology residents without prior DE CT experience each evaluated 10 extraluminal collections to identify the vascular and/or enteric origin of extravasation and assess their level of diagnostic confidence, first with virtual monochromatic images simulating conventional CT and then with DE CT material decomposition attenuation maps. RESULTS Overall accuracy of identification of source of extravasation increased from 78% with conventional CT to 92% with DE CT (157 of 200 diagnoses vs 184 of 200 diagnoses, respectively; P < .001). Nine radiologists were more accurate with DE CT; one had no change. Mean confidence increased from 67% to 81% with DE CT (P < .001). CONCLUSION In a rabbit abdominopelvic trauma model, dual-contrast DE CT significantly increased accuracy and confidence in the diagnosis of vascular versus enteric extravasated contrast material.
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Affiliation(s)
- John Mongan
- Department of Radiology and Biomedical Imaging, University of California San Francisco, 505 Parnassus Ave, San Francisco, CA 94143-0628, USA
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Krissak R, Elgert M, Kusch B, Hünerbein R. Gold as a Potential Contrast Agent for Dual-Energy CT. ACTA ACUST UNITED AC 2013. [DOI: 10.4236/ami.2013.34006] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Hupfer M, Nowak T, Brauweiler R, Eisa F, Kalender WA. Spectral optimization for micro-CT. Med Phys 2012; 39:3229-39. [PMID: 22755706 DOI: 10.1118/1.4718575] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
PURPOSE To optimize micro-CT protocols with respect to x-ray spectra and thereby reduce radiation dose at unimpaired image quality. METHODS Simulations were performed to assess image contrast, noise, and radiation dose for different imaging tasks. The figure of merit used to determine the optimal spectrum was the dose-weighted contrast-to-noise ratio (CNRD). Both optimal photon energy and tube voltage were considered. Three different types of filtration were investigated for polychromatic x-ray spectra: 0.5 mm Al, 3.0 mm Al, and 0.2 mm Cu. Phantoms consisted of water cylinders of 20, 32, and 50 mm in diameter with a central insert of 9 mm which was filled with different contrast materials: an iodine-based contrast medium (CM) to mimic contrast-enhanced (CE) imaging, hydroxyapatite to mimic bone structures, and water with reduced density to mimic soft tissue contrast. Validation measurements were conducted on a commercially available micro-CT scanner using phantoms consisting of water-equivalent plastics. Measurements on a mouse cadaver were performed to assess potential artifacts like beam hardening and to further validate simulation results. RESULTS The optimal photon energy for CE imaging was found at 34 keV. For bone imaging, optimal energies were 17, 20, and 23 keV for the 20, 32, and 50 mm phantom, respectively. For density differences, optimal energies varied between 18 and 50 keV for the 20 and 50 mm phantom, respectively. For the 32 mm phantom and density differences, CNRD was found to be constant within 2.5% for the energy range of 21-60 keV. For polychromatic spectra and CMs, optimal settings were 50 kV with 0.2 mm Cu filtration, allowing for a dose reduction of 58% compared to the optimal setting for 0.5 mm Al filtration. For bone imaging, optimal tube voltages were below 35 kV. For soft tissue imaging, optimal tube settings strongly depended on phantom size. For 20 mm, low voltages were preferred. For 32 mm, CNRD was found to be almost independent of tube voltage. For 50 mm, voltages larger than 50 kV were preferred. For all three phantom sizes stronger filtration led to notable dose reduction for soft tissue imaging. Validation measurements were found to match simulations well, with deviations being less than 10%. Mouse measurements confirmed simulation results. CONCLUSIONS Optimal photon energies and tube settings strongly depend on both phantom size and imaging task at hand. For in vivo CE imaging and density differences, strong filtration and voltages of 50-65 kV showed good overall results. For soft tissue imaging of animals the size of a rat or larger, voltages higher than 65 kV allow to greatly reduce scan times while maintaining dose efficiency. For imaging of bone structures, usage of only minimum filtration and low tube voltages of 40 kV and below allow exploiting the high contrast of bone at very low energies. Therefore, a combination of two filtrations could prove beneficial for micro-CT: a soft filtration allowing for bone imaging at low voltages, and a variable stronger filtration (e.g., 0.2 mm Cu) for soft tissue and contrast-enhanced imaging.
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Affiliation(s)
- Martin Hupfer
- Institute of Medical Physics, University of Erlangen-Nürnberg, Henkestrasse 91, 91052 Erlangen, Germany.
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McCollough CH, Chen GH, Kalender W, Leng S, Samei E, Taguchi K, Wang G, Yu L, Pettigrew RI. Achieving routine submillisievert CT scanning: report from the summit on management of radiation dose in CT. Radiology 2012; 264:567-80. [PMID: 22692035 PMCID: PMC3401354 DOI: 10.1148/radiol.12112265] [Citation(s) in RCA: 217] [Impact Index Per Article: 18.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
This Special Report presents the consensus of the Summit on Management of Radiation Dose in Computed Tomography (CT) (held in February 2011), which brought together participants from academia, clinical practice, industry, and regulatory and funding agencies to identify the steps required to reduce the effective dose from routine CT examinations to less than 1 mSv. The most promising technologies and methods discussed at the summit include innovations and developments in x-ray sources; detectors; and image reconstruction, noise reduction, and postprocessing algorithms. Access to raw projection data and standard data sets for algorithm validation and optimization is a clear need, as is the need for new, clinically relevant metrics of image quality and diagnostic performance. Current commercially available techniques such as automatic exposure control, optimization of tube potential, beam-shaping filters, and dynamic z-axis collimators are important, and education to successfully implement these methods routinely is critically needed. Other methods that are just becoming widely available, such as iterative reconstruction, noise reduction, and postprocessing algorithms, will also have an important role. Together, these existing techniques can reduce dose by a factor of two to four. Technical advances that show considerable promise for additional dose reduction but are several years or more from commercial availability include compressed sensing, volume of interest and interior tomography techniques, and photon-counting detectors. This report offers a strategic roadmap for the CT user and research and manufacturer communities toward routinely achieving effective doses of less than 1 mSv, which is well below the average annual dose from naturally occurring sources of radiation.
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