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Sample records for agents including gadolinium

  1. Tumor growth suppression by gadolinium-neutron capture therapy using gadolinium-entrapped liposome as gadolinium delivery agent.

    Science.gov (United States)

    Dewi, Novriana; Yanagie, Hironobu; Zhu, Haito; Demachi, Kazuyuki; Shinohara, Atsuko; Yokoyama, Kazuhito; Sekino, Masaki; Sakurai, Yuriko; Morishita, Yasuyuki; Iyomoto, Naoko; Nagasaki, Takeshi; Horiguchi, Yukichi; Nagasaki, Yukio; Nakajima, Jun; Ono, Minoru; Kakimi, Kazuhiro; Takahashi, Hiroyuki

    2013-07-01

    Neutron capture therapy (NCT) is a promising non-invasive cancer therapy approach and some recent NCT research has focused on using compounds containing gadolinium as an alternative to currently used boron-10 considering several advantages that gadolinium offers compared to those of boron. In this study, we evaluated gadolinium-entrapped liposome compound as neutron capture therapy agent by in vivo experiment on colon-26 tumor-bearing mice. Gadolinium compound were injected intravenously via tail vein and allowed to accumulate into tumor site. Tumor samples were taken for quantitative analysis by ICP-MS at 2, 12, and 24 h after gadolinium compound injection. Highest gadolinium concentration was observed at about 2 h after gadolinium compound injection with an average of 40.3 μg/g of wet tumor tissue. We performed neutron irradiation at JRR-4 reactor facility of Japan Atomic Energy Research Institute in Tokaimura with average neutron fluence of 2×10¹² n/cm². The experimental results showed that the tumor growth suppression of gadolinium-injected irradiated group was revealed until about four times higher compared to the control group, and no significant weight loss were observed after treatment suggesting low systemic toxicity of this compound. The gadolinium-entrapped liposome will become one of the candidates for Gd delivery system on NCT.

  2. Extracellular gadolinium contrast agents: Differences in stability

    International Nuclear Information System (INIS)

    Extracellular gadolinium contrast agents (Gd-CA) are either linear or macrocyclic chelates available as ionic or non-ionic preparations. The molecular structure whether cyclic or linear and ionicity determines the stability of Gd-CA. Linear chelates are flexible open chains which do not offer a strong binding to Gd3+. In contrast, the macrocyclic chelates offer a strong binding to Gd3+ by the virtue of being preorganized rigid rings of almost optimal size to cage the gadolinium atom. Non-ionic preparations are also less stable in comparison to the ionic ones as the binding between Gd3+ with the negatively charged carboxyl groups is stronger in comparison to that with amides or alcohol in the non-ionic preparations. According to stability constants and kinetic measurements, the most stable Gd-CM is the ionic-macrocyclic chelate Gd-DOTA and the least stable agents are the non-ionic linear chelates gadodiamide and gadoversetamide. In vivo data confirmed the low stability of non-ionic linear chelates but no significant difference was observed amongst the macrocyclic agents whether ionic (Gd-DOTA) or non-ionic such as Gd-HP-DO3A and Gd-BT-DO3A. The stability of Gd-CA seems to be an important factor in the pathogenesis of the serious complication of nephrogenic systemic fibrosis. Gd-CA of low stability are likely to undergo transmetallation and release free Gd ions that deposit in tissue and attract circulating fibrocytes to initiate the process of fibrosis. No cases of NSF have been observed so far after the exclusive use of the stable macrocyclic Gd-CA

  3. Extracellular gadolinium contrast agents: Differences in stability

    Energy Technology Data Exchange (ETDEWEB)

    Morcos, S.K. [Department of Diagnostic Imaging, Sheffield Teaching Hospitals NHS Foundation Trust, Northern General Hospital, Sheffield S5 7AU (United Kingdom)], E-mail: sameh.morcos@sth.nhs.uk

    2008-05-15

    Extracellular gadolinium contrast agents (Gd-CA) are either linear or macrocyclic chelates available as ionic or non-ionic preparations. The molecular structure whether cyclic or linear and ionicity determines the stability of Gd-CA. Linear chelates are flexible open chains which do not offer a strong binding to Gd{sup 3+}. In contrast, the macrocyclic chelates offer a strong binding to Gd{sup 3+} by the virtue of being preorganized rigid rings of almost optimal size to cage the gadolinium atom. Non-ionic preparations are also less stable in comparison to the ionic ones as the binding between Gd{sup 3+} with the negatively charged carboxyl groups is stronger in comparison to that with amides or alcohol in the non-ionic preparations. According to stability constants and kinetic measurements, the most stable Gd-CM is the ionic-macrocyclic chelate Gd-DOTA and the least stable agents are the non-ionic linear chelates gadodiamide and gadoversetamide. In vivo data confirmed the low stability of non-ionic linear chelates but no significant difference was observed amongst the macrocyclic agents whether ionic (Gd-DOTA) or non-ionic such as Gd-HP-DO3A and Gd-BT-DO3A. The stability of Gd-CA seems to be an important factor in the pathogenesis of the serious complication of nephrogenic systemic fibrosis. Gd-CA of low stability are likely to undergo transmetallation and release free Gd ions that deposit in tissue and attract circulating fibrocytes to initiate the process of fibrosis. No cases of NSF have been observed so far after the exclusive use of the stable macrocyclic Gd-CA.

  4. Magnetic resonance imaging using gadolinium-based contrast agents.

    Science.gov (United States)

    Mitsumori, Lee M; Bhargava, Puneet; Essig, Marco; Maki, Jeffrey H

    2014-02-01

    The purpose of this article was to review the basic properties of available gadolinium-based magnetic resonance contrast agents, discuss their fundamental differences, and explore common and evolving applications of gadolinium-based magnetic resonance contrast throughout the body excluding the central nervous system. A more specific aim of this article was to explore novel uses of these gadolinium-based contrast agents and applications where a particular agent has been demonstrated to behave differently or be better suited for certain applications than the other contrast agents in this class.

  5. Gadolinium deposition within the dentate nucleus and globus pallidus after repeated administrations of gadolinium-based contrast agents - current status

    Energy Technology Data Exchange (ETDEWEB)

    Stojanov, Dragan [University of Nis, Faculty of Medicine, Nis (Serbia); Center for Radiology, Nis (Serbia); Aracki-Trenkic, Aleksandra [Center for Radiology, Nis (Serbia); Benedeto-Stojanov, Daniela [University of Nis, Faculty of Medicine, Nis (Serbia)

    2016-05-15

    Gadolinium-based contrast agents (GBCAs) have been used clinically since 1988 for contrast-enhanced magnetic resonance imaging (CE-MRI). Generally, GBCAs are considered to have an excellent safety profile. However, GBCA administration has been associated with increased occurrence of nephrogenic systemic fibrosis (NSF) in patients with severely compromised renal function, and several studies have shown evidence of gadolinium deposition in specific brain structures, the globus pallidus and dentate nucleus, in patients with normal renal function. Gadolinium deposition in the brain following repeated CE-MRI scans has been demonstrated in patients using T1-weighted unenhanced MRI and inductively coupled plasma mass spectroscopy. Additionally, rodent studies with controlled GBCA administration also resulted in neural gadolinium deposits. Repeated GBCA use is associated with gadolinium deposition in the brain. This is especially true with the use of less-stable, linear GBCAs. In spite of increasing evidence of gadolinium deposits in the brains of patients after multiple GBCA administrations, the clinical significance of these deposits continues to be unclear. Here, we discuss the current state of scientific evidence surrounding gadolinium deposition in the brain following GBCA use, and the potential clinical significance of gadolinium deposition. There is considerable need for further research, both to understand the mechanism by which gadolinium deposition in the brain occurs and how it affects the patients in which it occurs. (orig.)

  6. Gadolinium as a Neutron Capture Therapy Agent

    Science.gov (United States)

    Shih, Jing-Luen Allen

    The clinical results of treating brain tumors with boron neutron capture therapy are very encouraging and researchers around the world are once again making efforts to develop this therapeutic modality. Boron-10 is the agent receiving the most attention for neutron capture therapy but ^{157}Gd is a nuclide that also holds interesting properties of being a neutron capture therapy agent. The objective of this study is to evaluate ^{157}Gd as a neutron capture therapy agent. In this study it is determined that tumor concentrations of about 300 mug ^{157}Gd/g tumor can be achieved in brain tumors with some FDA approved MRI contrast agents such as Gd-DTPA and Gd-DOTA, and up to 628 mug ^{157 }Gd/g tumor can be established in bone tumors with Gd-EDTMP. Monte Carlo calculations show that with only 250 ppm of ^{157}Gd in tumor, neutron capture therapy can deliver 2,000 cGy to a tumor of 2 cm diameter or larger with 5 times 10^{12} n/cm ^2 fluence at the tumor. Dose measurements which were made with films and TLD's in phantoms verified these calculations. More extended Monte Carlo calculations demonstrate that neutron capture therapy with Gd possesses comparable dose distribution to B neutron capture therapy. With 5 times 10^{12 } n/cm^2 thermal neutrons at the tumor, Auger electrons from the Gd produced an optical density enhancement on the films that is similar to the effect caused by about 300 cGy of Gd prompt gamma dose which will further enhance the therapeutic effects. A technique that combines brachytherapy with Gd neutron capture therapy has been evaluated. Monte Carlo calculations show that 5,000 cGy of prompt gamma dose can be delivered to a treatment volume of 40 cm^3 with a 3-plane implant of a total of 9 Gd needles. The tumor to normal tissue advantage of this method is as good as ^{60} Co brachytherapy. Measurements of prompt gamma dose with films and TLD-700's in a lucite phantom verify the Monte Carlo evaluation. A technique which displays the Gd

  7. Gadolinium nanoparticles and contrast agent as radiation sensitizers.

    Science.gov (United States)

    Taupin, Florence; Flaender, Mélanie; Delorme, Rachel; Brochard, Thierry; Mayol, Jean-François; Arnaud, Josiane; Perriat, Pascal; Sancey, Lucie; Lux, François; Barth, Rolf F; Carrière, Marie; Ravanat, Jean-Luc; Elleaume, Hélène

    2015-06-01

    The goal of the present study was to evaluate and compare the radiosensitizing properties of gadolinium nanoparticles (NPs) with the gadolinium contrast agent (GdCA) Magnevist(®) in order to better understand the mechanisms by which they act as radiation sensitizers. This was determined following either low energy synchrotron irradiation or high energy gamma irradiation of F98 rat glioma cells exposed to ultrasmall gadolinium NPs (GdNPs, hydrodynamic diameter of 3 nm) or GdCA. Clonogenic assays were used to quantify cell survival after irradiation in the presence of Gd using monochromatic x-rays with energies in the 25 keV-80 keV range from a synchrotron and 1.25 MeV gamma photons from a cobalt-60 source. Radiosensitization was demonstrated with both agents in combination with X-irradiation. At the same concentration (2.1 mg mL(-1)), GdNPS had a greater effect than GdCA. The maximum sensitization-enhancement ratio at 4 Gy (SER4Gy) was observed at an energy of 65 keV for both the nanoparticles and the contrast agent (2.44   ±   0.33 and 1.50   ±   0.20, for GdNPs and GdCA, respectively). At a higher energy (1.25 MeV), radiosensitization only was observed with GdNPs (1.66   ±   0.17 and 1.01   ±   0.11, for GdNPs and GdCA, respectively). The radiation dose enhancements were highly 'energy dependent' for both agents. Secondary-electron-emission generated after photoelectric events appeared to be the primary mechanism by which Gd contrast agents functioned as radiosensitizers. On the other hand, other biological mechanisms, such as alterations in the cell cycle may explain the enhanced radiosensitizing properties of GdNPs.

  8. Gadolinium nanoparticles and contrast agent as radiation sensitizers

    Science.gov (United States)

    Taupin, Florence; Flaender, Mélanie; Delorme, Rachel; Brochard, Thierry; Mayol, Jean-François; Arnaud, Josiane; Perriat, Pascal; Sancey, Lucie; Lux, François; Barth, Rolf F.; Carrière, Marie; Ravanat, Jean-Luc; Elleaume, Hélène

    2015-06-01

    The goal of the present study was to evaluate and compare the radiosensitizing properties of gadolinium nanoparticles (NPs) with the gadolinium contrast agent (GdCA) Magnevist® in order to better understand the mechanisms by which they act as radiation sensitizers. This was determined following either low energy synchrotron irradiation or high energy gamma irradiation of F98 rat glioma cells exposed to ultrasmall gadolinium NPs (GdNPs, hydrodynamic diameter of 3 nm) or GdCA. Clonogenic assays were used to quantify cell survival after irradiation in the presence of Gd using monochromatic x-rays with energies in the 25 keV-80 keV range from a synchrotron and 1.25 MeV gamma photons from a cobalt-60 source. Radiosensitization was demonstrated with both agents in combination with X-irradiation. At the same concentration (2.1 mg mL-1), GdNPS had a greater effect than GdCA. The maximum sensitization-enhancement ratio at 4 Gy (SER4Gy) was observed at an energy of 65 keV for both the nanoparticles and the contrast agent (2.44   ±   0.33 and 1.50   ±   0.20, for GdNPs and GdCA, respectively). At a higher energy (1.25 MeV), radiosensitization only was observed with GdNPs (1.66   ±   0.17 and 1.01   ±   0.11, for GdNPs and GdCA, respectively). The radiation dose enhancements were highly ‘energy dependent’ for both agents. Secondary-electron-emission generated after photoelectric events appeared to be the primary mechanism by which Gd contrast agents functioned as radiosensitizers. On the other hand, other biological mechanisms, such as alterations in the cell cycle may explain the enhanced radiosensitizing properties of GdNPs.

  9. The effect of a gadolinium-based contrast agent on diffusion tensor imaging

    International Nuclear Information System (INIS)

    Objective: The aim of this study was to investigate in detail the effect of gadolinium contrast on diffusion tensor imaging scans. As the present literature offers conflicting results, we have included a large selection of indices in the analysis. Materials and methods: Sixteen patients harboring an intra-axial contrast enhancing brain tumor were included in this study. Two diffusion tensor imaging scans were performed—one natively, and the second following a gadolinium contrast agent application. Maps of the invariant indices fractional anisotropy (FA), linear, planar, and spherical indices, trace, eigenvalues λ1, λ2, λ3 as well as of the components of the diffusion tensor matrix Dxx, Dyy, Dzz, Dxy, Dxz and Dyz were co-registered and compared statistically with matching ROI pairs in the contrast enhancing areas, peritumoral edema and the normal appearing white matter. Results: We have observed a significant increase in the FA and disproportional decrease of the eigenvalues in the post-contrast scans. In accordance with these findings, the spherical index was decreased and the linear and planar indices were increased. There was a significant decrease of all diagonal components of the diffusion tensor matrix. These changes have been strongest in the contrast enhancing areas, but there were also significant changes in the peritumoral edema and the normal appearing white matter. Conclusion: Diffusion tensor imaging scans performed after gadolinium contrast agent administration may display artificially increased FA values due to disproportional changes of the measured eigenvalues. The distortion of the diffusion measurement is strongest in, but not limited to the contrasting areas.

  10. Gadolinium contrast agent-induced CD163+ ferroportin+ osteogenic cells in nephrogenic systemic fibrosis.

    Science.gov (United States)

    Swaminathan, Sundararaman; Bose, Chhanda; Shah, Sudhir V; Hall, Kimberly A; Hiatt, Kim M

    2013-09-01

    Gadolinium-based contrast agents are linked to nephrogenic systemic fibrosis in patients with renal insufficiency. The pathology of nephrogenic systemic fibrosis is characterized by abnormal tissue repair: fibrosis and ectopic ossification. The mechanisms by which gadolinium could induce fibrosis and ossification are not known. We examined in vitro the effect of a gadolinium-based contrast agent on human peripheral blood mononuclear cells for phenotype and function relevant to the pathology of nephrogenic systemic fibrosis using immunofluorescence, flow cytometry, real-time PCR, and osteogenic assays. We also examined tissues from patients with nephrogenic systemic fibrosis, using IHC to identify the presence of cells with phenotype induced by gadolinium. Gadolinium contrast induced differentiation of human peripheral blood mononuclear cells into a unique cellular phenotype--CD163(+) cells expressing proteins involved in fibrosis and bone formation. These cells express fibroblast growth factor (FGF)23, osteoblast transcription factors Runt-related transcription factor 2, and osterix, and show an osteogenic phenotype in in vitro assays. We show in vivo the presence of CD163(+)/procollagen-1(+)/osteocalcin(+) cells in the fibrotic and calcified tissues of nephrogenic systemic fibrosis patients. Gadolinium contrast-induced CD163(+)/ferroportin(+)/FGF23(+) cells with osteogenic potential may play a role in systemic fibrosis and ectopic ossification in nephrogenic systemic fibrosis.

  11. Determination of gadolinium-based MRI contrast agents in biological and environmental samples: A review

    Energy Technology Data Exchange (ETDEWEB)

    Telgmann, Lena [University of Münster, Institute of Inorganic and Analytical Chemistry, Münster (Germany); Sperling, Michael [University of Münster, Institute of Inorganic and Analytical Chemistry, Münster (Germany); European Virtual Institute for Speciation Analysis (EVISA), Münster (Germany); Karst, Uwe, E-mail: uk@uni-muenster.de [University of Münster, Institute of Inorganic and Analytical Chemistry, Münster (Germany)

    2013-02-18

    Highlights: ► All major methods for the analysis of Gd-based MRI contrast agents are discussed. ► Biological and environmental samples are covered. ► Pharmacokinetics and species transformation can be investigated. ► The figures of merit as limit of detection and analysis time are described. -- Abstract: The development of analytical methods and strategies to determine gadolinium and its complexes in biological and environmental matrices is evaluated in this review. Gadolinium (Gd) chelates are employed as contrast agents for magnetic resonance imaging (MRI) since the 1980s. In general they were considered as safe and well-tolerated, when in 2006, the disease nephrogenic systemic fibrosis (NSF) was connected to the administration of MRI contrast agents based on Gd. Pathogenesis and etiology of NSF are yet unclear and called for the development of several analytical methods to obtain elucidation in this field. Determination of Gd complex stability in vitro and in vivo, as well as the quantification of Gd in body fluids like blood and urine was carried out. Separation of the Gd chelates was achieved with high performance liquid chromatography (HPLC) and capillary electrophoresis (CE). For detection, various methods were employed, including UV–vis absorbance and fluorescence spectroscopy, electrospray ionization mass spectrometry (ESI-MS) and inductively coupled plasma mass spectrometry (ICP-MS). A second challenge for analysts was the discovery of high concentrations of anthropogenic Gd in surface waters draining populated areas. The source could soon be determined to be the increasing administration of Gd complexes during MRI examinations. Identification and quantification of the contrast agents was carried out in various surface and groundwater samples to determine the behavior and fate of the Gd chelates in the environment. The improvement of limits of detection (LOD) and limits of quantification (LOQ) was and still is the goal of past and ongoing

  12. A small MRI contrast agent library of gadolinium(III)-encapsulated supramolecular nanoparticles for improved relaxivity and sensitivity**

    OpenAIRE

    Chen, Kuan-Ju; Wolahan, Stephanie M.; Wang, Hao; Hsu, Chao-Hsiung; Chang, Hsing-Wei; Durazo, Armando; Hwang, Lian-Pin; Garcia, Mitch A.; Jiang, Ziyue Karen; Wu, Lily; Lin, Yung-Ya; Tseng, Hsian-Rong

    2010-01-01

    We introduce a new category of nanoparticle-based T1 MRI contrast agents (CAs) by encapsulating paramagnetic chelated gadolinium(III), i.e., Gd3+·DOTA, through supramolecular assembly of molecular building blocks that carry complementary molecular recognition motifs, including adamantane (Ad) and β-cyclodextrin (CD). A small library of Gd3+·DOTA-encapsulated supramolecular nanoparticles (Gd3+·DOTA⊂SNPs) was produced by systematically altering the molecular building block mixing ratios. A broa...

  13. The evolution of gadolinium based contrast agents: from single-modality to multi-modality

    Science.gov (United States)

    Zhang, Li; Liu, Ruiqing; Peng, Hui; Li, Penghui; Xu, Zushun; Whittaker, Andrew K.

    2016-05-01

    Gadolinium-based contrast agents are extensively used as magnetic resonance imaging (MRI) contrast agents due to their outstanding signal enhancement and ease of chemical modification. However, it is increasingly recognized that information obtained from single modal molecular imaging cannot satisfy the higher requirements on the efficiency and accuracy for clinical diagnosis and medical research, due to its limitation and default rooted in single molecular imaging technique itself. To compensate for the deficiencies of single function magnetic resonance imaging contrast agents, the combination of multi-modality imaging has turned to be the research hotpot in recent years. This review presents an overview on the recent developments of the functionalization of gadolinium-based contrast agents, and their application in biomedicine applications.

  14. Insights into the use of gadolinium and gadolinium/boron-based agents in imaging-guided neutron capture therapy applications.

    Science.gov (United States)

    Deagostino, Annamaria; Protti, Nicoletta; Alberti, Diego; Boggio, Paolo; Bortolussi, Silva; Altieri, Saverio; Crich, Simonetta Geninatti

    2016-05-01

    Gadolinium neutron capture therapy (Gd-NCT) is currently under development as an alternative approach for cancer therapy. All of the clinical experience to date with NCT is done with (10)B, known as boron neutron capture therapy (BNCT), a binary treatment combining neutron irradiation with the delivery of boron-containing compounds to tumors. Currently, the use of Gd for NCT has been getting more attention because of its highest neutron cross-section. Although Gd-NCT was first proposed many years ago, its development has suffered due to lack of appropriate tumor-selective Gd agents. This review aims to highlight the recent advances for the design, synthesis and biological testing of new Gd- and B-Gd-containing compounds with the task of finding the best systems able to improve the NCT clinical outcome. PMID:27195428

  15. Complications from the use of intravenous gadolinium-based contrast agents for magnetic resonance imaging

    Energy Technology Data Exchange (ETDEWEB)

    Elias Junior, Jorge; Santos, Antonio Carlos dos; Nogueira-Barbosa, Marcello Henrique; Muglia, Valdair Francisco; Koenigkam-Santos, Marcel [Universidade de Sao Paulo (USP), Ribeirao Preto, SP (Brazil). Hospital das Clinicas. Centro de Ciencias das Imagens e Fisica Medica]. E-mail: jejunior@fmrp.usp.br

    2008-07-15

    Gadolinium-based contrast agents are much safer than the iodinated ones; however complications may occur and should be recognized for appropriate orientation and management. The total incidence of adverse reactions to contrast agents in magnetic resonance imaging ranges between 2% and 4%. Cases of severe acute reactions to gadolinium, such as laryngospasm and anaphylactic shock, are rare. Chronic complications secondary to the use of gadolinium also can occur and, recently an association between its use and a rare dermatologic disease occurring in patients with renal failure has been reported. Nephrogenic systemic fibrosis was the subject of an official health notification issued by the American Food and Drug Administration. This progressive disease is characterized by hardened skin with fibrotic nodules and plaques which may involve other parts of the body. Patients who have been affected by this disorder presented chronic renal failure, with metabolic acidosis and had been submitted to magnetic resonance angiography, probably involving exposure to large amounts of intravenous paramagnetic contrast. This review is aimed at presenting a succinct description of the gadolinium-based contrast agent types, possible secondary complications, their preventive measures and management. (author)

  16. Field strength and dose dependence of contrast enhancement by gadolinium-based MR contrast agents

    International Nuclear Information System (INIS)

    The relaxivities r1 and r2 of magnetic resonance contrast agents and the T1 relaxation time values of tissues are strongly field dependent. We present quantitative data and simulations of different gadolinium-based extracellular fluid contrast agents and the modulation of their contrast enhancement by the magnetic field to be able to answer the following questions: How are the dose and field dependences of their contrast enhancement? Is there an interrelationship between dose and field dependence? Should one increase or decrease doses at specific fields? Nuclear magnetic relaxation dispersion data were acquired for the following contrast agents: gadopentetate dimeglumine, gadoterate meglumine, gadodiamide injection, and gadoteridol injection, as well as for several normal and pathological human tissue samples. The magnetic field range stretched from 0.0002 to 4.7 T, including the entire clinical imaging range. The data acquired were then fitted with the appropriate theoretical models. The combination of the diamagnetic relaxation rates (R1 = 1/T1 and R2 = 1/T2) of tissues with the respective paramagnetic contributions of the contrast agents allowed the prediction of image contrast at any magnetic field. The results revealed a nearly identical field and dose-dependent increase of contrast enhancement induced by these contrast agents within a certain dose range. The target tissue concentration (TTC) was an important though nonlinear factor for enhancement. The currently recommended dose of 0.1 mmol/kg body weight seems to be a compromise close to the lower limits of diagnostically sufficient contrast enhancement for clinical imaging at all field strengths. At low field contrast enhancement might be insufficient. Adjustment of dose or concentration, or a new class of contrast agents with optimized relaxivity, would be a valuable contribution to a better diagnostic yield of contrast enhancement at all fields. (orig.)

  17. A new biodegradable and biocompatible gadolinium (III) -polymer for liver magnetic resonance imaging contrast agent.

    Science.gov (United States)

    Xiao, Yan; Xue, Rong; You, Tianyan; Li, Xiaojing; Pei, Fengkui

    2015-07-01

    A new biodegradable and biocompatible gadolinium (III) -copolymer (ACL-A2-DOTA-Gd) has been developed as a potential liver magnetic resonance imaging (MRI) contrast agent. ACL-A2-DOTA-Gd consisted of a poly (aspartic acid-co-leucine) unit bound with 1,4,7,10-tetraazacyclododecan-1,4,7,10-tetraacetic acid-gadolinium (Gd-DOTA) via the linkage of ethylenediamine. In vitro, the biodegradable experiment and cytotoxicity assay showed the biodegradability and biocompatibility of this gadolinium-polymer. ACL-A2-DOTA-Gd presented an increase in relaxivity of 2.4 times than the clinical Gd-DOTA. In vivo, gadolinium (III)-copolymer was mainly accumulated in the liver, and it could be excreted via the renal and hepatobiliary mechanism. The average enhancement of ACL-A2-DOTA-Gd (60.71±5.93%, 50-80 min) in liver was 2.62-fold greater than that of Gd-DOTA (23.16±3.55%, 10-30 min). ACL-A2-DOTA-Gd could be as a potential liver MRI contrast agent with a long time-window.

  18. High prevalence of nephrogenic systemic fibrosis in chronic renal failure patients exposed to gadodiamide, a gadolinium-containing magnetic resonance contrast agent

    DEFF Research Database (Denmark)

    Rydahl, Casper; Thomsen, Henrik S; Marckmann, Peter

    2008-01-01

    OBJECTIVE: Nephrogenic systemic fibrosis (NSF) is a serious disease affecting renal failure patients. It may be caused by some gadolinium (Gd)-containing contrast agents, including gadodiamide. The study aimed at estimating the prevalence of NSF after gadodiamide exposure for patients with chronic...

  19. Re-evaluating gadolinium(III) texaphyrin as a radiosensitizing agent.

    Science.gov (United States)

    Bernhard, E J; Mitchell, J B; Deen, D; Cardell, M; Rosenthal, D I; Brown, J M

    2000-01-01

    Gadolinium(III) texaphyrin (Gd-tex) was recently proposed as a radiosensitizing agent that combines preferential tumor uptake with detection of drug localization by magnetic resonance imaging (S. W. Young et al., Proc. Natl. Acad. Sci. USA, 93: 6610-6615, 1996). In view of the initial report on this compound, four radiobiology laboratories undertook independent efforts to further study radiosensitization by Gd-tex. In addition to repeating the previously reported studies on Gd-tex in HT-29 cells, we tested five other human tumor cell lines (U-87 MG, U251-NCI, SW480, A549, and MCF-7). These studies included a Gd-tex treatment period of 24 h before irradiation (as in the original publication), with concentrations of Gd-tex ranging from 20-500 microM. In neither the HT-29 cells nor any of the other five human cell lines did we see radiation sensitization by Gd-tex. Two cell lines (MCF-7 and U-87 MG) were further tested for radiosensitization by Gd-tex under hypoxic conditions. No radiosensitization was observed in either case. Finally, the radiation response of two tumor lines were assessed in vivo. Neither HT-29 xenografts in severe combined immunodeficient (SCID) mice nor RIF-1 tumors growing in C3H mice demonstrated radiosensitization after Gd-tex treatment before single or fractionated doses of radiation. Our results raise questions about the efficacy of Gd-tex as a radiosensitizing agent. PMID:10646858

  20. Biocompatible Polyhydroxyethylaspartamide-based Micelles with Gadolinium for MRI Contrast Agents

    Directory of Open Access Journals (Sweden)

    Kim Hyo Jeong

    2010-01-01

    Full Text Available Abstract Biocompatible poly-[N-(2-hydroxyethyl-d,l-aspartamide]-methoxypoly(ethyleneglycol-hexadecylamine (PHEA-mPEG-C16 conjugated with 1,4,7,10-tetraazacyclododecan-1,4,7,10-tetraacetic acid-gadolinium (DOTA-Gd via ethylenediamine (ED was synthesized as a magnetic resonance imaging (MRI contrast agent. Amphiphilic PHEA-mPEG-C16-ED-DOTA-Gd forms micelle in aqueous solution. All the synthesized materials were characterized by proton nuclear magnetic resonance (1H NMR. Micelle size and shape were examined by dynamic light scattering (DLS and atomic force microscopy (AFM. Micelles with PHEA-mPEG-C16-ED-DOTA-Gd showed higher relaxivities than the commercially available gadolinium contrast agent. Moreover, the signal intensity of a rabbit liver was effectively increased after intravenous injection of PHEA-mPEG-C16-ED-DOTA-Gd.

  1. Biocompatible Polyhydroxyethylaspartamide-based Micelles with Gadolinium for MRI Contrast Agents

    Science.gov (United States)

    Jeong, Sang Young; Kim, Hyo Jeong; Kwak, Byung-Kook; Lee, Ha-Young; Seong, Hasoo; Shin, Byung Cheol; Yuk, Soon Hong; Hwang, Sung-Joo; Cho, Sun Hang

    2010-12-01

    Biocompatible poly-[ N-(2-hydroxyethyl)- d, l-aspartamide]-methoxypoly(ethyleneglycol)-hexadecylamine (PHEA-mPEG-C16) conjugated with 1,4,7,10-tetraazacyclododecan-1,4,7,10-tetraacetic acid-gadolinium (DOTA-Gd) via ethylenediamine (ED) was synthesized as a magnetic resonance imaging (MRI) contrast agent. Amphiphilic PHEA-mPEG-C16-ED-DOTA-Gd forms micelle in aqueous solution. All the synthesized materials were characterized by proton nuclear magnetic resonance (1H NMR). Micelle size and shape were examined by dynamic light scattering (DLS) and atomic force microscopy (AFM). Micelles with PHEA-mPEG-C16-ED-DOTA-Gd showed higher relaxivities than the commercially available gadolinium contrast agent. Moreover, the signal intensity of a rabbit liver was effectively increased after intravenous injection of PHEA-mPEG-C16-ED-DOTA-Gd.

  2. [Physico-chemical and toxicological profile of gadolinium chelates as contrast agents for magnetic resonance imaging].

    Science.gov (United States)

    Idée, J-M; Fretellier, N; Thurnher, M M; Bonnemain, B; Corot, C

    2015-07-01

    Gadolinium chelates (GC) are contrast agents widely used to facilitate or to enable diagnosis using magnetic resonance imaging (MRI). From a regulatory viewpoint, GC are drugs. GC have largely contributed to the success of MRI, which has become a major component of clinician's diagnostic armamentarium. GC are not metabolised and are excreted by the kidneys. They distribute into the extracellular compartment. Because of its high intrinsic toxicity, gadolinium must be administered as a chelate. GC can be classified according to two key molecular features: (a) nature of the chelating moiety: either macrocyclic molecules in which gadolinium is caged in the pre-organized cavity of the ligand, or linear, open-chain molecules, (b) ionicity: Gd chelates can be ionic (meglumine or sodium salts) or non-ionic. The thermodynamic and kinetic stabilities of the various GCs differ according to these structural characteristics. The kinetic stability of macrocyclic GCs is much higher than that of linear GCs and the thermodynamic stability of ionic GCs is generally higher than that of non-ionic GC, thus leading to a lower risk of gadolinium dissociation. This class of drugs has enjoyed an excellent reputation in terms of safety for a long time, until a causal link with a recently-described serious disease, nephrogenic systemic fibrosis (NSF), was evidenced. It is acknowledged that the vast majority of NSF cases are related to the administration of some linear CG in renally-impaired patients. Health authorities, worldwide, released recommendations which drastically reduced the occurrence of new cases. PMID:25731664

  3. Accumulation of MRI contrast agents in malignant fibrous histiocytoma for gadolinium neutron capture therapy

    Energy Technology Data Exchange (ETDEWEB)

    Fujimoto, T. [Department of Orthopaedic Surgery, Hyogo Cancer Center, Akashi 673-0021 (Japan)], E-mail: fujitaku@hp.pref.hyogo.jp; Ichikawa, H. [Faculty of Pharmaceutical Sciences and Cooperative Research Center of Life Sciences, Kobe Gakuin University, Kobe 650-8586 (Japan); Akisue, T. [Department of Orthopaedic Surgery, Kobe University Graduate School of Medicine, Kobe 650-0017 (Japan); Fujita, I. [Department of Orthopaedic Surgery, Hyogo Cancer Center, Akashi 673-0021 (Japan); Kishimoto, K.; Hara, H. [Department of Orthopaedic Surgery, Kobe University Graduate School of Medicine, Kobe 650-0017 (Japan); Imabori, M. [Department of Orthopaedic Surgery, Hyogo Cancer Center, Akashi 673-0021 (Japan); Kawamitsu, H. [Department of Radiology, Kobe University Graduate School of Medicine, Kobe 650-0017 (Japan); Sharma, P.; Brown, S.C.; Moudgil, B.M. [Particle Engineering Research Center, University of Florida, Gainesville, FL32611 (United States); Fujii, M. [Department of Radiology, Kobe University Graduate School of Medicine, Kobe 650-0017 (Japan); Yamamoto, T. [Department of Orthopaedic Surgery, Kagawa University, Kagawa 761-0793 (Japan); Kurosaka, M. [Department of Orthopaedic Surgery, Kobe University Graduate School of Medicine, Kobe 650-0017 (Japan); Fukumori, Y. [Faculty of Pharmaceutical Sciences and Cooperative Research Center of Life Sciences, Kobe Gakuin University, Kobe 650-8586 (Japan)

    2009-07-15

    Neutron-capture therapy with gadolinium (Gd-NCT) has therapeutic potential, especially that gadolinium is generally used as a contrast medium in magnetic resonance imaging (MRI). The accumulation of gadolinium in a human sarcoma cell line, malignant fibrosis histiocytoma (MFH) Nara-H, was visualized by the MRI system. The commercially available MRI contrast medium Gd-DTPA (Magnevist, dimeglumine gadopentetate aqueous solution) and the biodegradable and highly gadopentetic acid (Gd-DTPA)-loaded chitosan nanoparticles (Gd-nanoCPs) were prepared as MRI contrast agents. The MFH cells were cultured and collected into three falcon tubes that were set into the 3-tesra MRI system to acquire signal intensities from each pellet by the spin echo method, and the longitudinal relaxation time (T1) was calculated. The amount of Gd in the sample was measured by inductively coupled plasma atomic emission spectrography (ICP-AES). The accumulation of gadolinium in cells treated with Gd-nanoCPs was larger than that in cells treated with Gd-DTPA. In contrast, and compared with the control, Gd-DTPA was more effective than Gd-nanoCPs in reducing T1, suggesting that the larger accumulation exerted the adverse effect of lowering the enhancement of MRI. Further studies are warranted to gain insight into the therapeutic potential of Gd-NCT.

  4. Tracing gadolinium-based contrast agents from surface water to drinking water by means of speciation analysis.

    Science.gov (United States)

    Birka, Marvin; Wehe, Christoph A; Hachmöller, Oliver; Sperling, Michael; Karst, Uwe

    2016-04-01

    In recent decades, a significant amount of anthropogenic gadolinium has been released into the environment as a result of the broad application of contrast agents for magnetic resonance imaging (MRI). Since this anthropogenic gadolinium anomaly has also been detected in drinking water, it has become necessary to investigate the possible effect of drinking water purification on these highly polar microcontaminats. Therefore, a novel highly sensitive method for speciation analysis of gadolinium is presented. For that purpose, the hyphenation of hydrophilic interaction liquid chromatography (HILIC) and inductively coupled plasma-mass spectrometry (ICP-MS) was employed. In order to enhance the detection power, sample introduction was carried out by ultrasonic nebulization. In combination with a novel HILIC method using a diol-based stationary phase, it was possible to achieve superior limits of detection for frequently applied gadolinium-based contrast agents below 20pmol/L. With this method, the contrast agents Gd-DTPA, Gd-DOTA and Gd-BT-DO3A were determined in concentrations up to 159pmol/L in samples from several waterworks in a densely populated region of Germany alongside the river Ruhr as well as from a waterworks near a catchment lake. Thereby, the direct impact of anthropogenic gadolinium species being present in the surface water on the amount of anthropogenic gadolinium in drinking water was shown. There was no evidence for the degradation of contrast agents, the release of Gd(3+) or the presence of further Gd species.

  5. Tracing gadolinium-based contrast agents from surface water to drinking water by means of speciation analysis.

    Science.gov (United States)

    Birka, Marvin; Wehe, Christoph A; Hachmöller, Oliver; Sperling, Michael; Karst, Uwe

    2016-04-01

    In recent decades, a significant amount of anthropogenic gadolinium has been released into the environment as a result of the broad application of contrast agents for magnetic resonance imaging (MRI). Since this anthropogenic gadolinium anomaly has also been detected in drinking water, it has become necessary to investigate the possible effect of drinking water purification on these highly polar microcontaminats. Therefore, a novel highly sensitive method for speciation analysis of gadolinium is presented. For that purpose, the hyphenation of hydrophilic interaction liquid chromatography (HILIC) and inductively coupled plasma-mass spectrometry (ICP-MS) was employed. In order to enhance the detection power, sample introduction was carried out by ultrasonic nebulization. In combination with a novel HILIC method using a diol-based stationary phase, it was possible to achieve superior limits of detection for frequently applied gadolinium-based contrast agents below 20pmol/L. With this method, the contrast agents Gd-DTPA, Gd-DOTA and Gd-BT-DO3A were determined in concentrations up to 159pmol/L in samples from several waterworks in a densely populated region of Germany alongside the river Ruhr as well as from a waterworks near a catchment lake. Thereby, the direct impact of anthropogenic gadolinium species being present in the surface water on the amount of anthropogenic gadolinium in drinking water was shown. There was no evidence for the degradation of contrast agents, the release of Gd(3+) or the presence of further Gd species. PMID:26931429

  6. Comparison of gadolinium Cy2DOTA, a new hepatobiliary agent, and gadolinium HP-DO3A, an extracellular agent, in healthy liver and metastatic disease

    International Nuclear Information System (INIS)

    A new gadolinium (Gd) chelate with preferential hepatobiliary uptake, Gd Cy2DOTA, was compared in two animal species with Gd HP-DO3A (gadoteridol), a clinically approved contrast agent with extracellular distribution. Liver enhancement was evaluated for these two contrast agents using magnetic resonance imaging, whereas an experimental model of metastatic disease was used to evaluate the agents' efficacy for liver-lesion delineation. The two agents were compared in four healthy Rhesus monkeys (eight studies) and five New Zealand White rabbits with implanted VX-2 liver tumors (ten studies). The contrast dose was 0.1 mmol/kg, with the agents given in random order and at least 72 hours between contrast injections. Breathhold T1-weighted spin echo scans were obtained at 1.5 tesla (T) before and after contrast was administered. Postcontrast scans were obtained 1 to 90 minutes after injection in the monkeys and 1 to 240 minutes after injection in the rabbits. Prolonged hepatic enhancement, superior in degree to that with Gd HP-DO3A, was noted to both monkeys and rabbits after injection of Gd Cy2DOTA. Two minutes after contrast, liver SI was 1.94 ± 0.05 with Gd Cy2DOTA compared with 1.5 ± 0.05 with Gd HP-DO3A in monkeys. Sixty minutes after contrast, liver SI was 1.60 ± 0.09 compared with 1.20 ± 0.02. The difference between agents was significant at all times from 2 to 60 minutes after contrast injection (P 2DOTA but not with Gd HP-DO3A. The maximum improvement in lesion conspicuity (rabbit) occurred 45 minutes after injection of Gd Cy2DOTA and 5 minutes after injection of Gd HP-DO3A. 22 refs., 12 figs

  7. Gadolinium contrast agent selection and optimal use for body MR imaging.

    Science.gov (United States)

    Guglielmo, Flavius F; Mitchell, Donald G; Gupta, Shiva

    2014-07-01

    Proper selection of a gadolinium-based contrast agent (GBCA) for body magnetic resonance imaging (MRI) cases requires understanding the indication for the MRI exam, the key features of the different GBCAs, and the effect that the GBCA has on the selected imaging protocol. The different categories of GBCAs require timing optimization on postcontrast sequences and adjusting imaging parameters to obtain the highest T1 contrast. Gadoxetate disodium has many advantages when evaluating liver lesions, although there are caveats and limitations that need to be understood. Gadobenate dimeglumine, a high-relaxivity GBCA, can be used for indications when stronger T1 relaxivity is needed.

  8. Gadolinium MRI Contrast Agents Based on Triazine Dendrimers: Relaxivity and In Vivo Pharmacokinetics

    OpenAIRE

    Lim, Jongdoo; Turkbey, Baris; Bernardo, Marcelino; Bryant, L. Henry; Garzoni, Matteo; Pavan, Giovanni M.; Nakajima, Takahito; Choyke, Peter L; Simanek, Eric E; Kobayashi, Hisataka

    2012-01-01

    Four gadolinium (Gd)-based macromolecular contrast agents, G3-(Gd-DOTA)24, G5-(Gd-DOTA)96, G3-(Gd-DTPA)24, and G5-(Gd-DTPA)96, were prepared that varied in the size of dendrimer (generation three and five), the type of chelate group (DTPA or DOTA), and the theoretical number of metallated chelates (24 and 96). Synthesis relied on a dichlorotriazine derivatized with a DOTA or DTPA ligand that was incorporated into the dendrimer and ultimately metallated with Gd ions. Paramagnetic characteristi...

  9. Gadolinium Contrast Agent is of Limited Value for Magnetic Resonance Imaging Assessment of Synovial Hypertrophy in Hemophiliacs

    Energy Technology Data Exchange (ETDEWEB)

    Lundin, B.; Berntorp, E.; Pettersson, H.; Wirestam, R.; Jonsson, K.; Staahlberg, F.; Ljung, R. [Dept. of Radiology, Univ Hospital of Lund, Lund (Sweden)

    2007-07-15

    Purpose: To examine the influence of different doses of gadolinium contrast agent on synovial enhancement, to compare magnetic resonance imaging (MRI) findings of synovial hypertrophy and radiographic joint changes in hemophiliacs, and to investigate the value of gadolinium in MRI assessment of synovial hypertrophy in hemophiliacs using dynamic MRI and MRI scoring. Material and Methods: Twenty-one hemophiliacs on prophylactic factor treatment without recent bleeds were subjected to radiography and gadolinium contrast-enhanced dynamic and static MRI of the knee using a standard dose of 0.1 mmol/kg b.w. gadoteridol. In 17 of the patients, the MRI procedure was repeated after a triple dose of gadoteridol. Results: MRI findings of synovial hypertrophy were significantly correlated with Pettersson radiographic scores. In 19 of the 21 MRI investigated joints, administration of contrast agent did not alter the result of the evaluation of synovial hypertrophy. Conclusion: The optimal time interval for volume assessment of synovial hypertrophy after injection of gadolinium contrast agent is dose dependent. Hemophiliacs without recent bleeds have minor to abundant synovial hypertrophy in joints with pronounced radiographic changes. Dynamic MRI is not useful for evaluating hemophilic arthropathy, and gadolinium contrast agent is not routinely indicated for MRI scoring of joints in hemophiliacs.

  10. The use of innovative gadolinium-based contrast agent for MR-diagnosis of cancer in the experiment

    Science.gov (United States)

    Chernov, V.; Medvedeva, A.; Sinilkin, I.; Zelchan, R.; Grigorev, E.; Frolova, I.; Nam, I.

    2016-02-01

    The present study of the functional suitability and specific activity of the contrast agent gadolinium-based for magnetic resonance imaging demonstrated that the investigated contrast agent intensively accumulates in organs and anatomical structures of the experimental animals. In the model of tumor lesions in animals, study have shown that investigational contrast agent accumulates in the tumor tissue and retained there in for a long enough time.

  11. Efficient labeling in vitro with non-ionic gadolinium magnetic resonance imaging contrast agent and fluorescent transfection agent in bone marrow stromal cells of neonatal rats.

    Science.gov (United States)

    Li, Ying-Qin; Tang, Ying; Fu, Rao; Meng, Qiu-Hua; Zhou, Xue; Ling, Ze-Min; Cheng, Xiao; Tian, Su-Wei; Wang, Guo-Jie; Liu, Xue-Guo; Zhou, Li-Hua

    2015-07-01

    Although studies have been undertaken on gadolinium labeling-based molecular imaging in magnetic resonance imaging (MRI), the use of non-ionic gadolinium in the tracking of stem cells remains uncommon. To investigate the efficiency in tracking of stem cells with non-ionic gadolinium as an MRI contrast agent, a rhodamine-conjugated fluorescent reagent was used to label bone marrow stromal cells (BMSCs) of neonatal rats in vitro, and MRI scanning was undertaken. The fluorescent-conjugated cell uptake reagents were able to deliver gadodiamide into BMSCs, and cell uptake was verified using flow cytometry. In addition, the labeled stem cells with paramagnetic contrast medium remained detectable by an MRI monitor for a minimum of 28 days. The present study suggested that this method can be applied efficiently and safely for the labeling and tracking of bone marrow stromal cells in neonatal rats.

  12. Gadolinium(III) Complexes with N-Alkyl-N-methylglucamine Surfactants Incorporated into Liposomes as Potential MRI Contrast Agents

    Science.gov (United States)

    Silva, Simone Rodrigues; Duarte, Érica Correia; Ramos, Guilherme Santos; Kock, Flávio Vinícius Crizóstomo; Andrade, Fabiana Diuk; Frézard, Frédéric; Colnago, Luiz Alberto; Demicheli, Cynthia

    2015-01-01

    Complexes of gadolinium(III) with N-octanoyl-N-methylglucamine (L8) and N-decanoyl-N-methylglucamine (L10) with 1 : 2 stoichiometry were synthesized and characterized by elemental analysis, electrospray ionization-tandem mass spectrometry (ESI-MS), infrared (IR) spectroscopy, and molar conductivity measurements. The transverse (r2) and longitudinal (r1) relaxivity protons were measured at 20 MHz and compared with those of the commercial contrasts. These complexes were incorporated in liposomes, resulting in the increase of the vesicle zeta potential. Both the free and liposome-incorporated gadolinium complexes showed high relaxation effectiveness, compared to commercial contrast agent gadopentetate dimeglumine (Magnevist). The high relaxivity of these complexes was attributed to the molecular rotation that occurs more slowly, because of the elevated molecular weight and incorporation in liposomes. The results establish that these paramagnetic complexes are highly potent contrast agents, making them excellent candidates for various applications in molecular MR imaging. PMID:26347596

  13. Investigating the stability of gadolinium based contrast agents towards UV radiation.

    Science.gov (United States)

    Birka, Marvin; Roscher, Jörg; Holtkamp, Michael; Sperling, Michael; Karst, Uwe

    2016-03-15

    Since the 1980s, the broad application of gadolinium(Gd)-based contrast agents for magnetic resonance imaging (MRI) has led to significantly increased concentrations of Gd in the aqueous environment. Little is known about the stability of these highly polar xenobiotics under environmental conditions, in wastewater and in drinking water treatment. Therefore, the stability of frequently applied Gd-based MRI contrast agents towards UV radiation was investigated. The hyphenation of hydrophilic interaction liquid chromatography (HILIC) with inductively coupled plasma mass spectrometry (ICP-MS) and of HILIC with electrospray ionization mass spectrometry (ESI-MS) provided quantitative elemental information as well as structural information. The contrast agents Gd-DTPA, Gd-DOTA and Gd-BT-DO3A showed a high stability in irradiation experiments applying a wavelength range from 220 nm to 500 nm. Nevertheless, the degradation of Gd-BOPTA as well as the formation of Gd-containing transformation products was observed by means of HILIC-ICP-MS. Matrix-dependent irradiation experiments showed a degradation of Gd-BOPTA down to 3% of the initial amount in purified water after 300 min, whereas the degradation was slowed down in drinking water and surface water. Furthermore, it was observed that the sum of species continuously decreased with proceeding irradiation in all matrices. After irradiation in purified water for 300 min only 16% of the sum of species was left. This indicates a release of Gd(III) ions from the complex in course of irradiation. HILIC-ESI-MS measurements revealed that the transformation products mostly resulted from O-dealkylation and N-dealkylation reactions. In good correlation with retention times, the majority of transformation products were found to be more polar than Gd-BOPTA itself. Based on accurate masses, sum formulas were obtained and structures could be proposed. PMID:26802476

  14. Dopamine-containing gadolinium complex as magnetic resonance imaging contrast agent

    Institute of Scientific and Technical Information of China (English)

    ZHOU Xin; ZHAO Qi; YANG Lian; YAN Guoping; XU Wei; ZHOU Chengkai; ZHANG Qiao; LI Liang; LIU Fan; GUO Junfang

    2012-01-01

    Gadolinium diethylenetriamine-pentaacetic bisdopamide (Gd-DTPA-2DA) was synthesized by the incorporation of dopamine to diethylenetriaminepentaacetic acid (DTPA) and further reaction with gadolinium chloride.In vitro and in vivo properties were also evaluated.Gadolinium complex Gd-DTPA-2DA possessed higher relaxation effectiveness and less cytotoxicity to HeLa cells than that of Gd-DTPA.Moreover,Gd-DTPA-2DA greatly enhanced the contrast of MR images of the brains,provided prolonged intravascular duration,and produced highly contrasted visualization of the brain.

  15. Application of extracellular gadolinium-based MRI contrast agents and the risk of nephrogenic systemic fibrosis.

    Science.gov (United States)

    Heverhagen, J T; Krombach, G A; Gizewski, E

    2014-07-01

    Nephrogenic systemic fibrosis (NSF) is a serious, sometimes fatal disease. Findings in recent years have shown that a causal association between gadolinium containing contrast media and NSF is most likely. Therefore, the regulatory authorities have issued guidelines on the use of gadolinium-containing contrast media which have reduced the number of new cases of NSF to almost zero. However, it is for precisely this reason that the greatest care must still be taken to ensure that these guidelines are complied with. The most important factors are renal function, the quantity of gadolinium administered and coexisting diseases such as inflammation. All of these factors crucially influence the quantity of gadolinium released from the chelat in the body. This free gadolinium is thought to be the trigger for NSF. Other important factors are the stability of the gadolinium complex and furthermore the route of its elimination from the body. Partial elimination via the liver might be an additional protective mechanism. In conclusion, despite the NSF risk, contrast-enhanced MRI is a safe diagnostic procedure which can be used reliably and safely even in patients with severe renal failure, and does not necessarily have to be replaced by other methods.

  16. Gadolinium(III-DOTA Complex Functionalized with BODIPY as a Potential Bimodal Contrast Agent for MRI and Optical Imaging

    Directory of Open Access Journals (Sweden)

    Matthias Ceulemans

    2015-11-01

    Full Text Available The synthesis and characterization of a novel gadolinium(III DOTA complex functionalized with a boron-dipyrromethene derivative (BODIPY is described. The assembly of the complex relies on azide diazotransfer chemistry in a copper tube flow reactor. The azide thus formed is coupled directly with an alkyne via click chemistry, resulting into a paramagnetic and luminescent gadolinium(III complex. Luminescent data and relaxometric properties of the complex have been evaluated, suggesting the potential applicability of the complexes as a bimodal contrast agent for magnetic resonance and optical imaging. The complex displays a bright emission at 523 nm with an absorption maximum of 507 nm and high quantum yields of up to 83% in water. The proton relaxivity of the complex measured at 310 K and at frequencies of 20 and 60 MHz had the values of 3.9 and 3.6 s−1·mM−1, respectively.

  17. Stimuli-Responsive Biodegradable Hyperbranched Polymer-Gadolinium Conjugates as Efficient and Biocompatible Nanoscale Magnetic Resonance Imaging Contrast Agents.

    Science.gov (United States)

    Sun, Ling; Li, Xue; Wei, Xiaoli; Luo, Qiang; Guan, Pujun; Wu, Min; Zhu, Hongyan; Luo, Kui; Gong, Qiyong

    2016-04-27

    The efficacy and biocompatibility of nanoscale magnetic resonance imaging (MRI) contrast agents depend on optimal molecular structures and compositions. Gadolinium [Gd(III)] based dendritic macromolecules with well-defined and tunable nanoscale sizes are excellent candidates as multivalent MRI contrast agents. Here, we propose a novel alternate preparation of biodegradable hyperbranched polymer-gadolinium conjugates via a simple strategy and report potentially efficient and biocompatible nanoscale MRI contrast agents for cancer diagnosis. The enzyme-responsive hyperbranched poly(oligo-(ethylene glycol) methacrylate)-gadolinium conjugate (HB-POEGMA-Gd) was prepared via one-step reversible addition-fragmentation chain transfer (RAFT) polymerization and Gd(III) chelating, and the cRGDyK functionalized polymer (HB-POEGMA-cRGD-Gd) was obtained via click chemistry. By using an enzyme similar to lysosomal cathepsin B, hyperbranched conjugates of high molecular weights (MW) (180 and 210 kDa) and nanoscale sizes (38 and 42 nm) were degraded into low MW (25 and 30 kDa) and smaller products (4.8 and 5.2 nm) below the renal threshold. Conjugate-based nanoscale systems had three-fold more T1 relaxivity compared to clinical agent diethylenediaminepentaacetic acid (DTPA)-Gd. Animal studies with the nanoscale system offered greater tumor accumulation and enhanced signal intensity (SI) in mouse U87 tumors of which the greatest activity was conferred by the cRGDyK moiety functionalized hyperbranched conjugate. In vitro cytotoxicity, hemocompatibility and in vivo toxicity studies confirmed no adverse events. This design strategy for multifunctional Gd(III)-labeled biodegradable dendritic macromolecules may have significant potential as future efficient, biocompatible polymeric nanoscale MRI diagnostic contrast agents for cancer.

  18. Effects of iodinated contrast agent, xylocaine and gadolinium concentration on the signal emitted in magnetic resonance arthrography: a samples study

    Directory of Open Access Journals (Sweden)

    Yvana Lopes Pinheiro da Silva

    2015-04-01

    Full Text Available Objective: To investigate the effects of dilution of paramagnetic contrast agent with iodinated contrast and xylocaine on the signal intensity during magnetic resonance arthrography, and to improve the paramagnetic contrast agent concentration utilized in this imaging modality. Materials and Methods: Samples specially prepared for the study with three different concentrations of paramagnetic contrast agent diluted in saline, iodinated contrast agent and xylocaine were imaged with fast spin echo T1-weighted sequences with fat saturation. The samples were placed into flasks and graphical analysis of the signal intensity was performed as a function of the paramagnetic contrast concentration. Results: As compared with samples of equal concentrations diluted only with saline, the authors have observed an average signal intensity decrease of 20.67% for iodinated contrast agent, and of 28.34% for xylocaine. However, the increased gadolinium concentration in the samples caused decrease in signal intensity with all the dilutions. Conclusion: Minimizing the use of iodinated contrast media and xylocaine and/or the use of a gadolinium concentration of 2.5 mmol/L diluted in saline will improve the sensitivity of magnetic resonance arthrography.

  19. Gadolinium detection via in vivo prompt gamma neutron activation analysis following gadolinium-based contrast agent injection: a pilot study in 10 human participants

    International Nuclear Information System (INIS)

    Gadolinium (Gd) based contrast agents are routinely used as part of many magnetic resonance imaging (MRI) procedures. The widespread use of these agents and concerns about Gd toxicity, motivated us to develop a monitoring procedure that could non-invasively measure quantitatively potential retention of toxic free Gd in tissues after use of the agent. We have been developing a method to measure Gd painlessly and non-invasively by prompt gamma neutron activation analysis. In this paper we present the results of a pilot study where we show that we can measure Gd, quantitatively in vivo, in the lower leg muscle of 10 participants. A series of three neutron leg scans were performed. The effective radiation dose for a single neutron leg scan was very low, 0.6 µSv, so multiple scans were possible. Calibration phantom and in vivo detection limits were determined to be identical: 0.58 ppm. Gd was not detectable in muscle prior to exposure to the contrast agent Gadovist®. Gd was detected, at greater than 99% confidence, in 9 participants within 1 h of contrast administration and in 1 participant approximately 3.3 h post-contrast administration. The measured concentrations of Gd ranged from 2.0 to 17.3 ppm (6.9 to 56 uncertainties different from zero). No detectable Gd was measured in any participant in the third neutron scan (conducted 0.7 to 5.9 d post-contrast). The results of this study validate our new measurement technology. This technique could be used as a non-invasive monitoring procedure for exposure and retention of Gd from Gd-based chelates used in MRI. (paper)

  20. Biodistribution of ultra small gadolinium-based nanoparticles as theranostic agent: application to brain tumors.

    Science.gov (United States)

    Miladi, Imen; Duc, Géraldine Le; Kryza, David; Berniard, Aurélie; Mowat, Pierre; Roux, Stéphane; Taleb, Jacqueline; Bonazza, Pauline; Perriat, Pascal; Lux, François; Tillement, Olivier; Billotey, Claire; Janier, Marc

    2013-09-01

    Gadolinium-based nanoparticles are novel objects with interesting physical properties, allowing their use for diagnostic and therapeutic applications. Gadolinium-based nanoparticles were imaged following intravenous injection in healthy rats and rats grafted with 9L gliosarcoma tumors using magnetic resonance imaging and scintigraphic imaging. Quantitative biodistribution using gamma-counting of each sampled organ confirmed that these nanoparticles were rapidly cleared essentially by renal excretion. Accumulation of these nanoparticles in 9L gliosarcoma tumors implanted in the rat brain was quantitated. This passive and long-duration accumulation of gadolinium-based nanoparticles in tumor, which is related to disruption of the blood-brain barrier, is in good agreement with the use of these nanoparticles as radiosensitizers for brain tumors.

  1. Study on the uptake and distribution of gadolinium based contrast agents in biological samples using laser ablation with inductively coupled plasma mass spectroscopy

    International Nuclear Information System (INIS)

    Gadolinium based contrast agents are used for magnetic resonance imaging. After their excretion by medicated patients they reach surface water passing waste water treatment plants where they are not removed sufficiently. The behavior of the contrast agents in the environment and the interaction with organisms was investigated in this work due to the toxicity of the free Gd3+ ion and the associated risks, such as accumulation in the human food chain. In this work, the two elemental analytical imaging methods laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) and synchrotron radiation X-ray fluorescence analysis (SRXRF) have been used to investigate the uptake, distribution, and excretion of Gd-based contrast agents by various biological systems. Both methods were analytically characterized and compared for this application. The detection limits of gadolinium were determined under optimized conditions by LA-ICP-MS and SRXRF. With calibration by remains of dried elemental standard droplets detection limits of 0.78 pg absolute amount of gadolinium (LA-ICP-MS), respectively 89 pg (SRXRF) were reached. Based on filamentous algae as water plants the uptake and the excretion of Gd-based contrast agents were revealed. The dependence on concentration of the contrast agent in the exposition solution and the independence of temporal uptake within one to seven days were studied for duckweed. By LA-ICP-MS gadolinium was quantified in a leaf of cress plant. The verification of the results was performed by SRXRF and ICP-MS after digestion. Furthermore, the uptake and distribution of Gd-based contrast agents in higher organisms (water flea) were observed. The exact location of gadolinium was resolved by three-dimensional μ-computed tomography by the comparison of an exposed with a Gd-free water flea. In all studies, gadolinium was detected in the investigated exposed model organisms. It can be concluded that the contrast agents were taken from the environment.

  2. Gadolinium-Induced Fibrosis.

    Science.gov (United States)

    Todd, Derrick J; Kay, Jonathan

    2016-01-01

    Gadolinium-based contrast agents (GBCAs), once believed to be safe for patients with renal disease, have been strongly associated with nephrogenic systemic fibrosis (NSF), a severe systemic fibrosing disorder that predominantly afflicts individuals with advanced renal dysfunction. We provide a historical perspective on the appearance and disappearance of NSF, including its initial recognition as a discrete clinical entity, its association with GBCA exposure, and the data supporting a causative relationship between GBCA exposure and NSF. On the basis of this body of evidence, we propose that the name gadolinium-induced fibrosis (GIF) more accurately reflects the totality of knowledge regarding this disease. Use of high-risk GBCAs, such as formulated gadodiamide, should be avoided in patients with renal disease. Restriction of GBCA use in this population has almost completely eradicated new cases of this debilitating condition. Emerging antifibrotic therapies may be useful for patients who suffer from GIF.

  3. Intercellular imaging by a polyarginine derived cell penetrating peptide labeled magnetic resonance contrast agent,diethylenetriamine pentaacetic acid gadolinium

    Institute of Scientific and Technical Information of China (English)

    GUO You-min; LIU Min; YANG Jun-le; GUO Xiao-juan; WANG Si-cen; DUAN Xiao-yi; WANG Peng

    2007-01-01

    Background The cellular plasma membrane represents a natural barrier to many exogenous molecules including magnetic resonance (MR) contrast agent. Cell penetrating peptide (CPP) is used to internalize proteins, peptides, and radionuclide. This study was undertaken to assess the value of a new intracellular MR contrast medium, CPP labeled diethylenetriamine pentaacetic acid gadolinium (Gd-DTPA) in molecular imaging in vitro. Methods Fluorescein-5-isothiocyanate (FITC) and Gd-DTPA respectively labeled with CPP (FITC-CPP, Gd-DTPA-CPP) were synthesized by the solid-phase method. Human hepatic cancer cell line-HepG2 was respectively stained by FITC-CPP and FITC to observe the uptake and intracellular distribution. HepG2 was respectively incubated with 100 nmol/ml Gd-DTPA-CPP for 0, 10, 30, 60 minutes, and imaged by MR for studying the relationship between the incubation time and T1WI signal. The cytotoxicity to NIH3T3 fibroblasts cells was measured by 3-(4,5-dimethylthiazol-2-yl)- 2,5-diphenyltetrazolium bromide reduction assay (MTT). Results The molecular weights of CPP labeled imaging agents, which were determined by MALDI mass spectrometry (FITC-CPP MW=2163.34, Gd-DTPA-CPP MW=2285.99), were similar to the calculated molecular weights. Confocal microscopy suggested HepG2 translocated FITC-CPP in cytoplasm and nucleus independent with the incubation temperature. MR images showed HepG2 uptaken Gd-DTPA-CPP had a higher T1 weighted imaging (T1WI) signal, and that the T1WI signal intensity was increasing in a time-dependent manner (r=0.972, P=0.001), while the signal intensity between the cells incubated by Gd-DTPA for 60 minutes and the controlled cells was not significantly different (P=0.225). By MTT, all concentrations from 50 nmol/ml to 200 nmol/ml had no significant (F=0.006, P=1.000) effect on cell viability of mouse NIH3T3 fibroblasts, compared with the control group. Conclusions The newly constructed CPP based on polyarginine can translocate cells by carrying FITC

  4. Folate-targeted gadolinium-lipid-based nanoparticles as a bimodal contrast agent for tumor fluorescent and magnetic resonance imaging.

    Science.gov (United States)

    Nakamura, Taro; Kawano, Kumi; Shiraishi, Kouichi; Yokoyama, Masayuki; Maitani, Yoshie

    2014-01-01

    To enhance tumor magnetic resonance imaging (MRI) signals via the selective accumulation of contrast agents, we prepared folate-modified gadolinium-lipid-based nanoparticles as MRI contrast agents. Folate-modified nanoparticles were comprised of polyethylene glycol (PEG)-lipid, gadolinium diethylenetriamine pentaacetic acid lipid, cationic cholesterol derivatives, folate-conjugated PEG-lipid, and Cy7-PEG-lipid. Folate receptor-mediated cellular nanoparticle association was examined in KB cells, which overexpress the folate receptor. The biodistribution of nanoparticles after their intravenous injection into KB tumor-bearing mice was measured. Mice were imaged through in vivo fluorescence imaging and MRI 24 h after nanoparticle injection, and the intensity enhancement of the tumor MRI signal was evaluated. Increased cellular association of folate-modified nanoparticles was inhibited by excess free folic acid, indicating that nanoparticle association was folate receptor-mediated. Irrespective of folate modification, the amount of nanoparticles in blood 24 h after injection was ca. 10% of the injected dose. Compared with non-modified nanoparticles, folate-modified nanoparticles exhibited significant accumulation in tumor tissues without altering other biodistribution, as well as enhanced tumor fluorescence and MRI signal intensity. The results support the feasibility of MRI- and in vivo fluorescence imaging-based tumor visualization using folate-modified nanoparticles and provide opportunities to develop folate targeting-based imaging applications.

  5. Gadolinium(III Complexes with N-Alkyl-N-methylglucamine Surfactants Incorporated into Liposomes as Potential MRI Contrast Agents

    Directory of Open Access Journals (Sweden)

    Simone Rodrigues Silva

    2015-01-01

    Full Text Available Complexes of gadolinium(III with N-octanoyl-N-methylglucamine (L8 and N-decanoyl-N-methylglucamine (L10 with 1 : 2 stoichiometry were synthesized and characterized by elemental analysis, electrospray ionization-tandem mass spectrometry (ESI-MS, infrared (IR spectroscopy, and molar conductivity measurements. The transverse (r2 and longitudinal (r1 relaxivity protons were measured at 20 MHz and compared with those of the commercial contrasts. These complexes were incorporated in liposomes, resulting in the increase of the vesicle zeta potential. Both the free and liposome-incorporated gadolinium complexes showed high relaxation effectiveness, compared to commercial contrast agent gadopentetate dimeglumine (Magnevist. The high relaxivity of these complexes was attributed to the molecular rotation that occurs more slowly, because of the elevated molecular weight and incorporation in liposomes. The results establish that these paramagnetic complexes are highly potent contrast agents, making them excellent candidates for various applications in molecular MR imaging.

  6. Parallel Comparative Studies on Mouse Toxicity of Oxide Nanoparticle- and Gadolinium-Based T1 MRI Contrast Agents.

    Science.gov (United States)

    Chen, Rui; Ling, Daishun; Zhao, Lin; Wang, Shuaifei; Liu, Ying; Bai, Ru; Baik, Seungmin; Zhao, Yuliang; Chen, Chunying; Hyeon, Taeghwan

    2015-12-22

    Magnetic resonance imaging (MRI) contrast agents with high relaxivity are highly desirable because they can significantly increase the accuracy of diagnosis. However, they can be potentially toxic to the patients. In this study, using a mouse model, we investigate the toxic effects and subsequent tissue damage induced by three T1 MRI contrast agents: gadopentetate dimeglumine injection (GDI), a clinically used gadolinium (Gd)-based contrast agent (GBCAs), and oxide nanoparticle (NP)-based contrast agents, extremely small-sized iron oxide NPs (ESIONs) and manganese oxide (MnO) NPs. Biodistribution, hematological and histopathological changes, inflammation, and the endoplasmic reticulum (ER) stress responses are evaluated for 24 h after intravenous injection. These thorough assessments of the toxic and stress responses of these agents provide a panoramic description of safety concerns and underlying mechanisms of the toxicity of contrast agents in the body. We demonstrate that ESIONs exhibit fewer adverse effects than the MnO NPs and the clinically used GDI GBCAs, providing useful information on future applications of ESIONs as potentially safe MRI contrast agents.

  7. Adverse allergic reactions to linear ionic gadolinium-based contrast agents: experience with 194, 400 injections

    International Nuclear Information System (INIS)

    Aim: To report the authors' experience with the administration of four gadolinium-based contrast agents (GBCA; gadopentetate dimeglumine, gadofosveset trisodium, gadoxetate disodium and gadobenate dimeglumine) in a large study population at a single, large academic medical centre. Materials and methods: The institutional review board approved this retrospective study in which data in the electronic incident reporting system were searched. A total of 194, 400 intravenous administrations of linear ionic GBCAs were assessed for the incidence of adverse reactions and risk factors from 1 January 2007 to 14 January 2014. The severity of reactions (mild, moderate, and severe), patient type (outpatients, inpatients, and emergency), examination type, and treatment options were also investigated. Results: In total, 204/194400 (0.1%) patients (mean age 45.7 ± 14.9) showed adverse reactions, consisting of 6/746 (0.80%), 10/3200 (0.31%), 14/6236 (0.22%) and 174/184218 (0.09%), for gadofosveset trisodium, gadoxetate disodium, gadobenate dimeglumine, and gadopentetate dimeglumine, respectively. An overall significant difference was found between different GBCAs regarding the total number of reactions (p < 0.0001). When comparing the GBCAs together, significant differences were found between gadofosveset trisodium versus gadopentetate dimeglumine (p < 0.0001), gadofosveset trisodium versus gadobenate dimeglumine (p = 0.0051), gadoxetate disodium versus gadopentetate dimeglumine (p < 0.0001) and gadopentetate dimeglumine versus gadobenate dimeglumine (p = 0.0013). Rate of reaction was higher in females (F: 146/113187, 0.13%/M: 58/81213, 0.07%; p < 0.0001). Rate of reactions was higher in outpatient (180/158885, 0.11%), emergency (10/10413, 0.10%), and inpatients (14/25102, 0.05%), respectively (p < 0.0001). Most of the patients had mild symptoms 171/204 (83.8%). Abdomen–pelvis, liver, and thoracic examinations had highest rates of reactions (0.17 versus 0

  8. Non-Specific Zn2+ Ion Sensing Using Ultrasmall Gadolinium Oxide Nanoparticle as a Magnetic Resonance Imaging Contrast Agent.

    Science.gov (United States)

    Bony, Badrul Alam; Baeck, Jong Su; Chang, Yongmin; Lee, Gang Ho

    2016-03-01

    The gadolinium oxide (Gd2O3) nanoparticles are well-known potential candidates for a positive magnetic resonance imaging (MRI) contrast agent owing to their large longitudinal water proton relaxivity (r1) value with r2/r1 ratio close to one (r2 = transverse water proton relaxivity). In addition they may be used to sense metal ions because their r1 and r2 values can be altered in the presence of metal ions. This may allow us to study metabolic processes involving metal ions and to diagnose disease related to abnormal concentrations of metal ions in the body in a non-invasive way. In this study ultrasmall Gd2O3 nanoparticles were for the first time applied to non-specifically sense Zn2+ ions in aqueous solution. We explored this by measuring r1 and r2 values in the presence of Zn2+ ions in solution.

  9. [Gadolinium as an alternative radiocontrast agent in patients with allergy to iodine-based contrast provide for useful diagnostic imagings and safely treatment of biliary tract diseases].

    Science.gov (United States)

    Natsume, Makoto; Sano, Hitoshi; Fukusada, Shigeki; Kachi, Kenta; Inoue, Tadahisa; Anbe, Kaiki; Nishie, Hirotada; Nishi, Yuji; Yoshimura, Norihiro; Mizushima, Takashi; Okumura, Fumihiro; Miyabe, Katsuyuki; Naitoh, Itaru; Hayashi, Kazuki; Nakazawa, Takahiro

    2013-05-01

    Diagnosis and treatment of biliary tract disease requires an intraductal radiocontrast agent. Although iodine-based contrast medium is commonly used, some patients show severe allergy to iodinated contrast agent. We have retrospectively reviewed the usefulness and safety of gadolinium as an alternative radiocontrast agent in 3 patients with allergy to iodine-based contrast medium in the diagnosis and treatment of biliary tract diseases. In case 1, percutaneous transhepatic biliary drainage and cholangiography were performed successfully and it was possible to visualize an intrahepatic bile duct stone. Percutaneous transhepatic cholangioscopic lithotomy was performed and the intrahepatic bile duct stone was removed. In case 2, endoscopic biliary lithotripsy was performed. In case 3, percutaneous transhepatic cholangiography and cholangioscopy provided a diagnosis of moderately differentiated carcinoma. He underwent pancreatoduodenectomy. Postoperative cholangiograms were also obtained successfully. Gadolinium contrast agent is an alternative to iodine-based cholangiography for the patients with allergy to iodine.

  10. Nephrogenic systemic fibrosis after application of gadolinium-based contrast agents - a status paper; Nephrogene systemische Fibrose nach Anwendung gadoliniumhaltiger Kontrastmittel - ein Statuspapier zum aktuellen Stand des Wissens

    Energy Technology Data Exchange (ETDEWEB)

    Heinrich, M.; Uder, M. [Erlangen-Nuernberg Univ., Erlangen (Germany). Inst. fuer Radiologie

    2007-06-15

    Recently the association of a rare disease named ''nephrogenic systemic fibrosis'' (NSF) with the administration of gadolinium-containing contrast media, especially gadodiamide (Omniscan, GE-Healthcare), was described. NSF is a scleroderma-like disease characterised by widespread tissue fibrosis. Until now, NSF cases were observed only in patients with kidney disease. Almost all patients were suffering from chronic renal insufficiency, 90 % of them required renal replacement therapy. The true incidence of the disease is unknown. First retrospective analyses of selected collectives of patients with end-stage renal disease showed 2 - 5 % cases of NSF after administration of Gadolinium-containing contrast agents with an odds ratio of 20 - 50 in comparison to non-exposed controls. NSF is a serious adverse reaction, which may result in severe disabilities and even death. Therefore all radiologists applying gadolinium-based contrast agents should be informed about this disease and the recent recommendations for its prevention. On the basis of the published data, Omniscan should not be used in patients with severe renal impairment (GFR < 30 ml/min/1.73 m{sup 2}) and those who have had or are undergoing liver transplantation. In neonates and infants up to 1 year of age, Omniscan should only be used after careful consideration. Also the other gadolinium-based contrast agents should be used in high-risk patients only after careful consideration using the lowest dose possible.

  11. GADOLINIUM(Gd)-BASED and Ion Oxide Nanoparticle Contrast Agents for Pre-Clinical and Clinical Magnetic Resonance Imaging (mri) Research

    Science.gov (United States)

    Ng, Thian C.

    2012-06-01

    It is known that one strength of MRI is its excellent soft tissue discrimination. It naturally provides sufficient contrast between the structural differences of normal and pathological tissues, their spatial extent and progression. However, to further extend its applications and enhance even more contrast for clinical studies, various Gadolinium (Gd)-based contrast agents have been developed for different organs (brain strokes, cancer, cardio-MRI, etc). These Gd-based contrast agents are paramagnetic compounds that have strong T1-effect for enhancing the contrast between tissue types. Gd-contrast can also enhance magnetic resonance angiography (CE-MRA) for studying stenosis and for measuring perfusion, vascular susceptibility, interstitial space, etc. Another class of contrast agents makes use of ferrite iron oxide nanoparticles (including Superparamagnetic Ion Oxide (SPIO) and Ultrasmall Superparamagnetic Iron Oxide (USPIO)). These nanoparticles have superior magnetic susceptibility effect and produce a drop in signal, namely in T2*-weighted images, useful for the determination of lymph nodes metastases, angiogenesis and arteriosclerosis plaques.

  12. Dermal inorganic gadolinium concentrations: evidence for in vivo transmetallation and long-term persistence in nephrogenic systemic fibrosis

    DEFF Research Database (Denmark)

    Abraham, J.L.; Thakral, C.; Skov, L.;

    2008-01-01

    Background Gadolinium (Gd)-based magnetic resonance contrast agents (GBMCA), including gadodiamide, have been identified as the probable causative agents of the serious disease, nephrogenic systemic fibrosis (NSF). Objectives To investigate retained Gd-containing deposits in skin biopsies from...

  13. Dermal inorganic gadolinium concentrations: evidence for in vivo transmetallation and long-term persistence in nephrogenic systemic fibrosis

    DEFF Research Database (Denmark)

    Abraham, J L; Thakral, C; Skov, L;

    2008-01-01

    BACKGROUND: Gadolinium (Gd)-based magnetic resonance contrast agents (GBMCA), including gadodiamide, have been identified as the probable causative agents of the serious disease, nephrogenic systemic fibrosis (NSF). OBJECTIVES: To investigate retained Gd-containing deposits in skin biopsies from...

  14. Diffusion weighted MR imaging in patients with HCC and liver cirrhosis after administration of different gadolinium contrast agents: Is it still reliable?

    International Nuclear Information System (INIS)

    Purpose: Diffusion weighted imaging (DWI) is an emerging technique for abdominal MR and usually performed before intravenous contrast injection. Recent studies performed in patients with normal liver function have shown that DWI can be performed after gadolinium administration. Aim of this study was to compare DWI before and after administration of different gadolinium compounds in patients with HCC and liver cirrhosis. Materials and methods: 15 patients with known HCC and liver cirrhosis underwent liver MRI at 1.5 T (Magnetom Avanto, Siemens) including DWI on day 1 before and after administration of gadobutrol (Gadovist®) and on day 2 after administration of EOB-Gadolinium-DTPA (Primovist®). Signal to noise ratios (SNR) and contrast to noise ratios (CNR) of HCC lesions were determined for all DWI data sets. Furthermore, ADC values were compared using a Wilcoxon test. A p-value 2). Similarly, no significant differences were found for CNR (average values:34.4 vs. 32.3 vs. 30.7; b = 50 s/mm2) nor for ADC-values (mean: 1.5 vs. 1.4 vs. 1.5 × 10−3 mm2/s) of HCC. Conclusion: There is no significant difference regarding DWI in patients with cirrhosis before and after contrast injection. Hence, it is reliable to run DWI after gadolinium either as an alternative for unsuccessful pre-contrast DWI or as a gap filler to spare time in EOB-Gadolinium-DTPA imaging.

  15. Evaluation of Visibility of Celiac and Renal Arteries on Digital Subtraction Angiography Using Iodine, Gadolinium and Carbon dioxide Contrast Agents: A Porcine Experimental Study

    OpenAIRE

    SHINMURA, Kohei; Baba, Yasutaka; HAYASHI, SADAO; Ikeda, Shunichiro; MOTOMURA, Eriko; KIYAO, Yutaro; NAKAJO, Masayuki; 新村, 耕平; 馬場, 康貴; 林, 完勇; 池田, 俊一郎; 本村, 江利子; 木屋尾, 祐太郎; 中條, 政敬

    2014-01-01

    Purpose: To examine the differences in visibility of celiac, renal arteries and nephrogram on digital subtraction angiography (DSA)among 3 different contrast agents in a porcine model.Methods: Six swine underwent percutaneous catheterization and DSA. Celiac and bilateral renal DSA angiograms with iodine,gadolinium and CO2 were obtained by the same injection protocols for each swine. The arterial diameter, contrast enhancement andrenal density were measured using the Image-J software. Assessme...

  16. Study of suspending agents for gadolinium(III)-exchanged hectorite. An oral magnetic resonance imaging contrast agent

    International Nuclear Information System (INIS)

    Clays modified with paramagnetic ions have been shown to be effective magnetic resonance imaging contrast agents. The efficacy in part relies on the suspension of the small clay particles in aqueous solution. In this study a series of macromolecules were eveluated as suspending agents for Gd(III) ion exchanged hectorite clay in water. The room temperature relaxivities for the Gd-hectorite clays were enhanced by the addition of poly(ethylene oxide), poly(ethylene glycol), cyclodextrins, and cholic acid to aqueous suspensions. Additionally, there was no evidence of free Gd(III) in solution in the presence of these suspending agents. In contrast the combination of alginic acid or poly(sodium 4-styrenesulfonate) with the clays resulted in release of the Gd(III) into solution. Xanthan gum, which is often used as an emulsifier and stabilizer in food products, forms a viscous suspension but also reacts with free Gd(III) ions. 25 refs., 10 figs., 2 tabs

  17. Preclinical animal acute toxicity studies of new developed MRI contrast agent based on gadolinium

    Science.gov (United States)

    Nam, I. F.; Zhuk, V. V.

    2015-04-01

    Acute toxicity test of new developed MRI contrast agent based on disodium salt of gadopentetic acid complex were carried out on Mus musculus and Sprague Dawley rats according to guidelines of preclinical studies [1]. Groups of six animals each were selected for experiment. Death and clinical symptoms of animals were recorded during 14 days. As a result the maximum tolerated dose (MTD) for female mice is 2.8 mM/kg of body weight, male mice - 1.4 mM/kg, female rats - 2.8 mM/kg, male rats - 5.6 mM/kg of body weight. No Observed Adverse Effect Dose (NOAEL) for female mice is 1.4 mM/kg, male mice - 0.7 mM/kg, male and female rats - 0.7 mM/kg. According to experimental data new developed MRI contrast agent based on Gd-DTPA complex is low-toxic.

  18. Contrast-enhanced voiding urosonography phantom study: intravenous iodinated and gadolinium-based contrast agents may cause false-negative results in assessment of vesicoureteral reflux in children

    Energy Technology Data Exchange (ETDEWEB)

    Veldhoen, Simon; Sauer, Alexander; Gassenmaier, Tobias; Petritsch, Bernhard; Herz, Stefan; Blanke, Philipp; Bley, Thorsten A.; Wirth, Clemens [University Hospital Wuerzburg, Department of Diagnostic and Interventional Radiology, Wuerzburg (Germany); Derlin, Thorsten [University Hospital Wuerzburg, Department of Diagnostic and Interventional Radiology, Wuerzburg (Germany); Hannover Medical School, Department of Nuclear Medicine, Hannover (Germany)

    2015-06-15

    Contrast-enhanced voiding urosonography (ce-VUS) is commonly requested simultaneously to other diagnostic imaging necessitating intravenous contrast agents. To date there is limited knowldedge about intravesical interactions between different types of contrast agents. To assess the effect of excreted intravenous iodinated and gadolinium-based contrast agents on the intravesical distribution of ultrasound contrast within contrast-enhanced voiding urosonography. Iodinated (iomeprol, iopamidol) and gadolinium-based (gadoterate meglumine) contrast agents were diluted to bladder concentration and injected into balloons filled with saline solution. CT scans were performed to assess the contrast distribution in these phantoms. Regions of interest were placed at the top and bottom side of each balloon and Hounsfield units (HU) were measured. Three other balloons were filled with saline solution and contrast media likewise. The ultrasound contrast agent sulphur hexafluoride was added and its distribution was assessed using sonography. MDCT scans showed a separation of two liquid layers in all bladder phantoms with the contrast layers located at the bottom and the saline solution at the top. Significant differences of the HU measurements at the top and bottom side were observed (P < 0.001-0.007). Following injection of ultrasound contrast agent, US showed its distribution exclusively among the saline solution. False-negative results of contrast-enhanced voiding urosonography may occur if it is performed shortly after imaging procedures requiring intravenous contrast. (orig.)

  19. Gadolinium-based contrast agents and nephrogenic systemic fibrosis%含钆对比剂与肾源性系统性纤维化

    Institute of Scientific and Technical Information of China (English)

    高华; 曾新伟; 李冬梅

    2011-01-01

    @@ 含钆(gadolinium,Gd)对比剂(gadolinium-based contrast agents,GBCA) 是临床上应用最多的MRI对比剂,全世界范围内已经使用超过2亿次.但随着对肾源性系统性纤维化(nephrogenic systemic fibrosis,NSF) 的不断报道,越来越多的证据表明NSF的发病与GBCA 的使用有着密切联系,在肾功能不全患者如何使用GBCA已受到越来越多地关注.虽然国内对NSF的病例报道较少,但仍需要密切关注相关研究进展,从而可合理选择医学影像检查方式,尽量减少NSF的发生.

  20. Gadolinium-labeled dendronized gold nanoparticles as new targeted MRI contrast agent

    Science.gov (United States)

    Pan, Hongmu; Daniel, Marie-Christine

    2010-04-01

    Early diagnosis is critical for positive outcome of cancer treatments. In many cases, lives would be saved if the tumor could be detected at a very early stage. Nanoparticles have the property of passively targeting tumor sites due to their enhanced permeation and retention (EPR) effect. Thus they can play a critical role in improving the ability to find cancer in its earliest and most treatable stages. Furthermore magnetic resonance imaging is one of the most precise techniques for cancer screening since it can show 3D images of the tumors. For a better enhancement of the sensitivity of this method, MRI contrast agent (DOTA)Gd was attached to poly(propylene imine) dendrons of third generation and the obtained dendrons were used for modification of gold nanoparticles.

  1. Gadolinium Nanoparticles Conjugated with Therapeutic Bifunctional Chelate as a Potential T1 Theranostic Magnetic Resonance Imaging Agent.

    Science.gov (United States)

    Kang, Min-Kyoung; Lee, Gang Ho; Jung, Ki-Hye; Jung, Jae-Chang; Kim, Hee-Kyung; Kim, Yeon-Hee; Lee, Jongmin; Ryeom, Hun-Kyu; Kim, Tae-Jeong; Chang, Yongmin

    2016-05-01

    This work is directed toward the synthesis of two types of gadolinium oxide nanoparticles (Gd-oxide NPs), abbreviated as Gd@SiO2-DO3A and Gd@SiO2-DO2A-BTA, with diameters of 50-60 nm. The synthesis involves sequential coating of Gd-oxide NPs with tetraethyl orthosilicate (TEOS) and (3-aminopropyl) triethoxysilane (APTES), followed by functionalization of the aminopropylsilane group with 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA) or 1,4,7,10-tetraazacyclododecane-1,4,7-trisacetic acid conjugates of benzothiazoles (DO3A-BTA). Gd@SiO2-DO3A and Gd@SiO2-DO2A-BTA exhibit high water solubility and colloidal stability. The r1 relaxivities of both Gd@SiO2-DO3A and Gd@SiO2-DO2A-BTA are higher than those of the corresponding low-molecular-weight magnetic resonance imaging contrast agents (MRI CAs), and their r2/r1 ratios are close to 1, indicating that both can be used as potential T1 MRI CAs. Biodistribution studies demonstrated that Gd@SiO2-DO2A-BTA was excreted via both hepatobiliary and renal pathways. Gd@SiO2-DO2A-BTA exhibits a strong intracellular uptake property in a series of tumor cell lines, and has significant anticancer characteristics against cell lines such as SK-HEP-1, MDA-MB-231, HeLa, and Hep-3B.

  2. Gadolinium Nanoparticles Conjugated with Therapeutic Bifunctional Chelate as a Potential T1 Theranostic Magnetic Resonance Imaging Agent.

    Science.gov (United States)

    Kang, Min-Kyoung; Lee, Gang Ho; Jung, Ki-Hye; Jung, Jae-Chang; Kim, Hee-Kyung; Kim, Yeon-Hee; Lee, Jongmin; Ryeom, Hun-Kyu; Kim, Tae-Jeong; Chang, Yongmin

    2016-05-01

    This work is directed toward the synthesis of two types of gadolinium oxide nanoparticles (Gd-oxide NPs), abbreviated as Gd@SiO2-DO3A and Gd@SiO2-DO2A-BTA, with diameters of 50-60 nm. The synthesis involves sequential coating of Gd-oxide NPs with tetraethyl orthosilicate (TEOS) and (3-aminopropyl) triethoxysilane (APTES), followed by functionalization of the aminopropylsilane group with 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA) or 1,4,7,10-tetraazacyclododecane-1,4,7-trisacetic acid conjugates of benzothiazoles (DO3A-BTA). Gd@SiO2-DO3A and Gd@SiO2-DO2A-BTA exhibit high water solubility and colloidal stability. The r1 relaxivities of both Gd@SiO2-DO3A and Gd@SiO2-DO2A-BTA are higher than those of the corresponding low-molecular-weight magnetic resonance imaging contrast agents (MRI CAs), and their r2/r1 ratios are close to 1, indicating that both can be used as potential T1 MRI CAs. Biodistribution studies demonstrated that Gd@SiO2-DO2A-BTA was excreted via both hepatobiliary and renal pathways. Gd@SiO2-DO2A-BTA exhibits a strong intracellular uptake property in a series of tumor cell lines, and has significant anticancer characteristics against cell lines such as SK-HEP-1, MDA-MB-231, HeLa, and Hep-3B. PMID:27305813

  3. Induction of a type I interferon signature in normal human monocytes by gadolinium-based contrast agents: comparison of linear and macrocyclic agents.

    Science.gov (United States)

    Wermuth, P J; Jimenez, S A

    2014-01-01

    The gadolinium-based contrast agent (GdBCA) Omniscan activates human macrophages through Toll-like receptor (TLR)-4 and TLR-7 signalling. To explore the mechanisms responsible we compared the ability of linear and macrocyclic GdBCA to induce a type I interferon signature and a proinflammatory/profibrotic phenotype in normal human monocytes in vitro. Expression of genes associated with type I interferon signalling and inflammation and production of their corresponding proteins were determined. Both linear and macrocyclic GdBCA stimulated expression of multiple type I interferon-regulated genes and the expression of numerous chemokines, cytokines and growth factors in normal human peripheral blood monocytes. There was no correlation between the magnitude of the measured response and the Gd chelate used. To explore the mechanisms responsible for GdBCA induction of fibrosis in nephrogenic systemic fibrosis (NSF) in vitro, normal human dermal fibroblasts were incubated with GdBCA-treated monocyte culture supernatants and the effects on profibrotic gene expression were examined. Supernatants from monocytes exposed to all GdBCA stimulated types I and III collagen, fibronectin and α-smooth muscle actin (α-SMA) expression in normal dermal fibroblasts. The results indicate that the monocyte activation induced by GdBCA may be the initial step in the development of GdBCA associated fibrosis in NSF.

  4. Terbium-doped gadolinium oxide nanoparticles prepared by laser ablation in liquid for use as a fluorescence and magnetic resonance imaging dual-modal contrast agent.

    Science.gov (United States)

    Chen, Fei; Chen, Min; Yang, Chuan; Liu, Jun; Luo, Ningqi; Yang, Guowei; Chen, Dihu; Li, Li

    2015-01-14

    Dual-modal lanthanide-doped gadolinium nanoparticles (NPs), which exhibit an excellent magnetic resonance imaging (MRI) spatial resolution and high fluorescence imaging (FI) sensitivity, have attracted tremendous attention in biotechnology and nanomedicine applications. In this paper, terbium (Tb) ion doped gadolinium oxide (Gd2O3:Tb) NPs with varied Tb concentrations were synthesized by a laser ablation in liquid (LAL) method. The characterization of the structure, morphology, and composition shows that these NPs are spherical with excellent crystallinity. The effects of Tb ion concentration on the visible green fluorescence and longitudinal relaxivity were investigated, indicating that the fluorescence properties were significantly influenced by the Tb ion concentration, but all samples were still efficient T1-weighted contrast agents. Furthermore, the optimum Tb doping concentration was determined to be 1%. The cell viability, cellular fluorescence imaging and in vivo MRI of this dual-modal nano-probe were studied, with the results revealing that the Gd2O3:Tb NPs did not have a significant cytotoxic effect, making them good candidates for use as a dual-modal contrast agent for MRI and fluorescence imaging.

  5. Effect of ionic interaction between a hyperpolarized magnetic resonance chemical probe and a gadolinium contrast agent for the hyperpolarized lifetime after dissolution

    Science.gov (United States)

    Takakusagi, Yoichi; Inoue, Kaori; Naganuma, Tatsuya; Hyodo, Fuminori; Ichikawa, Kazuhiro

    2016-09-01

    In hyperpolarization of 13C-enriched magnetic resonance chemical probes in the solid-state, a trace amount of gadolinium (Gd) contrast agent can be used to maximize polarization of the 13C nuclear spins. Here, we report systematic measurement of the spin-lattice relaxation time (T1) and enhancement level of 13C-enriched chemical probes in the presence of various Gd contrast agents in the liquid-state after dissolution. Using two different 13C probes having opposite electric charges at neutral pH, we clearly show the T1 of hyperpolarized 13C was barely affected by the use of a Gd complex that displays repulsive interaction with the 13C probe in solution, whilst T1 was drastically shortened when there was ionic attraction between probe and complex.

  6. A Reactive Behavior Agent: Including Emotions into a Video Game

    Directory of Open Access Journals (Sweden)

    A. L. Laureano-Cruces

    2012-10-01

    Full Text Available Why we have emotions and how they influence human behavior are two questions we constantly ask ourselves.According to researchers in the field, there are two kinds of information that the person receives to make a decision.This information is integrated to generate a whole. One comes from ourselves it is proprioceptive and refers toemotions; the other one is external, it comes from the environment. Thus, emotions are immersed in different areas ofa person’s life, including social, functional, and cognitive aspects. It has an important role in the decision-makingprocess. It is on this last point that this paper focuses its approach, which consists of including a cognitive structure ofemotions in a reactive behavior in order to enrich behavior, including the information generated through internalevaluation of the external physical stimuli. Our work is based on the OCC theory (named after the name of its authors:Ortony, Collins and Clore. This theory proposes that a decision-making process is affected through differentperspectives: a goals and events, b agents and their actions, and c objects and their capacity for attraction. Thecase study is situated within a scenario that represents an approach that seeks to include a module of emotions withinthe design of the architecture of a videogame.

  7. 磁共振钆造影剂纳米制剂的研究进展%Progress in research of nanomedicine-based gadolinium contrast agents for magnetic resonance imaging

    Institute of Scientific and Technical Information of China (English)

    柳盈盈; 范田园

    2013-01-01

    Magnetic resonance imaging (MRI) is a powerful and non-invasive imaging technique that provides very high resolution. It shows both physiological and anatomical details to a certain extent and has no ionizing radiation. However, its resolution cannot meet the clinical needs in some cases, so contrast agents should be used to achieve higher resolution MR images. Data show that about 30% of MRI exams need the use of contrast agents. Gadolinium chelates is one of the most common clinical MRI contrast agents. Traditional gadolinium contrast agents lack specific targeting property, have short half-life and low relaxivity, and cause side effects when large doses of them are used. Recently, the field of nanomedicine-based contrast agents holds great promise for overcoming many traditional hurdles of contrast agents including specific targeting property, half-life, relaxivity, and toxicities. These nanomedicine-based contrast agents mainly include liposomes, dendrimers, micelles, nanoparticles, nanotubes and fullerenes.%磁共振成像作为一种有效的非侵入性的成像技术,具有较高的分辨率,在一定程度上可以显示生理学和解剖学细节,且没有电离辐射.但是磁共振成像的分辨率在某些情况下还不能满足临床需要,所以在某些磁共振检查中需要使用磁共振造影剂以达到增强造影的目的.据文献报道大约30%的磁共振检查需要使用造影剂.钆螯合物是临床上常用的一种磁共振造影剂.传统的钆造影剂缺乏靶向性、半衰期较短、弛豫效能较低且大量使用可导致毒副作用等.目前,已有较多文献报道将钆造影剂制备成纳米制剂后可以使其具有靶向性,延长血中滞留时间,提高弛豫效能,减少总剂量从而降低毒副作用等.钆造影剂纳米制剂主要包括:脂质体、树形分子、胶束、纳米粒、碳纳米管和富勒烯等.

  8. 7 CFR 4290.1620 - Functions of agents, including Central Registration Agent, Selling Agent and Fiscal Agent.

    Science.gov (United States)

    2010-01-01

    ..., DEPARTMENT OF AGRICULTURE RURAL BUSINESS INVESTMENT COMPANY (âRBICâ) PROGRAM Financial Assistance for RBICs (Leverage) Funding Leverage by Use of Guaranteed Trust Certificates (âtcsâ) § 4290.1620 Functions of agents... to: (i) Establish performance criteria for Poolers. (ii) Monitor and evaluate the financial...

  9. 13 CFR 107.1620 - Functions of agents, including Central Registration Agent, Selling Agent and Fiscal Agent.

    Science.gov (United States)

    2010-01-01

    ... Assistance SMALL BUSINESS ADMINISTRATION SMALL BUSINESS INVESTMENT COMPANIES SBA Financial Assistance for Licensees (Leverage) Funding Leverage by Use of Sba-Guaranteed Trust Certificates (âtcsâ) § 107.1620... Fiscal Agent to: (i) Establish performance criteria for Poolers. (ii) Monitor and evaluate the...

  10. Poly(acrylic acid) Bridged Gadolinium Metal-Organic Framework-Gold Nanoparticle Composites as Contrast Agents for Computed Tomography and Magnetic Resonance Bimodal Imaging.

    Science.gov (United States)

    Tian, Chixia; Zhu, Liping; Lin, Feng; Boyes, Stephen G

    2015-08-19

    Imaging contrast agents for magnetic resonance imaging (MRI) and computed tomography (CT) have received significant attention in the development of techniques for early stage cancer diagnosis. Gadolinium (Gd)(III), which has seven unpaired electrons and a large magnetic moment, can dramatically influence the water proton relaxation and hence exhibits excellent MRI contrast. On the other hand, gold (Au), which has a high atomic number and high X-ray attenuation coefficient, is an ideal contrast agent candidate for X-ray-based CT imaging. Gd metal-organic framework (MOF) nanoparticles with tunable size, high Gd(III) loading and multivalency can potentially overcome the limitations of clinically utilized Gd chelate contrast agents. In this work, we report for the first time the integration of GdMOF nanoparticles with gold nanoparticles (AuNPs) for the preparation of a MRI/CT bimodal imaging agent. Highly stable hybrid GdMOF/AuNPs composites have been prepared by using poly(acrylic acid) as a bridge between the GdMOF nanoparticles and AuNPs. The hybrid nanocomposites were then evaluated in MRI and CT imaging. The results revealed high longitudinal relaxivity in MRI and excellent CT imaging performance. Therefore, these GdMOF/AuNPs hybrid nanocomposites potentially provide a new platform for the development of multimodal imaging probes.

  11. Dual-mode T1 and T2 magnetic resonance imaging contrast agent based on ultrasmall mixed gadolinium-dysprosium oxide nanoparticles: synthesis, characterization, and in vivo application

    Science.gov (United States)

    Tegafaw, Tirusew; Xu, Wenlong; Wasi Ahmad, Md; Baeck, Jong Su; Chang, Yongmin; Bae, Ji Eun; Chae, Kwon Seok; Kim, Tae Jeong; Lee, Gang Ho

    2015-09-01

    A new type of dual-mode T1 and T2 magnetic resonance imaging (MRI) contrast agent based on mixed lanthanide oxide nanoparticles was synthesized. Gd3+ (8S7/2) plays an important role in T1 MRI contrast agents because of its large electron spin magnetic moment resulting from its seven unpaired 4f-electrons, and Dy3+ (6H15/2) has the potential to be used in T2 MRI contrast agents because of its very large total electron magnetic moment: among lanthanide oxide nanoparticles, Dy2O3 nanoparticles have the largest magnetic moments at room temperature. Using these properties of Gd3+ and Dy3+ and their oxide nanoparticles, ultrasmall mixed gadolinium-dysprosium oxide (GDO) nanoparticles were synthesized and their potential to act as a dual-mode T1 and T2 MRI contrast agent was investigated in vitro and in vivo. The D-glucuronic acid coated GDO nanoparticles (davg = 1.0 nm) showed large r1 and r2 values (r2/r1 ≈ 6.6) and as a result clear dose-dependent contrast enhancements in R1 and R2 map images. Finally, the dual-mode imaging capability of the nanoparticles was confirmed by obtaining in vivo T1 and T2 MR images.

  12. Gadolinium and nephrogenic systemic fibrosis: an update.

    Science.gov (United States)

    Weller, Alex; Barber, Joy L; Olsen, Oystein E

    2014-10-01

    Nephrogenic systemic fibrosis (NSF) is a multisystem disease seen exclusively in patients with renal impairment. It can be severely debilitating and sometimes fatal. There is a strong association with gadolinium-based contrast agents used in magnetic resonance imaging (MRI). Risk factors include renal impairment and proinflammatory conditions, e.g. major surgery and vascular events. Although there is no single effective treatment for NSF, the most successful outcomes are seen following restoration of renal function, either following recovery from acute kidney injury or following renal transplantation. There have been ten biopsy-proved pediatric cases of NSF, with no convincing evidence that children have a significantly altered risk compared with the adult population. After implementation of guidelines restricting the use of gadolinium-based contrast agents in at-risk patients, there has been a sharp reduction in new cases and no new reports in children. Continued vigilance is recommended: screening for renal impairment, use of more stable gadolinium chelates, consideration of non-contrast-enhanced MRI or alternative imaging modalities where appropriate.

  13. Radioprotection: mechanism and radioprotective agents including honeybee venom

    International Nuclear Information System (INIS)

    Since 1949, a great deal of research has been carried on the radioprotective action of chemical substances. These substances have shown to reduce mortality when administered to animals prior to exposure to a lethal dose of radiation. This fact is of considerable importance since it permits reduction of radiation-induced damage and provides prophylactic treatment for the damaging effects produced by radiotherapy. The following radioprotection mechanisms were proposed: free radical scavenger, repair by hydrogen donation to target molecules formation of mixed disulfides, delay of cellular division and induction of hypoxia in the tissues. Radioprotective agents have been divided into four major groups: the thiol compounds, other sulfur compounds, pharmacological agents (anesthetic drugs, analgesics, tranquilizers, etc.) and other radioprotective agents (WR-1065, WR-2721, vitamins C and E, glutathione, etc.). Several studies revealed the radioprotective action of Apis mellifera honeybee venom as well as that of its components mellitin and histamine. Radioprotective activity of bee venom involves mainly the stimulation of the hematopoietic system. In addition, release of histamine and reduction in oxygen tension also contribute to the radioprotective action of bee venom. (author)

  14. Radioprotection: mechanism and radioprotective agents including honeybee venom

    Energy Technology Data Exchange (ETDEWEB)

    Varanda, E.A.; Tavares, D.C. [UNESP, Araraquara, SP (Brazil). Escola de Ciencias Farmaceuticas. Dept. de Ciencias Biologicas

    1998-07-01

    Since 1949, a great deal of research has been carried on the radioprotective action of chemical substances. These substances have shown to reduce mortality when administered to animals prior to exposure to a lethal dose of radiation. This fact is of considerable importance since it permits reduction of radiation-induced damage and provides prophylactic treatment for the damaging effects produced by radiotherapy. The following radioprotection mechanisms were proposed: free radical scavenger, repair by hydrogen donation to target molecules formation of mixed disulfides, delay of cellular division and induction of hypoxia in the tissues. Radioprotective agents have been divided into four major groups: the thiol compounds, other sulfur compounds, pharmacological agents (anesthetic drugs, analgesics, tranquilizers, etc.) and other radioprotective agents (WR-1065, WR-2721, vitamins C and E, glutathione, etc.). Several studies revealed the radioprotective action of Apis mellifera honeybee venom as well as that of its components mellitin and histamine. Radioprotective activity of bee venom involves mainly the stimulation of the hematopoietic system. In addition, release of histamine and reduction in oxygen tension also contribute to the radioprotective action of bee venom. (author)

  15. Gadolinium-1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid conjugate of arabinogalactan as a potential liver-targeting magnetic resonance imaging contrast agent.

    Science.gov (United States)

    Xiao, Yan; Xue, Rong; You, Tianyan; Li, Xiaojing; Pei, Fengkui; Wang, Xuxia; Lei, Hao

    2014-08-18

    A novel biocompatible macromolecule (AG-CM-EDA-DOTA-Gd) was synthesized as a liver magnetic resonance imaging (MRI) contrast agent. AG-CM-EDA-DOTA-Gd consisted of a carboxymethyl-arabinogalactan unit conjugated with gadolinium-1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (Gd-DOTA) via ethylenediamine, and was specifically designed to bind to hepatocyte asialoglycoprotein in vivo, in an effort to develop a potential new tool for the diagnosis of liver diseases. The T1-relaxivity (8.87mmol(-1)Ls(-1)) of AG-CM-EDA-DOTA-Gd was 1.86 times than that of Gd-DOTA (4.76mmol(-1)Ls(-1)) in D2O at 9.4 T and 25°C. MRI experiments showed significant enhancement in rat liver following the intravenous administration of AG-CM-EDA-DOTA-Gd (0.094mmol Gd(3+)/kg body weight), which persisted for longer than Gd-DOTA (0.098mmol Gd(3+)/kg body weight). The mean percentage enhancements in the liver parenchyma were 85.2±6.5% and 19.3±3.3% for AG-CM-EDA-DOTA-Gd and Gd-DOTA, respectively. The results of this study therefore indicate that AG-CM-EDA-DOTA-Gd could be used as a potential liver-targeting contrast agent for MRI.

  16. The influence of collagen network integrity on the accumulation of gadolinium-based MR contrast agents in articular cartilage

    Energy Technology Data Exchange (ETDEWEB)

    Wiener, Edzard; Schmidt, C.; Diederichs, G. [Charite - Universitaetsmedizin Berlin (Germany). Inst. fuer Radiologie; Settles, M. [Klinikum rechts der Isar, Muenchen (Germany). Inst. fuer Roentgendiagnostik; Weirich, G. [Klinikum Rechts der Isar, Muenchen (Germany). Inst. fuer Pathologie und Pathologische Anatomie

    2011-03-15

    Delayed gadolinium-enhanced MR imaging of cartilage is used to quantify the proteoglycan loss in early osteoarthritis. It is assumed that T 1 after Gd-DTPA administration in the near equilibrium state reflects selective proteoglycan loss from cartilage. To investigate the influence of the collagen network integrity on contrast accumulation, the relaxation rates {delta}R1 and {delta}R2 were compared after Gd-DTPA administration in a well established model of osteoarthritis. Collagen or proteoglycan depletion was induced by the proteolytic enzymes papain and collagenase in healthy bovine patellar cartilage. Using a dedicated MRI sequence, T{sub 1} and T{sub 2} maps were simultaneously acquired before and 11 h after Gd-DTPA administration. Depth-dependent profiles of {delta}R1 and {delta}R2 were calculated in healthy, proteoglycan and collagen-depleted articular cartilage and the mean values of different cartilage layers were compared using the Mann-Whitney-U test. In superficial layers (1 mm) there was no significant difference (p > 0.05) in either {delta}R1 or {delta}R2 between proteoglycan-depleted (16.6 {+-} 1.2 s{sup -1}, 15.9 {+-} 1.0 s{sup -1}) and collagen-depleted articular cartilage (15.3 {+-} 0.9 s{sup -1}, 15.5 {+-} 0.9 s{sup -1}). In deep layers (3 mm) both parameters were significantly higher (p = 0.005, 0.03) in proteoglycan-depleted articular cartilage (12.3 {+-} 1.1 s{sup -1}, 9.8 {+-} 0.8 s{sup -1}) than in collagen-depleted articular cartilage (9.1 {+-} 1.1 s{sup -1}, 8.7 {+-} 0.7 s{sup -1}). Both proteoglycan loss and alterations in the collagen network influence the accumulation of Gd-DTPA in articular cartilage with significant differences between superficial and deep cartilage layers. (orig.)

  17. Optimizing dose and administration regimen of a high-relaxivity contrast agent for myocardial MRI late gadolinium enhancement

    Energy Technology Data Exchange (ETDEWEB)

    Secchi, Francesco; Di Leo, Giovanni; Papini, Giacomo D.E. [Universita degli Studi di Milano, Dipartimento di Scienze Medico-Chirurgiche, Milan (Italy); IRCCS Policlinico San Donato, Radiology Unit, Via Morandi 30, 20097 San Donato Milanese, Milan (Italy); Giacomazzi, Francesca [IRCCS Policlinico San Donato, Unit of Cardiac Surgery, Via Morandi 30, 20097 San Donato Milanese, Milan (Italy); Di Donato, Marisa [University of Florence, Department of Critical Care Medicine, IRCCS Policlinico San Donato, Via Morandi 30, 20097 San Donato Milanese, Milan (Italy); Sardanelli, Francesco, E-mail: francesco.sardanelli@unimi.it [Universita degli Studi di Milano, Dipartimento di Scienze Medico-Chirurgiche, Milan (Italy); IRCCS Policlinico San Donato, Radiology Unit, Via Morandi 30, 20097 San Donato Milanese, Milan (Italy)

    2011-10-15

    Objectives: To investigate the time-course of late gadolinium enhancement of infarcted myocardium using gadobenate dimeglumine at different dosages and administration regimens. Materials and methods: After institutional review board approval and informed consent, we studied 13 patients (aged 63 {+-} 11 years) with chronic myocardial infarction. They underwent two gadobenate dimeglumine-enhanced MR examinations (interval 24-48 h) using short-axis inversion-recovery gradient-echo sequences, with the following two different protocols, in randomized order: 0.05 mmol/kg and imaging at the 2.5th, 5th, 7.5th and 10th minute plus 0.05 mmol/kg and imaging at the 12.5th, 15th, 17.5th and 20th minute; the same as before but using 0.1 mmol/kg for both contrast injections. Contrast-to-noise ratios (CNRs) between infarcted myocardium, non-infarcted myocardium and left ventricle cavity were calculated for each time-point (2.5-min steps). Friedman ANOVA was used for comparing the CNR time-course; Wilcoxon test for comparing CNR at the 10th and the 20th minute. Results: The CNR between infarcted and non-infarcted myocardium obtained at the 20th minute with 0.05 plus 0.05 mmol/kg resulted significantly higher than that obtained at the 10th minute with 0.05 mmol/kg (P = 0.033) while not significantly different from that obtained at the 10th (0.1 mm/kg) or at the 20th minute with 0.1 plus 0.1 mmol/kg. The CNR between infarcted myocardium and the left ventricle cavity obtained at the 20th minute with 0.05 plus 0.05 mmol/kg resulted significantly higher than all other measured values (P {<=} 0.017). Conclusion: Using gadobenate dimeglumine, 0.05 plus 0.05 mmol/kg allows for a higher CNR between infarcted myocardium and the left ventricle cavity allowing for reliable assessment of the sub-endocardial infarctions.

  18. In an animal model nephrogenic systemic fibrosis cannot be induced by intraperitoneal injection of high-dose gadolinium based contrast agents

    Energy Technology Data Exchange (ETDEWEB)

    Langer, R.D., E-mail: rlanger@uaeu.ac.ae [Faculty of Medicine and Health Sciences (FMHS), United Arab Emirates University, Al Ain (United Arab Emirates); Lorke, D.E. [Florida International University, Miami, FL (United States); Neidl van Gorkom, K.F. [Faculty of Medicine and Health Sciences (FMHS), United Arab Emirates University, Al Ain (United Arab Emirates); Petroianu, G. [Florida International University, Miami, FL (United States); Azimullah, S.; Nurulain, S.M.; Singh, S. [Faculty of Medicine and Health Sciences (FMHS), United Arab Emirates University, Al Ain (United Arab Emirates); Fuchsjäger, M. [Al Ain Hospital, MUV-VAMED, Al Ain (United Arab Emirates)

    2012-10-15

    Aim and objective: Nephrogenic systemic fibrosis (NSF) has been reported in humans to be most likely induced by gadolinium based contrast agents (GBCA), namely by gadodiamide, gadopentetate dimeglumine, and gadoversetamide, rarely by other GBCA. The pathogenesis of NSF remains unclear; different hypotheses are under discussion. The objective of the study is to assess if in the animal model human-like NSF changes can be induced by high-dose, intraperitoneal GBCA injections over four weeks. Materials and methods: After approval by the institutional animal ethics committee, six rats each were randomly assigned to groups, and treated with seven different GBCA. Intraperitoneal (IP) injections – proven in the animal model to be effective – were chosen to prolong the animals’ exposure to the respective GBCA. GBCA doses of previous intravenous (IV) animal studies were applied. After five weeks all rats were sacrificed. Sham controls were treated with IP saline injections, employing the same regimen. Results: No findings comparable with human NSF were observed in all animals after IP treatment with all seven GBCA at daily doses of 2.5 and 5.0 mmol/kg body weight (BW). No histopathological abnormalities of all examined organs were noted. Weight loss was stated in weeks three and four with GBCA injections at doses of 5.0 mmol/kg BW, but rats regained weight after cessation of GBCA treatment. Conclusions: NSF-comparable pathological findings could not be induced by high dose intraperitoneal injection of seven GBCA.

  19. In an animal model nephrogenic systemic fibrosis cannot be induced by intraperitoneal injection of high-dose gadolinium based contrast agents

    International Nuclear Information System (INIS)

    Aim and objective: Nephrogenic systemic fibrosis (NSF) has been reported in humans to be most likely induced by gadolinium based contrast agents (GBCA), namely by gadodiamide, gadopentetate dimeglumine, and gadoversetamide, rarely by other GBCA. The pathogenesis of NSF remains unclear; different hypotheses are under discussion. The objective of the study is to assess if in the animal model human-like NSF changes can be induced by high-dose, intraperitoneal GBCA injections over four weeks. Materials and methods: After approval by the institutional animal ethics committee, six rats each were randomly assigned to groups, and treated with seven different GBCA. Intraperitoneal (IP) injections – proven in the animal model to be effective – were chosen to prolong the animals’ exposure to the respective GBCA. GBCA doses of previous intravenous (IV) animal studies were applied. After five weeks all rats were sacrificed. Sham controls were treated with IP saline injections, employing the same regimen. Results: No findings comparable with human NSF were observed in all animals after IP treatment with all seven GBCA at daily doses of 2.5 and 5.0 mmol/kg body weight (BW). No histopathological abnormalities of all examined organs were noted. Weight loss was stated in weeks three and four with GBCA injections at doses of 5.0 mmol/kg BW, but rats regained weight after cessation of GBCA treatment. Conclusions: NSF-comparable pathological findings could not be induced by high dose intraperitoneal injection of seven GBCA

  20. A Theranostic Agent Combining a Two-Photon-Absorbing Photosensitizer for Photodynamic Therapy and a Gadolinium(III) Complex for MRI Detection.

    Science.gov (United States)

    Schmitt, Julie; Heitz, Valérie; Sour, Angélique; Bolze, Frédéric; Kessler, Pascal; Flamigni, Lucia; Ventura, Barbara; Bonnet, Célia S; Tóth, Éva

    2016-02-18

    The convergent synthesis and characterization of a potential theranostic agent, [DPP-ZnP-GdDOTA](-), which combines a diketopyrrolopyrrole-porphyrin component DPP-ZnP as a two-photon photosensitizer for photodynamic therapy (PDT) with a gadolinium(III) DOTA complex as a magnetic resonance imaging probe, is presented. [DPP-ZnP-GdDOTA](-) has a remarkably high longitudinal water proton relaxivity (19.94 mm(-1)  s(-1) at 20 MHz and 25 °C) for a monohydrated molecular system of this size. The Nuclear Magnetic Relaxation Dispersion (NMRD) profile is characteristic of slow rotation, related to the extended and rigid aromatic units integrated in the molecule and to self-aggregation occurring in aqueous solution. The two-photon properties were examined and large two-photon absorption cross-sections around 1000 GM were determined between 910 and 940 nm in DCM with 1 % pyridine and in DMSO. Furthermore, the new conjugate was able to generate singlet oxygen, with quantum yield of 0.42 and 0.68 in DCM with 1 % pyridine and DMSO, respectively. Cellular studies were also performed. The [DPP-ZnP-GdDOTA](-) conjugate demonstrated low dark toxicity and was able to induce high one-photon and moderate two-photon phototoxicity on cancer cells.

  1. 钆类造影剂用于肿瘤靶向性成像%Gadolinium-Based Contrast Agents for Tumor Targeting Imaging

    Institute of Scientific and Technical Information of China (English)

    沈爱军; 董海青; 温惠云; 徐梦; 李永勇; 王培军

    2011-01-01

    Magnetic resonance imaging (MRI) is an important technique of medical imaging for the tumor diagnosis, due to its high spatial and temporal resolutions and excellent soft tissue contrast, especially after the usage of various contrast agents. However, the current contrast agents for MRI, such as Gd-DTPA-BMA, Gd-DOTA etc. ,are all small molecules, which are associated with the intrinsic drawbacks such as nonspecificity for the interesting tissue,rapid excretion in vivo. To address the above questions, the novel specific MRI contrast agents with high efficiency and low toxicity are thus becoming research hot spots in both material and medical fields. In this review, particular attention is paid on the recent progress of gadolinium-based MRI contrast agents for tumor targeting imaging by summarizing the relevant research papers. Both passive and active approach for tumor targeting imaging are involved in this review. The synthesis, principle and determined factors of MRI contrast agents for tumor targeting imaging and their in vitro or in vivo effects on the interesting tissue are discussed.%核磁共振成像(MRI)是肿瘤诊断的重要手段,特别是各种造影剂的使用加速了临床应用范围.目前临床MRI检查所用各类造影剂如Gd-DTPA-BMA、Gd-DOTA等均为小分子造影剂,存在组织特异性低、体内停留时间短等缺点.构建具有组织特异性的新一代高效、低毒MRI造影剂成为材料界、医学界的研究热点之一.本文在综合最新文献的研究基础之上,重点关注含钆类造影剂在肿瘤靶向成像中的应用及发展.

  2. Approaching the Kinetic Inertness of Macrocyclic Gadolinium(III)-Based MRI Contrast Agents with Highly Rigid Open-Chain Derivatives.

    Science.gov (United States)

    Tircsó, Gyula; Regueiro-Figueroa, Martín; Nagy, Viktória; Garda, Zoltán; Garai, Tamás; Kálmán, Ferenc Krisztián; Esteban-Gómez, David; Tóth, Éva; Platas-Iglesias, Carlos

    2016-01-18

    A highly rigid open-chain octadentate ligand (H4 cddadpa) containing a diaminocylohexane unit to replace the ethylenediamine bridge of 6,6'-[(ethane-1,2 diylbis{(carboxymethyl)azanediyl})bis(methylene)]dipicolinic acid (H4 octapa) was synthesized. This structural modification improves the thermodynamic stability of the Gd(3+) complex slightly (log KGdL =20.68 vs. 20.23 for [Gd(octapa)](-) ) while other MRI-relevant parameters remain unaffected (one coordinated water molecule; relaxivity r1 =5.73 mm(-1)  s(-1) at 20 MHz and 295 K). Kinetic inertness is improved by the rigidifying effect of the diaminocylohexane unit in the ligand skeleton (half-life of dissociation for physiological conditions is 6 orders of magnitude higher for [Gd(cddadpa)](-) (t1/2 =1.49×10(5)  h) than for [Gd(octapa)](-) . The kinetic inertness of this novel chelate is superior by 2-3 orders of magnitude compared to non-macrocyclic MRI contrast agents approved for clinical use. PMID:26583317

  3. Isotope effects in the gadolinium amalgam system

    International Nuclear Information System (INIS)

    Gadolinium is a good neutron absorbent used in uranium oxide nuclear fuel for LWR. The157 Gd has a very large cross section for neutron absorption, namely 254000 barn. One of the isotope separation method for gadolinium is the isotopic exchange in the Gd3+ - GdHg system. In this work, the separation elemental factors for this isotopic exchange reaction, determined experimentally, are presented. Gadolinium amalgam was prepared by electrolysis of aqueous solution of gadolinium acetate with lithium citrate as complexing agent ([Li+]/[Gd3+] = 12), in a glass electrolyzer with a Hg cathode and a Pt anode. The gadolinium amalgam was treated with HCl 1-2N and the extracted Gd3+ was precipitated as oxalate and converted in Gd2O3. Gadolinium in acetic solution was precipitated as oxalate and converted in Gd2O3. The isotopic ratios 154 Gd/160 Gd, 155 Gd/160 Gd, 156 Gd/160 Gd, 157 Gd/160 Gd and 158 Gd/160 Gd were determined in Gd2O3 samples by a mass spectrometer MAT 261 equipped with thermoionization ion source. After the isotopic exchange, GdHg enriches with the light Gd isotopes and the solution (Gd3+) enriches with 160 Gd. The dependence of separation elemental factor on mass difference between gadolinium isotopes is presented. (authors)

  4. Emerging Concepts for Myocardial Late Gadolinium Enhancement MRI

    OpenAIRE

    Doltra, Adelina; Amundsen, Brage Høyem; Gebker, Rolf; Fleck, Eckart; Kelle, Sebastian

    2013-01-01

    Late gadolinium enhancement is a useful tool for scar detection, based on differences in the volume of distribution of gadolinium, an extracellular agent. The presence of fibrosis in the myocardium amenable to be detected with late gadolinium enhancement MRI is found not only in ischemic cardiomyopathy, in which it offers information regarding viability and prognosis, but also in a wide variety of non-ischemic cardiomyopathies. In the following review we will discuss the methodological aspect...

  5. Effects of Gadolinium-Based Contrast Agents on Thyroid Hormone Receptor Action and Thyroid Hormone-Induced Cerebellar Purkinje Cell Morphogenesis.

    Science.gov (United States)

    Ariyani, Winda; Iwasaki, Toshiharu; Miyazaki, Wataru; Khongorzul, Erdene; Nakajima, Takahito; Kameo, Satomi; Koyama, Hiroshi; Tsushima, Yoshito; Koibuchi, Noriyuki

    2016-01-01

    Gadolinium (Gd)-based contrast agents (GBCAs) are used in diagnostic imaging to enhance the quality of magnetic resonance imaging or angiography. After intravenous injection, GBCAs can accumulate in the brain. Thyroid hormones (THs) are critical for the development and functional maintenance of the central nervous system. TH actions in brain are mainly exerted through nuclear TH receptors (TRs). We examined the effects of GBCAs on TR-mediated transcription in CV-1 cells using transient transfection-based reporter assay and TH-mediated cerebellar Purkinje cell morphogenesis in primary culture. We also measured the cellular accumulation and viability of Gd after representative GBCA treatments in cultured CV-1 cells. Both linear (Gd-diethylene triamine pentaacetic acid-bis methyl acid, Gd-DTPA-BMA) and macrocyclic (Gd-tetraazacyclododecane tetraacetic acid, Gd-DOTA) GBCAs were accumulated without inducing cell death in CV-1 cells. By contrast, Gd chloride (GdCl3) treatment induced approximately 100 times higher Gd accumulation and significantly reduced the number of cells. Low doses of Gd-DTPA-BMA (10(-8) to 10(-6)M) augmented TR-mediated transcription, but the transcription was suppressed at higher dose (10(-5) to 10(-4)M), with decreased β-galactosidase activity indicating cellular toxicity. TR-mediated transcription was not altered by Gd-DOTA or GdCl3, but the latter induced a significant reduction in β-galactosidase activity at high doses, indicating cellular toxicity. In cerebellar cultures, the dendrite arborization of Purkinje cells induced by 10(-9)M T4 was augmented by low-dose Gd-DTPA-BMA (10(-7)M) but was suppressed by higher dose (10(-5)M). Such augmentation by low-dose Gd-DTPA-BMA was not observed with 10(-9)M T3, probably because of the greater dendrite arborization by T3; however, the arborization by T3 was suppressed by a higher dose of Gd-DTPA-BMA (10(-5)M) as seen in T4 treatment. The effect of Gd-DOTA on dendrite arborization was much weaker

  6. Effects of gadolinium-based contrast agents on thyroid hormone receptor action and thyroid hormone-induced cerebellar Purkinje cell morphogenesis

    Directory of Open Access Journals (Sweden)

    Noriyuki Koibuchi

    2016-08-01

    Full Text Available Gadolinium (Gd-based contrast agents (GBCAs are used in diagnostic imaging to enhance the quality of magnetic resonance imaging or angiography. After intravenous injection, GBCAs can accumulate in the brain. Thyroid hormones (THs are critical to the development and functional maintenance of the central nervous system. TH actions in brain are mainly exerted through nuclear TH receptors (TRs. We examined the effects of GBCAs on TR-mediated transcription in CV-1 cells using transient transfection-based reporter assay and thyroid hormone-mediated cerebellar Purkinje cell morphogenesis in primary culture. We also measured the cellular accumulation and viability of Gd after representative GBCA treatments in cultured CV-1 cells. Both linear (Gd-diethylene triamine pentaacetic acid-bis methyl acid, Gd-DTPA-BMA and macrocyclic (Gd-tetraazacyclododecane tetraacetic acid, Gd-DOTA GBCAs were accumulated without inducing cell death in CV-1 cells. In contrast, Gd chloride (GdCl3 treatment induced approximately 100 times higher Gd accumulation and significantly reduced the number of cells. Low doses of Gd-DTPA-BMA (10−8–10−6 M augmented TR-mediated transcription, but the transcription was suppressed at higher dose (10−5 – 10−4 M, with decreased β-galactosidase activity indicating cellular toxicity. TR-mediated transcription was not altered by Gd-DOTA or GdCl3, but the latter induced a significant reduction in β-galactosidase activity at high doses, indicating cellular toxicity. In cerebellar cultures, the dendrite arborization of Purkinje cells induced by 10-9 M T4 was augmented by low-dose Gd-DTPA-BMA (10−7 M but was suppressed by higher dose (10−5 M. Such augmentation by low-dose Gd-DTPA-BMA was not observed with 10-9 M T3, probably because of the greater dendrite arborization by T3; however, the arborization by T3 was suppressed by a higher dose of Gd-DTPA-BMA (10-5 M as seen in T4 treatment. The effect of Gd-DOTA on dendrite arborization

  7. Effects of Gadolinium-Based Contrast Agents on Thyroid Hormone Receptor Action and Thyroid Hormone-Induced Cerebellar Purkinje Cell Morphogenesis

    Science.gov (United States)

    Ariyani, Winda; Iwasaki, Toshiharu; Miyazaki, Wataru; Khongorzul, Erdene; Nakajima, Takahito; Kameo, Satomi; Koyama, Hiroshi; Tsushima, Yoshito; Koibuchi, Noriyuki

    2016-01-01

    Gadolinium (Gd)-based contrast agents (GBCAs) are used in diagnostic imaging to enhance the quality of magnetic resonance imaging or angiography. After intravenous injection, GBCAs can accumulate in the brain. Thyroid hormones (THs) are critical for the development and functional maintenance of the central nervous system. TH actions in brain are mainly exerted through nuclear TH receptors (TRs). We examined the effects of GBCAs on TR-mediated transcription in CV-1 cells using transient transfection-based reporter assay and TH-mediated cerebellar Purkinje cell morphogenesis in primary culture. We also measured the cellular accumulation and viability of Gd after representative GBCA treatments in cultured CV-1 cells. Both linear (Gd-diethylene triamine pentaacetic acid-bis methyl acid, Gd-DTPA-BMA) and macrocyclic (Gd-tetraazacyclododecane tetraacetic acid, Gd-DOTA) GBCAs were accumulated without inducing cell death in CV-1 cells. By contrast, Gd chloride (GdCl3) treatment induced approximately 100 times higher Gd accumulation and significantly reduced the number of cells. Low doses of Gd-DTPA-BMA (10−8 to 10−6M) augmented TR-mediated transcription, but the transcription was suppressed at higher dose (10−5 to 10−4M), with decreased β-galactosidase activity indicating cellular toxicity. TR-mediated transcription was not altered by Gd-DOTA or GdCl3, but the latter induced a significant reduction in β-galactosidase activity at high doses, indicating cellular toxicity. In cerebellar cultures, the dendrite arborization of Purkinje cells induced by 10−9M T4 was augmented by low-dose Gd-DTPA-BMA (10−7M) but was suppressed by higher dose (10−5M). Such augmentation by low-dose Gd-DTPA-BMA was not observed with 10−9M T3, probably because of the greater dendrite arborization by T3; however, the arborization by T3 was suppressed by a higher dose of Gd-DTPA-BMA (10−5M) as seen in T4 treatment. The effect of Gd-DOTA on dendrite arborization was much weaker

  8. Study on the uptake and distribution of gadolinium based contrast agents in biological samples using laser ablation with inductively coupled plasma mass spectroscopy; Untersuchungen zur Aufnahme und Verteilung von gadoliniumbasierten Kontrastmitteln in biologischen Proben mittels Laserablation mit induktiv gekoppelter Plasma-Massenspektrometrie

    Energy Technology Data Exchange (ETDEWEB)

    Lingott, Jana

    2016-01-05

    Gadolinium based contrast agents are used for magnetic resonance imaging. After their excretion by medicated patients they reach surface water passing waste water treatment plants where they are not removed sufficiently. The behavior of the contrast agents in the environment and the interaction with organisms was investigated in this work due to the toxicity of the free Gd{sup 3+} ion and the associated risks, such as accumulation in the human food chain. In this work, the two elemental analytical imaging methods laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) and synchrotron radiation X-ray fluorescence analysis (SRXRF) have been used to investigate the uptake, distribution, and excretion of Gd-based contrast agents by various biological systems. Both methods were analytically characterized and compared for this application. The detection limits of gadolinium were determined under optimized conditions by LA-ICP-MS and SRXRF. With calibration by remains of dried elemental standard droplets detection limits of 0.78 pg absolute amount of gadolinium (LA-ICP-MS), respectively 89 pg (SRXRF) were reached. Based on filamentous algae as water plants the uptake and the excretion of Gd-based contrast agents were revealed. The dependence on concentration of the contrast agent in the exposition solution and the independence of temporal uptake within one to seven days were studied for duckweed. By LA-ICP-MS gadolinium was quantified in a leaf of cress plant. The verification of the results was performed by SRXRF and ICP-MS after digestion. Furthermore, the uptake and distribution of Gd-based contrast agents in higher organisms (water flea) were observed. The exact location of gadolinium was resolved by three-dimensional μ-computed tomography by the comparison of an exposed with a Gd-free water flea. In all studies, gadolinium was detected in the investigated exposed model organisms. It can be concluded that the contrast agents were taken from the

  9. Emerging concepts for myocardial late gadolinium enhancement MRI.

    Science.gov (United States)

    Doltra, Adelina; Amundsen, Brage Hoyem; Gebker, Rolf; Fleck, Eckart; Kelle, Sebastian

    2013-08-01

    Late gadolinium enhancement is a useful tool for scar detection, based on differences in the volume of distribution of gadolinium, an extracellular agent. The presence of fibrosis in the myocardium amenable to be detected with late gadolinium enhancement MRI is found not only in ischemic cardiomyopathy, in which it offers information regarding viability and prognosis, but also in a wide variety of non-ischemic cardiomyopathies. In the following review we will discuss the methodological aspects of gadolinium-based imaging, as well as its applications and anticipated future developments.

  10. Emerging concepts for myocardial late gadolinium enhancement MRI.

    Science.gov (United States)

    Doltra, Adelina; Amundsen, Brage Hoyem; Gebker, Rolf; Fleck, Eckart; Kelle, Sebastian

    2013-08-01

    Late gadolinium enhancement is a useful tool for scar detection, based on differences in the volume of distribution of gadolinium, an extracellular agent. The presence of fibrosis in the myocardium amenable to be detected with late gadolinium enhancement MRI is found not only in ischemic cardiomyopathy, in which it offers information regarding viability and prognosis, but also in a wide variety of non-ischemic cardiomyopathies. In the following review we will discuss the methodological aspects of gadolinium-based imaging, as well as its applications and anticipated future developments. PMID:23909638

  11. Complications of nephrogenic systemic fibrosis following repeated exposure to gadolinium in a man with hypothyroidism: a case report

    Directory of Open Access Journals (Sweden)

    Aggarwal Arpita

    2011-12-01

    Full Text Available Abstract Introduction Nephrogenic systemic fibrosis is a condition that has recently been recognized in patients with chronic renal disease and is associated with use of gadolinium-based contrast agents of ubiquitous use in magnetic resonance imaging scans. The condition is believed to arise through inadequate renal clearance of the gadolinium-based contrast agents, resulting in bodily deposition of the gadolinium; this is most widely recognized in the skin, but also occurs in other tissues. Case presentation We report the case of a 52-year-old Caucasian man with hypothyroidism and chronic renal disease who developed nephrogenic systemic fibrosis upon repeated exposure to gadolinium, and who presented with a subsequent malabsorption of levothyroxine. This malabsorption resolved only partially upon amelioration of other conditions that might contribute to malabsorption, including edema and infectious diarrhea. The presence of gadolinium was quantified in specimens from his gastrointestinal tract. Our patient otherwise demonstrated adequate gastrointestinal nutritive absorption, objectively shown by normal albumin levels, resolution of diarrhea, and maintenance of his bodily weight. Conclusions Our observations suggest that nephrogenic systemic fibrosis can also affect tissue of the gastrointestinal tract, potentially contributing to partial malabsorption of levothyroxine in patients with hypothyroidism.

  12. Intracranial neoplasms: MR imaging with gadolinium - DOTA

    International Nuclear Information System (INIS)

    After a review of the capabilities of magnetic resonance without contrast in the diagnostic assessment of intracranial tumors, the authors report the literature and their own experience concerning the use of the paramagnetic contrast agent gadolinium-DOTA in MR imaging. A 0.5 T superconducting system (Toshiba MRT-50A) was used in the evaluation of these tumors. The intravenous administration of gadolinium-DOTA does not substantially increase the sensitivity of MR to primary intra-axial tumors. However, it may provide better delineation of tumor macroscopic extension and separation of the nidus from the surrounding edema. The presence of enhancement reflects areas of alteration of the blood brain barrier and may anticipate malignant changes at the histopathological examination. The role of gadolinium-DOTA administration for differentiation of intra-axial tumor recurrence from parenchyma changes induced by surgery or radiotherapy remains to be established. On the other hand, gadolinium-DOTA dramatically increases the sensitivity and specificity of MR in the investigation of extra-axial primary tumors (meningiomas, neurinomas), sellar tumors and secondary neoplastic lesions as well as in the investigation of their recurrence. Gadolinium-DOTA may be indirectly useful in the identification of the dysontogenetic tumors do not show enhancement as the low grade tumors do. (author)

  13. Gadolinium photoionization process

    Science.gov (United States)

    Paisner, J.A.; Comaskey, B.J.; Haynam, C.A.; Eggert, J.H.

    1993-04-13

    A method is provided for selective photoionization of the odd-numbered atomic mass gadolinium isotopes 155 and 157. The selective photoionization is accomplished by circular or linear parallel polarized laser beam energy effecting a three-step photoionization pathway.

  14. The isotope effect in gadolinium amalgam system

    International Nuclear Information System (INIS)

    Gadolinium is a neutron absorbing material and has been used as a burnable poison contained in the U fuel pellets for LWRs. Among the 7 isotopes of gadolinium, 157 Gd has a special large neutron absorption cross section of 254 000 barn (10 -24 cm2). In this paper gadolinium isotope separation factor for isotopic exchange between Gd 3+ (in solution) and gadolinium amalgam (GdHg) is determined. By electrolysis of aqueous solutions containing gadolinium acetate and lithium citrate, as complexing agent, using the ratio (Li +/Gd3+) = 12, gadolinium amalgam was prepared using a glass electrolyser with Hg as cathode and platinum as anode. The gadolinium amalgam was stirred with HCl solution 1-2N and Gd 3+ is precipitated as oxalate at weak acid pH and then converted to Gd2O3. The remained gadolinium in acetate solution (after electrolysis) was also precipitated as oxalate and converted to Gd2O3. On Gd2O3 samples the isotopic ratios 156 Gd/160 Gd were determined by mass spectrometry, using MAT 261 equipped with a thermal ionisation ion source. Between Gd3+ and Gadolinium amalgam there is an isotopic exchange, the heavy isotope 160 Gd was found to be enriched in Gd3+ while the lighter isotope, 156 Gd, was enriched in GdHg.. The single stage separation factor α (156 Gd/160 Gd) was determined in different experimental conditions: contact time between Gd3+ and GdHg, the yield of GdHg formation, current density. The range of the measured values of α was 1.0013 - 1.00456, average value being 1.0023 at 26 deg. C. The yield of GdHg formation has increased from 37-75.5% for the electrolyser of 40 mm i.d. (S = 12.56 cm2), to 89.6%, for electrolyser of 53 mm i.d. (S = 22 cm2).. After 30 minutes of contact (in electrolysis conditions) between Gd3+ and GdHg there is not an important passage of Gd between the two phases, in these conditions the isotopic exchange of Gd is studied. (authors)

  15. Is the transport of a gadolinium-based contrast agent decreased in a degenerated or aged disc? A post contrast MRI study.

    Directory of Open Access Journals (Sweden)

    Marta Tibiletti

    Full Text Available A post contrast magnetic resonance imaging study has been performed in a wide population of low back pain patients to investigate which radiological and phenotypic characteristics influence the penetration of the contrast agent in lumbar discs in vivo. 37 patients affected by different pathologies (disc herniation, spondylolisthesis, foraminal stenosis, central canal stenosis were enrolled in the study. The selected population included 26 male and 11 female subjects, with a mean age of 42.4 ± 9.3 years (range 18-60. Magnetic resonance images of the lumbar spine were obtained with a 1.5 T scanner (Avanto, Siemens, Erlangen, Germany with a phased-array back coil. A paramagnetic non-ionic contrast agent was injected with a dose of 0.4 ml/kg. T1-weighted magnetic resonance images were subsequently acquired at 5 time points, 5 and 10 minutes, 2, 4 and 6 hours after injection. Endplates presented clear enhancement already 5 minutes after injection, and showed an increase in the next 2 hours followed by a decrease. At 5 and 10 minutes, virtually no contrast medium was present inside the intervertebral disc; afterwards, enhancement significantly increased. Highly degenerated discs showed higher enhancement in comparison with low and medium degenerated discs. Discs classified as Pfirrmann 5 showed a statistically significant higher enhancement than Pfirrmann 1, 2 and 3 at all time points but the first one, possibly due to vascularization. Disc height collapse and Modic changes significantly increased enhancement. Presence of endplate defects did not show any significant influence on post contrast enhancement, but the lack of a clear classification of endplate defects as seen on magnetic resonance scans may be shadowing some effects. In conclusion, disc height, high level of degeneration and presence of Modic changes are factors which increase post contrast enhancement in the intervertebral disc. The effect of age could not be demonstrated.

  16. Cost and availability of gadolinium for nuclear fuel reprocessing plants

    International Nuclear Information System (INIS)

    Gadolinium is currently planned for use as a soluble neutron poison in nuclear fuel reprocessing plants to prevent criticality of solutions of spent fuel. Gadolinium is relatively rare and expensive. The present study was undertaken therefore to estimate whether this material is likely to be available in quantities sufficient for fuel reprocessing and at reasonable prices. It was found that gadolinium, one of 16 rare earth elements, appears in the marketplace as a by-product and that its present supply is a function of the production rate of other more prevalent rare earths. The potential demand for gadolinium in a fuel reprocessing facility serving a future fast reactor industry amounts to only a small fraction of the supply. At the present rate of consumption, domestic supplies of rare earths containing gadolinium are adequate to meet national needs (including fuel reprocessing) for over 100 years. With access to foreign sources, US demands can be met well beyond the 21st century. It is concluded therefore that the supply of gadolinium will quite likely be more than adequate for reprocessing spent fuel for the early generation of fast reactors. The current price of 99.99% pure gadolinium oxide lies in the range $50/lb to $65/lb (1984 dollars). By the year 2020, in time for reprocessing spent fuel from an early generation of large fast reactors, the corresponding values are expected to lie in the $60/lb to $75/lb (1984 dollars) price range. This increase is modest and its economic impact on nuclear fuel reprocessing would be minor. The economic potential for recovering gadolinium from the wastes of nuclear fuel reprocessing plants (which use gadolinium neutron poison) was also investigated. The cost of recycled gadolinium was estimated at over twelve times the cost of fresh gadolinium, and thus recycle using current recovery technology is not economical. 15 refs., 4 figs., 11 tabs

  17. Gain of a 500-fold sensitivity on an intravital MR Contrast Agent based on an endohedral Gadolinium-Cluster-Fullerene-Conjugate: A new chance in cancer diagnostics

    OpenAIRE

    Braun, Klaus; Dunsch, Lothar; Pipkorn, Ruediger; Bock, Michael; Baeuerle, Tobias; Yang, Shangfeng; Waldeck, Waldemar; Wiessler, Manfred

    2010-01-01

    Among the applications of fullerene technology in health sciences the expanding field of magnetic resonance imaging (MRI) of molecular processes is most challenging. Here we present the synthesis and application of a GdxSc3-xN@C80-BioShuttle-conjugate referred to as Gd-cluster@-BioShuttle, which features high proton relaxation and, in comparison to the commonly used contrast agents, high signal enhancement at very low Gd concentrations. This modularly designed contrast agent represents a new ...

  18. Gain of a 500-fold sensitivity on an intravital MR Contrast Agent based on an endohedral Gadolinium-Cluster-Fullerene-Conjugate: A new chance in cancer diagnostics

    Directory of Open Access Journals (Sweden)

    Klaus Braun, Lothar Dunsch, Ruediger Pipkorn, Michael Bock, Tobias Baeuerle, Shangfeng Yang, Waldemar Waldeck, Manfred Wiessler

    2010-01-01

    Full Text Available Among the applications of fullerene technology in health sciences the expanding field of magnetic resonance imaging (MRI of molecular processes is most challenging. Here we present the synthesis and application of a GdxSc3-xN@C80-BioShuttle-conjugate referred to as Gd-cluster@-BioShuttle, which features high proton relaxation and, in comparison to the commonly used contrast agents, high signal enhancement at very low Gd concentrations. This modularly designed contrast agent represents a new tool for improved monitoring and evaluation of interventions at the gene transcription level. Also, a widespread monitoring to track individual cells is possible, as well as sensing of microenvironments. Furthermore, BioShuttle can also deliver constructs for transfection or active pharmaceutical ingredients, and scaffolding for incorporation with the host's body. Using the Gd-cluster@-BioShuttle as MRI contrast agent allows an improved evaluation of radio- or chemotherapy treated tissues.

  19. Gain of a 500-fold sensitivity on an intravital MR Contrast Agent based on an endohedral Gadolinium-Cluster-Fullerene-Conjugate: A new chance in cancer diagnostics

    Science.gov (United States)

    Braun, Klaus; Dunsch, Lothar; Pipkorn, Ruediger; Bock, Michael; Baeuerle, Tobias; Yang, Shangfeng; Waldeck, Waldemar; Wiessler, Manfred

    2010-01-01

    Among the applications of fullerene technology in health sciences the expanding field of magnetic resonance imaging (MRI) of molecular processes is most challenging. Here we present the synthesis and application of a GdxSc3-xN@C80-BioShuttle-conjugate referred to as Gd-cluster@-BioShuttle, which features high proton relaxation and, in comparison to the commonly used contrast agents, high signal enhancement at very low Gd concentrations. This modularly designed contrast agent represents a new tool for improved monitoring and evaluation of interventions at the gene transcription level. Also, a widespread monitoring to track individual cells is possible, as well as sensing of microenvironments. Furthermore, BioShuttle can also deliver constructs for transfection or active pharmaceutical ingredients, and scaffolding for incorporation with the host's body. Using the Gd-cluster@-BioShuttle as MRI contrast agent allows an improved evaluation of radio- or chemotherapy treated tissues. PMID:20567614

  20. MR imaging of musculoskeletal tumors and tumor mimickers with intravenous gadolinium: experience with 242 patients

    International Nuclear Information System (INIS)

    Purpose. This pictorial essay reviews our experience with MR scans with gadolinium in patients with musculoskeletal tumors and tumor mimickers. Design. Review of 242 MR scans obtained in the initial evaluation of a possible primary musculoskeletal neoplasm. All scans included a T1-weighted, fat-suppressed sequence following intravenous administration of gadolinium. Results. MR scans with gadolinium did not contribute to differential diagnosis or patient management in 89% of the patients in this series. However, intravenous gadolinium did assist in guiding the biopsy of bulky lesions and evaluating treated tumor beds for possible recurrence. MR scans with gadolinium were sometimes helpful when the differential diagnosis included synovitis, Morton's neuroma or intramuscular myxoma, and when it was important to differentiate cystic from solid lesions. Conclusions. Routine use of gadolinium in every initial MR examination of a possible musculoskeletal mass is not warranted. However, there are appropriate selected indications for gadolinium administration as outlined above. (orig.). With 19 figs., 1 tab

  1. MR imaging of musculoskeletal tumors and tumor mimickers with intravenous gadolinium: experience with 242 patients

    Energy Technology Data Exchange (ETDEWEB)

    May, D.A. [Department of Radiology, Wilford Hall USAF Medical Center, San Antonio, TX (United States)]|[WHMC/PSRD, Lackland AFB, TX (United States); Good, R.B. [Department of Radiology, Wilford Hall USAF Medical Center, San Antonio, TX (United States); Smith, D.K. [Department of Radiology, Wilford Hall USAF Medical Center, San Antonio, TX (United States); Parsons, T.W. [Department of Orthopaedic Surgery, Wilford Hall USAF Medical Center, San Antonio, TX (United States)

    1997-01-01

    Purpose. This pictorial essay reviews our experience with MR scans with gadolinium in patients with musculoskeletal tumors and tumor mimickers. Design. Review of 242 MR scans obtained in the initial evaluation of a possible primary musculoskeletal neoplasm. All scans included a T1-weighted, fat-suppressed sequence following intravenous administration of gadolinium. Results. MR scans with gadolinium did not contribute to differential diagnosis or patient management in 89% of the patients in this series. However, intravenous gadolinium did assist in guiding the biopsy of bulky lesions and evaluating treated tumor beds for possible recurrence. MR scans with gadolinium were sometimes helpful when the differential diagnosis included synovitis, Morton`s neuroma or intramuscular myxoma, and when it was important to differentiate cystic from solid lesions. Conclusions. Routine use of gadolinium in every initial MR examination of a possible musculoskeletal mass is not warranted. However, there are appropriate selected indications for gadolinium administration as outlined above. (orig.). With 19 figs., 1 tab.

  2. A Prototype for an Agent-based Secure Electronic Marketplace including Reputation Tracking Mechanisms

    OpenAIRE

    Padovan Boris; Sackmann Stefan; Eymann Thorsten; Pippow Ingo

    2002-01-01

    The future of electronic commerce will be shaped by open, heterogeneous and complex structures, consisting of networked marketplaces. Software agents will interact and negotiate on behalf of their human (or organizational) principals. Principals will be able to implement fraudulent strategies in their agents, which cannot be countered by technical security alone. In the absence of a single correctional institution, agents will have to rely on social mechanisms for assessing reliability and re...

  3. Application of extracellular gadolinium-based MRI contrast agents and the risk of nephrogenic systemic fibrosis; Anwendung von extrazellulaeren gadoliniumhaltigen MR-Kontrastmitteln und Risiko der Nephrogenen Systemischen Fibrose

    Energy Technology Data Exchange (ETDEWEB)

    Heverhagen, J.T. [Univ. Hospital Bern (Switzerland). Inst. of Diagnostic, Interventional and Pediatric Radiology, Inselspital; Krombach, G.A. [Justus Liebig Univ. Hopsital Giessen (Germany). Diagnostic and Interventional Radiology; Gizewski, E. [Medical Univ. Innsbruck (Austria). Dept. of Neuroradiology

    2014-07-15

    Nephrogenic systemic fibrosis (NSF) is a serious, sometimes fatal disease. Findings in recent years have shown that a causal association between gadolinium containing contrast media and NSF is most likely. Therefore, the regulatory authorities have issued guidelines on the use of gadolinium-containing contrast media which have reduced the number of new cases of NSF to almost zero. However, it is for precisely this reason that the greatest care must still be taken to ensure that these guidelines are complied with. The most important factors are renal function, the quantity of gadolinium administered and coexisting diseases such as inflammation. All of these factors crucially influence the quantity of gadolinium released from the chelat in the body. This free gadolinium is thought to be the trigger for NSF. Other important factors are the stability of the gadolinium complex and furthermore the route of its elimination from the body. Partial elimination via the liver might be an additional protective mechanism. In conclusion, despite the NSF risk, contrast-enhanced MRI is a safe diagnostic procedure which can be used reliably and safely even in patients with severe renal failure, and does not necessarily have to be replaced by other methods.

  4. Novel sorbents for removal of gadolinium-based contrast agents in sorbent dialysis and hemoperfusion: preventive approaches to nephrogenic systemic fibrosis

    Energy Technology Data Exchange (ETDEWEB)

    Yantasee, Wassana; Fryxell, Glen E.; Porter, George A.; Pattamakomsan, Kanda; Sukwarotwat, Vichaya; Chouyyok, Wilaiwan; Koonsiripaiboon, View; Xu, Jide; Raymond, Kenneth N.

    2010-02-01

    Gd based contrast agents in many forms of organocomplex have recently been linked to a debilitating and a potentially fatal skin disease called Nephrogenic Systemic Fibrosis (NSF) in patients with renal failures. Free Gd released from the complexes by transmetallation is believed to be the most important trigger for NSF. Removal of Gd complex from the patients immediately after the contrast study would prevent the dissociation of Gd and should eliminate NSF as a complication. Although removal of Gd based contrast agents may be accomplished with conventional hemodialysis, it requires three hemodialysis sessions at 3 hours each to remove 98% of the contrast agents. In this work, mesoporous silica material that are functionalized with 1-hydroxy-2-pyridinone (1,2-HOPO-SAMMS®) has been evaluated for effective removal of both free and chelated Gd (Magnevist, a brand of gadopentetate dimeglumine) from the dialysate and sodium chloride solution. The material has high affinity, rapid removal rate, and large sorption capacity for both free and chelated Gd, the properties that are far superior to those of activated carbon and zirconium phosphate currently used in the state-of-the-art sorbent dialysis systems. 99% of both free and chelated Gd would be removed in a single pass thru the sorbent bed of 1,2-HOPO-SAMMS®. The sorbent provides an effective and predicable strategy for removing Gd from patients with impaired renal function, thus it would allow for the continued use of contrast MRI while removing the risk of NSF and would represent a safe alternative to traditional contrast studies in the patient population.

  5. The effect of demagnetization on the magnetocaloric properties of gadolinium

    DEFF Research Database (Denmark)

    Bahl, Christian Robert Haffenden; Nielsen, Kaspar Kirstein

    2009-01-01

    Gadolinium displays a strong magnetocaloric effect at temperatures close to room temperature making it useful in the field of room temperature magnetic refrigeration. We discuss the importance of including the effects of the demagnetization field when considering the magnetocaloric properties...... of gadolinium. The adiabatic temperature change DeltaTad of gadolinium sheets upon application of a magnetic field has been measured at a range of applied magnetic fields and sample orientations. A significant dependence of DeltaTad on the sample orientation is observed. This can be accounted...

  6. On the Use of Molecular Weight Cutoff Cassettes to Measure Dynamic Relaxivity of Novel Gadolinium Contrast Agents: Example Using Hyaluronic Acid Polymer Complexes in Phosphate-Buffered Saline

    Directory of Open Access Journals (Sweden)

    Nima Kasraie

    2011-01-01

    Full Text Available The aims of this study were to determine whether standard extracellular contrast agents of Gd(III ions in combination with a polymeric entity susceptible to hydrolytic degradation over a finite period of time, such as Hyaluronic Acid (HA, have sufficient vascular residence time to obtain comparable vascular imaging to current conventional compounds and to obtain sufficient data to show proof of concept that HA with Gd-DTPA ligands could be useful as vascular imaging agents. We assessed the dynamic relaxivity of the HA bound DTPA compounds using a custom-made phantom, as well as relaxation rates at 10.72 MHz with concentrations ranging between 0.09 and 7.96 mM in phosphate-buffered saline. Linear dependences of static longitudinal relaxation rate (R1 on concentration were found for most measured samples, and the HA samples continued to produce high signal strength after 24 hours after injection into a dialysis cassette at 3T, showing superior dynamic relaxivity values compared to conventional contrast media such as Gd-DTPA-BMA.

  7. On the Use of Molecular Weight Cutoff Cassettes to Measure Dynamic Relaxivity of Novel Gadolinium Contrast Agents: Example Using Hyaluronic Acid Polymer Complexes in Phosphate-Buffered Saline

    International Nuclear Information System (INIS)

    The aims of this study were to determine whether standard extracellular contrast agents of Gd(III) ions in combination with a polymeric entity susceptible to hydrolytic degradation over a finite period of time, such as Hyaluronic Acid (HA), have sufficient vascular residence time to obtain comparable vascular imaging to current conventional compounds and to obtain sufficient data to show proof of concept that HA with Gd-DTPA ligands could be useful as vascular imaging agents. We assessed the dynamic relaxivity of the HA bound DTPA compounds using a custom-made phantom, as well as relaxation rates at 10.72 MHz with concentrations ranging between 0.09 and 7.96 mM in phosphate-buffered saline. Linear dependences of static longitudinal relaxation rate (R1) on concentration were found for most measured samples, and the HA samples continued to produce high signal strength after 24 hours after injection into a dialysis cassette at 3T, showing superior dynamic relaxivity values compared to conventional contrast media such as Gd-DTPA-BMA

  8. Gadolinium and nephrogenic systemic fibrosis: time to tighten practice

    Energy Technology Data Exchange (ETDEWEB)

    Mendichovszky, Iosif A. [University College London, Radiology and Physics Unit, Institute of Child Health, London (United Kingdom); Marks, Stephen D. [Great Ormond Street Hospital for Children NHS Trust, Department of Paediatric Nephrology, London (United Kingdom); Simcock, Clare M.; Olsen, Oeystein E. [Great Ormond Street Hospital for Children NHS Trust, Department of Radiology, London (United Kingdom)

    2008-05-15

    Nephrogenic systemic fibrosis (NSF) is a relatively new entity, first described in 1997. Few cases have been reported, but the disease has high morbidity and mortality. To date it has been seen exclusively in patients with renal dysfunction. There is an emerging link with intravenous injection of gadolinium contrast agents, which has been suggested as a main triggering factor, with a lag time of days to weeks. Risk factors include the severity of renal impairment, major surgery, vascular events and other proinflammatory conditions. There is no reason to believe that children have an altered risk compared to the adult population. It is important that the paediatric radiologist acknowledges emerging information on NSF but at the same time considers the risk:benefit ratio prior to embarking on alternative investigations, as children with chronic kidney disease require high-quality diagnostic imaging. (orig.)

  9. Nephrogenic systemic fibrosis and gadolinium-based contrast media

    DEFF Research Database (Denmark)

    Thomsen, Henrik S; Morcos, Sameh K; Almén, Torsten;

    2012-01-01

    PURPOSE: To update the guidelines of the Contrast Media Safety Committee (CMSC) of the European Society of Urogenital Radiology (ESUR) on nephrogenic systemic fibrosis and gadolinium-based contrast media. AREAS COVERED: Topics reviewed include the history, clinical features and prevalence...... of nephrogenic systemic fibrosis and the current understanding of its pathophysiology. The risk factors for NSF are discussed and prophylactic measures are recommended. The stability of the different gadolinium-based contrast media and the potential long-term effects of gadolinium in the body have also been...... reviewed. KEY POINTS : • Clinical features, risk factors and prevention of nephrogenic systemic fibrosis are reviewed • Patients with GFR below 30 ml/min/1.73 m ( 2 ) have increased risk of developing NSF • Low stability gadolinium contrast media show the strongest association with NSF • Following...

  10. Importance of outer-sphere and aggregation phenomena in the relaxation properties of phosphonated gadolinium complexes with potential applications as MRI contrast agents.

    Science.gov (United States)

    Elhabiri, Mourad; Abada, Sabah; Sy, Mohamadou; Nonat, Aline; Choquet, Philippe; Esteban-Gómez, David; Cassino, Claudio; Platas-Iglesias, Carlos; Botta, Mauro; Charbonnière, Loïc J

    2015-04-20

    A series composed of a tetra-, a tris- and a bisphosphonated ligand based on a pyridine scaffold (L(4) , L(3) and L(2) , respectively) was studied within the frame of lanthanide (Ln) coordination. The stability constants of the complexes formed with lanthanide cations (Ln=La, Nd, Eu, Gd, Tb, Er and Lu) were determined by potentiometry in aqueous solutions (25.0 °C, 0.1 M NaClO4 ), showing that the tetraphosphonated complexes are among the most stable Ln(III) complexes reported in the literature. The complexation of L(4) was further studied by different titration experiments using mass spectrometry and various spectroscopic techniques including UV/Vis absorption, and steady state and time-resolved luminescence (Ln=Eu and Tb). Titration experiments confirmed the formation of highly stable [LnL(4) ] complexes. (31) P NMR experiments of the LuL(4) complex revealed an intramolecular interconversion process which was studied at different temperatures and was rationalized by DFT modelling. The relaxivity properties of the Gd(III) complexes were studied by recording their (1) H NMRD profiles at various temperatures, by temperature dependent (17) O NMR experiments (GdL(4) ) and by pH dependent relaxivity measurements at 0.47 T (GdL(3) and GdL(2) ). In addition to the high relaxivity values observed for all complexes, the results showed an important second-sphere contribution to relaxivity and pH dependent variations associated with the formation of aggregates for GdL(2) and GdL(3) . Finally, intravenous injection of GdL(4) to a mouse was followed by dynamic MRI imaging at 1.5 T, which showed that the complex can be immediately found in the blood stream and rapidly eliminated through the liver and in large part through the kidneys.

  11. Distribution profile of gadolinium in gadolinium chelate-treated renally-impaired rats: role of pharmaceutical formulation.

    Science.gov (United States)

    Fretellier, Nathalie; Salhi, Mariem; Schroeder, Josef; Siegmund, Heiko; Chevalier, Thibaut; Bruneval, Patrick; Jestin-Mayer, Gaëlle; Delaloge, Francette; Factor, Cécile; Mayer, Jean-François; Fabicki, Jean-Michel; Robic, Caroline; Bonnemain, Bruno; Idée, Jean-Marc; Corot, Claire

    2015-05-25

    While not acutely toxic, chronic hepatic effect of certain gadolinium chelates (GC), used as contrast agent for magnetic resonance imaging, might represent a risk in renally-impaired patients due to free gadolinium accumulation in the liver. To answer this question, this study investigated the consequences of the presence of small amounts of either a soluble gadolinium salt ("free" Gd) or low-stability chelating impurity in the pharmaceutical solution of gadoteric acid, a macrocyclic GC with high thermodynamic and kinetic stabilities, were investigated in renally-impaired rats. Renal failure was induced by adding 0.75% adenine in the diet for three weeks. The pharmaceutical and commercial solution of gadoteric acid was administered (5 daily intravenous injections of 2.5 mmol Gd/kg) either alone or after being spiked with either "free" gadolinium (i.e., 0.04% w/v) or low-stability impurity (i.e., 0.06 w/v). Another GC, gadodiamide (low thermodynamic and kinetic stabilities) was given as its commercial solution at a similar dose. Non-chelated gadolinium was tested at two doses (0.005 and 0.01 mmol Gd/kg) as acetate salt. Gadodiamide induced systemic toxicity (mortality, severe epidermal and dermal lesions) and substantial tissue Gd retention. The addition of very low amounts of "free", non-chelated gadolinium or low thermodynamic stability impurity to the pharmaceutical solution of the thermodynamically stable GC gadoteric acid resulted in substantial capture of metal by the liver, similar to what was observed in "free" gadolinium salt-treated rats. Relaxometry studies strongly suggested the presence of free and soluble gadolinium in the liver. Electron microscopy examinations revealed the presence of free and insoluble gadolinium deposits in hepatocytes and Kupffer cells of rats treated with gadoteric acid solution spiked with low-stability impurity, free gadolinium and gadodiamide, but not in rats treated with the pharmaceutical solution of gadoteric acid. The

  12. MR imaging with metal artifact-reducing sequences and gadolinium contrast agent in a case-control study of periprosthetic abnormalities in patients with metal-on-metal hip prostheses

    Energy Technology Data Exchange (ETDEWEB)

    Mueller, Gunilla M.; Mueller, Markus F.; Ekberg, Olle [Lund University, Skaane University Hospital, Department of Radiology, Malmoe (Sweden); Maansson, Sven [Lund University, Skaane University Hospital, Department of Medical Radiation Physics, Malmoe (Sweden); Schewelov, Thord von [Lund University, Skaane University Hospital, Department of Orthopedic Surgery, Malmoe (Sweden); Nittka, Mathias [Siemens AG, Healthcare Sector, Erlangen (Germany); Lundin, Bjoern [Lund University, Skaane University Hospital, Department of Radiology, Lund (Sweden)

    2014-08-15

    To apply and compare magnetic resonance imaging (MRI) metal artifact reducing sequences (MARS) including subtraction imaging after contrast application in patients with metal-on-metal (MoM) hip prostheses, investigate the prevalence and characteristics of periprosthetic abnormalities, as well as their relation with pain and risk factors. Fifty-two MoM prostheses (35 cases with pain and or risk factors, and 17 controls) in 47 patients were examined in a 1.5-T MR scanner using MARS: turbo spin echo (TSE) with high readout bandwidth with and without view angle tilting (VAT), TSE with VAT and slice encoding for metal artifact correction (SEMAC), short tau inversion recovery (STIR) with matched RF pulses, and post-contrast imaging. The relations of MRI findings to pain and risk factors were analyzed and in five revised hips findings from operation, histology, and MRI were compared. TSE VAT detected the highest number of osteolyses. Soft tissue mass, effusion, and capsular thickening were common, whereas osteolysis in acetabulum and femur were less frequent. Contrast enhancement occurred in bone, synovia, joint capsule, and the periphery of soft tissue mass. There was no significant relation between MRI findings and pain or risk factors. MARS and gadolinium subtraction imaging are useful for evaluation of complications to MoM prosthesis. TSE VAT had the highest sensitivity for osteolysis. Contrast enhancement might indicate activation of aseptic lymphocyte-dominated vasculitis-associated lesion (ALVAL). Pain, small head, or steep prosthesis inclination angle are not useful predictors of periprosthetic abnormalities, and wide indications for MR follow-up are warranted. (orig.)

  13. Studies of MRI relaxivities of gadolinium-labeled dendrons

    Science.gov (United States)

    Pan, Hongmu; Daniel, Marie-Christine

    2011-05-01

    In cancer detection, imaging techniques have a great importance in early diagnosis. The more sensitive the imaging technique and the earlier the tumor can be detected. Contrast agents have the capability to increase the sensitivity in imaging techniques such as magnetic resonance imaging (MRI). Until now, gadolinium-based contrast agents are mainly used for MRI, and show good enhancement. But improvement is needed for detection of smaller tumors at the earliest stage possible. The dendrons complexed with Gd(DOTA) were synthesized and evaluated as a new MRI contrast agent. The longitudinal and transverse relaxation effects were tested and compared with commercial drug Magnevist, Gd(DTPA).

  14. Toxic effects of mercury, lead and gadolinium on vascular reactivity

    Directory of Open Access Journals (Sweden)

    D.V. Vassallo

    2011-09-01

    Full Text Available Heavy metals have been used in a wide variety of human activities that have significantly increased both professional and environmental exposure. Unfortunately, disasters have highlighted the toxic effects of metals on different organs and systems. Over the last 50 years, the adverse effects of chronic lead, mercury and gadolinium exposure have been underscored. Mercury and lead induce hypertension in humans and animals, affecting endothelial function in addition to their other effects. Increased cardiovascular risk after exposure to metals has been reported, but the underlying mechanisms, mainly for short periods of time and at low concentrations, have not been well explored. The presence of other metals such as gadolinium has raised concerns about contrast-induced nephropathy and, interestingly, despite this negative action, gadolinium has not been defined as a toxic agent. The main actions of these metals, demonstrated in animal and human studies, are an increase of free radical production and oxidative stress and stimulation of angiotensin I-converting enzyme activity, among others. Increased vascular reactivity, highlighted in the present review, resulting from these actions might be an important mechanism underlying increased cardiovascular risk. Finally, the results described in this review suggest that mercury, lead and gadolinium, even at low doses or concentrations, affect vascular reactivity. Acting via the endothelium, by continuous exposure followed by their absorption, they can increase the production of free radicals and of angiotensin II, representing a hazard for cardiovascular function. In addition, the actual reference values, considered to pose no risk, need to be reduced.

  15. Toxic effects of mercury, lead and gadolinium on vascular reactivity.

    Science.gov (United States)

    Vassallo, D V; Simões, M R; Furieri, L B; Fioresi, M; Fiorim, J; Almeida, E A S; Angeli, J K; Wiggers, G A; Peçanha, F M; Salaices, M

    2011-09-01

    Heavy metals have been used in a wide variety of human activities that have significantly increased both professional and environmental exposure. Unfortunately, disasters have highlighted the toxic effects of metals on different organs and systems. Over the last 50 years, the adverse effects of chronic lead, mercury and gadolinium exposure have been underscored. Mercury and lead induce hypertension in humans and animals, affecting endothelial function in addition to their other effects. Increased cardiovascular risk after exposure to metals has been reported, but the underlying mechanisms, mainly for short periods of time and at low concentrations, have not been well explored. The presence of other metals such as gadolinium has raised concerns about contrast-induced nephropathy and, interestingly, despite this negative action, gadolinium has not been defined as a toxic agent. The main actions of these metals, demonstrated in animal and human studies, are an increase of free radical production and oxidative stress and stimulation of angiotensin I-converting enzyme activity, among others. Increased vascular reactivity, highlighted in the present review, resulting from these actions might be an important mechanism underlying increased cardiovascular risk. Finally, the results described in this review suggest that mercury, lead and gadolinium, even at low doses or concentrations, affect vascular reactivity. Acting via the endothelium, by continuous exposure followed by their absorption, they can increase the production of free radicals and of angiotensin II, representing a hazard for cardiovascular function. In addition, the actual reference values, considered to pose no risk, need to be reduced.

  16. Gadolinium study for a water Cherenkov detector

    CERN Document Server

    Kibayashi, Atsuko

    2009-01-01

    Modification of large water Cherenkov detectors by addition of gadolinium has been proposed. The large cross section for neutron capture on Gd will greatly improve the sensitivity to antielectron neutrinos from supernovae and reactors. A five-year project to build and develop a prototype detector based on Super-Kamiokande (SK) has started. We are performing various studies, including a material soak test in Gd solution, light attenuation length measurements, purification system development, and neutron tagging efficiency measurements using SK data and a Geant4-based simulation. We present an overview of the project and the recent R&D results.

  17. Gadolinium-based nanoparticles for theranostic MRI-radiosensitization

    OpenAIRE

    Lux, François; Sancey, Lucie; Bianchi, Andrea; Crémillieux, Yannick; Roux, Stéphane; Tillement, Olivier

    2015-01-01

    A rapid development of gadolinium-based nanoparticles is observed due to their attractive properties as MRI-positive contrast agents. Indeed, they display high relaxivity, adapted biodistribution and passive uptake in the tumor thanks to enhanced permeability and retention effect. In addition to these imaging properties, it has been recently shown that they can act as effective radiosensitizers under different types of irradiation (radiotherapy, neutron therapy or hadron therapy). These new t...

  18. Laser isotope separation of gadolinium

    International Nuclear Information System (INIS)

    Basic studies on laser isotope separation of gadolinium were performed. Spectroscopic data were obtained such as isotope shifts and hyperfine structures using an atomic beam. Enrichment of 157Gd up to 80% was observed by three-step photoionization experiment using linearly polarized dye lasers. Design of an separation system was discussed by the help of computer calculation of excitation dynamics. (author)

  19. Structural and chemical analysis of gadolinium halides encapsulated within WS2 nanotubes

    Science.gov (United States)

    Anumol, E. A.; Enyashin, Andrey N.; Batra, Nitin M.; Costa, Pedro M. F. J.; Deepak, Francis Leonard

    2016-06-01

    The hollow cavities of nanotubes serve as templates for the growth of size- and shape-confined functional nanostructures, giving rise to novel materials and properties. In this work, considering their potential application as MRI contrast agents, gadolinium halides are encapsulated within the hollow cavities of WS2 nanotubes by capillary filling to obtain GdX3@WS2 nanotubes (where X = Cl, Br or I and @ means encapsulated in). Aberration corrected scanning/transmission electron microscopy (S/TEM) and spectroscopy is employed to understand the morphology and composition of the GdI3@WS2 nanotubes. The three dimensional morphology is studied with STEM tomography but understanding the compositional information is non-trivial due to the presence of multiple high atomic number elements. Therefore, energy dispersive X-ray spectroscopy (EDS) tomography was employed revealing the three dimensional chemical composition. Molecular dynamics simulations of the filling procedure shed light into the mechanics behind the formation of the confined gadolinium halide crystals. The quasi-1D system employed here serves as an example of a TEM-based chemical nanotomography method that could be extended to other materials, including beam-sensitive soft materials.The hollow cavities of nanotubes serve as templates for the growth of size- and shape-confined functional nanostructures, giving rise to novel materials and properties. In this work, considering their potential application as MRI contrast agents, gadolinium halides are encapsulated within the hollow cavities of WS2 nanotubes by capillary filling to obtain GdX3@WS2 nanotubes (where X = Cl, Br or I and @ means encapsulated in). Aberration corrected scanning/transmission electron microscopy (S/TEM) and spectroscopy is employed to understand the morphology and composition of the GdI3@WS2 nanotubes. The three dimensional morphology is studied with STEM tomography but understanding the compositional information is non-trivial due to the

  20. Discovery of Samarium, Europium, Gadolinium, and Terbium Isotopes

    CERN Document Server

    May, E

    2012-01-01

    Currently, thirty-four samarium, thirty-four europium, thirty-one gadolinium, and thirty-one terbium isotopes have been observed and the discovery of these isotopes is discussed here. For each isotope a brief synopsis of the first refereed publication, including the production and identification method, is presented.

  1. Nuclear-grade gadolinium oxide (Gd2O3) powder

    International Nuclear Information System (INIS)

    The specification covers the minimum chemical and physical characteristics of nuclear-grade gadolinium oxide powder intended for subsequent processing for use in nuclear fuel application, for example, as an addition to uranium dioxide. The specification includes a description of chemical and physical requirements, cleanliness, quality control, inspection, certification, rejection, packaging, and shipping

  2. 一种肝脏类生物相容性氨基酸共聚物磁共振成像造影剂%A Biocompatible Gadolinium (III)-Poly (Aspartic Acid-Co-Phenylalanine) for Liver Magnetic Resonance Imaging Contrast Agent

    Institute of Scientific and Technical Information of China (English)

    肖研; 湛游洋; 薛蓉; 李晓晶; 裴奉奎; 冯江华; 占博涵

    2015-01-01

    A new biocompatible gadolinium (III)-macromolecule (AP-EDA-DOTA-Gd) was developed as a magnetic resonance imaging (MRI) contrast agent. Poly (aspartic acid-co- phenylalanine) was synthesized, modified via ethylenediamine, conjugated with 1,4,7,10- tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA) and finally chelated gadolinium (III), yielding gadolinium (III)-based macromolecule (AP-EDA-DOTA-Gd). The hemolytic tests showed the hemocompatibility of this gadolinium (III)-based macromolecular conjugate.In vitro, AP-EDA-DOTA-Gd could be degraded, when it was incubated with cathepsin B in phosphate buffered solution (pH = 5.5). TheT1-relaxivity (15.95 mmol–1·L·s–1) of AP-EDA-DOTA-Gd was 2.9 times of that (5.59 mmol–1·L·s–1) of the clinical MRI contrast agent (Gd-DOTA) at 1.5 T and 25℃. The liver enhancement of AP-EDA-DOTA-Gd was 63.5±6.1% during the maximum enhancement time (50-80 min), which was much better than that of Gd-DOTA (24.2±2.9%, 10-30 min). AP-EDA-DOTA-Gd was expected to be a potential liver MRI contrast agent.%一种新型的以天门冬氨酸-苯丙氨酸共聚物为载体的大分子生物相容性材料(AP-EDA-DOTA-Gd)被制备出来作为磁共振成像造影剂.首先合成了天门冬氨酸-苯丙氨酸共聚物,之后利用乙二胺将1,4,7,10-四氮杂环十二烷-1,4,7,10-四乙酸(DOTA)连接到共聚物上,最后将钆离子通过配位的作用方式连接到 DOTA 上,最终得到大分子AP-EDA-DOTA-Gd.体外溶血性试验表明AP-EDA-DOTA-Gd具有较好的血液相容性.在pH =5.5的组织蛋白酶B的磷酸缓冲液中,AP-EDA-DOTA-Gd能够降解.AP- EDA-DOTA-Gd的体外弛豫效率(15.95 mmol–1×L×s–1)为目前临床应用的Gd-DOTA (5.59 mmol–1×L×s–1)的2.9倍.大鼠肝脏成像实验结果表明,AP-EDA-DOTA-Gd对于肝组织的成像增强对比度为63.5±6.1%远高于Gd-DOTA (24.2±2.9%).

  3. Type of MRI contrast, tissue gadolinium, and fibrosis.

    Science.gov (United States)

    Do, Catherine; Barnes, Jeffrey L; Tan, Chunyan; Wagner, Brent

    2014-10-01

    It has been presupposed that the thermodynamic stability constant (K(therm)) of gadolinium-based MRI chelates relate to the risk of precipitating nephrogenic systemic fibrosis. The present study compared low-K(therm) gadodiamide with high-K(therm) gadoteridol in cultured fibroblasts and rats with uninephrectomies. Gadolinium content was assessed using scanning electron microscopy equipped with energy-dispersive X-ray spectroscopy in paraffin-embedded tissues. In vitro, fibroblasts demonstrated dose-dependent fibronectin generation, transforming growth factor-β production, and expression of activated myofibroblast stress fiber protein α-smooth muscle actin. There were negligible differences with respect to toxicity or proliferation between the two contrast agents. In the rodent model, gadodiamide treatment led to greater skin fibrosis and dermal cellularity than gadoteridol. In the kidney, both contrast agents led to proximal tubule vacuolization and increased fibronectin accumulation. Despite large detectable gadolinium signals in the spleen, skin, muscle, and liver from the gadodiamide-treated group, contrast-induced fibrosis appeared to be limited to the skin and kidney. These findings support the hypothesis that low-K(therm) chelates have a greater propensity to elicit nephrogenic systemic fibrosis and demonstrate that certain tissues are resistant to these effects.

  4. Growth control in colon epithelial cells: gadolinium enhances calcium-mediated growth regulation.

    Science.gov (United States)

    Attili, Durga; Jenkins, Brian; Aslam, Muhammad Nadeem; Dame, Michael K; Varani, James

    2012-12-01

    Gadolinium, a member of the lanthanoid family of transition metals, interacts with calcium-binding sites on proteins and other biological molecules. The overall goal of the present investigation was to determine if gadolinium could enhance calcium-induced epithelial cell growth inhibition in the colon. Gadolinium at concentrations as low as 1-5 μM combined with calcium inhibits proliferation of human colonic epithelial cells more effectively than calcium alone. Gadolinium had no detectable effect on calcium-induced differentiation in the same cells based on change in cell morphology, induction of E-cadherin synthesis, and translocation of E-cadherin from the cytosol to the cell surface. When the colon epithelial cells were treated with gadolinium and then exposed to increased calcium concentrations, movement of extracellular calcium into the cell was suppressed. In contrast, gadolinium treatment had no effect on ionomycin-induced release of stored intracellular calcium into the cytoplasm. Whether these in vitro observations can be translated into an approach for reducing abnormal proliferation in the colonic mucosa (including polyp formation) is not known. These results do, however, provide an explanation for our recent findings that a multi-mineral supplement containing all of the naturally occurring lanthanoid metals including gadolinium are more effective than calcium alone in preventing colon polyp formation in mice on a high-fat diet.

  5. 含钆对比剂与肾源性系统性纤维化关联度变化趋势的Meta分析及因果解析%The change of association between nephrogenic systemic ifbrosis and gadolinium-based contrast agents:an updated meta-analysis applying Hill’s criteria

    Institute of Scientific and Technical Information of China (English)

    张斌; 梁龙; 陈文波; 李新云; 郑君惠; 梁长虹; 张水兴

    2015-01-01

    目的:探讨含钆对比剂(gadolinium-based contrast agents, GBCAs)与肾源性系统性纤维化(nephrogenic systemic fibrosis, NSF)二者之间是否为因果相关以及关联强度随时间变化的趋势。材料与方法检索PubMed、Wiley Online Library、Cochrane Library数据库。采用R软件进行统计学分析,计算OR值及95%CI,并进行累积Meta分析,采用希尔标准(Hill’s criteria)证明是否为因果相关。结果本研究共纳入14篇文献,6398例患者,其中3篇由于NSF发生例数为0而未能纳入最后的定量分析。Meta分析结果显示,钆对比剂暴露可能会增加肾源性系统性纤维化发生的风险(OR=16.50,95%CI:7.46~36.53,P<0.01),其中包括钆双胺(OR=20.04,95%CI:3.72~107.78,P<0.01)。希尔标准相关证据基本达到,表明二者之间为因果关系。累积Meta分析结果显示自2007年之后OR值呈减小趋势。结论钆对比剂暴露与肾源性系统性纤维化之间较强相关,且该相关性为因果关系,其关联强度在2007年之后较明显减弱。%Objective:To examine whether a causal link exists between gadolinium-based contrast agents (GBCAs) and nephrogenic systemic ifbrosis (NSF) and if the link changes over time. Materials and Methods:Studies for analysis were identiifed by searching the PubMed, the Wiley Online Library, and the Cochrane Central Register of Controlled Trials up to December 18, 2014. Pooled odds ratios (OR) with 95%conifdence intervals (CI) was calculated by using the ifxed-effects model. Statistical heterogeneity was assessed by Cochrane’s Q test and I2 statistics. Publication bias was evaluated using peters test, funnel plots and fail-safe N. Quality assessment of included studies using Newcastle-Ottawa Scale (NOS). Inlfuence analysis and cumulative meta –analysis were also conducted in this study. All statistical analyses were performed by R software (R Core Team. R:A language and environment for statistical

  6. Structural and Chemical Analysis of Gadolinium Halides Encapsulated within WS 2 Nanotubes

    KAUST Repository

    Anumol, E A

    2016-05-18

    The hollow cavities of nanotubes could serve as templates for the growth of size- and shape-confined functional nanostructures, giving rise to novel materials and properties. In this work, considering their potential application as MRI contrast agents, gadolinium halides are encapsulated within the hollow cavities of inorganic nanotubes of WS2 by capillary filling to obtain GdX3@WS2 nanotubes (where X = Cl, Br or I and @ means encapsulated in). Aberration corrected scanning/transmission electron microscopy (S/TEM) and spectroscopy is employed to understand the morphology and composition of the GdI3@WS2 nanotubes. The three dimensional morphology is studied with STEM tomography but understanding the compositional information is a non-trivial matter due to the presence of multiple high atomic number elements. Therefore, energy dispersive X-ray spectroscopy (EDS) tomography was employed revealing the three dimensional chemical composition. Molecular dynamics simulations of the filling procedure shed light into the mechanics behind the formation of the confined gadolinium halide crystals. The quasi-1D system employed here serves as an example of a TEM-based chemical nanotomography method that could be extended to other materials, including beam-sensitive soft materials.

  7. Gadolinium-containing contrast media for radiographic examinations: a position paper

    Energy Technology Data Exchange (ETDEWEB)

    Thomsen, Henrik S. [Department of Diagnostic Radiology 54E2, Copenhagen University Hospital at Herlev, Herlev Ringvej 75, 2730 Herlev (Denmark); Almen, Torsten [Lybska vaegen 10, 23940 Falsterbo (Sweden); Morcos, Sameh K. [Department of Diagnostic Imaging, Northern General Hospital, Sheffield Teaching Hospitals NHS Trust, Sheffield S5 7AU (United Kingdom); 4

    2002-10-01

    Recently, it has been suggested that gadolinium-based contrast media could be used for radiological examinations in patients with significant renal impairment, previous severe generalized reaction to iodinated contrast media or thyroid disease about to undergo radioactive iodine treatment; however, the indications for and risks of using gadolinium agents in this way are not well known; hence, the Contrast Media Safety Committee of The European Society of Urogenital Radiology reviewed the literature to issue a position paper on this subject. A comprehensive literature review was performed and the resulting report was discussed at the Ninth European Symposium on Urogenital Radiology in Genoa, Italy, June 2002. Review of the literature indicates that according to experimental data on animals gadolinium-based contrast media have more nephrotoxic potential than iodinated contrast media in equivalent X-ray attenuating doses; therefore, gadolinium-based contrast media should not replace iodinated contrast media in patients with renal insufficiency for radiographic examinations. For patients with previous severe generalized reactions to iodinated contrast media, and in patients about to undergo thyroid treatment with radioactive iodine gadolinium-based contrast media in approved intravenous doses, up to 0.3 mmol/kg body weight will not give diagnostic radiographic information in most cases. Gadolinium-based contrast media are not approved for radiographic examinations. (orig.)

  8. Gadolinium-containing contrast media for radiographic examinations: a position paper

    International Nuclear Information System (INIS)

    Recently, it has been suggested that gadolinium-based contrast media could be used for radiological examinations in patients with significant renal impairment, previous severe generalized reaction to iodinated contrast media or thyroid disease about to undergo radioactive iodine treatment; however, the indications for and risks of using gadolinium agents in this way are not well known; hence, the Contrast Media Safety Committee of The European Society of Urogenital Radiology reviewed the literature to issue a position paper on this subject. A comprehensive literature review was performed and the resulting report was discussed at the Ninth European Symposium on Urogenital Radiology in Genoa, Italy, June 2002. Review of the literature indicates that according to experimental data on animals gadolinium-based contrast media have more nephrotoxic potential than iodinated contrast media in equivalent X-ray attenuating doses; therefore, gadolinium-based contrast media should not replace iodinated contrast media in patients with renal insufficiency for radiographic examinations. For patients with previous severe generalized reactions to iodinated contrast media, and in patients about to undergo thyroid treatment with radioactive iodine gadolinium-based contrast media in approved intravenous doses, up to 0.3 mmol/kg body weight will not give diagnostic radiographic information in most cases. Gadolinium-based contrast media are not approved for radiographic examinations. (orig.)

  9. Standard specification for sintered gadolinium oxide-uranium dioxide pellets

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2008-01-01

    1.1 This specification is for finished sintered gadolinium oxide-uranium dioxide pellets for use in light-water reactors. It applies to gadolinium oxide-uranium dioxide pellets containing uranium of any 235U concentration and any concentration of gadolinium oxide. 1.2 This specification recognizes the presence of reprocessed uranium in the fuel cycle and consequently defines isotopic limits for gadolinium oxide-uranium dioxide pellets made from commercial grade UO2. Such commercial grade UO2 is defined so that, regarding fuel design and manufacture, the product is essentially equivalent to that made from unirradiated uranium. UO2 falling outside these limits cannot necessarily be regarded as equivalent and may thus need special provisions at the fuel fabrication plant or in the fuel design. 1.3 This specification does not include (1) provisions for preventing criticality accidents or (2) requirements for health and safety. Observance of this specification does not relieve the user of the obligation to be aw...

  10. Removal of gadolinium nitrate from heavy water

    Energy Technology Data Exchange (ETDEWEB)

    Wilde, E.W.

    2000-03-22

    Work was conducted to develop a cost-effective process to purify 181 55-gallon drums containing spent heavy water moderator (D2O) contaminated with high concentrations of gadolinium nitrate, a chemical used as a neutron poison during former nuclear reactor operations at the Savannah River Site (SRS). These drums also contain low level radioactive contamination, including tritium, which complicates treatment options. Presently, the drums of degraded moderator are being stored on site. It was suggested that a process utilizing biological mechanisms could potentially lower the total cost of heavy water purification by allowing the use of smaller equipment with less product loss and a reduction in the quantity of secondary waste materials produced by the current baseline process (ion exchange).

  11. Gadolinium-induced nephrogenic systemic fibrosis: the rise and fall of an iatrogenic disease

    DEFF Research Database (Denmark)

    Bennett, Charles L; Qureshi, Zaina P; Sartor, A Oliver;

    2012-01-01

    % of these cases, and two hospitals in Denmark account for 4% of these reports. We review Denmark's identification and subsequent rapid eradication of NSF. METHODS.: NSF reports from clinicians, the Danish Medicines Agency (DMA) and gadolinium-based contrast agents (GBCAs) manufacturers were reviewed (2002...

  12. Gadolinium-based nanoparticles for theranostic MRI-radiosensitization.

    Science.gov (United States)

    Lux, François; Sancey, Lucie; Bianchi, Andrea; Crémillieux, Yannick; Roux, Stéphane; Tillement, Olivier

    2015-01-01

    A rapid development of gadolinium-based nanoparticles is observed due to their attractive properties as MRI-positive contrast agents. Indeed, they display high relaxivity, adapted biodistribution and passive uptake in the tumor thanks to enhanced permeability and retention effect. In addition to these imaging properties, it has been recently shown that they can act as effective radiosensitizers under different types of irradiation (radiotherapy, neutron therapy or hadron therapy). These new therapeutic modalities pave the way to therapy guided by imaging and to personalized medicine.

  13. The High Radiosensitizing Efficiency of a Trace of Gadolinium-Based Nanoparticles in Tumors

    Science.gov (United States)

    Dufort, Sandrine; Le Duc, Géraldine; Salomé, Murielle; Bentivegna, Valerie; Sancey, Lucie; Bräuer-Krisch, Elke; Requardt, Herwig; Lux, François; Coll, Jean-Luc; Perriat, Pascal; Roux, Stéphane; Tillement, Olivier

    2016-07-01

    We recently developed the synthesis of ultrasmall gadolinium-based nanoparticles (GBN), (hydrodynamic diameter contrast agents for magnetic resonance imaging (MRI) and as radiosensitizers. The attempt to determine the most opportune delay between the intravenous injection of GBN and the irradiation showed that a very low content of radiosensitizing nanoparticles in the tumor area is sufficient (0.1 μg/g of particles, i.e. 15 ppb of gadolinium) for an important increase of the therapeutic effect of irradiation. Such a promising and unexpected result is assigned to a suited distribution of GBN within the tumor, as revealed by the X-ray fluorescence (XRF) maps.

  14. The use of iodinated and gadolinium contrast media during pregnancy and lactation

    International Nuclear Information System (INIS)

    The use of iodinated or gadolinium-based contrast media in pregnant or lactating women often causes concerns in the radiology department because of the principle of not exposing a fetus or neonate to any drugs. Because of the uncertainty about the use of contrast media during pregnancy and lactation, the Contrast Media Safety Committee of the European Society of Urogenital Radiology decided to review the literature and draw up guidelines. An extensive literature search was carried out and summarized in a report. Based on the limited information available, simple guidelines have been drawn up. The report and guidelines were discussed at the 11th European Symposium on Urogenital Radiology in Santiago de Compostela, Spain. Mutagenic and teratogenic effects have not been described after administration of gadolinium or iodinated contrast media. Free iodide in radiographic contrast medium given to the mother has the potential to depress fetal/neonatal thyroid function. Neonatal thyroid function should be checked during the 1st week if iodinated contrast media have been given during pregnancy. No effect on the fetus has been seen after gadolinium contrast media. Only tiny amounts of iodinated or gadolinium-based contrast medium given to a lactating mother reach the milk, and only a minute proportion entering the baby's gut is absorbed. The very small potential risk associated with absorption of contrast medium may be considered insufficient to warrant stopping breast-feeding for 24 h following either iodinated or gadolinium contrast agents. (orig.)

  15. The use of iodinated and gadolinium contrast media during pregnancy and lactation

    Energy Technology Data Exchange (ETDEWEB)

    Webb, Judith A.W. [St. Bartholomew' s Hospital, Department of Diagnostic Imaging, London (United Kingdom); Thomsen, Henrik S. [Copenhagen University Hospital at Herlev, Department of Diagnostic Radiology 54E2, Herlev (Denmark); Morcos, Sameh K. [Northern General Hospital, Department of Diagnostic Imaging, Sheffield (United Kingdom)

    2005-06-01

    The use of iodinated or gadolinium-based contrast media in pregnant or lactating women often causes concerns in the radiology department because of the principle of not exposing a fetus or neonate to any drugs. Because of the uncertainty about the use of contrast media during pregnancy and lactation, the Contrast Media Safety Committee of the European Society of Urogenital Radiology decided to review the literature and draw up guidelines. An extensive literature search was carried out and summarized in a report. Based on the limited information available, simple guidelines have been drawn up. The report and guidelines were discussed at the 11th European Symposium on Urogenital Radiology in Santiago de Compostela, Spain. Mutagenic and teratogenic effects have not been described after administration of gadolinium or iodinated contrast media. Free iodide in radiographic contrast medium given to the mother has the potential to depress fetal/neonatal thyroid function. Neonatal thyroid function should be checked during the 1st week if iodinated contrast media have been given during pregnancy. No effect on the fetus has been seen after gadolinium contrast media. Only tiny amounts of iodinated or gadolinium-based contrast medium given to a lactating mother reach the milk, and only a minute proportion entering the baby's gut is absorbed. The very small potential risk associated with absorption of contrast medium may be considered insufficient to warrant stopping breast-feeding for 24 h following either iodinated or gadolinium contrast agents. (orig.)

  16. Actual clinical use of gadolinium-chelates for non-MRI applications

    Energy Technology Data Exchange (ETDEWEB)

    Strunk, Holger M.; Schild, H. [Department of Radiology, University of Bonn, Sigmund-Freud-Strasse 25, 53105, Bonn (Germany)

    2004-06-01

    For many years, alternatives to iodinated X-ray contrast media have been sought. Of the contrast media investigated to date, only CO{sub 2} and the gadolinium-chelates have been shown to be viable alternatives for selected X-ray examinations. Therefore, we have reviewed the general literature and that specific for gadopentetate (Magnevist) in particular, since this agent has been studied the most. This review indicates that diagnostic CT examinations can be achieved following the intravenous administration of gadolinium-containing contrast media (CM) for evaluation of aortic abnormalities. Gadolinium-containing CM at the dose approved for MR imaging are not useful for CT evaluation of the abdominal parenchymal organs. Intravenous/intraarterial injections have also been used in a variety of angiographic and interventional procedures. Image quality, however, is generally inferior to iodinated contrast media. Gadolinium-containing CM require no special handling and can be administered by hand injection or via conventional angiographic automated injectors with the same flow rates and pressures as are used with iodinated contrast media. For CT, a peripheral bolus injection of a diluted gadolinium agent (1:1 with saline) of 60-90 ml at 3-5 ml/s is usually performed. Similar to all other gadolinium-chelates, the non-MRI use of gadopentetate (Magnevist) is not approved by regulatory agencies. However, the literature suggests that a dose of 0.3-0.4 mmol/kg b.w. has been safely administered for CT as well as for angiography and interventional procedures intravenously and intraarterially. Even at this dose, though, this results in a relatively small overall volume to be injected, which limits utility somewhat. (orig.)

  17. Mitochondrial dysfunction induced by different concentrations of gadolinium ion.

    Science.gov (United States)

    Zhao, Jie; Zhou, Zhi-Qiang; Jin, Jian-Cheng; Yuan, Lian; He, Huan; Jiang, Feng-Lei; Yang, Xiao-Gang; Dai, Jie; Liu, Yi

    2014-04-01

    Gadolinium-based compounds are the most widely used paramagnetic contrast agents in magnetic resonance imaging on the world. But the tricationic gadolinium ion (Gd(3+)) could induce cell apoptosis probably because of its effects on mitochondria. Until now, the mechanism about how Gd(3+) interacts with mitochondria is not well elucidated. In this work, mitochondrial swelling, collapsed transmembrane potential and decreased membrane fluidity were observed to be important factors for mitochondrial permeability transition pore (mtPTP) opening induced by Gd(3+). The protection effect of CsA (Cyclosporin A) could confirm high concentration of Gd(3+) (500 μM) would trigger mtPTP opening. Moreover, mitochondrial outer membrane breakdown and volume expansion observed clearly by transmission electron microscopy and the release of Cyt c (Cytochrome c) could explain the mtPTP opening from another aspect. In addition, MBM(+) (monobromobimane(+)) and DTT (dithiothreitol) could protect thiol (-SH) groups from oxidation so that the toxicity of Gd(3+) might be resulted from the chelation of -SH of membrane proteins by free Gd(3+). Gd(3+) could inhibit the initiation of mitochondrial membrane lipid peroxidation, so it might interact with anionic lipids too. These findings will highly contribute to the safe applications of Gd-based agents.

  18. Extracellular gadolinium-based contrast media: An overview

    Energy Technology Data Exchange (ETDEWEB)

    Bellin, Marie-France [University Paris-Sud 11, Department of Radiology, University Hospital Paul-Brousse, AP-HP, 12, Avenue Paul Vaillant-Couturier, 94804 Villejuif Cedex (France)], E-mail: marie-france.bellin@pbr.aphp.fr; Van Der Molen, Aart J. [University Paris-Sud 11, Department of Radiology, University Hospital Paul-Brousse, AP-HP, 12, Avenue Paul Vaillant-Couturier, 94804 Villejuif Cedex (France)

    2008-05-15

    Increasing use is made of extracellular MRI contrast agents that alter the image contrast following intravenous administration; they predominantly shorten the T1 relaxation time of tissues. The degree and location of these changes provide substantial diagnostic information. However gadolinium-based contrast agents (Gd-CA) are not inert drugs. They may cause acute non-renal adverse reactions (e.g. anaphylactoid reactions), acute renal adverse reactions (e.g. contrast induced nephropathy), delayed adverse reactions (nephrogenic systemic fibrosis) and problems at the site of injection (e.g. local necrosis). This review describes the current status of Gd-CA, their mechanism of action, chemical structure, pharmacokinetics, dosage, elimination, nephrotoxicity and adverse events.

  19. Extracellular gadolinium-based contrast media: an overview.

    Science.gov (United States)

    Bellin, Marie-France; Van Der Molen, Aart J

    2008-05-01

    Increasing use is made of extracellular MRI contrast agents that alter the image contrast following intravenous administration; they predominantly shorten the T1 relaxation time of tissues. The degree and location of these changes provide substantial diagnostic information. However gadolinium-based contrast agents (Gd-CA) are not inert drugs. They may cause acute non-renal adverse reactions (e.g. anaphylactoid reactions), acute renal adverse reactions (e.g. contrast induced nephropathy), delayed adverse reactions (nephrogenic systemic fibrosis) and problems at the site of injection (e.g. local necrosis). This review describes the current status of Gd-CA, their mechanism of action, chemical structure, pharmacokinetics, dosage, elimination, nephrotoxicity and adverse events. PMID:18358659

  20. A polymeric fastener can easily functionalize liposome surfaces with gadolinium for enhanced magnetic resonance imaging.

    Science.gov (United States)

    Smith, Cartney E; Shkumatov, Artem; Withers, Sarah G; Yang, Binxia; Glockner, James F; Misra, Sanjay; Roy, Edward J; Wong, Chun-Ho; Zimmerman, Steven C; Kong, Hyunjoon

    2013-11-26

    Common methods of loading magnetic resonance imaging (MRI) contrast agents into nanoparticles often suffer from challenges related to particle formation, complex chemical modification/purification steps, and reduced contrast efficiency. This study presents a simple, yet advanced process to address these issues by loading gadolinium, an MRI contrast agent, exclusively on a liposome surface using a polymeric fastener. The fastener, so named for its ability to physically link the two functional components together, consisted of chitosan substituted with diethylenetriaminepentaacetic acid (DTPA) to chelate gadolinium, as well as octadecyl chains to stabilize the modified chitosan on the liposome surface. The assembly strategy, mimicking the mechanisms by which viruses and proteins naturally anchor to a cell, provided greater T1 relaxivity than liposomes loaded with gadolinium in both the interior and outer leaflet. Gadolinium-coated liposomes were ultimately evaluated in vivo using murine ischemia models to highlight the diagnostic capability of the system. Taken together, this process decouples particle assembly and functionalization and, therefore, has considerable potential to enhance imaging quality while alleviating many of the difficulties associated with multifunctional particle fabrication.

  1. The use of theranostic gadolinium-based nanoprobes to improve radiotherapy efficacy

    Science.gov (United States)

    Sancey, L; Kotb, S; Roux, S; Dufort, S; Bianchi, A; Crémillieux, Y; Fries, P; Coll, J-L; Rodriguez-Lafrasse, C; Janier, M; Dutreix, M; Barberi-Heyob, M; Boschetti, F; Denat, F; Louis, C; Porcel, E; Lacombe, S; Le Duc, G; Deutsch, E; Perfettini, J-L; Detappe, A; Verry, C; Berbeco, R; Butterworth, K T; McMahon, S J; Prise, K M; Perriat, P; Tillement, O

    2014-01-01

    A new efficient type of gadolinium-based theranostic agent (AGuIX®) has recently been developed for MRI-guided radiotherapy (RT). These new particles consist of a polysiloxane network surrounded by a number of gadolinium chelates, usually 10. Owing to their small size (<5 nm), AGuIX typically exhibit biodistributions that are almost ideal for diagnostic and therapeutic purposes. For example, although a significant proportion of these particles accumulate in tumours, the remainder is rapidly eliminated by the renal route. In addition, in the absence of irradiation, the nanoparticles are well tolerated even at very high dose (10 times more than the dose used for mouse treatment). AGuIX particles have been proven to act as efficient radiosensitizers in a large variety of experimental in vitro scenarios, including different radioresistant cell lines, irradiation energies and radiation sources (sensitizing enhancement ratio ranging from 1.1 to 2.5). Pre-clinical studies have also demonstrated the impact of these particles on different heterotopic and orthotopic tumours, with both intratumoural or intravenous injection routes. A significant therapeutical effect has been observed in all contexts. Furthermore, MRI monitoring was proven to efficiently aid in determining a RT protocol and assessing tumour evolution following treatment. The usual theoretical models, based on energy attenuation and macroscopic dose enhancement, cannot account for all the results that have been obtained. Only theoretical models, which take into account the Auger electron cascades that occur between the different atoms constituting the particle and the related high radical concentrations in the vicinity of the particle, provide an explanation for the complex cell damage and death observed. PMID:24990037

  2. Aging of coprecipitated gallium and gadolinium hydroxides

    International Nuclear Information System (INIS)

    The X-ray graphical and X-ray spectroscopic methods have been used to investigate aging under parent solution at 25, 50, 90 deg and thermolysis in the 250-1000 deg range of mixed gallium and gadolinium hydroxides coprecipitated at pH 8.6 by ammonium hydroxide from the nitrate solution (Gd:Ga=3:5). Hydroxopolycompounds With garnet prestructure are stated to be precipitated under the mentioned conditions. Their dehydration and crystallization of gallium-gadolinium garnet take place during aging under parent solution and thermolysis

  3. Study of burnable poisons and gadolinium qualification in light water reactors

    International Nuclear Information System (INIS)

    The aim of this work is to develop a calculation procedure for analyzing light water moderated reactors utilizing gadolinium as a burnable poison. The main points of this work can be summarized as follows: the available cross section data of gadolinium were analysed and corrected whenever it was necessary. The processes which include required precautions for obtaining multigroup cross sections were defined; an exhaustive study of the assumptions used in multicell calculation methods allowed the definition of option to be used for obtaining good results without excessive calculation cost. This study was followed by the interpretation of experimental results; when gadolinium is used in grain structure, a problem of double heterogeneity is encountered. A new calculation method was developed for such situations. Its validity was confirmed by a comparison with the Monte Carlo method; the problems encountered in performing a study of burn up of fuel elements containing gadolinium were analysed and the necessary precautions were established. The effect of the initial charge and geometrical form of the gadolinium and the behavior of lattices during the burn up were examined

  4. The alkaline single cell electrophoresis assay with eight mouse organs: results with 22 mono-functional alkylating agents (including 9 dialkyl N-nitrosoamines) and 10 DNA crosslinkers.

    Science.gov (United States)

    Tsuda, S; Matsusaka, N; Madarame, H; Miyamae, Y; Ishida, K; Satoh, M; Sekihashi, K; Sasaki, Y F

    2000-04-13

    The genotoxicity of 22 mono-functional alkylating agents (including 9 dialkyl N-nitrosoamines) and 10 DNA crosslinkers selected from IARC (International Agency for Research on Cancer) groups 1, 2A, and 2B was evaluated in eight mouse organs with the alkaline single cell gel electrophoresis (SCGE) (comet) assay. Groups of four mice were treated once intraperitoneally at the dose at which micronucleus tests had been conducted, and the stomach, colon, liver, kidney, bladder, lung, brain, and bone marrow were sampled 3, 8, and/or 24 h later. All chemicals were positive in the SCGE assay in at least one organ. Of the 22 mono-functional alkylating agents, over 50% were positive in all organs except the brain and bone marrow. The two subsets of mono-functional alkylating agents differed in their bone marrow genotoxicity: only 1 of the 9 dialkyl N-nitrosoamines was positive in bone marrow as opposed to 8 of the 13 other alkylating agents, reflecting the fact that dialkyl N-nitrosoamines are poor micronucleus inducers in hematopoietic cells. The two groups of mono-functional alkylating agents also differ in hepatic carcinogenicity in spite of the fact that they are similar in hepatic genotoxicity. While dialkyl N-nitrosoamines produce tumors primarily in mouse liver, only one (styrene-7,8-oxide) out of 10 of the other type of mono-functional alkylating agents is a mouse hepatic carcinogen. Taking into consideration our previous results showing high concordance between hepatic genotoxicity and carcinogenicity for aromatic amines and azo compounds, a possible explanation for the discrepancy might be that chemicals that require metabolic activation show high concordance between genotoxicity and carcinogenicity in the liver. A high percent of the 10 DNA crosslinkers were positive in the SCGE assay in the gastrointestinal mucosa, but less than 50% were positive in the liver and lung. In this study, we allowed 10 min alkali-unwinding to obtain low and stable control values

  5. Proteome Analysis of Inhibitory Effect of Gadolinium on Sinorhizobium fredii

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The inhibitory effect of gadolinium on Sinorhizobium fredii USDA 205 was studied on a global scale using two-dimensional gel electrophoresis and MALDI-TOF MS. The results indicated that 22 proteins were significantly affected by 1 mmol·L-1 Gd3+ treatment when compared with an untreated control. Among these proteins, nine were up-regulated and thirteen were down-regulated. The differently expressed proteins were classified into 8 functional categories based on their functions, including transporters, proteins for cellular defence, and proteins involved in metabolism.

  6. The feasibility of in vivo quantification of bone-gadolinium in humans by prompt gamma neutron activation analysis (PGNAA) following gadolinium-based contrast-enhanced MRI

    Science.gov (United States)

    Mostafaei, F.; McNeill, F. E.; Chettle, D. R.; Noseworthy, M. D.; Prestwich, W. V.

    2015-11-01

    The feasibility of using a 238Pu/Be-based in vivo prompt γ-ray neutron activation analysis (IVNAA) system, previously successfully used for measurements of muscle, for the detection of gadolinium (Gd) in bone was presented. Gd is extensively used in contrast agents in MR imaging. We present phantom measurement data for the measurement of Gd in the tibia. Gd has seven naturally occurring isotopes, of which two have extremely large neutron capture cross sections; 155Gd (14.8% natural abundance (NA), σ= 60,900 barns) and 157Gd (15.65% NA, σ= 254,000 barns). Our previous work focused on muscle but this only informs about the short term kinetics of Gd. We studied the possibility of measuring bone, as it may be a long term storage site for Gd. A human simulating bone phantom set was developed. The phantoms were doped with seven concentrations of Gd of concentrations 0.0, 25, 50, 75, 100, 120 and 150 ppm. Additional elements important for neutron activation analysis, Na, Cl and Ca, were also included to create an overall elemental composition consistent with Reference Man. The overall conclusion is that the potential application of this Pu-Be-based prompt in vivo NAA for the monitoring of the storage and retention of Gd in bone is not feasible.

  7. Gadolinium-DTPA-enhanced magnetic resonance imaging of musculoskeletal infectious processes

    Energy Technology Data Exchange (ETDEWEB)

    Hopkins, K.L. [Dept. of Diagnostic Radiology, Stanford Univ. Medical Center, CA (United States); Li, K.C.P. [Dept. of Diagnostic Radiology, Stanford Univ. Medical Center, CA (United States); Bergman, G. [Dept. of Diagnostic Radiology, Stanford Univ. Medical Center, CA (United States)

    1995-07-01

    The purpose of this study was to assess whether gadolinium-enhanced magnetic resonance imaging (MRI) provides diagnostic information beyond that given by nonenhanced imaging in the evaluation of musculoskeletal infectious processes and whether it can be used for differentiating infectious from noninfectious inflammatory lesions. Magnetic resonance images performed with and without intravenous gadolinium-DTPA in 34 cases in which musculoskeletal infection had been clinically suspected were reviewed. Infectious lesions-including osteomyelitis, pyarthrosis, abscess, and cellulitis-were confirmed in a total of 22 cases: in 15 by biopsy or drainage and in 7 by clinical course. Our results show that gadolinium-DTPA-enhanced MRI is a highly sensitive technique in diagnosing musculoskeletal infectious lesions. It is especially useful in distinguishing abscesses from surrounding cellulitis/myositis. Lack of contrast enhancement rules out infection with a high degree of certainty. However, contrast enhancement cannot be used to reliably distinguish infectious from noninfectious inflammatory conditions. (orig.)

  8. Effect of field strength on gadolinium enhancement in MR imaging

    International Nuclear Information System (INIS)

    This study was designed to evaluate the influence of magnetic field strength on the relative enhancement effect (RE) of gadolinium (Gd)-chelates. Dilution series of two paramagnetic contrast agents (Gd-DTPA and Gd-DOTA) were examined in three commercially available MR systems, operating at different field strengths (0.2 T, 1.0 T, and 1.5 T). The RE was plotted against Gd concentration. The highest increases in signal intensity occurred with Gd concentrations of approximately 1.0 mmol/L. No significant difference in RE was observed between MR systems ranging in field strength from 0.2 T to 1.5 T. The RE of Gd-DTPA and Gd-DOTA was found to be equivalent. (orig.)

  9. Gadolinium: Central Metal of the Lanthanoids

    Science.gov (United States)

    Laing, Michael

    2009-01-01

    The physical and chemical properties of gadolinium are compared with those of the other lanthanoids. Some properties are intermediate between those of lanthanum and lutetium; some between those of barium and hafnium; and others (unexpectedly) between those of ytterbium and lutetium. Both the remarkably high molar heat capacity of the metal and the…

  10. Gadolinium Deposition in Nephrogenic Systemic Fibrosis: An Examination of Tissue using Synchrotron X-ray Fluorescence Spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    High, W.; Ranville, J; Brown, M; Punshon, T; Lanzirotti, A; Jackson, B

    2010-01-01

    Nephrogenic systemic fibrosis is a fibrosing disorder associated with gadolinium (Gd)-based contrast agents dosed during renal insufficiency. In two patients, Gd deposition in tissue affected by nephrogenic systemic fibrosis was quantified using inductively coupled plasma mass spectrometry. The presence of Gd was confirmed and mapped using synchrotron x-ray fluorescence spectroscopy. Affected skin and soft tissue from the lower extremity demonstrated 89 and 209 ppm ({micro}g/g, dry weight, formalin fixed) in cases 1 and 2, respectively. In case 2, the same skin and soft tissue was retested after paraffin embedding, with the fat content removed by xylene washes, and this resulted in a measured value of 189 ppm ({micro}g/g, dry weight, paraffin embedded). Synchrotron x-ray fluorescence spectroscopy confirmed Gd in the affected tissue of both cases, and provided high-sensitivity and high-resolution spatial mapping of Gd deposition. A gradient of Gd deposition in tissue correlated with fibrosis and cellularity. Gd deposited in periadnexal locations within the skin, including hair and eccrine ducts, where it colocalized to areas of high calcium and zinc content. Because of the difficulty in obtaining synchrotron x-ray fluorescence spectroscopy scans, tissue from only two patients were mapped. A single control with kidney disease and gadolinium-based contrast agent exposure did not contain Gd. Gd content on a gravimetric basis was impacted by processing that removed fat and altered the dry weight of the specimens. Gradients of Gd deposition in tissue corresponded to fibrosis and cellularity. Adnexal deposition of Gd correlated with areas of high calcium and zinc content.

  11. Acute adverse reactions to magnetic resonance contrast media--gadolinium chelates.

    Science.gov (United States)

    Li, A; Wong, C S; Wong, M K; Lee, C M; Au Yeung, M C

    2006-05-01

    The objective of this study was to evaluate the clinical safety of intravenous gadolinium-based contrast media used in patients who underwent MRI at a single institution. Acute adverse reactions to intravenous gadolinium-based contrast media used for MRI at the Princess Margaret Hospital, Hong Kong, SAR, from January 1999 to November 2004 were recorded in an incidence log book. The medical records of patients' demographics were retrospectively reviewed and the nature, frequency and severity of the adverse reactions were investigated and documented. The incidence of acute adverse reactions to intravenous gadolinium-based contrast media was 0.48% (45 patients with 46 adverse reactions). The severity of these adverse reactions were 96% mild, 2% moderate (one patient developed shortness of breath that required oxygen supplementation and intravenous steroidal management) and 2% severe (one patient developed an anaphylactoid reaction, but successfully recovered through timely resuscitation). No patients were recorded as having contrast extravasation and none died as a result of any adverse reaction. Among the 45 patients who developed adverse reactions, three patients (6.7%) had prior adverse reactions to iodinated contrast media, three (6.7%) had prior reactions to a different gadolinium-based contrast agent, one (2%) had asthma and nine (20%) had a history of drug/food allergy. Overall, 41% of the adverse reactions were not documented in the final MRI report or the clinical medical records. Gadolinium-based contrast media are safe and well tolerated by the vast majority of patients. In our study, the adverse reaction rate (0.48%) and the incidence of severe anaphylactoid reaction (0.01%) concur with those reported in the literature. Although most of the symptoms are mild and transient, these adverse reactions must be accurately documented and managed. PMID:16632615

  12. Targeted gadolinium-loaded dendrimer nanoparticles for tumor-specific magnetic resonance contrast enhancement

    Directory of Open Access Journals (Sweden)

    Scott D Swanson

    2008-06-01

    nanoparticles for targeted cancer imaging with the prolonged clearance time compared with the current clinically approved gadodiamide (OmniscanTM contrast agent. Potential application of this approach may include determination of the folate receptor status of tumors and monitoring of drug therapy.Keywords: dendrimer, DOTA, gadolinium, MRI, folate receptor

  13. Standard specification for nuclear-grade gadolinium oxide (Gd2O3) powder

    International Nuclear Information System (INIS)

    This specification provides the chemical and physical requirements for nuclear-grade gadolinium oxide powder intended for subsequent processing and use in nuclear fuel applications, for example, as an addition to uranium dioxide. This specification does not include requirements for health and safety

  14. Characteristics of cerium-gadolinium oxide (CGO) suspensions as a function of dispersant and powder properties

    DEFF Research Database (Denmark)

    Phair, John; Lönnroth, Nadja; Lundberg, Mats;

    2009-01-01

    A series of concentrated suspensions ( = 0.18–0.34) of cerium-gadolinium oxide (CGO) in terpineol were prepared as a function of dispersant, powder surface area and solids concentration. The stability of the suspensions was assessed by rheological measurements including viscosity and oscillatory...

  15. Manufacturing and in vivo inner ear visualization of MRI traceable liposome nanoparticles encapsulating gadolinium

    Directory of Open Access Journals (Sweden)

    Kinnunen Paavo KJ

    2010-12-01

    Full Text Available Abstract Background Treatment of inner ear diseases remains a problem because of limited passage through the blood-inner ear barriers and lack of control with the delivery of treatment agents by intravenous or oral administration. As a minimally-invasive approach, intratympanic delivery of multifunctional nanoparticles (MFNPs carrying genes or drugs to the inner ear is a future therapy for treating inner ear diseases, including sensorineural hearing loss (SNHL and Meniere's disease. In an attempt to track the dynamics and distribution of nanoparticles in vivo, here we describe manufacturing MRI traceable liposome nanoparticles by encapsulating gadolinium-tetra-azacyclo-dodecane-tetra-acetic acid (Gd-DOTA (abbreviated as LPS+Gd-DOTA and their distribution in the inner ear after either intratympanic or intracochlear administration. Results Measurements of relaxivities (r1 and r2 showed that LPS+Gd-DOTA had efficient visible signal characteristics for MRI. In vivo studies demonstrated that LPS+Gd-DOTA with 130 nm size were efficiently taken up by the inner ear at 3 h after transtympanic injection and disappeared after 24 h. With intracochlear injection, LPS+Gd-DOTA were visualized to distribute throughout the inner ear, including the cochlea and vestibule with fast dynamics depending on the status of the perilymph circulation. Conclusion Novel LPS+Gd-DOTA were visible by MRI in the inner ear in vivo demonstrating transport from the middle ear to the inner ear and with dynamics that correlated to the status of the perilymph circulation.

  16. Dual contrast enhanced magnetic resonance imaging of the liver with superparamagnetic iron oxide followed by gadolinium for lesion detection and characterization

    International Nuclear Information System (INIS)

    AIM: Iron oxide contrast agents are useful for lesion detection, and extracellular gadolinium chelates are advocated for lesion characterization. We undertook a study to determine if dual contrast enhanced liver imaging with sequential use of ferumoxides particles and gadolinium (Gd)-DTPA can be performed in the same imaging protocol. MATERIALS AND METHODS: Sixteen patients underwent dual contrast magnetic resonance imaging (MRI) of the liver for evaluation of known/suspected focal lesions which included, metastases (n = 5), hepatocellular carcinoma (HCC;n = 3), cholangiocharcinoma(n = 1) and focal nodular hyperplasia (FNH;n = 3). Pre- and post-iron oxide T1-weighted gradient recalled echo (GRE) and T2-weighted fast spin echo (FSE) sequences were obtained, followed by post-Gd-DTPA (0.1 mmol/kg) multi-phase dynamic T1-weighted out-of-phase GRE imaging. Images were analysed in a blinded fashion by three experts using a three-point scoring system for lesion conspicuity on pre- and post-iron oxide T1 images as well as for reader's confidence in characterizing liver lesions on post Gd-DTPA T1 images. RESULTS: No statistically significant difference in lesion conspicuity was observed on pre- and post-iron oxide T1-GRE images in this small study cohort. The presence of iron oxide did not appreciably diminish image quality of post-gadolinium sequences and did not prevent characterization of liver lesions. CONCLUSION: Our results suggest that characterization of focal liver lesion with Gd-enhanced liver MRI is still possible following iron oxide enhanced imaging. Kubaska, S. et al. (2001)

  17. Geometrically confined ultrasmall gadolinium oxide nanoparticles boost the T1 contrast ability

    Science.gov (United States)

    Ni, Kaiyuan; Zhao, Zhenghuan; Zhang, Zongjun; Zhou, Zijian; Yang, Li; Wang, Lirong; Ai, Hua; Gao, Jinhao

    2016-02-01

    High-performance magnetic resonance imaging (MRI) contrast agents and novel contrast enhancement strategies are urgently needed for sensitive and accurate diagnosis. Here we report a strategy to construct a new T1 contrast agent based on the Solomon-Bloembergen-Morgan (SBM) theory. We loaded the ultrasmall gadolinium oxide nanoparticles into worm-like interior channels of mesoporous silica nanospheres (Gd2O3@MSN nanocomposites). This unique structure endows the nanocomposites with geometrical confinement, high molecular tumbling time, and a large coordinated number of water molecules, which results in a significant enhancement of the T1 contrast with longitudinal proton relaxivity (r1) as high as 45.08 mM-1 s-1. Such a high r1 value of Gd2O3@MSN, compared to those of ultrasmall Gd2O3 nanoparticles and gadolinium-based clinical contrast agents, is mainly attributed to the strong geometrical confinement effect. This strategy provides new guidance for developing various high-performance T1 contrast agents for sensitive imaging and disease diagnosis.High-performance magnetic resonance imaging (MRI) contrast agents and novel contrast enhancement strategies are urgently needed for sensitive and accurate diagnosis. Here we report a strategy to construct a new T1 contrast agent based on the Solomon-Bloembergen-Morgan (SBM) theory. We loaded the ultrasmall gadolinium oxide nanoparticles into worm-like interior channels of mesoporous silica nanospheres (Gd2O3@MSN nanocomposites). This unique structure endows the nanocomposites with geometrical confinement, high molecular tumbling time, and a large coordinated number of water molecules, which results in a significant enhancement of the T1 contrast with longitudinal proton relaxivity (r1) as high as 45.08 mM-1 s-1. Such a high r1 value of Gd2O3@MSN, compared to those of ultrasmall Gd2O3 nanoparticles and gadolinium-based clinical contrast agents, is mainly attributed to the strong geometrical confinement effect. This strategy

  18. Gadolinium-DTPA: value in MR imaging of extraspinal musculoskeletal infections

    Energy Technology Data Exchange (ETDEWEB)

    Haddad, M.C. [Dept. of Radiology, Riyadh Armed Forces Hospital, Riyadh (Saudi Arabia); Sharif, H.S. [Dept. of Radiology, Riyadh Armed Forces Hospital, Riyadh (Saudi Arabia); Aabed, M.Y. [Dept. of Radiology, Riyadh Armed Forces Hospital, Riyadh (Saudi Arabia); Al Shahed, M.S. [Dept. of Radiology, Riyadh Armed Forces Hospital, Riyadh (Saudi Arabia); Sammak, B.M. [Dept. of Radiology, Riyadh Armed Forces Hospital, Riyadh (Saudi Arabia); Clark, D.C. [Dept. of Radiology, Riyadh Armed Forces Hospital, Riyadh (Saudi Arabia)

    1993-12-01

    To determine if paramagnetic contrast agents can improve the detection, delineation, and characterization of extraspinal musculoskeletal infections (MSI) on magnetic resonance (MR) imaging, 42 patients with clinical suspicion of MSI underwent MR imaging before and after intravenous administration of gadolinium-DTPA. The lesions consisted of 27 proven infections and 15 noninfective conditions. Specificity and accuracy in identifying infective lesions averaged 80% and 84%, respectively, on precontrast studies and 80% and 89% on the enhanced examinations, with no statistically significant difference. Rim enhancement around abscess loculi was the only pathognomonic sign of infection seen in ten patients with chronic osteomyelitis and pyogenic or tuberculous infections. In 17 patients with acute osteomyelitis, brucellosis, or mycetoma, detection and delineation of the lesions were best on precontrast studies, while postcontrast examinations resulted in underestimation of the extent of abnormalities in all cases. We conclude that intravenous gadolinium-DTPA has limited usefulness in the MR evaluation of extraspinal MSI. (orig.)

  19. The role of gadolinium chelates in the mechanism of nephrogenic systemic fibrosis: A critical update.

    Science.gov (United States)

    Idée, Jean-Marc; Fretellier, Nathalie; Robic, Caroline; Corot, Claire

    2014-11-01

    Nephrogenic systemic fibrosis (NSF) is an iatrogenic scleroderma-like fibrosing systemic disorder occurring in patients with severe or end-stage renal disease. It was established as a new clinical entity in the year 2000. A causal role for gadolinium chelates (GC), widely used as contrast agents for magnetic resonance imaging, was suggested six years later. It rapidly appeared that the occurrence of NSF was associated with prior administration of GCs with lower thermodynamic stability, leading to warnings being published by health authorities and learned societies worldwide. Although a role for the chelated form of the less stable GCs has been proposed, the most commonly accepted hypothesis involves the gradual release of dissociated gadolinium in the body, leading to systemic fibrosis. However, the entire chain of events is still not fully understood in a causal way and many uncertainties remain.

  20. Nickel-based gadolinium alloy for neutron adsorption application in ram packages

    International Nuclear Information System (INIS)

    This paper will outline the results of a metallurgical development program that is investigating the alloying of gadolinium into a nickel-chromium-molybdenum alloy matrix. Gadolinium has been chosen as the neutron absorption alloying element due to its high thermal neutron absorption cross section and low solubility in the expected U.S. repository environment. The nickel-chromium-molybdenum alloy family was chosen for its known corrosion performance, mechanical properties, and weldability. The workflow of this program includes chemical composition definition, primary and secondary melting studies, ingot conversion processes, properties testing, and national consensus codes and standards work. The microstructural investigation of these alloys shows that the gadolinium addition is not soluble in the primary austenite metallurgical phase and is present in the alloy as gadolinium-rich second phase. This is similar to what is observed in a stainless steel alloyed with boron. The mechanical strength values are similar to those expected for commercial Ni-Cr-Mo alloys. The alloys have been corrosion tested in simulated Yucca Mountain aqueous chemistries with acceptable results. The initial results of weldability tests have also been acceptable. Neutronic testing in a moderated critical array has generated favorable results. An American Society for Testing and Materials material specification has been issued for the alloy and a Code Case has been submitted to the American Society of Mechanical Engineers for code qualification. The ultimate goal is acceptance of the alloy for use at the Yucca Mountain repository

  1. Amino acid PET tracers are reliable markers of treatment responses to single-agent or combination therapies including temozolomide, interferon-β, and/or bevacizumab for glioblastoma

    International Nuclear Information System (INIS)

    Introduction: We examined whether the amino acid PET tracers, trans-1-amino-3-18F-fluorocyclobutanecarboxylic acid (anti-18F-FACBC) and 11C-methyl-L-methionine (11C-Met), are suitable for detecting early responses to combination therapies including temozolomide (TMZ), interferon-β (IFN), and bevacizumab (Bev) in glioblastoma. Methods: Human glioblastoma U87MG (U87) cells were incubated with low dose TMZ to induce chemoresistance. Both trans-1-amino-3-fluoro-1-14C-cyclobutanecarboxylic acid (anti-14C-FACBC) and 3H-methyl-L-methionine (3H-Met) uptake were quantified using triple-label accumulation assays to examine the relationship between tracer uptake and proliferation (3H-thymidine (TdR) accumulation) in vitro. U87 and U87R (TMZ-resistant subculture) cells were inoculated into the right and left basal ganglia, respectively, of F344/N-rnu rats. The efficacy of single-agent (TMZ, Bev) and combination therapy (TMZ/IFN, TMZ/Bev, TMZ/IFN/Bev) was examined in orthotopic gliomas using MRI, Evans blue extravasation, anti-14C-FACBC, and 3H-Met autoradiography, and MIB-1 immunostaining. Results: TMZ treatment decreased 3H-TdR accumulation and the volume distribution of anti-14C-FACBC and 3H-Met in U87 but not U87R cells. TMZ/IFN combination therapy significantly decreased these parameters in U87R cells; however, Bev had no additional effect in vitro. In vivo, U87R-derived gliomas were observed as equivocal tumors on MRI and T2-high intensity lesions. Bev treatment, either alone or in combination, markedly decreased U87 enhancing lesions. By contrast, autoradiographic images using anti-14C-FACBC and 3H-Met clearly delineated tumor extent, which spread widely beyond T2-high intensity lesions and enhancing lesions. TMZ therapy significantly decreased tracer accumulation and proliferation of U87- but not U87R-derived tumors. TMZ/IFN combination treatment significantly decreased these parameters in U87R tumors, which were further reduced (in both tumor types) by Bev addition

  2. Cationic gadolinium chelate for magnetic resonance imaging of cartilaginous defects.

    Science.gov (United States)

    Nwe, Kido; Huang, Ching-Hui; Qu, Feini; Warden-Rothman, Robert; Zhang, Clare Y; Mauck, Robert L; Tsourkas, Andrew

    2016-05-01

    The ability to detect meniscus defects by magnetic resonance arthrography (MRA) can be highly variable. To improve the delineation of fine tears, we synthesized a cationic gadolinium complex, (Gd-DOTA-AM4 )(2+) , that can electrostatically interact with Glycosaminoglycans (GAGs). The complex has a longitudinal relaxivity (r1) of 4.2 mM(-1) s(-1) and is highly stable in serum. Its efficacy in highlighting soft tissue tears was evaluated in comparison to a clinically employed contrast agent (Magnevist) using explants obtained from adult bovine menisci. In all cases, Gd-DOTA-AM4 appeared to improve the ability to detect the soft tissue defect by providing increased signal intensity along the length of the tear. Magnevist shows a strong signal near the liquid-meniscus interface, but much less contrast is observed within the defect at greater depths. This provides initial evidence that cationic contrast agents can be used to improve the diagnostic accuracy of MRA. Copyright © 2016 John Wiley & Sons, Ltd.

  3. Cationic gadolinium chelate for magnetic resonance imaging of cartilaginous defects.

    Science.gov (United States)

    Nwe, Kido; Huang, Ching-Hui; Qu, Feini; Warden-Rothman, Robert; Zhang, Clare Y; Mauck, Robert L; Tsourkas, Andrew

    2016-05-01

    The ability to detect meniscus defects by magnetic resonance arthrography (MRA) can be highly variable. To improve the delineation of fine tears, we synthesized a cationic gadolinium complex, (Gd-DOTA-AM4 )(2+) , that can electrostatically interact with Glycosaminoglycans (GAGs). The complex has a longitudinal relaxivity (r1) of 4.2 mM(-1) s(-1) and is highly stable in serum. Its efficacy in highlighting soft tissue tears was evaluated in comparison to a clinically employed contrast agent (Magnevist) using explants obtained from adult bovine menisci. In all cases, Gd-DOTA-AM4 appeared to improve the ability to detect the soft tissue defect by providing increased signal intensity along the length of the tear. Magnevist shows a strong signal near the liquid-meniscus interface, but much less contrast is observed within the defect at greater depths. This provides initial evidence that cationic contrast agents can be used to improve the diagnostic accuracy of MRA. Copyright © 2016 John Wiley & Sons, Ltd. PMID:26853708

  4. First results on study of gadolinium as burnable absorber

    International Nuclear Information System (INIS)

    Following on with the work included in the 'Burnable absorbers research plan' several experiments were carried out oriented to determine Ga2O3 burn up. Cold tests were performed and samples were irradiated in the RA-3 reactor. In this paper, some calculated values are presented together with their comparisons with experimental ones. The parameters foreseen for performing the experiments were verified and also the predictions on burn up of uranium and gadolinium isotopes concentrations. These results imply that the nuclear data of these isotopes included in the library are satisfactory. Next steps will be to measure other isotopes concentrations, gamma spectrum, and the irradiation of one pellet to determine self shielding effects in order to obtain effective cross sections i.e. for CAREM geometry. (author)

  5. Detection of pulmonary embolism with gadolinium-enhanced dual energy CT: an experimental study

    International Nuclear Information System (INIS)

    Objective: To evaluate the feasibility of gadolinium-enhanced dual energy CT pulmonary angiography (CTPA) in detecting pulmonary embolism (PE). Methods: In vitro dual energy CT of phantoms of gadolinium and iodinated contrast agents with different diluted ratio was performed, and CT values were measured at different tube voltages. Ten rabbits which were grouped into 3 ml/kg and 5 ml/kg groups underwent dual energy CT scan. CT values of pulmonary artery trunk and the first branch of pulmonary artery were measured. Sponge gelatin were injected into the femoral vein of 6 rabbits to make PE model next day, then lungs were re-imaged with dual energy CT 2 h after embolization. Creatinine was repeatedly measured before and one day after injection of gadolinium via ear marginal vein or femoral vein sampling.One-way ANOVA test and independent student t test were used to analyze the difference of pulmonary artery enhancement between different groups. Results: (1) Compared with iodinated contrast agent, CT value of gadolinium-based contrast agent at 80 kV was higher than those at 140 kV and average-weighted 120 kV. (2) At 140, 80, and average weighted 120 kV, CT values of pulmonary artery trunk [CT values were (463.1 ± 118.0), (664.2 ± 188.0), (522.9 ± 137.7) HU] and of the first branch of pulmonary artery [ CT values were (445.1 ± 82.3), (606.7 ± 207.2), (493.4 ± 117.3) HU] were higher than those at 3 ml/kg [CT value of pulmonary artery trunk was (258.1 ± 55.1), (384.0 ± 92.3), (295.4 ± 73.6) HU, CT value of the first branch of pulmonary artery (245.0 ± 73.2), (309.1 ± 94.2), (263.8 ±78.5) HU; all P<0.05]. CT values of pulmonary artery trunk and the first branch of pulmonary artery at 80 kV were higher than those at 140 kV and average-weighted 120 kV (pulmonary artery trunk: F=6.004, P=0.005; the first branch of pulmonary artery: F=4.374, P=0.018). In 6 rabbits, CTPA showed the enhancement cut-off of bilateral pulmonary arteries, gadolinium mapping showed

  6. Possible involvement of gadolinium chelates in the pathophysiology of nephrogenic systemic fibrosis: A critical review

    International Nuclear Information System (INIS)

    Nephrogenic systemic fibrosis (NSF) is a recently described, highly debilitating scleroderma-like disease occurring in patients with severe or end-stage renal failure. NSF is characterized by cutaneous papules and coalescing plaques ('peau d'orange' appearance) and a wooden consistency. It may ultimately cause disabling contractures of several joints, thus making many patients wheelchair-dependent. NSF has been associated to prior administration of gadolinium chelates (GC) used as contrast agents for magnetic resonance imaging. The best available treatment option at the present time is renal transplantation. The mechanism of NSF has not been fully elucidated. Several hypotheses have been proposed so far and are critically discussed in the present review article. Gadolinium has been found in skin biopsy samples of patients. The most widely accepted hypothesis is related to dechelation of less stable GC, progressively releasing free Gd3+ which may subsequently lead to the attraction of CD34+, CD45+, pro-collagen+ circulating fibrocytes via the release of chemokines, thereby inducing systemic fibrosing disorders. Pre-existing renal failure may facilitate the process by delaying the excretion of GC. A complex interplay between gadolinium and co-factors (pro-inflammatory status, vascular injury, high dose of erythropoietin, high levels of calcium, phosphorus, etc.) may occur in patients with impaired renal function. This and other hypotheses remain to be investigated, as well as the role and independence of co-factors

  7. Specific lipase-responsive polymer-coated gadolinium nanoparticles for MR imaging of early acute pancreatitis.

    Science.gov (United States)

    Zhang, Hong-Wu; Wang, Li-Qin; Xiang, Qing-Feng; Zhong, Qian; Chen, Lu-Ming; Xu, Cai-Xia; Xiang, Xian-Hong; Xu, Bo; Meng, Fei; Wan, Yi-Qian; Deng, David Y B

    2014-01-01

    Currently, available methods for diagnosis of acute pancreatitis (AP) are mainly dependent on serum enzyme analysis and imaging techniques that are too low in sensitivity and specificity to accurately and promptly diagnose AP. The lack of early diagnostic tools highlights the need to search for a highly effective and specific diagnostic method. In this study, we synthesized a conditionally activated, gadolinium-containing, nanoparticle-based MRI nanoprobe as a diagnostic tool for the early identification of AP. Gadolinium diethylenetriaminepentaacetic fatty acid (Gd-DTPA-FA) nanoparticles were synthesized by conjugation of DTPA-FA ligand and gadolinium acetate. Gd-DTPA-FA exhibited low cytotoxicity and excellent biocompatibility when characterized in vitro and in vivo studies. L-arginine induced a gradual increase in the intensity of the T1-weighted MRI signal from 1 h to 36 h in AP rat models. The increase in signal intensity was most significant at 1 h, 6 h and 12 h. These results suggest that the Gd-DTPA-FA as an MRI contrast agent is highly efficient and specific to detect early AP.

  8. Substitution of gadolinium ethylenediaminetetraacetate with phosphites: towards gadolinium deposit in nephrogenic systemic fibrosis.

    Science.gov (United States)

    Gao, Song; Chen, Mao-Long; Zhou, Zhao-Hui

    2014-01-14

    In neutral media, reactions of gadolinium ethylenediaminetetraacetates with phosphorous acid result in the formation of the mixed-ligand polymeric complex K3n[Gd(EDTA)(HPO3)]n·7nH2O () and dimeric complex Na6[Gd2(EDTA)2(HPO3)2]·2.5NaCl·21H2O () (H4EDTA = ethylenediaminetetraacetic acid) in warm solution. Further substitution with citric acid gives the monomeric gadolinium citrate with EDTA (NH4)2Na[Gd(EDTA)(H2cit)]·4H2O (). The compounds were characterized by elemental analysis, single crystal X-ray diffraction, FT-IR, ESI-MS and thermogravimetric analysis. Structural analysis indicates that three coordinated water molecules in the gadolinium ethylenediaminetetraacetate trihydrates are replaced by phosphite ions (HPO3(2-)) in the compounds and . Gadolinium atoms are octa-coordinated by EDTA and the phosphite ion, the latter links adjacent Gd-EDTA units to generate an infinite one-dimensional chain in compound and a dimeric octatomic ring in . In complex , coordinated water molecules were substituted by the α-hydroxy, α-carboxy and β-carboxy groups of citrate. Citrate is favourable for inhibiting the formation of Gd-EDTA phosphite. All the complexes are very easily soluble in water. The solution behavior of the isostructural lanthanum complexes was probed with (13)C and (31)P NMR spectra in D2O for comparison. ESI-MS analysis and recrystallization proved that complexes and dissociate to the monomeric unit of Gd-EDTA and free HPO3(2-) in aqueous solution. Substitutions of gadolinium ethylenediaminetetraacetates to and are attributed to be the cause of nephrogenic systemic fibrosis in some way.

  9. Gadolinium-enhanced MR angiography (Gd-MRA) of thoracic vasculature in an animal model using double-dose gadolinium and quiet breathing

    International Nuclear Information System (INIS)

    Objective. To evaluate a gadolinium-enhanced MR angiography (Gd-MRA) imaging protocol for the assessment of thoracic vessels using double-dose gadolinium and quiet breathing. An animal model was used to simulate imaging in infants and young children. Material and methods. Six baboons (Papio anubis), mean weight 5.7 kg, were sedated and intubated. After the injection of double-dose Gd-DTPA (0.2 mmol/kg) through a peripheral vein, a coronal spoiled 3D gradient-echo volume acquisition was obtained during quiet breathing. Two radiologists reviewed the images for visualization of aortic arch, brachiocephalic vessel origins, pulmonary arteries (central, upper lobe and descending branches), and pulmonary veins (upper and lower). Results. Visualization was excellent for the aortic arch, brachiocephalic vessel origins, and pulmonary arteries, including the hilar branches. Visualization was excellent for the lower and right upper pulmonary veins and fair for the left upper pulmonary vein. There was excellent agreement between radiologists. Conclusion. Imaging of thoracic vessels with Gd-MRA using double gadolinium during quiet breathing was effective in our animal model. The advantages of this technique include a short imaging time and depiction of vascular segments - branches of pulmonary arteries and intraparenchymal segments of pulmonary veins - not optimally visualized with other non-invasive imaging techniques. (orig.)

  10. Light deflection in gadolinium molybdate ferroelastic crystals

    Science.gov (United States)

    Staniorowski, Piotr; Bornarel, Jean

    2000-02-01

    The deflection of a He-Ne light beam by polydomain gadolinium molybdate (GMO) crystals has been studied with respect to incidence angle icons/Journals/Common/alpha" ALT="alpha" ALIGN="TOP"/> i on the sample at room temperature. The A and B deflected beams do not cross each other during the icons/Journals/Common/alpha" ALT="alpha" ALIGN="TOP"/> i variation, in contrast to results and calculations previously published. The model using the Fresnel equation confirms this result. The model presented is more accurate for numerical calculation than that using the Huygens construction.

  11. Towards modeling gadolinium-lead-borate glasses

    International Nuclear Information System (INIS)

    Infrared spectra of gadolinium-lead-borate glasses of the xGd2O3.(100 - x)[3B2O3.PbO] system, where x = 0, 5, 10, 15, 25, 35 and 50 mol.%, have been recorded to explore the role of content of gadolinium ions behaving as glass modifier. The FTIR spectroscopy data for the xGd2O3.(1 - x)[3B2O3.PbO] glasses show the structural role of lead ions as a network-formers and of the gadolinium ions network modifiers. Adding of the rare earth ion up to 35 mol.% into the glass matrix, the IR bands characteristic to the studied glasses become sharper and more pronounced. Structural changes, as recognized by analyzing band shapes of IR spectra, revealed that Gd2O3 causes a change from the continuous borate network to the continuous lead-borate network interconnected through Pb-O-B and B-O-B bridges and the transformation of some tetrahedral [BO4] units into trigonal [BO3] units. Then, gadolinium ions have affinity towards [BO3] structural units which contain non-bridging oxygens necessary for the charge compensation because the more electronegative [BO3] structural units were implied in the formation of B-O-Gd bonds and the transformation of glass network into a glass ceramic. We propose a possible structural model of building blocks for the formation of continuous random 3B2O3.PbO network glass used by density functional theory (DFT) calculations. DFT calculations show that lead atoms occupy three different sites in the proposed model. The first is coordinated with six oxygen atoms forming distorted octahedral geometries. The second lead atom has an octahedral oxygen environment and the five longer Pb-O bonds are considered as participating in the metal coordination scheme. The third lead atom has ionic character. In agreement with the results offered by the experimental FTIR data, the theoretical IR data confirm that our proposed structure is highly possible.

  12. Improvement of post-gadolinium contrast with magnetization transfer

    International Nuclear Information System (INIS)

    Magnetization transfer (MT) provides post-gadolinium contrast improvement through decreasing the tissue signal. Our study had two aims: to analyse the effect of MT qualitatively and quantitatively in 13 patients, and to analyse in vitro the competition betwen two relaxation phenomena, dipole-dipole which is characteristic of MT and proton - electron which is characteristic of gadolinium. Contrast between lesion and white matter improved from 20.6 % before MT to 65.1 % after MT, enabling new lesions to be detected in two patients. The improvement was due mainly to the proton - electron effect of gadolinium rather than the dipole relaxation of MT. These results are in agreement with those in the literature. The existence of spontaneous high-signal induced by MT in the absence of gadolinium indicates that it is preferable to perform an MT sequence before and after administration of gadolinium. (orig.)

  13. Improvement of post-gadolinium contrast with magnetization transfer

    Energy Technology Data Exchange (ETDEWEB)

    Huot, P.; Hatier, F.; Carlier, P. [Service de Radiologie, Hopital d`Instruction des Armees Robert Picque, Route de Toulouse, F-33 998 Bordeaux Armees (France); Dousset, V.; Degreze, P.; Caille, J.M. [Service de Neuroradiologie, Hopital Universitaire Pellegrin, F-33 076 Bordeaux (France)

    1997-12-31

    Magnetization transfer (MT) provides post-gadolinium contrast improvement through decreasing the tissue signal. Our study had two aims: to analyse the effect of MT qualitatively and quantitatively in 13 patients, and to analyse in vitro the competition betwen two relaxation phenomena, dipole-dipole which is characteristic of MT and proton - electron which is characteristic of gadolinium. Contrast between lesion and white matter improved from 20.6 % before MT to 65.1 % after MT, enabling new lesions to be detected in two patients. The improvement was due mainly to the proton - electron effect of gadolinium rather than the dipole relaxation of MT. These results are in agreement with those in the literature. The existence of spontaneous high-signal induced by MT in the absence of gadolinium indicates that it is preferable to perform an MT sequence before and after administration of gadolinium. (orig.) With 5 figs., 14 refs.

  14. Magnetically Active and Coated Gadolinium-Filled Carbon Nanotubes

    KAUST Repository

    Fidiani, Elok

    2013-08-15

    Gd-filled carbon nanotubes (which include the so-called gadonanotubes(1)) have been attracting much interest due to their potential use in medical diagnostic applications. In the present work, a vacuum filling method was performed to confine gadolinium(III) iodide in carbon nanotubes (CNTs). Filling yields in excess of 50% were obtained. Cleaning and dosing of the external walls was undertaken, as well as the study of the filled CNT magnetic properties. Overall, we found that the encapsulating procedure can lead to reduction of the lanthanide metal and induce disorder in the initial GdI3-type structure. Notwithstanding, the magnetic response of the material is not compromised, retaining a strong paramagnetic response and an effective magnetic moment of similar to 6 mu B. Our results may entice further investigation into whether an analogous Gd3+ to Gd2+ reduction takes place in other Gd-filled CNT systems.

  15. Yellow luminescence of co-doped gadolinium oxyhydroxide

    Institute of Scientific and Technical Information of China (English)

    Hiroaki Samata; Shungo Imanaka; Masashi Hanioka; Tadashi C Ozawa

    2015-01-01

    Crystals of co-doped gadolinium oxyhydroxide (GdOOH), Gd0.98Eu0.02−xTbxOOH and Gd1−y−zDyyBizOOH, were synthe-sized by a flux method. The color coordinates in the Commission Internationale de I’Eclairage (CIE) chromaticity diagram of Gd0.98Eu0.02−xTbxOOH, obtained under 254 nm irradiation, shifted along a straight line with the changing values ofxto include the yellow region. The CIE coordinates of Dy3+ doped in GdOOH were located in the yellow region, while the emission intensity of Dy3+ under 286 nm irradiation increased by more than 40 times when co-doped with Bi3+.

  16. Effect of gadolinium covers on fast dosimeter response

    International Nuclear Information System (INIS)

    Gadolinium (Gd) has been used extensively at B and W Nuclear Technologies (BWNT) as a dosimetry shielding material for several years. Gadolinium has a significant cross section throughout the energy range of interest (i.e. above 1 MeV) in vessel fluence calculations. While Gd has a number of advantages as a dosimetry cover, it also has the potential for introducing a bias of unknown magnitude into the measured activities of covered fast response dosimeters such as U238 and iron. The Gd cover causes a reduction in the measured dosimeter activity, which means that the calculated fluxes normalized to those activities would be under-predicted. This is, of course, in the non-conservative direction. Since dosimeter covers are generally not included in the typical transport analysis model, corrections for this effect are not generally made. The calculated activities would not include the effects of the Gd while, of course, the measured activities would. The resulting calculation to measurement ratios, (C/M), which are used to remove biases in the calculated fluxes, would therefore be in error, in the non-conservative direction, by some undetermined amount. This study has determined the magnitude of the bias in the fast response dosimeters, U238 and iron caused by the absorption of fast (E > 1.0 MeV) neutrons in 2 mm (0.002 m) Gd covers. The results indicate that the bias is in the 2.9--3.4% range and that it is only a weak function of dosimeter material

  17. Liver-targeting macromolecular MRI contrast agents

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Macromolecular ligands with liver-targeting group (pyridoxamine, PM) PHEA-DTPA-PM and PAEA-DTPA-PM were prepared by the incorporation of different amount of diethylenetriaminepentaacetic acid monopyridoxamine group (DTPA-PM) into poly-a, b-[N-(2-hydroxyethyl)-L- aspartamide] (PHEA) and poly-a, b-[N-(2-aminoethyl)-L-aspartamide] (PAEA). The macromolecular ligands thus obtained were further complexed with gadolinium chloride to give macromolecular MRI contrast agents with different Gd(Ⅲ) contents. These macromolecular ligands and their gadolinium complexes were characterized by 1H NMR, IR, UV and elementary analysis. Relaxivity studies showed that these polyaspartamide gadolinium complexes possess higher relaxation effectiveness than that of the clinically used Gd-DTPA. Magnetic resonance imaging of the liver in rats and experimental data of biodistribution in mice indicate that these macromolecular MRI contrast agents containing pyridoxamine exhibit liver-targeting property.

  18. Low Temperature Spin Structure of Gadolinium Titanate

    Science.gov (United States)

    Javanparast, Behnam; McClarty, Paul; Gingras, Michel

    2012-02-01

    Many rare earth pyrochlore oxides exhibit exotic spin configurations at low temperatures due to frustration. The nearest neighbor coupling between spins on the corner-sharing tetrahedral network generate geometrical magnetic frustration. Among these materials, gadolinium titanate (Gd2Ti2O7) is of particular interest. Its low temperature ordered phases are not yet understood theoretically. Bulk thermal measurements such as specific heat and magnetic susceptibility measurements find two phase transitions in zero external field, in agreement with simple mean field calculations. However, recent neutron scattering experiments suggest a so-called 4-k spin structure for intermediate phase and a so called canted 4-k structure for lower temperature phase that does not agree with either mean-field theory or Monte Carlo simulation which find the 1-k state and Palmer-Chalker state respectively as the lowest free energy configuration for those phases. In our work, we study the 4-k structure in detail and present a new phase diagram for dipolar Heisenberg spins on a pyrochlore lattice, certain portions of which describe gadolinium titanate.

  19. Gadolinium-modified titanium oxide materials for photoenergy applications:a review

    Institute of Scientific and Technical Information of China (English)

    Maciej Zalas

    2014-01-01

    Gadolinium doped titania materials were explored for application in photoenergy production. Incorporation of gadolinium into titania permitted improvement of photocatalytic or photovoltaic performance of the latter. This review provided a deep analysis of gadolinium applications in photoenergy processes and devices with the main focus on explanation of gadolinium doping effect on physicochemical properties of titania.

  20. Bioconjugation of luminescent silicon quantum dots to gadolinium ions for bioimaging applications

    Science.gov (United States)

    Erogbogbo, Folarin; Chang, Ching-Wen; May, Jasmine L.; Liu, Liwei; Kumar, Rajiv; Law, Wing-Cheung; Ding, Hong; Yong, Ken Tye; Roy, Indrajit; Sheshadri, Mukund; Swihart, Mark T.; Prasad, Paras N.

    2012-08-01

    Luminescent imaging agents and MRI contrast agents are desirable components in the rational design of multifunctional nanoconstructs for biological imaging applications. Luminescent biocompatible silicon quantum dots (SiQDs) and gadolinium chelates can be applied for fluorescence microscopy and MRI, respectively. Here, we report the first synthesis of a nanocomplex incorporating SiQDs and gadolinium ions (Gd3+) for biological applications. The nanoconstruct is composed of a PEGylated micelle, with hydrophobic SiQDs in its core, covalently bound to DOTA-chelated Gd3+. Dynamic light scattering reveals a radius of 85 nm for these nanoconstructs, which is consistent with the electron microscopy results depicting radii ranging from 25 to 60 nm. Cellular uptake of the probes verified that they maintain their optical properties within the intracellular environment. The magnetic resonance relaxivity of the nanoconstruct was 2.4 mM-1 s-1 (in terms of Gd3+ concentration), calculated to be around 6000 mM-1 s-1 per nanoconstruct. These desirable optical and relaxivity properties of the newly developed probe open the door for use of SiQDs in future multimodal applications such as tumour imaging.Luminescent imaging agents and MRI contrast agents are desirable components in the rational design of multifunctional nanoconstructs for biological imaging applications. Luminescent biocompatible silicon quantum dots (SiQDs) and gadolinium chelates can be applied for fluorescence microscopy and MRI, respectively. Here, we report the first synthesis of a nanocomplex incorporating SiQDs and gadolinium ions (Gd3+) for biological applications. The nanoconstruct is composed of a PEGylated micelle, with hydrophobic SiQDs in its core, covalently bound to DOTA-chelated Gd3+. Dynamic light scattering reveals a radius of 85 nm for these nanoconstructs, which is consistent with the electron microscopy results depicting radii ranging from 25 to 60 nm. Cellular uptake of the probes verified that they

  1. Comparison of gadolinium depletion in CASMO-4 and CASMO-3

    Energy Technology Data Exchange (ETDEWEB)

    Knott, D.; Edenius, M. [Studsvik Company, Newton Centre, MA (United States)

    1995-12-31

    Since the mid-1980s, CASMO-3 has been used to generate two-group nodal data for SIMULATE-3. Development of CASMO-3 was based on the accuracy needed to analyze {approximately} 12-month cycle lengths. Fuel designs for these annual cycles contained low gadolinium loadings in only a few pins. As cycle lengths increased from 12 to 24 months, gadolinium loadings doubled and tripled, as did the number of pins containing gadolinium. The use of heavy burnable absorber loadings has been a driving force behind the development of CASMO-4.

  2. Alkali metal and alkali earth metal gadolinium halide scintillators

    Energy Technology Data Exchange (ETDEWEB)

    Bourret-Courchesne, Edith; Derenzo, Stephen E.; Parms, Shameka; Porter-Chapman, Yetta D.; Wiggins, Latoria K.

    2016-08-02

    The present invention provides for a composition comprising an inorganic scintillator comprising a gadolinium halide, optionally cerium-doped, having the formula A.sub.nGdX.sub.m:Ce; wherein A is nothing, an alkali metal, such as Li or Na, or an alkali earth metal, such as Ba; X is F, Br, Cl, or I; n is an integer from 1 to 2; m is an integer from 4 to 7; and the molar percent of cerium is 0% to 100%. The gadolinium halides or alkali earth metal gadolinium halides are scintillators and produce a bright luminescence upon irradiation by a suitable radiation.

  3. EPR character of gadolinium complexes with noncyclic polyether Schiff bases and its solvent effects

    Institute of Scientific and Technical Information of China (English)

    姚克敏; 陈德余; 王晓南; 邓宁

    1996-01-01

    EPR characters of three new gadolinium complexes with noncydic polyether Schiff bases in powder or organic solvents, including various oxyethylene chain lengths and different substituting groups in ligands, are investigated respectively. Some regularities are summed up. The difference of EPR character in various solvents, particularly at different temperatures, has been examined. The ’single peak effect’ due to THF solvent at low temperature is observed for the first time. This phenomenon is explicated.

  4. Monitoring of gadolinium-BOPTA uptake into the vessel wall during magnetic resonance (MR)-guided angioplasty of the peripheral arteries with a paclitaxel/gadolinium-BOPTA-coated balloon. An experimental study at 3 Tesla

    Energy Technology Data Exchange (ETDEWEB)

    Neizel, M.; Kelm, M. [University Hospital Duesseldorf (Germany). Dept. of Cardiology, Pneumology and Angiology; Ruebben, A.; Weiss, N. [Aachen Resonance, Aachen (Germany); Guenther, R.W. [University Hospital Aachen (Germany). Dept. of Radiology; Krombach, G.A. [University Hospital Giessen (Germany). Dept. of Radiology

    2014-04-15

    Purpose: The success of paclitaxel distribution within the vessel wall during paclitaxel-coated balloon angioplasty to prevent restenosis cannot be monitored under X-ray guidance. The aim of this pilot study was to demonstrate the feasibility of monitoring Gadolinium-BOPTA delivery within the vessel wall during magnetic resonance (MR)-guided paclitaxel/Gadolinium-BOPTA-coated balloon angioplasty of the peripheral arteries. Materials and methods: 6 pigs (47 ± 2 kg) were investigated. All experiments were performed using a 3 Tesla MR scanner. MR-guided bilaterial angioplasty of the iliac arteries was performed using a paclitaxel/MR contrast agent-coated balloon catheter. The feasibility of monitoring the delivery of Gadolinium-BOPTA to the vessel was assessed in 4 animals. In two additional animals, bilateral stenosis was surgically induced in the iliac arteries. Delivery of paclitaxel to the vessel wall was monitored using a 3 D T1-weighted gradient echo (GE) sequence for delineation of the vessel wall. Normalized signal intensity (SI) of the vessel wall was measured before and repeatedly after the intervention for 45 min. in all animals. Results: Paclitaxel/gadolinium-BOPTA-coated balloon angioplasty was successfully accomplished in all iliac arteries (n = 12). In animals with stenosis MR-angiography demonstrated successful dilatation (n = 4). The normalized SI of the vessel wall on T1-weighted GE images significantly increased after the intervention in all animals with and without stenosis for more than 45 min. (p < 0.001). Conclusion: Monitoring of Gadolinium-BOPTA into the vessel wall during MR-guided coated balloon angioplasty is feasible. This is a first step towards providing a tool for the online control of homogenous drug delivery after paclitaxel-coated balloon angioplasty. (orig.)

  5. Speciation of gadolinium in surface water samples and plants by hydrophilic interaction chromatography hyphenated with inductively coupled plasma mass spectrometry.

    Science.gov (United States)

    Lindner, Uwe; Lingott, Jana; Richter, Silke; Jakubowski, Norbert; Panne, Ulrich

    2013-02-01

    Hydrophilic interaction chromatography (HILIC) coupled with inductively coupled plasma mass spectrometry (ICP-MS) was optimized for speciation analysis of gadolinium-based contrast agents in environmental samples, in particular surface river waters and plants. Surface water samples from the Teltow channel, near Berlin, were investigated over a distance of 5 km downstream from the influx of a wastewater treatment plant. The total concentration of gadolinium increased significantly from 50 to 990 ng L(-1) due to the influx of the contrast agents. After complete mixing with the river water, the concentration remained constant over a distance of at least 4 km. Two main substances [Dotarem(®) (Gd-DOTA) and Gadovist(®) (Gd-BT-DO3A)] have been identified in the river water using standards. A gadolinium-based contrast agent, possibly Gd-DOTA (Dotarem(®)), was also detected in water plant samples taken from the Teltow channel. Therefore, uptake of contrast agents [Gadovist(®) (Gd-BTDO3A), Magnevist(®) (Gd-DTPA), Omniscan(®) (Gd-DTPA-BMA), Dotarem(®) (Gd-DOTA), and Multihance(®) (Gd-BOPTA)] by plants was investigated in a model experiment using Lepidium sativum (cress plants). HILIC-ICP-MS was used for identification of different contrast agents, and a first approach for quantification using aqueous standard solutions was tested. For speciation analysis, all investigated contrast agents could be extracted from the plant tissues with a recovery of about 54 % for Multihance(®) (Gd-BOPTA) up to 106 % for Gadovist(®) (Gd-BT-DO3A). These experiments demonstrate that all contrast agents investigated are transported from the roots to the leaves where the highest content was measured.

  6. Contrast agents in magnetic resonance imaging

    International Nuclear Information System (INIS)

    The origine of nuclear magnetic resonance signal is reminded and different ways for contrast enhancement in magnetic resonance imaging are presented, especially, modifications of tissus relaxation times. Investigations have focused on development of agents incorporating either paramagnetic ions or stable free radicals. Pharmacological and toxicological aspects are developed. The diagnostic potential of these substances is illustrated by the example of gadolinium complexes

  7. Dielectric characterization of gadolinium tartrate trihydrate crystals

    Energy Technology Data Exchange (ETDEWEB)

    Want, Basharat [Department of Physics, University of Kashmir, Srinagar 190006, Jammu and Kashmir (India); Ahmad, Farooq [Department of Physics, University of Kashmir, Srinagar 190006, Jammu and Kashmir (India); Kotru, P.N. [Department of Physics and Electronics, University of Jammu, Jammu 180006, Jammu and Kashmir (India)]. E-mail: pn_kotru@yahoo.com

    2007-01-15

    Single crystals of gadolinium tartrate trihydrate have been grown by gel diffusion technique. Single crystal X-ray diffraction analysis shows that the crystals belong to the tetragonal system with non-centrosymmetric space group. The dielectric constant, dielectric loss and ac conductivity have been measured as a function of frequency in the range 1 kHz-5 MHz and temperature range 20-300 deg. C. The dielectric constant increases with temperature, attains a peak around 240 deg. C and then decreases as the temperature exceeds 240 deg. C. The dielectric anomaly at 240 deg. C is suggested to be due to phase transition brought about in the material, which is further supported by the thermal studies. The variation of ac conductivity with temperature has been measured and the material is suggested to show protonic conductivity.

  8. Electronic Structure of Gadolinium Calcium Oxoborate

    Energy Technology Data Exchange (ETDEWEB)

    Nelson, A; Adams, J; Schaffers, K

    2004-07-01

    Gadolinium calcium oxoborate (GdCOB) is a nonlinear optical material that belongs to the calcium--rare-earth (R) oxoborate family, with general composition Ca{sub 4}RO(BO{sub 3}){sub 3} (R{sup 3+} = La, Sm, Gd, Lu, Y). X-ray photoemission was applied to study the valence band electronic structure and surface chemistry of this material. High resolution photoemission measurements on the valence band electronic structure and Gd 3d and 4d, Ca 2p, B 1s and O 1s core lines were used to evaluate the surface and near surface chemistry. These results provide measurements of the valence band electronic structure and surface chemistry of this rare-earth oxoborate.

  9. Phase-Bpre-simulation using boron and gadolinium as poison in the moderators system for Wolsong-1

    International Nuclear Information System (INIS)

    The Wolsong-1 (W-1) Phase-B pre-simulations were carried out in preparation for tests to be conducted for the restart of the reactor after a major refurbishment project that included replacement of the pressure tube. These pre-simulations for Wolsong-1 Phase-B differ from those in the past that were performed for the Wolsong-1,2,3,4 tests in that these tests use the WIMS/DRAGON/RFSP-IST code suite for verification of the tests and gadolinium instead of the traditional PPV/MULTICELL/RFSP code system and boron as poison in the moderator system. The use of gadolinium is deemed not to have domestically accumulated experience gained from the previous Phase-B tests. Thus, it is appropriate to conduct a study in order to gain a correct understanding and interpretation of potential differences in test results stemming from using gadolinium rather than boron. Although the calibration of the reactivity device will not be noticeably different using boron and gadolinium at a constant moderator temperature, the temperature dependency of the neutronic behavior due to the presence of gadolinium in the moderator system might be pronounced. The results of the pre-simulations using gadolinium revealed that the moderator temperature reactivity coefficients indeed showed significant differences in comparison with those with boron. In order to secure the validity of the analysis results, the newly acquired WIMS/DRAGON/RFSP-IST code suite was verified against the W-2,3,4 Phase-B test results. The results of the new code suite verifications revealed some overall improvements in accuracy; justification of the use of the code can be claimed for the validation of the W-1 Phase-B test results.

  10. Gadolinium-DOTA enhanced MRI of painful osseous crises in children with sickle cell anemia

    International Nuclear Information System (INIS)

    In order to evaluate the role of gadolinium-DOTA enhanced MRI in the management of painful osseous crises in children with sickle cell anemia (SCA), nine children with SCA underwent MRI, bone scans and ultrasonographic studies during 11 osseous crises. Imaging findings were compared with the final diagnosis: three acute osteomyelitis (AO) and 16 acute infarcts (AI). MRI could not differentiate AO from AI. The appearance of severe AI was very misleading and was similar to the usual appearance of AO, including soft tissue changes, periosteal reaction and patterns of enhancement. Gadolinium-DOTA enhanced MRI was useful for determining the anatomic site and extent of AO or AI and for distinguishing between necrotic material, fluid collection and vascularized inflammatory tissue. It can also help to guide the aspiration of intraosseous, subperiosteal and soft tissue fluid collections. (orig.)

  11. Gadolinium-DOTA enhanced MRI of painful osseous crises in children with sickle cell anemia

    Energy Technology Data Exchange (ETDEWEB)

    Bonnerot, V. (Dept. of Pediatric Radiology, Hopital des Enfants Malades, 75 - Paris (France)); Sebag, G. (Dept. of Pediatric Radiology, Hopital des Enfants Malades, 75 - Paris (France)); Montalembert, M. de (Dept. of Pediatric Hematology, Hopital des Enfants Malades, 75 - Paris (France)); Wioland, M. (Dept. of Nuclear Medicine, Hopital Saint-Antoine, 75 - Paris (France)); Glorion, C. (Dept. of Orthopedics, Hopital des Enfants Malades, 75 - Paris (France)); Girot, R. (Dept. of Pediatric Hematology, Hopital des Enfants Malades, 75 - Paris (France)); Lallemand, D. (Dept. of Pediatric Radiology, Hopital des Enfants Malades, 75 - Paris (France))

    1994-04-01

    In order to evaluate the role of gadolinium-DOTA enhanced MRI in the management of painful osseous crises in children with sickle cell anemia (SCA), nine children with SCA underwent MRI, bone scans and ultrasonographic studies during 11 osseous crises. Imaging findings were compared with the final diagnosis: three acute osteomyelitis (AO) and 16 acute infarcts (AI). MRI could not differentiate AO from AI. The appearance of severe AI was very misleading and was similar to the usual appearance of AO, including soft tissue changes, periosteal reaction and patterns of enhancement. Gadolinium-DOTA enhanced MRI was useful for determining the anatomic site and extent of AO or AI and for distinguishing between necrotic material, fluid collection and vascularized inflammatory tissue. It can also help to guide the aspiration of intraosseous, subperiosteal and soft tissue fluid collections. (orig.)

  12. Regression of gadolinium-enhanced lesions in patients affected by neurofibromatosis type 1.

    Science.gov (United States)

    Lucchetta, Marta; Manara, Renzo; Perilongo, Giorgio; Clementi, Maurizio; Trevisson, Eva

    2016-03-01

    Neurofibromatosis type I is a genetic condition with an autosomal dominant transmission characterized by neurocutaneous involvement and a predisposition to tumor development. Central nervous system manifestations include benign areas of dysmyelination and possibly hazardous glial tumors whose clinical management may result challenging. Here, we report on three patients diagnosed with Neurofibromatosis type I whose brain MRI follow-up showed the presence of gadolinium-enhancing lesions which spontaneously regressed. In none of the three cases, the lesions showed any clinical correlate and eventually presented a striking reduction in size while gadolinium enhancement disappeared despite no specific therapy administration during the follow-up. Although their nature remains undetermined, these lesions presented a benign evolution. However, they might be misdiagnosed as potentially life-threatening tumors. Hitherto, a similar behavior has been described only in scattered cases and we believe these findings may be of particular interest for the clinical management of patients affected by neurofibromatosis type I.

  13. Gadolinium EUV Multilayers for Solar Imaging Near 60 nm Project

    Data.gov (United States)

    National Aeronautics and Space Administration — We propose to develop and commercialize a new class of extreme ultraviolet (EUV) multilayer coatings containing the rare-earth element gadolinium (Gd), designed as...

  14. Deposit of isotopically modified gadolinium suitable to detect solar neutrinos

    Energy Technology Data Exchange (ETDEWEB)

    Cribier, M

    1999-04-01

    Consideration on the possibility to find gadolinium with a modified isotopic composition are envisaged, in particular with respect to the important use of this element by the nuclear energy. These possibility could exist in the far future. (author)

  15. Sensitive and transportable gadolinium-core plastic scintillator sphere for neutron detection and counting

    Science.gov (United States)

    Dumazert, Jonathan; Coulon, Romain; Carrel, Frédérick; Corre, Gwenolé; Normand, Stéphane; Méchin, Laurence; Hamel, Matthieu

    2016-08-01

    Neutron detection forms a critical branch of nuclear-related issues, currently driven by the search for competitive alternative technologies to neutron counters based on the helium-3 isotope. The deployment of plastic scintillators shows a high potential for efficient detectors, safer and more reliable than liquids, more easily scalable and cost-effective than inorganic. In the meantime, natural gadolinium, through its 155 and mostly 157 isotopes, presents an exceptionally high interaction probability with thermal neutrons. This paper introduces a dual system including a metal gadolinium core inserted at the center of a high-scale plastic scintillator sphere. Incident fast neutrons are thermalized by the scintillator shell and then may be captured with a significant probability by gadolinium 155 and 157 nuclei in the core. The deposition of a sufficient fraction of the capture high-energy prompt gamma signature inside the scintillator shell will then allow discrimination from background radiations by energy threshold, and therefore neutron detection. The scaling of the system with the Monte Carlo MCNPX2.7 code was carried out according to a tradeoff between the moderation of incident fast neutrons and the probability of slow neutron capture by a moderate-cost metal gadolinium core. Based on the parameters extracted from simulation, a first laboratory prototype for the assessment of the detection method principle has been synthetized. The robustness and sensitivity of the neutron detection principle are then assessed by counting measurement experiments. Experimental results confirm the potential for a stable, highly sensitive, transportable and cost-efficient neutron detector and orientate future investigation toward promising axes.

  16. Gadolinium-enhanced MR angiography of the breast: Is breast cancer associated with ipsilateral higher vascularity?

    Energy Technology Data Exchange (ETDEWEB)

    Mahfouz, A.E.; Sherif, H. [Dept. of Radiology, Charite Medical Center, Humboldt-Univ. zu Berlin (Germany); Dept. of Radiology, Cairo University Hospital, Cairo (Egypt); Saad, A. [Dept. of Radiology, Charite Medical Center, Humboldt-Univ. zu Berlin (Germany); Dept. of Public Health and Environmental Medicine, National Research Center, Cairo (Egypt); Taupitz, M.; Filimonow, S.; Kivelitz, D.; Hamm, B. [Dept. of Radiology, Charite Medical Center, Humboldt-Univ. zu Berlin (Germany)

    2001-06-01

    The aim of this study was to assess a possible association between breast malignancy and ipsilateral higher vascularity on gadolinium-enhanced MR angiography. One hundred six patients were examined by dynamic gadolinium-enhanced 3D MR imaging. Magnetic resonance angiographic views were generated by image subtraction and maximum intensity projection. The study included 85 patients with unilateral malignant breast neoplasms and 21 with unilateral benign lesions. Three blinded readers independently reviewed the MR angiograms after masking the lesions and the corresponding contralateral sites. The readers were asked to determine whether vascularity was higher on the right side, higher on the left side, or equal on both sides. The results were analyzed by the Kappa statistic and Pearson's chi-square test. The blood vessels of the breasts were clearly seen in all cases. There was good agreement among the observers (kappa > 0.54) in assessing vascularity on both sides. Breasts harboring malignant neoplasms were found to have a higher vascularity than the contralateral breasts (p < 0.005). This sign of malignancy had a sensitivity of 76.5 %, a specificity of 57 %, and an accuracy of 72.6 %. Blood vessels of the breast can be depicted by MR angiography. Unilateral malignant neoplasms are associated with a higher ipsilateral vascularity. In conjunction with other indications of malignancy on gadolinium-enhanced MR images, a higher ipsilateral vascularity may serve as an additional sign of malignancy. (orig.)

  17. Gadolinium enhancement patterns of tumefactive demyelinating lesions: correlations with brain biopsy findings and pathophysiology.

    Science.gov (United States)

    Kobayashi, Masaki; Shimizu, Yuko; Shibata, Noriyuki; Uchiyama, Shinichiro

    2014-10-01

    Tumefactive demyelinating lesions (TDLs) can mimic brain tumors on radiological images. TDLs are often referred to as tumefactive multiple sclerosis (TMS), but the heterogeneous nature and monophasic course of TDLs do not fulfill clinical and magnetic resonance imaging (MRI) criteria for multiple sclerosis. Redefining TDLs, TMS and other inflammatory brain lesions is essential for the accurate clinical diagnosis of extensive demyelinating brain lesions. We retrospectively analyzed MRI from nine TDL cases that underwent brain biopsy. Patterns of gadolinium enhancement on MRI were categorized as homogenous, inhomogeneous, patchy and diffuse, open ring or irregular rim, and were compared with pathological hallmarks including demyelination, central necrosis, macrophage infiltration, angiogenesis and perivascular lymphocytic cuffing. All cases had coexistence of demyelinating features and axonal loss. Open-ring and irregular rim patterns of gadolinium enhancement were associated with macrophage infiltrations and angiogenesis at the inflammatory border. An inhomogeneous pattern of gadolinium enhancement was associated with perivascular lymphocytic cuffing. Central necrosis was seen in cases of severe multiple sclerosis and hemorrhagic leukoencephalopathy. These results suggest that the radiological features of TDLs may be related to different pathological processes, and indicate that MRI may be useful in understanding their pathophysiology. Further investigation is needed to determine the precise disease entity of these inflammatory demyelinating brain lesions.

  18. Validation of gadolinium burnout using PWR benchmark specification

    Energy Technology Data Exchange (ETDEWEB)

    Oettingen, Mikołaj, E-mail: moettin@agh.edu.pl; Cetnar, Jerzy, E-mail: cetnar@mail.ftj.agh.edu.pl

    2014-07-01

    Graphical abstract: - Highlights: • We present methodology for validation of gadolinium burnout in PWR. • We model 17 × 17 PWR fuel assembly using MCB code. • We demonstrate C/E ratios of measured and calculated concentrations of Gd isotopes. • The C/E for Gd154, Gd156, Gd157, Gd158 and Gd160 shows good agreement of ±10%. • The C/E for Gd152 and Gd155 shows poor agreement below ±10%. - Abstract: The paper presents comparative analysis of measured and calculated concentrations of gadolinium isotopes in spent nuclear fuel from the Japanese Ohi-2 PWR. The irradiation of the 17 × 17 fuel assembly containing pure uranium and gadolinia bearing fuel pins was numerically reconstructed using the Monte Carlo Continuous Energy Burnup Code – MCB. The reference concentrations of gadolinium isotopes were measured in early 1990s at Japan Atomic Energy Research Institute. It seems that the measured concentrations were never used for validation of gadolinium burnout. In our study we fill this gap and assess quality of both: applied numerical methodology and experimental data. Additionally we show time evolutions of infinite neutron multiplication factor K{sub inf}, FIMA burnup, U235 and Gd155–Gd158. Gadolinium-based materials are commonly used in thermal reactors as burnable absorbers due to large neutron absorption cross-section of Gd155 and Gd157.

  19. Neutronics Design Flexibilities of the BigT Gadolinium Absorbers

    Energy Technology Data Exchange (ETDEWEB)

    Yahya, Mohd-Syukri; Kim, Yonghee [KAIST, Daejeon (Korea, Republic of); Kim, HyeongHeon [KEPCO Engineering and Construction Company, Daejeon (Korea, Republic of)

    2015-05-15

    A new BA design named 'Burnable absorber-Integrated Guide Thimble' (BigT) was recently proposed for PWR. The BigT offers flexibility in BA self-shielding adjustment per design specifications. It is upon this assertion that this paper was prepared; i.e. this research aims to demonstrate the neutronics design flexibilities of BigT gadolinium absorbers. Specifically, three studies were completed to investigate sensitivities of the BigT gadolinium absorbers: (1) at a constant BA mass, (2) with a similar initial reactivity hold-down, and (3) for an optimal burnup reactivity swing. The paper clearly demonstrates neutronics flexibilities of the BigT gadolinium absorbers. Ascertained design variables are: (1) gadolinium effective shape, (2) BigT loading per lattice, and (3) BigT location in the lattice. Hybrid combination of the BigT designs may also alter the lattice depletion pattern, as well as density of gadolinium installed in the BigT absorbers. It is concluded that self-shielding of Gd can easily be adjusted in the BigT applications.

  20. Validation of gadolinium burnout using PWR benchmark specification

    International Nuclear Information System (INIS)

    Graphical abstract: - Highlights: • We present methodology for validation of gadolinium burnout in PWR. • We model 17 × 17 PWR fuel assembly using MCB code. • We demonstrate C/E ratios of measured and calculated concentrations of Gd isotopes. • The C/E for Gd154, Gd156, Gd157, Gd158 and Gd160 shows good agreement of ±10%. • The C/E for Gd152 and Gd155 shows poor agreement below ±10%. - Abstract: The paper presents comparative analysis of measured and calculated concentrations of gadolinium isotopes in spent nuclear fuel from the Japanese Ohi-2 PWR. The irradiation of the 17 × 17 fuel assembly containing pure uranium and gadolinia bearing fuel pins was numerically reconstructed using the Monte Carlo Continuous Energy Burnup Code – MCB. The reference concentrations of gadolinium isotopes were measured in early 1990s at Japan Atomic Energy Research Institute. It seems that the measured concentrations were never used for validation of gadolinium burnout. In our study we fill this gap and assess quality of both: applied numerical methodology and experimental data. Additionally we show time evolutions of infinite neutron multiplication factor Kinf, FIMA burnup, U235 and Gd155–Gd158. Gadolinium-based materials are commonly used in thermal reactors as burnable absorbers due to large neutron absorption cross-section of Gd155 and Gd157

  1. Discovery and basic pharmacology of erythropoiesis-stimulating agents (ESAs), including the hyperglycosylated ESA, darbepoetin alfa: an update of the rationale and clinical impact.

    Science.gov (United States)

    Kiss, Zoltán; Elliott, Steven; Jedynasty, Kinga; Tesar, Vladimír; Szegedi, János

    2010-04-01

    Cloning of the human erythropoietin (EPO) gene and development of the first recombinant human erythropoietin (rHuEPO) drug were truly breakthroughs. This allowed a deeper understanding of the structure and pharmacology of rHuEpo, which in turn inspired the discovery and development of additional erythropoiesis-stimulating agents (ESAs). In vivo specific activity and serum half-life of rHuEPO are influenced by the amount and structure of the attached carbohydrate. Increased numbers of sialic acids on carbohydrate attached to rHuEPO correlated with a relative increase in in-vivo-specific activity and increased serum half-life. The effect of increasing the number of sialic-acid-containing carbohydrates on in-vivo-specific activity was explored. Initial research focused on solving the problem of how the protein backbone could be engineered so a cell would add more carbohydrate to it. Additional work resulted in darbepoetin alfa, a longer-acting molecule with two additional carbohydrate chains. PMID:20127232

  2. Contrast-enhanced peripheral MRA. Technique and contrast agents

    Energy Technology Data Exchange (ETDEWEB)

    Nielsen, Yousef W. [Dept. of Radiology, Copenhagen Univ. Hospital Bispebjerg, Bispebjerg (Denmark)], e-mail: ywnielsen@gmail.com; Thomsen, Henrik S. [Dept. of Diagnostic Radiology, Copenhagen Univ. Hospital Herlev, Herlev (Denmark)

    2012-09-15

    In the last decade contrast-enhanced magnetic resonance angiography (CE-MRA) has gained wide acceptance as a valuable tool in the diagnostic work-up of patients with peripheral arterial disease. This review presents current concepts in peripheral CE-MRA with emphasis on MRI technique and contrast agents. Peripheral CE-MRA is defined as an MR angiogram of the arteries from the aortic bifurcation to the feet. Advantages of CE-MRA include minimal invasiveness and lack of ionizing radiation. The basic technique employed for peripheral CE-MRA is the bolus-chase method. With this method a paramagnetic MRI contrast agent is injected intravenously and T1-weighted images are acquired in the subsequent arterial first-pass phase. In order to achieve high quality MR angiograms without interfering venous contamination or artifacts, a number of factors need to be taken into account. This includes magnetic field strength of the MRI system, receiver coil configuration, use of parallel imaging, contrast bolus timing technique, and k-space filling strategies. Furthermore, it is possible to optimize peripheral CE-MRA using venous compression techniques, hybrid scan protocols, time-resolved imaging, and steady-state MRA. Gadolinium(Gd)-based contrast agents are used for CE-MRA of the peripheral arteries. Extracellular Gd agents have a pharmacokinetic profile similar to iodinated contrast media. Accordingly, these agents are employed for first-pass MRA. Blood-pool Gd-based agents are characterized by prolonged intravascular stay, due to macromolecular structure or protein binding. These agents can be used for first-pass, as well as steady-state MRA. Some Gd-based contrast agents with low thermodynamic stability have been linked to development of nephrogenic systemic fibrosis in patients with severe renal insufficiency. Using optimized technique and a stable MRI contrast agent, peripheral CE-MRA is a safe procedure with diagnostic accuracy close to that of conventional catheter X

  3. Coordination chemistry of gadolinium complexes having pyridine carboxylate units in relation with the medical imagery; Chimie de coordination de complexes de gadolinium a motifs pyridine carboxylate en relation avec l'imagerie medicale

    Energy Technology Data Exchange (ETDEWEB)

    Gateau, C.; Chatterton, N.; Nonat, A.; Mazzanti, M. [CEA Grenoble, Dept. de Recherche Fondamentale sur la Matiere Condensee (DRFMC/SCIB/LAI) Lab. de Reconnaissance Ionique, 38 (France); Pecaut, J. [CEA Grenoble, Dept. de Recherche Fondamentale sur la Matiere Condensee (DRFMC/SCIB/LAI) Lab. de Coordination et Chiralite, 38 (France); Borel, A.; Merbach, A.; Heim, L. [Lausanne Univ., Institut de Chimie Minerale et Analytique (Switzerland)

    2005-07-01

    In order to study the influence of the coordination sphere on the properties which govern the relaxivity, ligands containing pyridine carboxylates units have been particularly studied. It has been shown that the tripodal ligand tpaa forms with gadolinium (III) a neutral complex having a relaxivity (r1p=13.3 mM{sup -1} at 298 K and 60 MHz) which is three times superior to the contrast agents currently used in NMR Imaging. To explain this remarkably relaxivity, two new ligands analogous to the tpaa: the tpatcn and the bpeda containing pyridine carboxylate units bound to one or several aliphatic nitrogen have been studied in modulating the number of coordination sites and the symmetry degree. The study of the relaxivity of the corresponding gadolinium (III) complexes gives precious data on the understanding of the results in the case of the complex [Gd(tpaa)]. The synthesis and the properties of these gadolinium (III) complexes will be presented during this conference. (O.M.)

  4. Gadolinium metallo nanocongregates as potential magnetosensors for detecting early stage cancers

    Energy Technology Data Exchange (ETDEWEB)

    Dutta, Ranu, E-mail: ranu.dutta16@gmail.com [Nanotechnology Application Centre, University of Allahabad, Allahabad 211002 (India); NanoeRA Medicare Private Limited, Uttar Pradesh (India); Pandey, Avinash C. [Nanotechnology Application Centre, University of Allahabad, Allahabad 211002 (India); Bundelkhand University, Jhansi (India)

    2015-04-27

    Gadolinium chelates and gadolinium based inorganic nanoparticles have been extensively studied, because of the high magnetic moment of gadolinium. Here, metallic gadolinium nanocongregates have been developed. Upon injecting these nanoparticles in the mice, they initially circulate in the blood stream and are localized at the cancer site, which could be visualized upon application of magnetic field hence acting as small magnetic nanosensors searching for even small cancers, detecting cancers at a very early stage.

  5. Standard specification for nuclear-grade gadolinium oxide (Gd2O3) powder

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2003-01-01

    1.1 This specification provides the chemical and physical requirements for nuclear-grade gadolinium oxide powder intended for subsequent processing and use in nuclear fuel applications, for example, as an addition to uranium dioxide. 1.2 This specification does not include requirements for health and safety. Observance of this specification does not relieve the user of the obligation to be aware of and comply with all federal, state, and local regulations pertaining to possessing, shipping, processing, or using this material. 1.3 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.

  6. Gadolinio y fibrosis sistémica nefrogénica Gadolinium and nephrogenic systemic fibrosis

    Directory of Open Access Journals (Sweden)

    Claudia Cejas

    2012-06-01

    Full Text Available Inicialmente llamada dermopatía fibrosante nefrogénica, la fibrosis sistémica nefrogénica (FSN está fuertemente ligada a la inyección endovenosa de medios de contraste -basados en gadolinio- en pacientes con insuficiencia renal. En esta revisión corta se analiza la fisiopatología y la clínica, la responsabilidad del radiólogo en la prevención a través de la puesta en práctica de las reglamentaciones vigentes y, por último, se mencionan algunos conceptos sobre el tratamiento de los pacientes con insuficiencia renal crónica que deben exponerse a la inyección de gadolinio.Nephrogenic systemic fibrosis (NSF, initially called nephrogenic fibrosing dermopathy, is strongly linked to the intravenous injection of gadolinium-based contrast agents in patients with renal insufficiency. In this short review, we analyze the pathophysiology and clinical signs and symptoms, the medical responsibility of the radiologist in prevention through the implementation of the existing regulations and, finally, some concepts on the treatment of patients with chronic renal insufficiency who must receive a gadolinium injection.

  7. Selective photoionization of gadolinium isotopes with a polarized laser

    International Nuclear Information System (INIS)

    The aim of this study is the use of gadolinium 157 as burnable poison in nuclear reactors. Spectroscopic isotopic displacements between Gd 156 and Gd 157 are low and the separation method studied is based on differentiated behavior, concerning polarized light, of even and odd gadolinium isotopes coming from their difference of nuclear spin. On this principle is based the simplest photoionization scheme. Selective ionization of odd isotopes is realized from the fundamental state with three resonating photons colinearly polarized. The experimental study confirms the possibility of efficient photoionization. The measured selectivity between Gd 157 and even isotope is over 48 in defined conditions because it can be destroyed by a magnetic field or if photons are not well polarized. Calculations and observations are in good agreement. Odd gadolinium isotope separation is feasible and effects preventing separation are evidenced

  8. Relaxivity enhancement of aquated Tris(β-diketonate)gadolinium(III) chelates by confinement within ultrashort single-walled carbon nanotubes.

    Science.gov (United States)

    Law, Justin J; Guven, Adem; Wilson, Lon J

    2014-01-01

    Ultrashort single-walled carbon nanotubes loaded with gadolinium ions (gadonanotubes) have been previously shown to exhibit extremely high T1 -weighted relaxivities (>100 mm(-1) s(-1) ). To further examine the effect of nanoconfinement on the relaxivity of gadolinium-based contrast agents for magnetic resonance imaging, a series of ultrashort single-walled carbon nanotube (US-tube) materials internally loaded with gadolinium chelates have been prepared and studied. US-tubes were loaded with Gd(acac)3  · 2H2 O, Gd(hfac)3  · 2H2 O, and Gd(thd)3 (acac = acetylacetone, hfac = hexafluoroacetylacetone, thd = tetramethylheptanedione). The longitudinal relaxivities of the prepared materials determined at 25°C in a 1.5 T field were 103 mm(-1) s(-1) for Gd(acac)3  · 2H2 O@US-tubes, 105 mm(-1) s(-1) for Gd(hfac)3  · 2H2 O@US-tubes and 26 mm(-1) s(-1) for Gd(thd)3 @US-tubes. Compared with the relaxivities obtained for the unloaded chelates (<10 mm(-1) s(-1) ) as well as accounting for the T1 reduction observed for the empty US-tubes, the boost in relaxivity for chelate-loaded US-tubes is attributed to confinement within the nanotube and depends on the number of coordinated water molecules.

  9. Glioblastoma, gadolinium (III) and NCT. An in vitro study

    International Nuclear Information System (INIS)

    We treated cultured human glioblastoma cells with gadolinium (III) [gadopentetic acid] and we found that: a) cells do internalise this element; b) gadolinium can be localised in the cells nuclei; c) exposure of the cultures to a neutron beam produced a significant and immediate cell death. Although cell survival was also influenced in the irradiated controls it was further reduced (about 50%) in cells pre-exposed to 10 mg/ml gadopentetic acid. We also found that Gd uptake, as measured by ICP-AES, was concentration dependent. (author)

  10. Growth of bulk gadolinium pyrosilicate single crystals for scintillators

    Science.gov (United States)

    Gerasymov, I.; Sidletskiy, O.; Neicheva, S.; Grinyov, B.; Baumer, V.; Galenin, E.; Katrunov, K.; Tkachenko, S.; Voloshina, O.; Zhukov, A.

    2011-03-01

    Ce, Pr, and La-doped gadolinium pyrosilicate Gd2Si2O7 (GPS) single crystals were grown by the Czochralski and Top Seeded Solution Growth (TSSG) techniques for the first time. Formation conditions of different pyrosilicate phases were determined. X-ray luminescence integral intensity of Ce-doped GPS is about one order of magnitude higher in comparison with gadolinium oxyorthosilicate Gd2SiO5:Ce (GSO:Ce). All samples demonstrate temperature stability of luminescence yield up to 400 K.

  11. Selective photoionization scheme for atomic gadolinium laser isotope separation

    International Nuclear Information System (INIS)

    The selective photoionization scheme for separating 157Gd from natural gadolinium and the laser irradiation conditions in order to enrich 157Gd to 60-80% are discussed in the case of two- and three-step photoionization. The dependence of excitation pathways on J-values is also discussed. From the view point of ionization rate it is preferable to select the four-colour three-step photoionization scheme by using both the ground and the lowest metastable levels. Optimum laser irradiation conditions for gadolinium isotope separation are presented. (author)

  12. Gadolinium-neutron capture reactions: A radiobiological assay

    International Nuclear Information System (INIS)

    Gadolinium neutron capture(GNC) takes advantage of its extraordinarily large cross section to thermal neutrons. In GNC reactions, prompt high energy gamma rays, x-rays and electrons are released. Because of the photons and electrons, the intracellular presence of gadolinium is not considered critical. This is an advantage over boron-neutron capture therapy where the intracellular presence of boron is required because of the short flight tracks of 2.4 MeV alpha particles. In this study, the radiation effect of GNC reactions was measured using Chinese hamster cells in an attempt to evaluate the contributions of neutrons, gamma rays and electrons on cell inactivation

  13. MRI Contrast Agents: Evolution of Clinical Practice and Dose Optimization.

    Science.gov (United States)

    Khan, Rihan

    2016-08-01

    Accurate detection of lesions throughout the body is of paramount importance in contrast-enhanced magnetic resonance imaging (MRI). Optimal contrast agent performance is therefore of great importance and given the number of MRI contrast agent options today, this topic is of much ongoing study. The goal of this review article is to bring the read up to date on pertinent articles that relate to the evolution of radiological clinical practice and dose optimization pertaining to gadolinium contrast agents. PMID:27367313

  14. A feasibility study to determine the potential of in vivo detection of gadolinium by x-ray fluorescence (XRF) following gadolinium-based contrast-enhanced MRI

    International Nuclear Information System (INIS)

    The feasibility of using a 109Cd γ-ray induced K x-ray fluorescence (K-XRF) system for the in vivo detection of gadolinium (Gd) in bone has been investigated. The K-XRF bone measurement system employs an array of four detectors, and is normally used for the non-invasive study of bone lead levels. The system was used to measure bone simulating phantoms doped with varying levels of gadolinium and fixed amounts of sodium (Na), chlorine (Cl) and calcium (Ca). The detection limits for bare bone phantoms, using a source of activity 0.17 GBq, were determined to be 3.9 ppm and 6.5 ppm (µg Gd per gram phantom) for the Kα1 and Kα2 Gd x-ray peaks, respectively. This leads to an overall detection limit of 3.3 ppm (µg Gd per gram phantom). Layers of plastic were used to simulate overlying soft tissue and this permitted prediction of a detection limit, using the current strength of our radioisotope source, of 6.1 ppm to 8.6 ppm (µg Gd per gram phantom) for fingers with 2–4 mm of overlying tissue. With a new source of activity 5 GBq, we predict that this system could achieve a detection limit of 4–5.6 µg Gd g−1 Ca. This is within the range of levels (2–30 µg Gd g−1 Ca) previously found in the bone of patients receiving Gd based contrast imaging agents. The technique is promising and warrants further investigation. (note)

  15. Characterizing ProstivaTM RF Treatments of the Prostate for BPH with Gadolinium-Enhanced MRI

    Directory of Open Access Journals (Sweden)

    Christian Huidobro

    2009-01-01

    Full Text Available Transurethral needle ablation (TUNA is an accepted and effective therapy for the treatment of lower urinary tract symptoms (LUTS due to benign prostatic hyperplasia (BPH. ProstivaTM (Medtronic, Shoreview, MN is the newest-generation device, which includes a new needle design and radio frequency (RF generator. This device creates temperatures of 120°C and necrotic lesions in less than 2.5 min. Using previously described techniques, we analyzed dynamic, gadolinium-enhanced MRIs to characterize the ablative properties of the new ProstivaTM RF device.

  16. Low Risk for Nephrogenic Systemic Fibrosis in Nondialysis Patients Who Have Chronic Kidney Disease and Are Investigated with Gadolinium-Enhanced Magnetic Resonance Imaging

    OpenAIRE

    Chrysochou, Constantina; Power, Albert; Shurrab, Aladdin E.; Husain, Sayed; Moser, Steven; Lay, James; Salama, Alan D.; Kalra, Philip A.

    2010-01-01

    Background and objectives: During the past decade, nephrogenic systemic fibrosis (NSF) has been reported in patients who have severe renal impairment and have been exposed to a gadolinium (Gd)-based contrast agent during magnetic resonance imaging (MRI). As a result of positive reporting bias, many suitable patients with chronic kidney disease (CKD) are being denied a highly important form of investigation that can be safely undertaken. We analyzed the safety of Gd-MRI in patients with CKD an...

  17. Structural and magnetic phase transitions in gadolinium under high pressures and low temperatures

    Science.gov (United States)

    Samudrala, Gopi K.; Tsoi, Georgiy M.; Weir, Samuel T.; Vohra, Yogesh K.

    2014-10-01

    High pressure structural transition studies have been carried out on rare earth metal gadolinium in a diamond anvil cell at room temperature to 169 GPa. Gadolinium has been compressed to 38% of its initial volume at this pressure. With increasing pressure, a crystal structure sequence of hcp → Sm-type → dhcp → fcc → dfcc → monoclinic has been observed in our studies on gadolinium. The measured equation of state of gadolinium is presented to 169 GPa at ambient temperature. Magnetic ordering temperature of gadolinium has been studied using designer diamond anvils to a pressure of 25 GPa and a temperature of 10 K. The magnetic ordering temperature has been determined from the four-point electrical resistivity measurements carried out on gadolinium. Our experiments show that the magnetic transition temperature decreases with increasing pressure to 19 GPa and then increases when gadolinium is subjected to higher pressures.

  18. Joint electroreduction of lanthanum, gadolinium and boron in halide melts

    OpenAIRE

    Khushkhov KH.B.; Vindizheva M.K.; Uzdenova A.S.; Zhanikaeva Z.A.

    2003-01-01

    The joint electroreduction of La, Gd and B from chloride-fluoride melts has been studied by cyclic voltametry. Based on the analysis of voltamograms the possibility of electrosynthesis of lanthanum-gadolinium borides from chloride-fluoride melts has been shown.

  19. Purification of cerium, neodymium and gadolinium for low background experiments

    Science.gov (United States)

    Boiko, R. S.; Barabash, A. S.; Belli, P.; Bernabei, R.; Cappella, F.; Cerulli, R.; Danevich, F. A.; Incicchitti, A.; Laubenstein, M.; Mokina, V. M.; Nisi, S.; Poda, D. V.; Polischuk, O. G.; Tretyak, V. I.

    2014-01-01

    Cerium, neodymium and gadolinium contain double beta active isotopes. The most interesting are 150Nd and 160Gd (promising for 0ν2β search), 136Ce (2β+ candidate with one of the highest Q2β). The main problem of compounds containing lanthanide elements is their high radioactive contamination by uranium, radium, actinium and thorium. The new generation 2β experiments require development of methods for a deep purification of lanthanides from the radioactive elements. A combination of physical and chemical methods was applied to purify cerium, neodymium and gadolinium. Liquid-liquid extraction technique was used to remove traces of Th and U from neodymium, gadolinium and for purification of cerium from Th, U, Ra and K. Co-precipitation and recrystallization methods were utilized for further reduction of the impurities. The radioactive contamination of the samples before and after the purification was tested by using ultra-low-background HPGe gamma spectrometry. As a result of the purification procedure the radioactive contamination of gadolinium oxide (a similar purification efficiency was reached also with cerium and neodymium oxides) was decreased from 0.12 Bq/kg to 0.007 Bq/kg in 228Th, from 0.04 Bq/kg to <0.006 Bq/kg in 226Ra, and from 0.9 Bq/kg to 0.04 Bq/kg in 40K. The purification methods are much less efficient for chemically very similar radioactive elements like actinium, lanthanum and lutetium.

  20. Joint electroreduction of lanthanum, gadolinium and boron in halide melts

    Directory of Open Access Journals (Sweden)

    Khushkhov KH.B.

    2003-01-01

    Full Text Available The joint electroreduction of La, Gd and B from chloride-fluoride melts has been studied by cyclic voltametry. Based on the analysis of voltamograms the possibility of electrosynthesis of lanthanum-gadolinium borides from chloride-fluoride melts has been shown.

  1. Gadolinium chloride pretreatment ameliorates acute cadmium-induced hepatotoxicity.

    Science.gov (United States)

    Kyriakou, Loukas G; Tzirogiannis, Konstantinos N; Demonakou, Maria D; Kourentzi, Kalliopi T; Mykoniatis, Michael G; Panoutsopoulos, Georgios I

    2013-08-01

    Cadmium is a known industrial and environmental pollutant. It causes hepatotoxicity upon acute administration. Features of cadmium-induced acute hepatoxicity encompass necrosis, apoptosis, peliosis and inflammatory infiltration. Gadolinium chloride (GdCl3) may prevent cadmium-induced hepatotoxicity by suppressing Kupffer cells. The effect of GdCl3 pretreatment on a model of acute cadmium-induced liver injury was investigated. Male Wistar rats 4-5 months old were injected intraperitoneally with normal saline followed by cadmium chloride (CdCl2; 6.5 mg/kg) or GdCl3 (10 mg/kg) followed by CdCl2 (6.5 mg/kg; groups I and II, respectively). Rats of both the groups were killed at 9, 12, 16, 24, 48 and 60 h after cadmium intoxication. Liver sections were analyzed for necrosis, apoptosis, peliosis and mitoses. Liver regeneration was also evaluated by tritiated thymidine incorporation into hepatic DNA. Serum levels of aspartate aminotransferase (AST) and alanine aminotransferase (ALT) were also determined. Hepatic necrosis, hepatocyte and nonparenchymal cell apoptosis and macroscopic and microscopic types of peliosis hepatis were minimized by gadolinium pretreatment. Serum levels of AST and ALT were also greatly diminished in rats of group II. Tritiated thymidine incorporation into hepatic DNA was increased in gadolinium pretreatment rats. Kupffer cell activation was minimal in both the groups of rats. Gadolinium pretreatment attenuates acute cadmium-induced liver injury in young Wistar rats, with mechanisms other than Kupffer cell elimination.

  2. Importance of the use of gadolinium in neurocysticercosis diagnosis

    International Nuclear Information System (INIS)

    Magnetic Resonance (MRI) and Computed Tomography (CT) features of neurocysticercosis are variable and depend fundamentally on the stage in evolution of the infection, location, number and size of the cysts. The authors retrospectively evaluated MRI obtained on O.5 Tesla superconducting unit in four neurocysticercosis patients and observed new MRI features only after Gadolinium enhancement. (author)

  3. MR imaging of gestational trophoblastic tumor: role of gadolinium enhancement

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Si Young; Byun, Jae Young; Kim, Bum Su; Yun, Young Hyun; Mun, Kyung Mi; Park, Kyung Sin; Kim, Byung Kee; Bae, Seog Nyeon; Shinn, Kyung Sub

    1997-12-01

    The purpose of this study is to investigate the role of gadolinium enhanced MR imaging in the evaluation of gestational trophoblastic tumors (invasive mole and choriocarcinoma). Pre-enhanced T1-and T2-weighted images and gadolinium enhanced T1-weighted images of 34 gestational trophoblastic tumors (15 choriocarcinomas, 19 invasive moles) were retrospectively evaluated and enhancement patterns were analyzed. Morphologica differences and structural characteristics were analyzed by the evaluation of tumor margin, patterns of hemorrhagic necroses, the development of intratumoral vascularity, and molar villi. Graded scores of MR findings between pre- and gadolinium enhanced images were based on the following criteria : 1) visualization of tumor margin 2) distinction between tumor necrosis and zone of trophoblastic proliferation ; and 3) molar villi. Statistical differences between graded scores of pre- and post-enhanced images were analyzed. Gadolinium enhanced MR imaging was helpful for the visualization of tumor characteristics in gestational trophoblastic tumors and in differential diagnosis between invasive mole and choriocarcinoma. (author). 16 refs., 4 tabs., 4 figs.

  4. Purification of cerium, neodymium and gadolinium for low background experiments

    Directory of Open Access Journals (Sweden)

    Boiko R.S.

    2014-01-01

    Full Text Available Cerium, neodymium and gadolinium contain double beta active isotopes. The most interesting are 150Nd and 160Gd (promising for 0ν2β search, 136Ce (2β+ candidate with one of the highest Q2β. The main problem of compounds containing lanthanide elements is their high radioactive contamination by uranium, radium, actinium and thorium. The new generation 2β experiments require development of methods for a deep purification of lanthanides from the radioactive elements. A combination of physical and chemical methods was applied to purify cerium, neodymium and gadolinium. Liquid-liquid extraction technique was used to remove traces of Th and U from neodymium, gadolinium and for purification of cerium from Th, U, Ra and K. Co-precipitation and recrystallization methods were utilized for further reduction of the impurities. The radioactive contamination of the samples before and after the purification was tested by using ultra-low-background HPGe gamma spectrometry. As a result of the purification procedure the radioactive contamination of gadolinium oxide (a similar purification efficiency was reached also with cerium and neodymium oxides was decreased from 0.12 Bq/kg to 0.007 Bq/kg in 228Th, from 0.04 Bq/kg to <0.006 Bq/kg in 226Ra, and from 0.9 Bq/kg to 0.04 Bq/kg in 40K. The purification methods are much less efficient for chemically very similar radioactive elements like actinium, lanthanum and lutetium.

  5. A Manganese Alternative to Gadolinium for MRI Contrast.

    Science.gov (United States)

    Gale, Eric M; Atanasova, Iliyana P; Blasi, Francesco; Ay, Ilknur; Caravan, Peter

    2015-12-16

    Contrast-enhanced computed tomography (CT) and magnetic resonance imaging (MRI) are routinely used to diagnose soft tissue and vascular abnormalities. However, safety concerns limit the use of iodinated and gadolinium (Gd)-based CT and MRI contrast media in renally compromised patients. With an estimated 14% of the US population suffering from chronic kidney disease (CKD), contrast media compatible with renal impairment is sorely needed. We present the new manganese(II) complex [Mn(PyC3A)(H2O)](-) as a Gd alternative. [Mn(PyC3A)(H2O)](-) is among the most stable Mn(II) complexes at pH 7.4 (log KML = 11.40). In the presence of 25 mol equiv of Zn at pH 6.0, 37 °C, [Mn(PyC3A)(H2O)](-) is 20-fold more resistant to dissociation than [Gd(DTPA)(H2O)](2-). Relaxivity of [Mn(PyC3A)(H2O)](-) in blood plasma is comparable to commercial Gd contrast agents. Biodistribution analysis confirms that [Mn(PyC3A)(H2O)](-) clears via a mixed renal/hepatobiliary pathway with >99% elimination by 24 h. [Mn(PyC3A)(H2O)](-) was modified to form a bifunctional chelator and 4 chelates were conjugated to a fibrin-specific peptide to give Mn-FBP. Mn-FBP binds the soluble fibrin fragment DD(E) with Kd = 110 nM. Per Mn relaxivity of Mn-FBP is 4-fold greater than [Mn(PyC3A)(H2O)](-) and increases 60% in the presence of fibrin, consistent with binding. Mn-FBP provided equivalent thrombus enhancement to the state of the art Gd analogue, EP-2104R, in a rat model of arterial thrombosis. Mn metabolite analysis reveals no evidence of dechelation and the probe was >99% eliminated after 24 h. [Mn(PyC3A)(H2O)](-) is a lead development candidate for an imaging probe that is compatible with renally compromised patients. PMID:26588204

  6. Gadolinium block of calcium channels: influence of bicarbonate.

    Science.gov (United States)

    Boland, L M; Brown, T A; Dingledine, R

    1991-11-01

    The selectivity of block of voltage-activated barium (Ba2+) currents by lanthanide ions was studied in a rat dorsal root ganglion (DRG) cell line (F11-B9), rat and frog peripheral neurons, and rat cardiac myocytes using the whole-cell patch clamp technique. Gadolinium (Gd3+) produced a dose-dependent and complete inhibition of whole-cell Ba2+ current in all cells studied, including cells expressing identified dihydropyridine-sensitive L-type currents and omega-conotoxin-sensitive N-type currents. Like Gd3+, lutetium (Lu3+) and lanthanum (La3+) blocked all Ba2+ current with little selectivity for different components of the whole-cell current. Gd3+ block of Ba2+ currents was incomplete, however, when sodium bicarbonate (5-22.6 mM) was added to the standard HEPES-buffered external Ba2+ solution. In rat DRG neurons and F11-B9 cells, a fraction of the whole-cell Ba2+ current recorded in the presence of bicarbonate was resistant to block by saturating concentrations of Gd3+ (50-100 microM). The resistant current inactivated more rapidly than the original current giving the appearance that, under these conditions, Gd3+ block is more selective for the slowly inactivating component of the whole-cell current. Bicarbonate modification of Gd3+ block occurred both before and after omega-conotoxin block of N-type currents in rat DRG neurons, suggesting that even in the presence of bicarbonate, Gd3+ block was not selective for N-type currents. PMID:1786527

  7. Prognostic value of late gadolinium enhancement in dilated cardiomyopathy patients: a meta-analysis

    International Nuclear Information System (INIS)

    Aim: To evaluate the association between late gadolinium enhancement (LGE) at cardiac magnetic resonance (CMR) and major adverse events in dilated cardiomyopathy (DCM) patients. Materials and methods: Databases, including PubMed, Ovid, and EMBASE, were searched for studies evaluating LGE at CMR in DCM patient prognostication. Clinical outcomes were analysed using fixed-effects models or, in cases of significant heterogeneity, random-effects models. Results: In the meta-analysis of 13 studies on 1675 DCM patients with a mean follow-up of 3 years, LGE is associated with all-cause mortality (pooled odds ratio, 3.43 [95% confidence interval, 2.26–5.22], p<0.00001), cardiac death/transplantation (3.65 [1.80–7.40], p=0.0003), hospitalisation for heart failure (2.87 [1.53–5.39], p=0.001), major arrhythmia events (sudden cardiac death, sustained ventricular tachycardia or fibrillation, appropriate implantable cardioverter–defibrillator (ICD) discharge/pacing, and syncope: 4.24 [2.95–6.08], p<0.00001), and sudden cardiac death (3.33 [1.80–6.17], p=0.0001). Conclusion: LGE in DCM patients appears to be associated with mortality and major cardiac events, underscoring its potential as an independent index for risk stratification and treatment guidance. -- Highlights: •Cardiac magnetic resonance imaging is a flourishing technique in the field of cardiomyopathy examination for its high space resolution. •Late gadolinium enhancement appears associated with increased risk for all-cause mortality and major cardiavascular events. •Late gadolinium enhancement by cardiac magnetic resonance might guide treatment and clinical care of heart failure patients

  8. Gadolinium Complex of 1,4,7,10-Tetraazacyclododecane-N,N',N'',N'''-1,4,7-trisacetic Acid (DO3A) Conjugate of Tranexamates: A Quest for a Liver-specific Magnetic Resonance Imaging Contrast Agent

    Energy Technology Data Exchange (ETDEWEB)

    Nam, Kisoo; Jeong, Hyunjeong; Kim, Heekyung; Choi, Garam; Chang, Yongmin; Kim, Taejeong [Kyungpook National Univ., Daegu (Korea, Republic of); Suh, Kyungjin [Dongguk Univ., Kyungju (Korea, Republic of)

    2014-01-15

    The work is directed toward the synthesis of a series of DO3A conjugates of tranexamates (1c-e) and their Gd complexes (2c-e) for use as a liver-specific MRI CA. All these complexes show thermodynamic and kinetic stabilities comparable to those of structurally related clinical agents such as Dotarem. Their R{sub 1} relaxivities also compare well with those of commercial agent, ranging 3.68-4.84 mM{sup -1}s{sup -1}. In vivo MR images of mice with 2a-e reveal that only 2a exhibits liver-specificity. Although 2b and 2c show strong enhancement in liver, yet no bile-excretion is observed to be termed as a liver-specific agent. The rest behaves much like ordinary ECF CAs like Dotarem. The new series possess no toxicity to be employed in vivo.

  9. Progressive increase of T1 signal intensity in the dentate nucleus and globus pallidus on unenhanced T1-weighted MR images in the pediatric brain exposed to multiple doses of gadolinium contrast.

    Science.gov (United States)

    Roberts, Donna R; Holden, Kenton R

    2016-03-01

    Recently, there have been reports of gadolinium accumulation in the brain and bone of adult patients with normal renal function who have undergone multiple gadolinium contrast administrations. This case report gives the first description of a pediatric patient who, following multiple contrasted MRI exams, demonstrated abnormal signal on unenhanced T1-weighted imaging involving the dentate nucleus and globus pallidus, a finding which has previously been shown to represent gadolinium deposition in adults. The patient presented here had no history of intracranial pathology which would alter the blood brain barrier or abnormal renal function. The clinical significance of gadolinium accumulation in the human body is currently unknown but is of concern, particularly in pediatric patients who have a lifetime to manifest any potential adverse consequences. Therefore, research is needed to address the clinical significance, if any, of gadolinium deposition in the developing pediatric brain. Given these current uncertainties, clinicians should continue to use prudence in selecting pediatric patients to undergo contrasted MRI and in selecting the appropriate contrast agents to use.

  10. Mapping of T1-Values and Gadolinium-Concentrations in MRI as Indicator of Disease Activity in Luminal Crohn's Disease: A Feasibility Study

    NARCIS (Netherlands)

    K. Horsthuis; A.J. Nederveen; M.W. de Feiter; C. Lavini; P.C.F. Stokkers; J. Stoker

    2009-01-01

    Purpose: To determine the feasibility of T1-mapping and calculation of Gadolinium-values in luminal Crohn's Disease (CD). Materials and Methods: Nine patients with active CD were included. For each patient disease activity was determined, based on endoscopic and histopathological results. The Crohn'

  11. Gadolinium oxide nanoplates with high longitudinal relaxivity for magnetic resonance imaging

    Science.gov (United States)

    Cho, Minjung; Sethi, Richa; Ananta Narayanan, Jeyarama Subramanian; Lee, Seung Soo; Benoit, Denise N.; Taheri, Nasim; Decuzzi, Paolo; Colvin, Vicki L.

    2014-10-01

    Molecular-based contrast agents for magnetic resonance imaging (MRI) are often characterized by insufficient relaxivity, thus requiring the systemic injection of high doses to induce sufficient contrast enhancement at the target site. In this work, gadolinium oxide (Gd2O3) nanoplates are produced via a thermal decomposition method. The nanoplates have a core diameter varying from 2 to 22 nm, a thickness of 1 to 2 nm and are coated with either an oleic acid bilayer or an octylamine modified poly(acrylic acid) (PAA-OA) polymer layer. For the smaller nanoplates, longitudinal relaxivities (r1) of 7.96 and 47.2 (mM s)-1 were measured at 1.41 T for the oleic acid bilayer and PAA-OA coating, respectively. These values moderately reduce as the size of the Gd2O3 nanoplates increases, and are always larger for the PAA-OA coating. Cytotoxicity studies on human dermal fibroblast cells documented no significant toxicity, with 100% cell viability preserved up to 250 μM for the PAA-OA coated Gd2O3 nanoplates. Given the 10 times increase in longitudinal relaxivity over the commercially available Gd-based molecular agents and the favorable toxicity profile, the 2 nm PAA-OA coated Gd2O3 nanoplates could represent a new class of highly effective T1 MRI contrast agents.Molecular-based contrast agents for magnetic resonance imaging (MRI) are often characterized by insufficient relaxivity, thus requiring the systemic injection of high doses to induce sufficient contrast enhancement at the target site. In this work, gadolinium oxide (Gd2O3) nanoplates are produced via a thermal decomposition method. The nanoplates have a core diameter varying from 2 to 22 nm, a thickness of 1 to 2 nm and are coated with either an oleic acid bilayer or an octylamine modified poly(acrylic acid) (PAA-OA) polymer layer. For the smaller nanoplates, longitudinal relaxivities (r1) of 7.96 and 47.2 (mM s)-1 were measured at 1.41 T for the oleic acid bilayer and PAA-OA coating, respectively. These values

  12. OUR APPROACH TOWARDS DEVELOPING A SPECIFIC TUMOR-TARGETED MRI CONTRAST AGENT FOR THE BRAIN

    NARCIS (Netherlands)

    GO, KG; BULTE, JWM; DELEY, L; THE, TH; KAMMAN, RL; HULSTAERT, CE; BLAAUW, EH; MA, LD

    1993-01-01

    This review presents various aspects of the technological development, and their assessment in the design of a contrast agent for MRI, tailored to visualise tumours in the brain. First, it was demonstrated that magnetite as a contrast agent exhibited a much stronger relaxivity than gadolinium. The p

  13. The study of in vivo x-ray fluorescence (XRF) technique for gadolinium (Gd) measurements in human bone

    Science.gov (United States)

    Mostafaei, F.; Nie, L. H.

    2016-08-01

    An in vivo K x-ray fluorescence system, based on 109Cd source, for the detection of gadolinium has been investigated. Gd is of interest because of the extensive use of Gd-based contrast agents in MR imaging. A human simulating bone phantom set has been developed. The phantoms were doped with seven concentrations of Gd. Additional elements important for in vivo x-ray fluorescence, Na, Cl and Ca, were also included to create an overall elemental composition consistent with the Reference Man. A new 5 GBq 109Cd source was purchased to improve the source activity in comparison to the previous study (0.17 GBq). The previously published minimum detection limit (MDL) for Gd phantom measurements using KXRF system was 3.3 ppm. In this study the minimum detection limit for bare bone phantoms was found to reduce the MDL to 0.8, a factor of 4.1. The previous published data used only three layers of plastic as soft tissue equivalent materials and found the MDL of 4–4.8 ppm. In this study we have used the plastic with more realistic thicknesses to simulate a soft tissue at tibia. The detection limits for phantoms with Lucite as a tissue equivalent, using a new source, was determined to be 1.81 to 3.47 ppm (μg Gd per gram phantom). Our next study would be testing an in vivo K x-ray fluorescence system, based on 109Cd source on human volunteers who went through MR imaging and were injected by Gd.

  14. Gadolinium oxide nanoplates with high longitudinal relaxivity for magnetic resonance imaging.

    Science.gov (United States)

    Cho, Minjung; Sethi, Richa; Narayanan, Jeyarama Subramanian Ananta; Lee, Seung Soo; Benoit, Denise N; Taheri, Nasim; Decuzzi, Paolo; Colvin, Vicki L

    2014-11-21

    Molecular-based contrast agents for magnetic resonance imaging (MRI) are often characterized by insufficient relaxivity, thus requiring the systemic injection of high doses to induce sufficient contrast enhancement at the target site. In this work, gadolinium oxide (Gd2O3) nanoplates are produced via a thermal decomposition method. The nanoplates have a core diameter varying from 2 to 22 nm, a thickness of 1 to 2 nm and are coated with either an oleic acid bilayer or an octylamine modified poly(acrylic acid) (PAA-OA) polymer layer. For the smaller nanoplates, longitudinal relaxivities (r1) of 7.96 and 47.2 (mM s)(-1) were measured at 1.41 T for the oleic acid bilayer and PAA-OA coating, respectively. These values moderately reduce as the size of the Gd2O3 nanoplates increases, and are always larger for the PAA-OA coating. Cytotoxicity studies on human dermal fibroblast cells documented no significant toxicity, with 100% cell viability preserved up to 250 μM for the PAA-OA coated Gd2O3 nanoplates. Given the 10 times increase in longitudinal relaxivity over the commercially available Gd-based molecular agents and the favorable toxicity profile, the 2 nm PAA-OA coated Gd2O3 nanoplates could represent a new class of highly effective T1 MRI contrast agents.

  15. Magneto-optical properties of gadolinium in interband absorption region

    International Nuclear Information System (INIS)

    Optical constants and magneto-optical effect of the change of reflected light intensity in equatorial magnetization for two incidence angles are measured in the range of 0.4-5 eV on polycrystalline gadolinium sample at the liquid nitrogen temperature. The frequency behaviour of diagonal and gyrotropic components of optical conductivity is calculated from the measurement data. In the framework of the Spicer indirect transition model the comparison is carried out of the conductivity frequency dispersion with the calculation of the energy dependence of the state density for the band systems with the spin projection parallel and perpendicular to magnetization, made by Harmon and Freeman. The main peculiarities of the interzone absorption in the optical and magnetooptical spectra are explained satisfactorily while the detailed correspondence between the experiment and calculation is absent. Therefore, a conclusion is made on the necessity of inclusion of vacant 4f-zones in the region of the Fermi level in the gadolinium zone spectra

  16. Gadolinium-enhanced magnetic resonance angiography in brain death

    Science.gov (United States)

    Luchtmann, M.; Beuing, O.; Skalej, M.; Kohl, J.; Serowy, S.; Bernarding, J.; Firsching, R.

    2014-01-01

    Confirmatory tests for the diagnosis of brain death in addition to clinical findings may shorten observation time required in some countries and may add certainty to the diagnosis under specific circumstances. The practicability of Gadolinium-enhanced magnetic resonance angiography to confirm cerebral circulatory arrest was assessed after the diagnosis of brain death in 15 patients using a 1.5 Tesla MRI scanner. In all 15 patients extracranial blood flow distal to the external carotid arteries was undisturbed. In 14 patients no contrast medium was noted within intracerebral vessels above the proximal level of the intracerebral arteries. In one patient more distal segments of the anterior and middle cerebral arteries (A3 and M3) were filled with contrast medium. Gadolinium-enhanced MRA may be considered conclusive evidence of cerebral circulatory arrest, when major intracranial vessels fail to fill with contrast medium while extracranial vessels show normal blood flow.

  17. Effect Of The Gadolinium Oxide Addition On The Electrical Properties Of Tetragonal Zirconium Dioxide

    Directory of Open Access Journals (Sweden)

    Cyran J.

    2015-06-01

    Full Text Available The aim of this work was examination of gadolinium-doped 3YSZ electrical and structural properties. Such materials may be used as electrolytes in intermediate temperature solid oxide fuel cells (IT-SOFC. First step of the research was synthesis of 3YSZ with different contents of gadolinium (0.25; 0.5; 1.0 at %. Prepared materials were characterized by high porosity. No effect of gadolinium addition on grain size was observed. The experimentally determined values of grain interiors electrical conductivities for gadolinium doped samples are comparable to grain interior conductivities of gadolinium free tetragonal zirconia. On the other hand, a clear effect of gadolinium addition on electrical conductivity of grain boundaries was observed. It was found that 3YSZ containing 0.25 at. % Gd was the most promising from the investigated materials as a solid electrolyte for IT SOFC.

  18. Differential diagnosis and prognosis of T1-weighted post-gadolinium intralabyrinthine hyperintensities

    Energy Technology Data Exchange (ETDEWEB)

    Dubrulle, F.; Puech, P.; Ernst, O. [University Nord of France, Department of Radiology, CHU Lille, Huriez Hospital INSERM, Lille (France); Kohler, R. [CHU Lille, Huriez Hospital, Department of Radiology, Lille (France); Vincent, C. [CHU Lille, Department of Otology and Oto-neurosurgery, Lille (France)

    2010-11-15

    The aim of this longitudinal study is to describe the different intralabyrinthine lesions yielding high signal intensity on T1-weighted (T1W) images after intravenous gadolinium and then to analyze the follow-up of these patients. Thirty-seven patients were included and followed clinically and radiologically. A precise analysis of MR labyrinthine signals allowed exact depiction of the different lesions. Special interest is focused on the intralabyrinthine fluid signal on 3D high-resolution T2W images. The enhanced T1W labyrinthine hyperintensities correspond to two different categories: intralabyrinthine enhancement (15 intralabyrinthine schwannomas, 13 labyrinthitis, 1 inflammatory granuloma) and spontaneous T1W hyperintensities (8 intralabyrinthine hemorrhages). Hemorrhagic lesions show a substantial decrease of the intralabyrinthine fluid signal on the 3D HRT2 that evolves to ossification. In labyrinthitis, the importance of the initial labyrinthine fluid signal decrease on the 3D HRT2 is well correlated with the hearing prognosis. A meticulous analysis of inner ear lesions allows various intralabyrinthine lesions, in particular schwannomas, to be differentiated from labyrinthitis. T1W imaging without gadolinium is essential for the correct diagnosis of rapidly evolving hearing loss. In labyrinthitis and intralabyrinthine hemorrhage, 3D HRT2 brings an interesting prognostic factor for the chance of hearing recovery. (orig.)

  19. High temperature interaction studies on equimolar nitrate mixture of uranyl nitrate hexahydrate and gadolinium nitrate hexahydrate

    International Nuclear Information System (INIS)

    Rare earths including gadolinium form a sizeable fraction of the fission products in the nuclear fission of fissile material in the reactor. These fission products can interact with uranium dioxide fuel and can form various compounds which can alter the thermal behavior of the fuel. The mixed oxide formed due to the high temperature interactions of mixture of uranyl nitrate hexahydrate (UNH) and gadolinium nitrate hexahydrate (GdNH) has been studied using thermal and X- ray diffraction techniques. The equimolar mixture of UNH and GdNH was prepared by mixing the weighed amount of individual nitrates and grinding gently with mortar and pestle. Thermogravimetry (TG) measurements were carried out by separately heating 100 mg of mixture and individual nitrates at heating rate of 10°C min-1 using Netzsch thermal analyzer (Model No.: STA 409 PC Luxx) in high purity nitrogen atmosphere with a flow rate of 120 mL min-1. The XRD measurement was carried out on a Philips X-ray diffractometer (Model PW1710) using nickel-filtered Cu-Kα radiation

  20. Gadolinium-containing phosphatidylserine liposomes for molecular imaging of atherosclerosis

    OpenAIRE

    Maiseyeu, Andrei; Mihai, Georgeta; Kampfrath, Thomas; Simonetti, Orlando P.; Sen, Chandan K.; Roy, Sashwati; Rajagopalan, Sanjay; Parthasarathy, Sampath

    2009-01-01

    Exteriorized phosphatidylserine (PS) residues in apoptotic cells trigger rapid phagocytosis by macrophage scavenger receptor pathways. Mimicking apoptosis with liposomes containing PS may represent an attractive approach for molecular imaging of atherosclerosis. We investigated the utility of paramagnetic gadolinium liposomes enriched with PS (Gd-PS) in imaging atherosclerotic plaque. Gd-PS-containing Gd-conjugated lipids, fluorescent rhodamine, and PS were prepared and characterized. Cellula...

  1. Dressler's syndrome demonstrated by late gadolinium enhancement cardiovascular magnetic resonance

    OpenAIRE

    Kovac Jan; Khoo Jeffrey; Steadman Christopher D; McCann Gerry P

    2009-01-01

    Abstract A 49-year old patient presented late with an anterolateral ST-elevation myocardial infarction and was treated with rescue angioplasty to an occluded left anterior descending artery. Her recovery was complicated by low-grade pyrexia and raised inflammatory markers. Cardiovascular magnetic resonance 5 weeks after the acute presentation showed transmural infarction and global late gadolinium enhancement of the pericardium in keeping with Dressler's syndrome.

  2. Is gadolinium a helical antiferromagnet or a collinear ferromagnet?

    Indian Academy of Sciences (India)

    S N Kaul

    2003-03-01

    Controversial issues concerning the nature of magnetic ordering in gadolinium are briefly reviewed. The recent experimental results are shown to resolve most of such issues in that they rule out the possibility of a helical spin structure in Gd and clearly bring out the role of long-range dipolar interactions in stabilising collinear ferromagnetic order for temperatures between the spin-reorientation temperature and the Curie point.

  3. Gadolinium Enhanced MR Coronary Vessel Wall Imaging at 3.0 Tesla

    Directory of Open Access Journals (Sweden)

    Sebastian Kelle

    2010-01-01

    Full Text Available Purpose. We evaluated the influence of the time between low-dose gadolinium (Gd contrast administration and coronary vessel wall enhancement (LGE detected by 3T magnetic resonance imaging (MRI in healthy subjects and patients with coronary artery disease (CAD. Materials and Methods. Four healthy subjects (4 men, mean age 29  ±  3 years and eleven CAD patients (6 women, mean age 61±10 years were studied on a commercial 3.0 Tesla (T whole-body MR imaging system (Achieva 3.0 T; Philips, Best, The Netherlands. T1-weighted inversion-recovery coronary magnetic resonance imaging (MRI was repeated up to 75 minutes after administration of low-dose Gadolinium (Gd (0.1 mmol/kg Gd-DTPA. Results. LGE was seen in none of the healthy subjects, however in all of the CAD patients. In CAD patients, fifty-six of 62 (90.3% segments showed LGE of the coronary artery vessel wall at time-interval 1 after contrast. At time-interval 2, 34 of 42 (81.0% and at time-interval 3, 29 of 39 evaluable segments (74.4% were enhanced. Conclusion. In this work, we demonstrate LGE of the coronary artery vessel wall using 3.0 T MRI after a single, low-dose Gd contrast injection in CAD patients but not in healthy subjects. In the majority of the evaluated coronary segments in CAD patients, LGE of the coronary vessel wall was already detectable 30–45 minutes after administration of the contrast agent.

  4. Nephrogenic systemic fibrosis: UK survey of the use of gadolinium-based contrast media

    Energy Technology Data Exchange (ETDEWEB)

    Rees, O., E-mail: owenrees1@gmail.co [Wrexham Maelor Hospital, Wrexham (United Kingdom); Agarwal, S.K. [Wrexham Maelor Hospital, Wrexham (United Kingdom)

    2010-08-15

    Aim: To identify the current practice of administration of gadolinium-based contrast media (Gd-CM) within the UK with respect to the European Society of Urogenital Radiology (ESUR) guidelines on nephrogenic systemic fibrosis (NSF). Materials and methods: One hundred and fifty-two institutions were contacted to request details regarding the use of Gd-CM at their institution, their awareness of NSF, and of the ESUR guidelines, and their departmental policy on the administration of Gd-CM agents associated with NSF (high-risk agents) in patients with diminished renal function. Results: Of the 100 institutions that replied, 72% used a cyclic agent as a first-line Gd-CM. The majority of institutions used more than one Gd-CM, and 57% used a high-risk Gd-CM. Seventy percent were aware of the ESUR guidelines, and of the 57% that used a high-risk Gd-CM, 9% did not check renal function at all prior to administration. The course of action of the remaining 48% was varied in patients with diminished renal function with some changing to a low-risk Gd-CM and others electing not to use Gd-CM at all. Five percent continued to use a high-risk Gd-CM with an estimated glomerular filtration rate <30 ml/min. Conclusion: The present survey shows that the majority of institutions use a low-risk Gd-CM as a first-line agent; however, a number of institutions do use a high-risk Gd-CM and their course of action for patients with diminished renal function is varied. Given current evidence, it is advisable to use a low-risk Gd-CM, such as a cyclic agent, in patients with diminished renal function.

  5. High-resolution cellular MRI: gadolinium and iron oxide nanoparticles for in-depth dual-cell imaging of engineered tissue constructs.

    Science.gov (United States)

    Di Corato, Riccardo; Gazeau, Florence; Le Visage, Catherine; Fayol, Delphine; Levitz, Pierre; Lux, François; Letourneur, Didier; Luciani, Nathalie; Tillement, Olivier; Wilhelm, Claire

    2013-09-24

    Recent advances in cell therapy and tissue engineering opened new windows for regenerative medicine, but still necessitate innovative noninvasive imaging technologies. We demonstrate that high-resolution magnetic resonance imaging (MRI) allows combining cellular-scale resolution with the ability to detect two cell types simultaneously at any tissue depth. Two contrast agents, based on iron oxide and gadolinium oxide rigid nanoplatforms, were used to "tattoo" endothelial cells and stem cells, respectively, with no impact on cell functions, including their capacity for differentiation. The labeled cells' contrast properties were optimized for simultaneous MRI detection: endothelial cells and stem cells seeded together in a polysaccharide-based scaffold material for tissue engineering appeared respectively in black and white and could be tracked, at the cellular level, both in vitro and in vivo. In addition, endothelial cells labeled with iron oxide nanoparticles could be remotely manipulated by applying a magnetic field, allowing the creation of vessel substitutes with in-depth detection of individual cellular components. PMID:23924160

  6. Thermodynamic properties of gadolinium in Ga-Sn and Ga-Zn eutectic based alloys

    Science.gov (United States)

    Maltsev, Dmitry S.; Volkovich, Vladimir A.; Yamshchikov, Leonid F.; Chukin, Andrey V.

    2016-09-01

    Thermodynamic properties of gadolinium in Ga-Sn and Ga-Zn eutectic based alloys were studied. Temperature dependences of gadolinium activity in the studied alloys were determined at 573-1073 K employing the EMF method. Solubility of gadolinium in the Ga-Sn and Ga-Zn alloys was measured at 462-1073 K using IMCs sedimentation method. Activity coefficients as well as partial and excess thermodynamic functions of gadolinium in the studied alloys were calculated on the basis of the obtained experimental data.

  7. Various ligand-coated ultrasmall gadolinium-oxide nanoparticles: Water proton relaxivity and in-vivo T1 MR image

    Science.gov (United States)

    Park, Ja Young; Kim, Sung June; Lee, Gang Ho; Jin, Seonguk; Chang, Yongmin; Bae, Ji Eun; Chae, Kwon Seok

    2015-04-01

    Surface coating of nanoparticles with ligands is essential in magnetic resonance imaging (MRI) because of solubility in water and biocompatibility. In this study, five organic molecules were used for surface coating of ultrasmall gadolinium-oxide (Gd2O3) nanoparticles (d avg = 2.0 nm). All of the samples showed large longitudinal (r1) and transverse (r2) water proton relaxivities with r2/r1 ratios that were close to one, corresponding to ideal conditions for T1 MRI contrast agents. Finally, in-vivo T1 MR images were acquired to prove the effectiveness of the surface-coated ultrasmall Gd2O3 nanoparticles as a T1 MRI contrast agent.

  8. Microwave and optical diagnostics in a gadolinium plasma; Diagnostics hyperfrequence et optique dans un plasma magnetise de gadolinium

    Energy Technology Data Exchange (ETDEWEB)

    Larousse, B. [CEA Centre d`Etudes de Saclay, 91 - Gif-sur-Yvette (France). Dept. des Procedes d`Enrichissement]|[Conservatoire National des Arts et Metiers (CNAM), 75 - Paris (France)

    1997-12-31

    The optimization of the separation process of the gadolinium isotopes by Ion Cyclotron Resonance requires a precise knowledge of the physical characteristics of the plasma. Thus, two kinds of diagnostics have been developed: the first one to estimate the microwave power inside the source and the second one to measure the density of atomic and ionic of the gadolinium inside the plasma source and in front of the collector. Microwave diagnostic: A microstrip antenna has been designed and developed in order to characterize the microwave at 36 GHz frequency in the plasma source. The experimental results for different plasma regimes are presented. The measurements inside the plasma source show a maximum of microwave absorption for an argon pressure of 10{sup -4} mb (93% of absorption of the incident wave in the conditions of isotope separation). Laser absorption diagnostic: The theory of laser absorption in presence of a magnetic field is recalled and the first results are presented. In the spectral range between 560 and 620 nm, corresponding to high energy levels of gadolinium, no signal is obtained so that the density is below the detection limit 10{sup 10} cm{sup -3}. In the spectral range between 380 and 400 nm, two lines are observed, issue from the fundamental and metastable (633 cm{sup -1}) levels. The density of metastable level of gadolinium ions is about 10{sup 10} cm{sup -3} with a relative precision of 15 % and its variation is studied as a function of argon pressure, at different sections of the plasma column (source, collector). The achieved set of measurements has been performed in order to check the theoretical models. (author) 32 refs.

  9. Synergistic enhancement of iron oxide nanoparticle and gadolinium for dual-contrast MRI

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Fan [Laboratory of Molecular Imaging and Nanomedicine (LOMIN), National Institute of Biomedical Imaging and Bioengineering (NIBIB), National Institutes of Health - NIH, Bethesda, MD 20892 (United States); Center for Molecular Imaging and Translational Medicine, School of Public Health, Xiamen University, Xiamen 361005 (China); Huang, Xinglu [Laboratory of Molecular Imaging and Nanomedicine (LOMIN), National Institute of Biomedical Imaging and Bioengineering (NIBIB), National Institutes of Health - NIH, Bethesda, MD 20892 (United States); Qian, Chunqi [Laboratory of Functional and Molecular Imaging, National Institute of Neurological Disorders and Stroke (NINDS), National Institutes of Health (NIH), Bethesda, MD 20892 (United States); Center for Molecular Imaging and Translational Medicine, School of Public Health, Xiamen University, Xiamen 361005 (China); Zhu, Lei [Laboratory of Molecular Imaging and Nanomedicine (LOMIN), National Institute of Biomedical Imaging and Bioengineering (NIBIB), National Institutes of Health - NIH, Bethesda, MD 20892 (United States); Center for Molecular Imaging and Translational Medicine, School of Public Health, Xiamen University, Xiamen 361005 (China); Hida, Naoki [Laboratory of Molecular Imaging and Nanomedicine (LOMIN), National Institute of Biomedical Imaging and Bioengineering (NIBIB), National Institutes of Health - NIH, Bethesda, MD 20892 (United States); Niu, Gang, E-mail: niug@mail.nih.gov [Laboratory of Molecular Imaging and Nanomedicine (LOMIN), National Institute of Biomedical Imaging and Bioengineering (NIBIB), National Institutes of Health - NIH, Bethesda, MD 20892 (United States); Chen, Xiaoyuan, E-mail: shawn.chen@nih.gov [Laboratory of Molecular Imaging and Nanomedicine (LOMIN), National Institute of Biomedical Imaging and Bioengineering (NIBIB), National Institutes of Health - NIH, Bethesda, MD 20892 (United States)

    2012-09-07

    Highlights: Black-Right-Pointing-Pointer MR contrast agents exert influence on T{sub 1} or T{sub 2} relaxation time of the surrounding tissue. Black-Right-Pointing-Pointer Combined use of iron oxide and Gd-DTPA can improve the sensitivity/specificity of lesion detection. Black-Right-Pointing-Pointer Dual contrast MRI enhances the delineation of tumor borders and small lesions. Black-Right-Pointing-Pointer The effect of DC-MRI can come from the high paramagnetic susceptibility of Gd{sup 3+}. Black-Right-Pointing-Pointer The effect of DC-MRI can also come from the distinct pharmacokinetic distribution of SPIO and Gd-DTPA. -- Abstract: Purpose: The use of MR contrast agents allows accurate diagnosis by exerting an influence on the longitudinal (T{sub 1}) or transverse (T{sub 2}) relaxation time of the surrounding tissue. In this study, we combined the use of iron oxide (IO) particles and nonspecific extracellular gadolinium chelate (Gd) in order to further improve the sensitivity and specificity of lesion detection. Procedures: With a 7-Tesla scanner, pre-contrasted, IO-enhanced and dual contrast agent enhanced MRIs were performed in phantom, normal animals, and animal models of lymph node tumor metastases and orthotopic brain tumor. For the dual-contrast (DC) MRI, we focused on the evaluation of T{sub 2} weighted DC MRI with IO administered first, then followed by the injection of a bolus of gadolinium diethylenetriamine pentaacetic acid (Gd-DTPA). Results: Based on the C/N ratios and MRI relaxometry, the synergistic effect of coordinated administration of Gd-DTPA and IO was observed and confirmed in phantom, normal liver and tumor models. At 30 min after administration of Feridex, Gd-DTPA further decreased T{sub 2} relaxation in liver immediately after the injection. Additional administration of Gd-DTPA also immediately increased the signal contrast between tumor and brain parenchyma and maximized the C/N ratio to -4.12 {+-} 0.71. Dual contrast MRI also enhanced the

  10. Diagnostic Magnetic Resonance Imaging of Atherosclerosis in Apolipoprotein E Knockout Mouse Model Using Macrophage-Targeted Gadolinium-Containing Synthetic Lipopeptide Nanoparticles.

    Directory of Open Access Journals (Sweden)

    Zu T Shen

    Full Text Available Cardiovascular disease is the leading cause of death in Western cultures. The vast majority of cardiovascular events, including stroke and myocardial infarction, result from the rupture of vulnerable atherosclerotic plaques, which are characterized by high and active macrophage content. Current imaging modalities including magnetic resonance imaging (MRI aim to characterize anatomic and structural features of plaques rather than their content. Previously, we reported that macrophage-targeted delivery of gadolinium (Gd-based contrast agent (GBCA-HDL using high density lipoproteins (HDL-like particles significantly enhances the detection of plaques in an apolipoprotein (apo E knockout (KO mouse model, with an atherosclerotic wall/muscle normalized enhancement ratio (NER of 120% achieved. These particles are comprised of lipids and synthetic peptide fragments of the major protein of HDL, apo A-I, that contain a naturally occurring modification which targets the particles to macrophages. Targeted delivery minimizes the Gd dose and thus reduces the adverse effects of Gd. The aims of the current study were to test whether varying the GBCA-HDL particle shape and composition can further enhance atherosclerotic plaque MRI and control organ clearance of these agents. We show that the optimized GBCA-HDL particles are efficiently delivered intracellularly to and uptaken by both J774 macrophages in vitro and more importantly, by intraplaque macrophages in vivo, as evidenced by NER up to 160% and higher. This suggests high diagnostic power of our GBCA-HDL particles in the detection of vulnerable atherosclerotic plaques. Further, in contrast to discoidal, spherical GBCA-HDL exhibit hepatic clearance, which could further diminish adverse renal effects of Gd. Finally, activated macrophages are reliable indicators of any inflamed tissues and are implicated in other areas of unmet clinical need such as rheumatoid arthritis, sepsis and cancer, suggesting the

  11. Diagnostic Magnetic Resonance Imaging of Atherosclerosis in Apolipoprotein E Knockout Mouse Model Using Macrophage-Targeted Gadolinium-Containing Synthetic Lipopeptide Nanoparticles

    Science.gov (United States)

    Shen, Zu T.; Zheng, Shaokuan; Gounis, Matthew J.; Sigalov, Alexander B.

    2015-01-01

    Cardiovascular disease is the leading cause of death in Western cultures. The vast majority of cardiovascular events, including stroke and myocardial infarction, result from the rupture of vulnerable atherosclerotic plaques, which are characterized by high and active macrophage content. Current imaging modalities including magnetic resonance imaging (MRI) aim to characterize anatomic and structural features of plaques rather than their content. Previously, we reported that macrophage-targeted delivery of gadolinium (Gd)-based contrast agent (GBCA-HDL) using high density lipoproteins (HDL)-like particles significantly enhances the detection of plaques in an apolipoprotein (apo) E knockout (KO) mouse model, with an atherosclerotic wall/muscle normalized enhancement ratio (NER) of 120% achieved. These particles are comprised of lipids and synthetic peptide fragments of the major protein of HDL, apo A-I, that contain a naturally occurring modification which targets the particles to macrophages. Targeted delivery minimizes the Gd dose and thus reduces the adverse effects of Gd. The aims of the current study were to test whether varying the GBCA-HDL particle shape and composition can further enhance atherosclerotic plaque MRI and control organ clearance of these agents. We show that the optimized GBCA-HDL particles are efficiently delivered intracellularly to and uptaken by both J774 macrophages in vitro and more importantly, by intraplaque macrophages in vivo, as evidenced by NER up to 160% and higher. This suggests high diagnostic power of our GBCA-HDL particles in the detection of vulnerable atherosclerotic plaques. Further, in contrast to discoidal, spherical GBCA-HDL exhibit hepatic clearance, which could further diminish adverse renal effects of Gd. Finally, activated macrophages are reliable indicators of any inflamed tissues and are implicated in other areas of unmet clinical need such as rheumatoid arthritis, sepsis and cancer, suggesting the expanded diagnostic

  12. Safety of Gadoterate Meglumine (Gd-DOTA) as a Contrast Agent for Magnetic Resonance Imaging

    OpenAIRE

    Ishiguchi, Tsuneo; Takahashi, Shoki

    2012-01-01

    Background: Safety is a primary concern with contrast agents used for MRI. If precautions could be taken before the repeated administration of gadolinium-based contrast media, then the awareness and management of adverse reactions would be more efficient. Objectives: To assess the safety and efficacy of gadoterate meglumine (Gd-DOTA) [Magnescope® in Japan, Dotarem® in other countries], a gadolinium-based contrast agent, in patients undergoing imaging of the brain/spinal cord and/or trunk/limb...

  13. Magnetic resonance lymphography of profundus lymph nodes with liposomal gadolinium-diethylenetriamine pentaacetic acid

    Energy Technology Data Exchange (ETDEWEB)

    Fujimoto, Yoshiko; Oku, Naoto [Univ. of Shizuoka (Japan). School of Pharmaceutical Sciences; Okuhata, Yoshitaka; Tyngi, Shia; Namba, Yukihiro

    2000-01-01

    Lymphography, especially imaging of profundus lymph nodes, is a useful tool for diagnosis of cancer metastases in lymph nodes. However, positive enhancement agents for magnetic resonance lymphography (MRL) have not been available, since the positive imaging agents so far introduced are low-molecular-weight materials that are not trapped in lymph nodes. For the purpose of improved positive enhanced MRL, we employed liposomes as carriers of a positive enhancer, gadolinium-diethylenetriamine pentaacetic acid (Gd-DTPA). Magnetic resonance (MR) imaging was performed after subcutaneous injection of Gd-liposomes into the hind feet of rabbits which had reactive enlarged retroperitoneal lymph nodes. As a result, not only popliteal but also profundus retroperitoneal lymph nodes were positively enhanced by Gd-liposomes, especially after 20 min massage of the injected sites. Gd-Liposomes containing dipalmitoylphosphatidylglycerol were more effective than Gd-liposomes containing palmityl-D-glucuronide, a type of long-circulating liposomes, suggesting that liposomal accumulation in lymph node is, at least partly, mediated by the trapping of liposomes by macrophages. These data show that liposomes modified with Gd-DTPA are effective for positive enhancement of both regional and profundus lymph nodes in MR lymphography. (author)

  14. Magnetic resonance lymphography of profundus lymph nodes with liposomal gadolinium-diethylenetriamine pentaacetic acid

    International Nuclear Information System (INIS)

    Lymphography, especially imaging of profundus lymph nodes, is a useful tool for diagnosis of cancer metastases in lymph nodes. However, positive enhancement agents for magnetic resonance lymphography (MRL) have not been available, since the positive imaging agents so far introduced are low-molecular-weight materials that are not trapped in lymph nodes. For the purpose of improved positive enhanced MRL, we employed liposomes as carriers of a positive enhancer, gadolinium-diethylenetriamine pentaacetic acid (Gd-DTPA). Magnetic resonance (MR) imaging was performed after subcutaneous injection of Gd-liposomes into the hind feet of rabbits which had reactive enlarged retroperitoneal lymph nodes. As a result, not only popliteal but also profundus retroperitoneal lymph nodes were positively enhanced by Gd-liposomes, especially after 20 min massage of the injected sites. Gd-Liposomes containing dipalmitoylphosphatidylglycerol were more effective than Gd-liposomes containing palmityl-D-glucuronide, a type of long-circulating liposomes, suggesting that liposomal accumulation in lymph node is, at least partly, mediated by the trapping of liposomes by macrophages. These data show that liposomes modified with Gd-DTPA are effective for positive enhancement of both regional and profundus lymph nodes in MR lymphography. (author)

  15. Thermal conductivity of the gadolinium calcium silicate apatites: Effect of different point defect types

    International Nuclear Information System (INIS)

    The apatite crystal structure of the gadolinium calcium silicates can accommodate a wide range of point defects, including oxygen and cation vacancies, as well as anti-site defects, depending on the Gd/Ca ratio. Compositions having only cation or oxygen vacancies were identified and the thermal diffusivity and conductivity were measured up to 1000 deg. C. All the compositions, including the stoichiometric composition, exhibit low thermal conductivities from room temperature to high temperature with the defect-containing compositions having even lower thermal conductivities. The high-temperature thermal conductivity, at temperatures below the onset of significant radiative heat transport, decreases with the inverse square root of the cation and anion vacancy concentration, consistent with simple defect scattering models. Based on the data, it is concluded that the oxygen vacancies are slightly more effective in reducing thermal conductivity.

  16. Recombinant high-density lipoprotein nanoparticles containing gadolinium-labeled cholesterol for morphologic and functional magnetic resonance imaging of the liver

    Directory of Open Access Journals (Sweden)

    Rui M

    2012-07-01

    Full Text Available Mengjie Rui,1 Wei Guo,2 Qian Ding,2 Xiaohui Wei,2 Jianrong Xu,3 Yuhong Xu21School of Life Science and Biotechnology, 2School of Pharmacy, Shanghai Jiao Tong University, Shanghai, People's Republic of China; 3Department of Radiology, Renji Hospital Affiliation with Medical School of Shanghai Jiao Tong University, Shanghai, People's Republic of ChinaBackground: Natural high-density lipoproteins (HDL possess important physiological functions to the transport of cholesterol from the peripheral tissues to the liver for metabolic degradation and excretion in the bile.Methods and results: In this work, we took advantage of this pathway and prepared two different gadolinium (Gd-DTPA-labeled cholesterol-containing recombinant HDL nanoparticles (Gd-chol-HDL and Gd-(chol2-HDL as liver-specific magnetic resonance imaging (MRI contrast agents. The reconstituted HDL nanoparticles had structural similarity to native HDL, and could be taken up by HepG2 cells via interaction with HDL receptors in vitro. In vivo MRI studies in rats after intravenous injections of 10 µmol gadolinium per kg of recombinant HDL nanoparticles indicated that both nanoparticles could provide signal enhancement in the liver and related organs. However, different T1-weighted image details suggested that they participated in different cholesterol metabolism and excretion pathways in the liver.Conclusion: Such information could be highly useful to differentiate functional changes as well as anatomic differences in the liver. These cholesterol-derived contrast agents and their recombinant HDL preparations may warrant further development as a new class of contrast agents for MRI of the liver and related organs.Keywords: magnetic resonance imaging, apolipoprotein, high-density lipoprotein, contrast agent, gadolinium, liver

  17. To gadolinium using for neutron capture therapy researches at WWR-SM reactor

    International Nuclear Information System (INIS)

    The analysis of using gadolinium (isotope and natural) for the medical purposes in neutron-capture therapy of cancer diseases is carried out. Results of definition of the epithermal neutron beam irradiation dose for biological objects with gadolinium-containing preparations are presented by using the WWR-SM reactor. (authors)

  18. Trace determination of gadolinium in biomedical samples by diode laser-based multi-step resonance ionization mass spectrometry.

    Science.gov (United States)

    Blaum, K; Geppert, C; Schreiber, W G; Hengstler, J G; Müller, P; Nörtershäuser, W; Wendt, K; Bushaw, B A

    2002-04-01

    The application of high-resolution multi-step resonance ionization mass spectrometry (RIMS) to the trace determination of the rare earth element gadolinium is described. Utilizing three-step resonant excitation into an autoionizing level, both isobaric and isotopic selectivity of >10(7) were attained. An overall detection efficiency of approximately 10(-7) and an isotope specific detection limit of 1.5 x 10(9) atoms have been demonstrated. When targeting the major isotope (158)Gd, this corresponds to a total Gd detection limit of 1.6 pg. Additionally, linear response has been demonstrated over a dynamic range of six orders of magnitude. The method has been used to determine the Gd content in various normal and tumor tissue samples, taken from a laboratory mouse shortly after injection of gadolinium diethylenetriaminepentaacetic acid dimeglumine (Gd-DTPA), which is used as a contrast agent for magnetic resonance imaging (MRI). The RIMS results show Gd concentrations that vary by more than two orders of magnitude (0.07-11.5 microg mL(-1)) depending on the tissue type. This variability is similar to that observed in MRI scans that depict Gd-DTPA content in the mouse prior to dissection, and illustrates the potential for quantitative trace analysis in microsamples of biomedical materials. PMID:12012186

  19. Monte Carlo study of radiation dose enhancement by gadolinium in megavoltage and high dose rate radiotherapy.

    Directory of Open Access Journals (Sweden)

    Daniel G Zhang

    Full Text Available MRI is often used in tumor localization for radiotherapy treatment planning, with gadolinium (Gd-containing materials often introduced as a contrast agent. Motexafin gadolinium is a novel radiosensitizer currently being studied in clinical trials. The nanoparticle technologies can target tumors with high concentration of high-Z materials. This Monte Carlo study is the first detailed quantitative investigation of high-Z material Gd-induced dose enhancement in megavoltage external beam photon therapy. BEAMnrc, a radiotherapy Monte Carlo simulation package, was used to calculate dose enhancement as a function of Gd concentration. Published phase space files for the TrueBeam flattening filter free (FFF and conventional flattened 6MV photon beams were used. High dose rate (HDR brachytherapy with Ir-192 source was also investigated as a reference. The energy spectra difference caused a dose enhancement difference between the two beams. Since the Ir-192 photons have lower energy yet, the photoelectric effect in the presence of Gd leads to even higher dose enhancement in HDR. At depth of 1.8 cm, the percent mean dose enhancement for the FFF beam was 0.38±0.12, 1.39±0.21, 2.51±0.34, 3.59±0.26, and 4.59±0.34 for Gd concentrations of 1, 5, 10, 15, and 20 mg/mL, respectively. The corresponding values for the flattened beam were 0.09±0.14, 0.50±0.28, 1.19±0.29, 1.68±0.39, and 2.34±0.24. For Ir-192 with direct contact, the enhanced were 0.50±0.14, 2.79±0.17, 5.49±0.12, 8.19±0.14, and 10.80±0.13. Gd-containing materials used in MRI as contrast agents can also potentially serve as radiosensitizers in radiotherapy. This study demonstrates that Gd can be used to enhance radiation dose in target volumes not only in HDR brachytherapy, but also in 6 MV FFF external beam radiotherapy, but higher than the currently used clinical concentration (>5 mg/mL would be needed.

  20. Monte Carlo study of radiation dose enhancement by gadolinium in megavoltage and high dose rate radiotherapy.

    Science.gov (United States)

    Zhang, Daniel G; Feygelman, Vladimir; Moros, Eduardo G; Latifi, Kujtim; Zhang, Geoffrey G

    2014-01-01

    MRI is often used in tumor localization for radiotherapy treatment planning, with gadolinium (Gd)-containing materials often introduced as a contrast agent. Motexafin gadolinium is a novel radiosensitizer currently being studied in clinical trials. The nanoparticle technologies can target tumors with high concentration of high-Z materials. This Monte Carlo study is the first detailed quantitative investigation of high-Z material Gd-induced dose enhancement in megavoltage external beam photon therapy. BEAMnrc, a radiotherapy Monte Carlo simulation package, was used to calculate dose enhancement as a function of Gd concentration. Published phase space files for the TrueBeam flattening filter free (FFF) and conventional flattened 6MV photon beams were used. High dose rate (HDR) brachytherapy with Ir-192 source was also investigated as a reference. The energy spectra difference caused a dose enhancement difference between the two beams. Since the Ir-192 photons have lower energy yet, the photoelectric effect in the presence of Gd leads to even higher dose enhancement in HDR. At depth of 1.8 cm, the percent mean dose enhancement for the FFF beam was 0.38±0.12, 1.39±0.21, 2.51±0.34, 3.59±0.26, and 4.59±0.34 for Gd concentrations of 1, 5, 10, 15, and 20 mg/mL, respectively. The corresponding values for the flattened beam were 0.09±0.14, 0.50±0.28, 1.19±0.29, 1.68±0.39, and 2.34±0.24. For Ir-192 with direct contact, the enhanced were 0.50±0.14, 2.79±0.17, 5.49±0.12, 8.19±0.14, and 10.80±0.13. Gd-containing materials used in MRI as contrast agents can also potentially serve as radiosensitizers in radiotherapy. This study demonstrates that Gd can be used to enhance radiation dose in target volumes not only in HDR brachytherapy, but also in 6 MV FFF external beam radiotherapy, but higher than the currently used clinical concentration (>5 mg/mL) would be needed.

  1. Electrical and optical properties of gadolinium doped bismuth ferrite nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Mukherjee, A., E-mail: soumen.basu@phy.nitdgp.ac.in; Banerjee, M., E-mail: soumen.basu@phy.nitdgp.ac.in; Basu, S., E-mail: soumen.basu@phy.nitdgp.ac.in [Department of Physics, National Institute of Technology, Durgapur-713209 (India); Pal, M. [CSIR-Central Mechanical Engineering Research Institute, Durgapur-713209 (India)

    2014-04-24

    Multiferroic bismuth ferrite (BFO) and gadolinium (Gd) doped bismuth ferrite had been synthesized by a sol-gel method. Particle size had been estimated by Transmission electron microscopy (TEM) and found to decrease with Gd doping. We studied the temperature and frequency dependence of impedance and electric modulus and calculated the grain and grain boundary resistance and capacitance of the investigated samples. We observed that electrical activation energy increases for all the doped samples. Optical band gap also increases for the doped samples which can be used in photocatalytic application of BFO.

  2. Peculiarities of electronic structure of gadolinium-scandium-gallium garnet

    International Nuclear Information System (INIS)

    Results of precision X-ray diffraction investigation into gadolinium-scandium-gallium garnet monocrystal (GSGG) grown from Gd3Se1.6Ga3.4O12 composition melt are presented. The crystal space group is Ia3d, Z=8, a=12.549A. The data obtained testify to a complex character of electron distribution in GSGG. Gd-O chemical bond is much of ion character and a part of electron density is transferred from cation to O atoms and auther part is aspherically concentrated near the cation

  3. Status of the Gadolinium project for Super-Kamiokande

    Energy Technology Data Exchange (ETDEWEB)

    Marti Magro, Lluis, E-mail: martillu@suketto.icrr.u-tokyo.ac.jp [Dept. de Fisica Teorica, Universidad Autonoma de Madrid, Ciudad Universitaria de Cantoblanco, 28049 Madrid (Spain)

    2011-08-15

    The Super-Kamiokande (SK) experiment has been developing an extensive R and D program to develop a technique that would allow tagging of antineutrinos at SK. This technique is based on the simple idea of adding Gadolinium (Gd) to water, a solute with exceptional properties. A 200 ton tank facility is now under construction in a new hall near SK. It simulates the conditions at SK in order to further develop this technique and serve as a ground field to test it. It will have its own water filtration system, photo-multipliers, data acquisition system (DAQ) and other ancillary equipment.

  4. EPR spectra of four gadolinium complexes with Schiff bases

    Institute of Scientific and Technical Information of China (English)

    姚克敏; 陈德余; 封子先; 李冬成; 冯亚菲; 何玲

    1995-01-01

    EPR spectra of four new gadolinium complexes with Schiff bases in polycrystalline powder and those of these complexes in three organic solvents were investigated at different temperatures. It has been observed for the first time that their freezing solution spectra are quite different from each other. In THF one peak was observed only, but there were three peaks and typical "U" spectral features appearing in DMF and DMSO at low temperatures. On the basis of spin Hamiltonian of S = 7/2 system, the correlations between crystal field strength in complexes and local symmetry around Gd3+ ions are discussed.

  5. Legg-Perthes-Calve disease: staging by MRI using gadolinium

    Energy Technology Data Exchange (ETDEWEB)

    Ducou le Pointe, H. (Dept. of Pediatric Radiology, Hopital d' Enfants Armand-Trousseau, 75 - Paris (France)); Haddad, S. (Dept. of Pediatric Radiology, Hopital d' Enfants Armand-Trousseau, 75 - Paris (France)); Silberman, B. (Dept. of Pediatric Radiology, Hopital d' Enfants Armand-Trousseau, 75 - Paris (France)); Filipe, G. (Dept. of Orthopedic Surgery, Hopital d' Enfants Armand-Trousseau, 75 - Paris (France)); Monroc, M. (Dept. of Pediatric Radiology, Hopital d' Enfants Armand-Trousseau, 75 - Paris (France)); Montagne, J.P. (Dept. of Pediatric Radiology, Hopital d' Enfants Armand-Trousseau, 75 - Paris (France))

    1994-04-01

    Twenty-one patients (26 hips) with typical signs of Legg-Perthes-Calve (LPC) disease on plain radiographs were explored by MRI. Patients were imaged with a 0.5 T MR unit. Gadolinium-enhanced spinecho MR images were obtained after nonenhanced T1-weighted (spin-echo) and T2[sup *]-weighted (gradient-echo) images. Four different areas were identified in the femoral epiphysis (necrosis, regenerative, cartilaginous and normal fatty bone tissue). The histological evolution of LPC is well described by Catterall and others. Comparing their descriptions with out MR findings, we suggest classification ofLPC into five phases: necrosis: regeneration, reconstruction, reossification and sequelae. (orig.)

  6. Multifunctional Silica Particles as Contrast Agents for Optical and Magnetic Resonance Imaging

    OpenAIRE

    Feldmann, Verena

    2011-01-01

    The development of magnetic resonance imaging (MRI) towards one of the most powerful techniques in clinical diagnosis is accompanied by progress in the design of paramagnetic contrast agents (CAs) to enhance imaging sensitivity. Most of the currently applied CAs for enhanced T1-contrast are based on gadolinium(III)-chelate-complexes and are mainly extracellular agents which only distribute non-specifically throughout the circulatory system and interstitial space. Since those agents are excret...

  7. Similar effects of disease-modifying antirheumatic drugs, glucocorticoids, and biologic agents on radiographic progression in rheumatoid arthritis: meta-analysis of 70 randomized placebo-controlled or drug-controlled studies, including 112 comparisons

    DEFF Research Database (Denmark)

    Graudal, Niels; Jürgens, Gesche

    2010-01-01

    To define the differences in effects on joint destruction in rheumatoid arthritis (RA) patients between therapy with single and combination disease-modifying antirheumatic drugs (DMARDs), glucocorticoids, and biologic agents.......To define the differences in effects on joint destruction in rheumatoid arthritis (RA) patients between therapy with single and combination disease-modifying antirheumatic drugs (DMARDs), glucocorticoids, and biologic agents....

  8. Observation of Neutrons with a Gadolinium Doped Water Cerenkov Detector

    CERN Document Server

    Dazeley, S; Bowden, N S; Svoboda, R

    2008-01-01

    Spontaneous and induced fission in Special Nuclear Material (SNM) such as 235U and 239Pu results in the emission of neutrons and high energy gamma-rays. The multiplicities of and time correlations between these particles are both powerful indicators of the presence of fissile material. Detectors sensitive to these signatures are consequently useful for nuclear material monitoring, search, and characterization. In this article, we demonstrate sensitivity to both high energy gamma-rays and neutrons with a water Cerenkov based detector. Electrons in the detector medium, scattered by gamma-ray interactions, are detected by their Cerenkov light emission. Sensitivity to neutrons is enhanced by the addition of a gadolinium compound to the water in low concentrations. Cerenkov light is similarly produced by an 8 MeV gamma-ray cascade following neutron capture on the gadolinium. The large solid angle coverage and high intrinsic efficiency of this detection approach can provide robust and low cost neutron and gamma-ray...

  9. Single step low temperature synthesis of gadolinium gallium garnet nanopowders

    Institute of Scientific and Technical Information of China (English)

    Rekha Mann; Kiranmala Laishram; Neelam Malhan

    2012-01-01

    Solution combustion synthesis of single-phase gadolinium gallium oxide (Gd3Ga5O12,GGG) nanopowders,by a fuel mixture approach using urea and glycine at a low temperature of 500 ℃,was being reported for the first time.Based on the fact that urea and glycine are good fuels for gallium oxide and gadolinium oxide synthesis,the fuel mixture composition was obtained,which could lead to direct phase pure cubic Gd3Ga5O12 formation without any subsequent calcination step.Combustion was carried out in furnace pre-heated at 500 ℃.Thermogravimetric analysis (TGA) of combustion product showed negligible mass loss indicating direct formation of GGG powder.Fourier transform infrared (FTIR) spectrum of combusted product showed peak characteristic of GGG in case of mixed fuel.X-ray diffraction (XRD) confirmed formation of phase pure GGG at 500 ℃ in preheated furnace.Very fine,well dispersed nanometric particles of size range of 50-100 nm were obtained,being uniform and close to spherical morphology as observed by transmission electron microscope (TEM).

  10. Breath-hold gadolinium-enhanced MRA : clinical application

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Sung Gwon; Kang, Ji Hee; Kim, Won Hong; Lim, Myung Kwan; Cho, Young Kook; Cho, Soon Gu; Suh, Chang Hae [Inha University Hospital, Inchon (Korea, Republic of)

    1998-05-01

    The purpose of this study is to compare breath-hold gadolinium enhanced MR angiography (MRA) with digital subtraction angiography. Ten patients underwent angiography and breath-hold gadolinium enhanced MRA; the latter performed at 1.5T with 3D FSPGR after a bolus injection of gadopentetate dimeglumine (0.4m mol/kg). Seven of ten pathologic conditions (70%) evaluated by both techniques had a similar appearance. The conditions examined were as follows: the artery feeding renal cell carcinoma(n=2); renal artery stenosis (n=2); pulmonary AVM(n=2); abdominal aortic aneurysm (n=1); atheromatous plaque in the lower abdominal aorta (n=1); an enlarged bronchial artery (n=1); and an aberrant renal artery (n=1). For evaluating an anatomic relationship, a reconstructed 3D image obtained by MRA is more advantageous. Breath hold contrast enhanced MRA is a potentially useful noninvasive screening method for detecting vascular abnormality of the aorta and its branches. (author). 13 refs., 1 tab., 4 figs.

  11. The role of gadolinium-enhanced MR imaging in the preoperative evaluation of inflammatory abdominal aortic aneurysm

    Energy Technology Data Exchange (ETDEWEB)

    Anbarasu, A.; McWilliams, R.G. [Department of Radiology, Royal Liverpool University Hospital, Prescot Street, Liverpool, L7 8XP (United Kingdom); Harris, P.L. [Department of Vascular Surgery, Royal Liverpool University Hospital, Prescot Street, Liverpool, L7 8XP (United Kingdom)

    2002-07-01

    Inflammatory abdominal aortic aneurysm is an uncommon variant of abdominal aortic aneurysms. Thorough preoperative imaging of the extent of the aneurysm and inflammation and the associated complications are crucial in the management of this condition. We report a case of inflammatory abdominal aortic aneurysm where, after the initial contrast-enhanced CT, gadolinium-enhanced MR imaging was used to define the true extent of the inflammation and differentiate inflammation from mural thrombus at the iliac extension of the aneurysm. The imaging appearances are presented and the impact of MR imaging on further surgical management options including endovascular repair are discussed. (orig.)

  12. Microwave-assisted polyol synthesis of gadolinium-doped green luminescent carbon dots as a bimodal nanoprobe.

    Science.gov (United States)

    Gong, Ningqiang; Wang, Hao; Li, Shuai; Deng, Yunlong; Chen, Xiao'ai; Ye, Ling; Gu, Wei

    2014-09-16

    The development of multimodal nanoprobes is highly desired in medical imaging because it integrates the advantages of multiple imaging modes. In this study, the gadolinium-doped green luminescent carbon dots (Gd-CDs) were prepared by the simple one-step microwave-assisted polyol method. The obtained Gd-CDs emitted a unique green photoluminescence with a quantum yield of 5.4%. The Gd-CDs exhibited a low cytotoxicity and could optically label the C6 glioma cells. Meanwhile, the r1 relaxivity of Gd-CDs was measured to be 11.356 mM(-1) s(-1). This high r1 value together with the r2/r1 ratio close to 1 nominates Gd-CDs as an excellent T1 contrast agent for magnetic resonance imaging. These Gd-CDs combining two complementary imaging modalities are therefore a promising bimodal nanoprobe in medical imaging for a better diagnosis. PMID:25157595

  13. Gadolinium-enhanced magnetic resonance imaging of the knee: an experimental approach

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Sirun; Shen, Si; Zhu, Tianyuan; Liang, Wenbin; Huang, Li; Chen, Hanfang; Wu, Hejia [Medical Imaging Center, the First Affiliated Hospital, Jinan University, Guangzhou, Guang Dong (China)

    2010-09-15

    The purpose of this study was to examine gadolinium-enhanced magnetic resonance imaging (MRI) for monitoring cartilage degeneration. This is a proof-of-concept study in an animal model. Adult New Zealand rabbits were randomly stratified into five groups. Papain was injected intra-articularly in the right knee in four groups to establish the stages of cartilage degeneration. The left knee and group 5 served as controls. Bilateral MRI was performed 24 h after the initial injection of papain, and 1 week, 1 month, and 3 months following three papain injections. Injection of the contrast agent was followed by bilateral MRI examination immediately upon injection, and at 2 and 4 h post-injection. Signal intensities of articular cartilage and peripheral soft tissues were obtained before animals were sacrificed. Post-mortem bilateral cartilage specimens were studied histologically. Histopathology results verified the staged degeneration of papain-treated articular cartilage. Differences in cartilage signal intensity were significant for the staged model using a special three-dimensional MRI method (P < 0.05) but not using ordinary MRI. No differences were observed within or between the control groups (P > 0.05). Contrast-enhanced MRI examination may be a viable tool for early diagnosis of osteoarticular disease. Prospective studies are warranted to evaluate the potential for clinical application. (orig.)

  14. Fabrication of gadolinium hydroxide nanoparticles using ion-exchange resin and their MRI property

    Directory of Open Access Journals (Sweden)

    Y. Kobayashi

    2016-03-01

    Full Text Available This paper describes a method to fabricate gadolinium hydroxide (Gd(OH3 nanoparticles. An opaque solution was prepared by adding basic anion exchange resin (BAER to a Gd(NO33 aqueous solution at room temperature and aging the solution for 12–24 h; the solution became basic because of the exchange of H2O with OH−. The particles in the opaque solution have a needle structure, and their crystal structure was hexagonal Gd(OH3. Their longitudinal and lateral average particle sizes tend to increase in the ranges of 175.0–222.1 and 33.9–52.3 nm when the aging time increases from 12 to 24 h, respectively. The relaxivity value for T1-weighted imaging was 0.79 mM−1 s−1 for the solution that was prepared at the aging time of 18 h, which was ca. 20% of that for a commercial Gd complex contrast agent.

  15. Rapid hydrothermal route to synthesize cubic-phase gadolinium oxide nanorods

    Indian Academy of Sciences (India)

    Samiran Hazarika; Nibedita Paul; Dambarudhar Mohanta

    2014-06-01

    An inexpensive fabrication route and growth mechanism is being reported for obtaining quality gadolinium oxide (Gd2O3) nanoscale rods. The elongated nanoscale systems, as produced via a hydrothermal process, were characterized by X-ray diffraction (XRD), high resolution transmission electron microscopy (HRTEM), optical absorption spectroscopy, photoluminescence (PL) spectroscopy, Raman spectroscopy and magnetic hysteresis measurements. XRD patterns of the nanorods, as-prepared from independent precursors of different pH, depict a cubic crystal phase and an average crystallite size of 5-6.5 nm. As revealed from HRTEM micrographs, diameter of the nanorods prepared at pH = 13.3 (∼ 7nm) was much smaller than the rods prepared at pH = 10.8 (∼ 19nm). However, the aspect ratio was more than double in the former case than the latter case. PL response was found to be dominated by defect mediated emissions, whereas Raman spectrum of a given specimen (pH = 10.8) has revealed characteristic g + g modes of cubic phase of Gd2O3 nanorods, apart from other independent modes. Furthermore, ∼ plot of the nanorod system (pH = 10.8) exhibited slight departure from the ideal superparamagnetic behaviour, with low remanence and coercive field values. The exploitation of one-dimensional Gd2O3 nanorods have immense potential in the production of advanced contrast agents, smart drives and also in making novel ferrofluids of technological relevance.

  16. Graphene Oxide and Gadolinium-Chelate Functionalized Poly(lactic acid) Nanocapsules Encapsulating Perfluorooctylbromide for Ultrasound/Magnetic Resonance Bimodal Imaging Guided Photothermal Ablation of Cancer.

    Science.gov (United States)

    Li, Zhenglin; Ke, Hengte; Wang, Jinrui; Miao, Zhaohua; Yue, Xiuli

    2016-03-01

    This paper successfully fabricated a novel multifunctional theranostic agent (PFOB@PLA/GO/Gd-DTPA NCs) by loading perfluorooctylbromide (PFOB) into poly(lactic acid) (PLA) nanocapsules (NCs) followed by surface functionalization with graphene oxide (GO) and gadolinium-chelate (Gd-DTPA). It was found that the resulting nanoagent could serve as a contrast agent simultaneously to enhance ultrasound (US) and magnetic resonance imaging (MRI). Benefiting from the strong absorption in the near infrared (NIR) region, the nanocapsules could efficiently kill cancer cells under NIR laser irradiation. Thus, such a single theranostic agent with the combination of realtime US imaging and high-resolution MR imaging could achieve great therapeutic effectiveness without systemic damage to the body. In addition, the cytotoxicity assay on HUVEC cells revealed a good biocompatibility of PFOB@PLA/GO/Gd-DTPA NCs, showing that the versatile nanocapsule system may hold great potential as an effective nanoplatform for contrast enhanced imaging guided photothermal therapy.

  17. Dynamic contrast-enhanced MRI using a macromolecular MR contrast agent (P792): Evaluation of antivascular drug effect in a rabbit VX2 liver tumor model

    Energy Technology Data Exchange (ETDEWEB)

    Park, Hee Sun [Dept. of Radiology, Konkuk University School of Medicine, Seoul (Korea, Republic of); Han, Joon Koo; Lee, Jeong Min; Woo, Sung Min; Choi, Byung Ihn [Seoul National University Hospital, Seoul (Korea, Republic of); Kim, Young Il [Dept. of Radiology, Sheikh Khalifa Specialty Hospital, Ras Al Khaimah (United Arab Emirates); Choi, Jin Young [Dept. of Radiology, Yonsei University College of Medicine, Seoul (Korea, Republic of)

    2015-10-15

    To evaluate the utility of dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) using macromolecular contrast agent (P792) for assessment of vascular disrupting drug effect in rabbit VX2 liver tumor models. This study was approved by our Institutional Animal Care and Use Committee. DCE-MRI was performed with 3-T scanner in 13 VX2 liver tumor-bearing rabbits, before, 4 hours after, and 24 hours after administration of vascular disrupting agent (VDA), using gadomelitol (P792, n = 7) or low molecular weight contrast agent (gadoterate meglumine [Gd-DOTA], n = 6). P792 was injected at a of dose 0.05 mmol/kg, while that of Gd-DOTA was 0.2 mmol/kg. DCE-MRI parameters including volume transfer coefficient (Ktrans) and initial area under the gadolinium concentration-time curve until 60 seconds (iAUC) of tumors were compared between the 2 groups at each time point. DCE-MRI parameters were correlated with tumor histopathology. Reproducibility in measurement of DCE-MRI parameters and image quality of source MR were compared between groups. P792 group showed a more prominent decrease in Ktrans and iAUC at 4 hours and 24 hours, as compared to the Gd-DOTA group. Changes in DCE-MRI parameters showed a weak correlation with histologic parameters (necrotic fraction and microvessel density) in both groups. Reproducibility of DCE-MRI parameters and overall image quality was not significantly better in the P792 group, as compared to the Gd-DOTA group. Dynamic contrast-enhanced magnetic resonance imaging using a macromolecular contrast agent shows changes of hepatic perfusion more clearly after administration of the VDA. Gadolinium was required at smaller doses than a low molecular contrast agent.

  18. Magnetic resonance arthrography of the shoulder: accuracy of gadolinium versus saline for rotator cuff and labral pathology

    Energy Technology Data Exchange (ETDEWEB)

    Helms, Clyde A.; McGonegle, Shane J.; Vinson, Emily N.; Whiteside, Michael B. [Duke University Medical Center, Department of Radiology, Durham, NC (United States)

    2011-02-15

    The purpose of this study was to evaluate the necessity of intra-articular gadolinium versus saline alone in magnetic resonance arthrography (MRA) of the shoulder. Our database was reviewed for 100 consecutive shoulder MRA examinations performed between January 2007 and December 2007. Patient information was blinded and images were retrospectively reviewed by at least two radiologists with dedicated musculoskeletal training. T2-weighted (T2W) images were initially analyzed in isolation to simulate MRA with saline alone. After a delay, the full study was analyzed including T1-weighted (T1W) and T2W images. If there was a significant discordance between the two analyses with regard to rotator cuff or labral pathology, the study was again reviewed by all evaluators in consensus to determine if the T1W images offered additional diagnostic information and increased diagnostic confidence. Of the 100 MRA examinations, there were 15 discordant cases. Two cases were discordant with regard to rotator cuff pathology and 13 were discordant on the basis of labral pathology. When the discordant cases were reviewed in consensus, the T2W images appeared to display rotator cuff and labral pathology as definitively as the T1W images. Interobserver and intraobserver variability was favored to have played a role in causing the discordances. MRA of the shoulder performed with joint distention provided by saline alone appears to offer equivalent diagnostic information to MRA performed with gadolinium enhancement. This protocol modification improves efficiency by eliminating several image series and provides a small cost savings by eliminating gadolinium. (orig.)

  19. Spectroscopic Characterization of Nd-Doped Gadolinium Vanadate Crystals

    Institute of Scientific and Technical Information of China (English)

    马会龙; 臧竞存; 刘玉龙; 朱建慧; 宋雪梅

    2003-01-01

    The Nd3+-doped gadolinium vanadate Nd∶GdVO4 is a new type of crystal with laser properties superior to Nd∶YVO4. Experiment results show that the former has larger absorption cross section (3.261×10-19 cm2) and larger emission cross section (9.283×10-20 cm2). The heat conductivity of Nd∶GdVO4 is similar to that of Nd∶YAG, therefore it is a promising crystal for LD pumped laser. It is used to gain compact, high effect and all solid state lasers. The absorption spectra and fluorescence spectra were reported and the relationship between spectra and crystal structure was analyzed. Characteristics of energy levels of Nd3+ in the Nd∶GdVO4 crystal were discussed. The possibility of achieving laser oscillation at 0.91 μm was discussed.

  20. Epiphyseal and Physeal Cartilage: Normal Gadolinium-enhanced MR Imaging

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    To evaluate the normal appearance of epiphyseal and physeal cartilage on Gadolinium (Gd)-enhanced MR imaging. The appearance and enhancement ratios of 20 proximal and distal femoral epiphyses in 10 normal piglets were analyzed on Gd-enhanced MR images. The correlation of the MR imaging appearance with corresponding histological findings of immature epiphyses was examined. Our results showed that Gd-enhanced MRI could differentiate the differences in enhancement between physeal and epiphyseal cartilage and show vascular canals within the epiphyseal cartilage. Enhanced ratios in the physeal were greater than those in the epiphyseal cartilage (P<0.005). It is concluded that Gd-enhanced MR imaging reveals epiphyseal vascular canals and shows difference in enhancement of physeal and epiphyseal cartilage.

  1. Research and Development for a Gadolinium Doped Water Cherenkov Detector

    CERN Document Server

    Renshaw, Andrew

    2012-01-01

    The proposed introduction of a soluble gadolinium (Gd) compound into water Cherenkov detectors can result in a high efficiency for the detection of free neutrons capturing on the Gd. The delayed 8 MeV gamma cascades produced by these captures, in coincidence with a prompt positron signal, serve to uniquely identify electron antineutrinos interacting via inverse beta decay. Such coincidence detection can reduce backgrounds, allowing a large Gd-enhanced water Cherenkov detector to make the first observation of supernova relic neutrinos and high precision measurements of Japan's reactor antineutrino flux, while still allowing for all current physics studies to be continued. Now, a dedicated Gd test facility is operating in the Kamioka Mine. This new facility houses everything needed to successfully operate a Gd doped water Cherenkov detector. Successful running of this facility will demonstrate that adding Gd salt to SK is both safe for the detector and is capable of delivering the expected physics benefits.

  2. Corrosion Behavior of Commercial Magnetic Refrigerant Gadolinium in Water

    Institute of Scientific and Technical Information of China (English)

    Zhang Zeyu; Long Yi; Wen Da; Ye Rongchang; Wan Farong

    2004-01-01

    Gadolinium(Gd) used as magnetic refrigerant always works in water environment.However, its poor corrosion resistance is serious impediment against wider application of Gd.In this paper, the corrosion behavior of two types of commercial Gd ( A, B both are 98.9 at.% pure) with the same oxygen content has been studied.The results show that the corrosion rate of A is 3.226 times higher than that of B in deionized water and 6.039 times in tap water.According to SEM, the different corrosion rate is because of the different distribution of impurity in matrix.In addition,NaOH solution was chosen as inhibitor to prevent Gd from being corroded successfully.No pitting corrosion and weight loss were observed for commercial Gd even after immersion for nearly 2000 h in NaOH solution.

  3. Magnetocaloric effect at cryogenic temperature in gadolinium oxide nanotubes

    Science.gov (United States)

    Paul, Rima; Paramanik, Tapas; Das, Kalipada; Sen, Pintu; Satpati, B.; Das, I.

    2016-11-01

    We have synthesized fascinating nano-structure of Gadolinium oxide (Gd2O3) using controlled template-assisted electrochemical deposition technique which showed interesting anisotropic magnetic behavior. The nanotubes of Gd2O3 with average diameter 200 nm, length 10 μm and wall thickness 20 nm are constituted of nanoclusters with average diameter 7.5 nm. The tubes are aligned and are almost uniform throughout their length. Detailed magnetic measurements of aligned Gd2O3 nanotubes have been performed for both parallel and perpendicular magnetic field orientations with respect to the axis of the Gd2O3 nanotube array. Significant differences in magnetization values have been observed between the parallel and perpendicular orientations. Experimental results indicate the superparamagnetic nature of the nanomaterial. Large magnetocaloric effect, associated with the sharp change in magnetization of the Gd2O3 nanotubes, has been observed in the cryogenic temperature regime that shows anisotropic behavior.

  4. The structural response of gadolinium phosphate to pressure

    Science.gov (United States)

    Heffernan, Karina M.; Ross, Nancy L.; Spencer, Elinor C.; Boatner, Lynn A.

    2016-09-01

    Accurate elastic constants for gadolinium phosphate (GdPO4) have been measured by single-crystal high-pressure diffraction methods. The bulk modulus of GdPO4 determined under hydrostatic conditions, 128.1(8) GPa (Kʹ=5.8(2)), is markedly different from that obtained with GdPO4 under non-hydrostatic conditions (160(2) GPa), which indicates the importance of shear stresses on the elastic response of this phosphate. High pressure Raman and diffraction analysis indicate that the PO4 tetrahedra behave as rigid units in response to pressure and that contraction of the GdPO4 structure is facilitated by bending/twisting of the Gd-O-P links that result in increased distortion in the GdO9 polyhedra.

  5. Growth and characterisation of gadolinium samarium oxalate single crystals

    Energy Technology Data Exchange (ETDEWEB)

    Korah, I. [Dept. of Physics, St. George College, Aruvithura - 686122, Kerala (India); Joseph, C. [School of Pure and Applied Physics, Mahatma Gandhi University, Kottayam - 686562 (India); Ittyachan, M.A. [Dept. of Physics, Cochin University of Science and Technology, Cochin (India)

    2007-10-15

    Single crystals of Gadolinium Samarium Oxalate (GSO) are grown by gel method. The crystals are pale yellowish in colour. Morphology and size of the crystals are found to depend on pH of the medium, gel density, concentration of the reactants and acidity of the feed solution. The crystallinity of the grown sample was confirmed by X-ray diffraction studies and the lattice parameters were determined. X-ray diffractogram shows well defined peaks. IR spectrum confirms the presence of water molecules and carboxylic group. EDAX analysis confirms the presence of Gd and Sm in the sample. The thermal decomposition behaviour of the crystal was analysed using TGA and DTA studies. (copyright 2007 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  6. Low-lying ($K^{} = 0^{+}$) states of gadolinium isotopes

    Indian Academy of Sciences (India)

    Harun Reşit Yazar

    2013-10-01

    The sd-interacting boson approximation (sd-IBA) and the df-interacting boson approximation (df-IBA) can be related to each other and the states of the interacting boson approximation model can be identified with the fully symmetric states in the sdf interacting boson approximation model. A systematic study of the sdf-IBA model showed that the constructed Hamiltonian can successfully describe the strong octupole correlations in the deformed nuclei. We showed that the interacting boson approximation may account for many of these $K^{} = 0^{+}$ states. It was found that the calculated energy spectra of the gadolinium isotopes agree quite well with the experimental data. The observed (2) values were also calculated and compared with the experimental data.

  7. Nanoparticles in magnetic resonance imaging: from simple to dual contrast agents

    Directory of Open Access Journals (Sweden)

    Estelrich J

    2015-03-01

    Full Text Available Joan Estelrich,1,2 María Jesús Sánchez-Martín,1 Maria Antònia Busquets1,2 1Departament de Fisicoquímica, Facultat de Farmàcia, Universitat de Barcelona, Barcelona, Catalonia, Spain; 2Institut de Nanociència I Nanotecnologia (IN2UB, Barcelona, Catalonia, SpainAbstract: Magnetic resonance imaging (MRI has become one of the most widely used and powerful tools for noninvasive clinical diagnosis owing to its high degree of soft tissue contrast, spatial resolution, and depth of penetration. MRI signal intensity is related to the relaxation times (T1, spin–lattice relaxation and T2, spin–spin relaxation of in vivo water protons. To increase contrast, various inorganic nanoparticles and complexes (the so-called contrast agents are administered prior to the scanning. Shortening T1 and T2 increases the corresponding relaxation rates, 1/T1 and 1/T2, producing hyperintense and hypointense signals respectively in shorter times. Moreover, the signal-to-noise ratio can be improved with the acquisition of a large number of measurements. The contrast agents used are generally based on either iron oxide nanoparticles or ferrites, providing negative contrast in T2-weighted images; or complexes of lanthanide metals (mostly containing gadolinium ions, providing positive contrast in T1-weighted images. Recently, lanthanide complexes have been immobilized in nanostructured materials in order to develop a new class of contrast agents with functions including blood-pool and organ (or tumor targeting. Meanwhile, to overcome the limitations of individual imaging modalities, multimodal imaging techniques have been developed. An important challenge is to design all-in-one contrast agents that can be detected by multimodal techniques. Magnetoliposomes are efficient multimodal contrast agents. They can simultaneously bear both kinds of contrast and can, furthermore, incorporate targeting ligands and chains of polyethylene glycol to enhance the accumulation of

  8. The effectiveness and cost-effectiveness of erythropoiesis-stimulating agents (epoetin and darbepoetin) for treating cancer treatment-induced anaemia (including review of technology appraisal no. 142): a systematic review and economic model.

    Science.gov (United States)

    Crathorne, Louise; Huxley, Nicola; Haasova, Marcela; Snowsill, Tristan; Jones-Hughes, Tracey; Hoyle, Martin; Briscoe, Simon; Coelho, Helen; Long, Linda; Medina-Lara, Antonieta; Mujica-Mota, Ruben; Napier, Mark; Hyde, Chris

    2016-01-01

    BACKGROUND Anaemia is a common side effect of cancer treatments and can lead to a reduction in quality of life. Erythropoiesis-stimulating agents (ESAs) are licensed for use in conjunction with red blood cell transfusions to improve cancer treatment-induced anaemia (CIA). OBJECTIVE To investigate the effectiveness and cost-effectiveness of ESAs in anaemia associated with cancer treatment (specifically chemotherapy). DATA SOURCES The following databases were searched from 2004 to 2013: The Cochrane Library, MEDLINE, MEDLINE In-Process & Other Non-Indexed Citations, EMBASE, Web of Science, Cumulative Index to Nursing and Allied Health Literature, British Nursing Index, Health Management Information Consortium, Current Controlled Trials and ClinicalTrials.gov. The US Food and Drug Administration and European Medicines Agency websites were also searched. Bibliographies of included papers were scrutinised for further potentially includable studies. REVIEW METHODS The clinical effectiveness review followed principles published by the NHS Centre for Reviews and Dissemination. Randomised controlled trials (RCTs), or systematic reviews of RCTs, of ESAs (epoetin or darbepoetin) for treating people with CIA were eligible for inclusion in the review. Comparators were best supportive care, placebo or other ESAs. Anaemia- and malignancy-related outcomes, health-related quality of life (HRQoL) and adverse events (AEs) were evaluated. When appropriate, data were pooled using meta-analysis. An empirical health economic model was developed comparing ESA treatment with no ESA treatment. The model comprised two components: one evaluating short-term costs and quality-adjusted life-years (QALYs) (while patients are anaemic) and one evaluating long-term QALYs. Costs and benefits were discounted at 3.5% per annum. Probabilistic and univariate deterministic sensitivity analyses were performed. RESULTS Of 1457 titles and abstracts screened, 23 studies assessing ESAs within their licensed

  9. Poly(vinylpyrrolidone) as dispersing agent for cerium-gadolinium oxide (CGO) suspensions

    DEFF Research Database (Denmark)

    Marani, Debora; Sudireddy, Bhaskar Reddy; Nielsen, Lotte;

    2016-01-01

    The behaviour of selected poly(vinylpyrrolidone) grades to act as dispersant for ethanol-based ceriumgadolinium oxide suspensions was investigated and related to the molecular weight characteristics. The number, weight, and z-average molecular weights Mn, Mw, and Mz were determined by gel permeat...

  10. Theoretical study of structure and stability of small gadolinium carboxylate complexes in liquid scintillator solvents.

    Science.gov (United States)

    Huang, Pin-Wen

    2014-09-01

    The structural properties of three small gadolinium carboxylate complexes in three liquid scintillator solvents (pseudocumene, linear alkylbenzene, and phenyl xylylethane) were theoretically investigated using density functional theory (B3LYP/LC-RECP) and polarizable continuum model (PCM). The average interaction energy between gadolinium atom and carboxylate ligand (E(int)) and the energy difference of the highest singly occupied molecular orbital and lowest unoccupied molecular orbital (Δ(SL)) were calculated to evaluate and compare the relative stability of these complexes in solvents. The calculation results show that the larger (with a longer alkyl chain) gadolinium carboxylate complex has greater stability than the smaller one, while these gadolinium carboxylates in linear alkylbenzene were found to have greater stability than those in the other two solvents.

  11. Standard test methods for analysis of sintered gadolinium oxide-uranium dioxide pellets

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2006-01-01

    1.1 These test methods cover procedures for the analysis of sintered gadolinium oxide-uranium dioxide pellets to determine compliance with specifications. 1.2 The analytical procedures appear in the following order: Section Carbon (Total) by Direct CombustionThermal Conductivity Method C1408 Test Method for Carbon (Total) in Uranium Oxide Powders and Pellets By Direct Combustion-Infrared Detection Method Chlorine and Fluorine by Pyrohydrolysis Ion-Selective Electrode Method C1502 Test Method for Determination of Total Chlorine and Fluorine in Uranium Dioxide and Gadolinium Oxide Gadolinia Content by Energy-Dispersive X-Ray Spectrometry C1456 Test Method for Determination of Uranium or Gadolinium, or Both, in Gadolinium Oxide-Uranium Oxide Pellets or by X-Ray Fluorescence (XRF) Hydrogen by Inert Gas Fusion C1457 Test Method for Determination of Total Hydrogen Content of Uranium Oxide Powders and Pellets by Carrier Gas Extraction Isotopic Uranium Composition by Multiple-Filament Surface-Ioni...

  12. Optimization of micro-strip gas chamber as two-dimensional neutron detector using gadolinium converter

    Energy Technology Data Exchange (ETDEWEB)

    Masaoka, Sei; Nakamura, Tatsuya; Yamagishi, Hideshi; Soyama, Kazuhiko [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    2002-02-01

    A micro-strip gas chamber (MSGC) has been developing as a two-dimensional position sensitive neutron detector for neutron scattering experiments using high-intensity pulsed-neutron source in a high-intensity proton accelerator facility. MSGC is required for the high count rate, high detective efficiency, high positional resolution, stabilization and covering large area. Our purpose in this paper is to verify the proper of Gadolinium as MSGC converter. First, the basic property of Gadolinium converter was examined by simple experiments using a zero-dimensional neutron detector on the purpose of deriving the detective efficiency. Second, the optimization of the arrangement of a capillary plate in MSGC has been done by simulation on the MSGC using Gadolinium converter. As a result of that, it has been proved that Gadolinium can be theoretically used as a converter of MSGC. (author)

  13. Calculation and preliminary analysis of group cross sections for gadolinium and its isotopes

    International Nuclear Information System (INIS)

    Evaluated nuclear data files ENDL 78 and ENDF/B-IV and the cross section generation code FEDGROUP-R were used to produce averaged group cross sections for group systems BNAB and THSIG for gadolinium and its isotopes. Different sets of group cross sections for gadolinium (due to different evaluated data files or different processing codes) were compared and significant differences analyzed. The group capture cross sections for the isotopes of gadolinium were compared with published data. The group cross sections data sets prepared are analyzed as to what extent they can meet the requirements of cell calculations for gadolinium-loaded fuel. Some group cross section tables and cross section plots are presented. (author)

  14. Perturbed angular correlations for Gd in gadolinium: in-beam comparisons of relative magnetizations

    OpenAIRE

    Stuchbery, A. E.; Wilson, A. N.; Davidson, P. M.; Benczer-Koller, N.

    2006-01-01

    Perturbed angular correlations were measured for Gd ions implanted into gadolinium foils following Coulomb excitation with 40 MeV O-16 beams. A technique for measuring the relative magnetizations of ferromagnetic gadolinium hosts under in-beam conditions is described and discussed. The combined electric-quadrupole and magnetic-dipole interaction is evaluated. The effect of nuclei implanted onto damaged or non-substitutional sites is assessed, as is the effect of misalignment between the inter...

  15. NMR RELAXIVITY AND IMAGING OF NEUTRAL MACROMOLECULAR POLYESTER GADOLINIUM (Ⅲ) COMPLEXES

    Institute of Scientific and Technical Information of China (English)

    Kai-chao Yu; Hong-bing Hu; Mai-li Liu; Han-zhen Yuan; Chao-hui Ye; Ren-xi Zhuo

    1999-01-01

    Five neutral macromolecular polyester gadolinium (Ⅲ) complexes with pendant hydrophobic alkyl and aromatic functional groups were prepared. The longitudinal relaxation rates of these complexes were measured. One of these Gd (Ⅲ) complexes was chosen for the acute toxicity test and T1-weighted imaging measurement. Preliminary results showed that. compared with Gd-DTPA, the neutral macromolecular gadolinium (Ⅲ) complexes provide higher T1 relaxivity enhancement and longer function duration.

  16. Gadolinium-Induced Multi-Effect on Properties of IR Transmitting Chalcogenide Glasses

    Institute of Scientific and Technical Information of China (English)

    ZHAO Dong-Hui; XIA Fang; NIE Jia-Xiang; CHEN Guo-Rong; ZHANG Xiang-Hua; MA Hong-Li; ADAM Jean-Luc

    2004-01-01

    @@ We introduce gadolinium in chalcogenide glasses to exert unexpectedly the multiple magical effects on both optical and thermal mechanical properties of chalcogenide glasses. Notable increases in transition temperature Tg and microhardness Hv were observed due to structural densitication and microcrystallization. Calculated molar volume values, differential scanning calorimetry and x-ray diffraction measurements provide supporting evidences. Gadolinium also acts as oxygen getter by removing or weakening oxygen-related absorption bands,which is associated with the higher negative electrode potential.

  17. Breakthrough reactions of iodinated and gadolinium contrast media after oral steroid premedication protocol

    OpenAIRE

    Jingu, Akiko; Fukuda, Junya; Taketomi-Takahashi, Ayako; Tsushima, Yoshito

    2014-01-01

    Background Adverse reactions to iodinated and gadolinium contrast media are an important clinical issue. Although some guidelines have proposed oral steroid premedication protocols to prevent adverse reactions, some patients may have reactions to contrast media in spite of premedication (breakthrough reaction; BTR). The purpose of this study was to assess the frequency, type and severity of BTR when following an oral steroid premedication protocol. Methods All iodinated and gadolinium contras...

  18. Gadolinium Use in Spine Pain Management Procedures for Patients with Contrast Allergies: Results in 527 Procedures

    International Nuclear Information System (INIS)

    Introduction. To review the safety and efficacy of gadolinium in spine pain management procedures in patients at high risk for a contrast reaction and who are not suitable candidates for the use of standard non-ionic contrast. Methods. We reviewed records over a 61-month period of all image-guided spinal pain management procedures where patients had allergies making them unsuitable candidates for standard non-ionic contrast and where gadolinium was used to confirm needle tip placement prior to injection of medication. Results. Three hundred and four outpatients underwent 527 procedures. A spinal needle was used in all but 41 procedures. Gadolinium was visualized using portable C-arm fluoroscopy in vivo allowing for confirmation of needle tip location. The gadolinium dose ranged from 0.2 to 10 ml per level. The highest dose received by one patient was 15.83 ml intradiscally during a three-level discogram. Three hundred and one patients were discharged without complication or known delayed complications. One patient had documented intrathecal injection but without sequelae and 2 patients who underwent cervical procedures experienced seizures requiring admission to the intensive care unit. Both the latter patients were discharged without any further complications. Conclusion. Based on our experience we recommend using gadolinium judiciously for needle tip confirmation. We feel more confident using gadolinium in the lumbar spine and in cervical nerve blocks. Gadolinium should probably not be used as an injectate volume expander. The indications for gadolinium use in cervical needle-guided spine procedures are less clear and use of a blunt-tipped needle should be considered

  19. Recovery of methamphetamine associated cardiomyopathy predicted by late gadolinium enhanced cardiovascular magnetic resonance

    OpenAIRE

    Buonocore Michael; Caputo Gary; Yeo Khung; Lopez Javier E; Schaefer Saul

    2009-01-01

    Abstract Methamphetamine is known to cause a cardiomyopathy which may be reversible with appropriate medical therapy and cessation of use. Late gadolinium enhancement cardiovascular magnetic resonance (CMR) has been shown to identify fibrosis in ischemic and non-ischemic cardiomyopathies. We present a case of severe methamphetamine-associated cardiomyopathy in which cardiac function recovered after 6 months. Evaluation by CMR using late gadolinium enhancement was notable for an absence of enh...

  20. Investigation of gadolinium alloys and intermetallic compounds by the Moessbauer spectroscopy method

    International Nuclear Information System (INIS)

    The resonance absorption of the gamma quanta by 155Gd nuclei was utilized to determine the hyperfine parameters for the alloys of gadolinium with scandium and yttrium and for intermetallic compounds of gadolinium with iron, cobalt and nickel. In all cases, values of hyperfine magnetic fields, electric field gradients and isomer shifts of the Moessbauer line were obtained. Moreover, in some cases, the angle between the direction of the hyperfine field and the main axis of the electric field gradient was determined. (author)

  1. [Subclavian artery stenting using gadolinium contrast medium in a case with iodine allergy].

    Science.gov (United States)

    Miyamoto, Michiyuki; Asano, Takeshi; Osanai, Toshiya; Endo, Shogo; Nakayama, Naoki; Kuroda, Satoshi; Houkin, Kiyohiro

    2012-05-01

    The authors reported a subclavian artery stenting (SAS) using gadolinium contrast medium. The patient was a 65-year-old female who presented dizziness and right upper extremity pain with movement. Digital subtraction angiography revealed right subclavian artery occlusion with subclavian steal phenomenon. We tried to treat this lesion using SAS. However, iodinated contrast medium caused the allergy in this patient and the treatment was discontinued. Therefore, SAS was performed with gadolinium contrast medium. Using gadolinium contrast medium, it is possible to confirm large arteries like innominate artery and subclavian artery. The stenting procedure was performed without complication. The usage of gadolinium contrast medium has the limit and some strategies are important to reduce the usage of gadolinium contrast medium in SAS. First, PercuSurge GuardWire® was placed in the right internal carotid artery to confirm the anatomy, to decide working angle, and to treat the common carotid artery in case of dissection. Second, a "U" shaped guide wire was placed in the distal end from the brachial artery. Guide wire from femoral side was able to pass the lesion at midpoint of the "U" shaped one. SAS using gadolinium contrast medium may be an alternative treatment if a patient with subclavian artery stenosis or occlusion is allergic to iodinated contrast medium.

  2. Improvement of ESR dosimetry for thermal neutron beams through the addition of gadolinium

    Energy Technology Data Exchange (ETDEWEB)

    Brai, M [Dipartimento di Fisica e Tecnologie Relative, Universita di Palermo, Viale delle Scienze, Edificio 18, 90128 Palermo (Italy); Marrale, M [Dipartimento di Fisica e Tecnologie Relative, Universita di Palermo, Viale delle Scienze, Edificio 18, 90128 Palermo (Italy); Gennaro, G [Dipartimento di Fisica e Tecnologie Relative, Universita di Palermo, Viale delle Scienze, Edificio 18, 90128 Palermo (Italy); Bartolotta, A [Dipartimento Farmacochimico, Tossicologico e Biologico, Universita di Palermo, via Archirafi 32, 90123 Palermo (Italy); D' Oca, M C [Dipartimento Farmacochimico, Tossicologico e Biologico, Universita di Palermo, via Archirafi 32, 90123 Palermo (Italy); Rosi, G [Centro di Ricerche ENEA, Casaccia, Rome (Italy)

    2007-09-07

    In this paper, the addition of gadolinium is proposed as a useful tool to enhance the electron spin resonance (ESR) sensitivity of organic compounds to thermal neutrons. The target of this work is the detection, through the ESR technique, of the thermal neutron fluence in a mixed field of photons and neutrons. Gadolinium was chosen because it has a very high capture cross section to thermal neutrons; its nuclear reaction with thermal neutrons induces complex inner shell transitions that generate, besides other particles, Auger electrons, which in turn release their energy in the neighborhood (only several nanometers) of the place of reaction. Gadolinium was added to two organic molecules: alanine and ammonium tartrate. The main result obtained was a greater neutron sensitivity for dosimeters with gadolinium than for those without gadolinium for both organic molecules used. Since a dosimeter pair is required to discriminate between the two components of a mixed field, we studied the response of each dosimeter pair irradiated in a mixed field. Through a blind test we verified the usefulness of this dosimetric system and we obtained an estimate of the fluence in the mixed field with a relative uncertainty of 3%, when the pair composed of an alanine dosimeter and a dosimeter with alanine and gadolinium is used.

  3. Basic study for development of new tumor specific agents for neutron capture therapy

    International Nuclear Information System (INIS)

    New tissue specific agents for neutron capture therapy was studied. Monoclonal labeled gadolinium-DTPA (Gd-MoAb) and porphyrin (ATN-10)-Gd-DTPA (Gd-ATN10) were studied as possible agents by using 9-L experimental brain tumor model. The tissue concentration were analyzed with magnetic resonance imaging (MRI) and inductively coupled plasma (ICP) analyzer. Gd-MoAb showed persistent retention in the tumor on MRI, but tissue gadolinium concentration was not detectable in the tumor by ICP analyzer, while there was high accumulation of Gd-MoAb in the liver. Gd-ATN10 showed prolonged and high accumulation in the tumor up to 48 hours on MRI. Gadolinium concentration reached up to 9 ppm in the tumor by 0.02 mmol/kg administration, but it disappeared within 6 hours after administration. This dissociation between MRI and ICP analysis was due to separation of ATN-10 and Gd-DTPA. As conclusions, the porphyrin compounds are potential agents for delivering gadolinium or boron specific to the tumor tissue, thus further improvement such as more stable conjugation between porphyrinfic to the tumor tissue, thus further improvement such as more stable conjugation between porphyrin and Gd-DTPA is needed. (author)

  4. Reversible Low-Light Induced Photoswitching of Crowned Spiropyran-DO3A Complexed with Gadolinium(III Ions

    Directory of Open Access Journals (Sweden)

    André Knoesen

    2012-05-01

    Full Text Available Photoswitchable spiropyran has been conjugated to the crowned ring system DO3A, which improves its solubility in dipolar and polar media and stabilizes the merocyanine isomer. Adding the lanthanide ion gadolinium(III to the macrocyclic ring system leads to a photoresponsive magnetic resonance imaging contrast agent that displays an increased spin-lattice relaxation time (T1 upon visible light stimulation. In this work, the photoresponse of this photochromic molecule to weak light illumination using blue and green light emitting diodes was investigated, simulating the emission spectra from bioluminescent enzymes. Photon emission rate of the light emitting diodes was changed, from 1.75 × 1016 photons·s−1 to 2.37 × 1012 photons·s−1. We observed a consistent visible light-induced isomerization of the merocyanine to the spiropyran form with photon fluxes as low as 2.37 × 1012 photons·s−1 resulting in a relaxivity change of the compound. This demonstrates the potential for use of the described imaging probes in low light level applications such as sensing bioluminescence enzyme activity. The isomerization behavior of gadolinium(III-ion complexed and non-complexed spiropyran-DO3A was analyzed in water and ethanol solution in response to low light illumination and compared to the emitted photon emission rate from over-expressed Gaussia princeps luciferase.

  5. XAFS study of gadolinium and samarium bisporphyrinate complexes.

    Science.gov (United States)

    Agondanou, J H; Spyroulias, G A; Purans, J; Tsikalas, G; Souleau, C; Coutsolelos, A G; Bénazeth, S

    2001-11-19

    The comparative X-ray absorption spectroscopy study of gadolinium and samarium bisporphyrinate complexes represented by the formulas Gd(III)H(oep)(tpp), Gd(III)(oep)(2), Gd(III)H(tpp)(2) and Sm(III)H(oep)(tpp), Sm(III)(oep)(2), Sm(III)H(tpp)(2) is reported. The XAFS spectra are recorded on the LURE-DCI storage ring (Orsay, France) in transmission mode on the microcrystalline samples at the Gd and Sm L(3) edges. The local environment for Ln(3+) ions has been reconstructed applying one-shell and two-shell XAFS analysis procedures. The protonated and nonprotonated bisporphyrinate complexes present different XAFS features. After our analysis on the title derivatives, the gadolinium ion (at 80 K) is found to be bonded: (i) to eight nitrogen atoms at R(Gd-N) 2.50 A, for Gd(III)(oep)(2) [Debye-Waller (DW) factor 0.004 A(2)]; (ii) to seven nitrogen atoms at R(Gd-N) 2.49 A, for Gd(III)H(oep)(tpp) [DW factor 0.005 A(2)] and one nitrogen at long distance; and (iii) to six nitrogen atoms at R(Gd-N) 2.50 A [DW factor 0.006 A(2)] and two nitrogen atoms at long distance for Gd(III)H(tpp)(2). A similar coordination sphere has been detected for the corresponding Sm derivatives. So, the samarium ion (at room temperature) is bonded: (i) to eight nitrogen atoms at R(Sm-N) 2.53 A, for Sm(III)(oep)(2) [DW factor 0.006 A(2)]; (ii) to seven nitrogen atoms at R(Sm-N) 2.53 A, for Sm(III)H(oep)(tpp) [DW factor 0.006 A(2)] and one nitrogen at long distance; and (iii) to six nitrogen atoms at R(Sm-N) 2.50 A, for Sm(III)H(tpp)(2) [DW factor 0.006 A(2)] and two nitrogen atoms at long distance. As far as concerns Ln(III)(oep)(2) complexes, the increase of Ln-N distance in the series Gd(3+) agreement with previously published XRD data on Eu(III)(oep)(2). Moreover, the protonated Ln(III)H(oep)(tpp) and Ln(III)H(tpp)(2) complexes possess systematically shorter distances of about 0.02 A between the XAFS and XRD data. This difference is attributed to the asymmetry of the distribution concerning Ln

  6. Preferred hydride growth orientations on oxide-coated gadolinium surfaces

    International Nuclear Information System (INIS)

    Highlights: ► The preferred hydride growth orientations on gadolinium metal coated by a thin oxide layer are presented. ► A preferred growth of the (1 0 0)h plane of the face centered cubic (FCC) GdH2 is observed for the hydride spots forming below the oxidation layer. ► A change to the (1 1 1)h plane of the cubic hydride dominates for the hydride's Growth Centers. ► The texture change is attributed to the surface normal compressive stress component exerted by the oxidation layer on the developing hydride. - Abstract: The initial development of hydrides on polycrystalline gadolinium (Gd), as on some other hydride forming metals, is characterized by two sequential steps. The first step involves the rapid formation of a dense pattern of small hydride spots (referred to as the “small family” of hydrides) below the native oxidation layer. The second stage takes place when some of the “small family” nucleants (referred to as “growth centers”, GCs) break the oxide layer, leading to their rapid growth and finally to the massive hydriding of the sample. In the present study, the texture of the two hydride families was studied, by combining X-ray diffraction (XRD) analysis with a microscopic analysis of the hydride, using scanning electron microscopy (SEM) and atomic force microscopy (AFM). It has been observed that for the “small family”, a preferred growth of the (1 0 0)h plane of the cubic GdH2 takes place, whereas for the GCs, a change to the (1 1 1)h plane of the cubic hydride dominates. These preferred growth orientations were analyzed by their structure relation with the (0 0 .1)m basal plane of the Gd metal. It has been concluded that the above texture change is due to the surface normal compressive stress component exerted by the oxidation overlayer on the developing hydride, preventing the (0 0 .1)m||(1 1 1)h growth orientation. This stress is relieved upon the rupture of that overlayer and the development of the GCs, leading to the

  7. Nanoparticles in magnetic resonance imaging: from simple to dual contrast agents

    Science.gov (United States)

    Estelrich, Joan; Sánchez-Martín, María Jesús; Busquets, Maria Antònia

    2015-01-01

    Magnetic resonance imaging (MRI) has become one of the most widely used and powerful tools for noninvasive clinical diagnosis owing to its high degree of soft tissue contrast, spatial resolution, and depth of penetration. MRI signal intensity is related to the relaxation times (T1, spin–lattice relaxation and T2, spin–spin relaxation) of in vivo water protons. To increase contrast, various inorganic nanoparticles and complexes (the so-called contrast agents) are administered prior to the scanning. Shortening T1 and T2 increases the corresponding relaxation rates, 1/T1 and 1/T2, producing hyperintense and hypointense signals respectively in shorter times. Moreover, the signal-to-noise ratio can be improved with the acquisition of a large number of measurements. The contrast agents used are generally based on either iron oxide nanoparticles or ferrites, providing negative contrast in T2-weighted images; or complexes of lanthanide metals (mostly containing gadolinium ions), providing positive contrast in T1-weighted images. Recently, lanthanide complexes have been immobilized in nanostructured materials in order to develop a new class of contrast agents with functions including blood-pool and organ (or tumor) targeting. Meanwhile, to overcome the limitations of individual imaging modalities, multimodal imaging techniques have been developed. An important challenge is to design all-in-one contrast agents that can be detected by multimodal techniques. Magnetoliposomes are efficient multimodal contrast agents. They can simultaneously bear both kinds of contrast and can, furthermore, incorporate targeting ligands and chains of polyethylene glycol to enhance the accumulation of nanoparticles at the site of interest and the bioavailability, respectively. Here, we review the most important characteristics of the nanoparticles or complexes used as MRI contrast agents. PMID:25834422

  8. Delayed Gadolinium-Enhanced Magnetic Resonance Imaging (dGEMRIC) of Hip Joint Cartilage: Better Cartilage Delineation after Intra-Articular than Intravenous Gadolinium Injection

    DEFF Research Database (Denmark)

    Boesen, M.; Jensen, K.E.; Quistgaard, E.;

    2006-01-01

    PURPOSE: To investigate and compare delayed gadolinium (Gd-DTPA)-enhanced magnetic resonance imaging (MRI) of cartilage (dGEMRIC) in the hip joint using intravenous (i.v.) or ultrasound-guided intra-articular (i.a.) Gd-DTPA injection. MATERIAL AND METHODS: In 10 patients (50% males, mean age 58...

  9. Pinhole X-ray Fluorescence Imaging of Gadolinium Nanoparticles: A Preliminary Monte Carlo Study

    Energy Technology Data Exchange (ETDEWEB)

    Jung, Seong Moon; Sung, Won Mo; Ye, Sung Joon [Seoul National University, Seoul (Korea, Republic of)

    2014-10-15

    X-ray fluorescence imaging is a modality for the element-specific imaging of a subject through analysis of characteristic x-rays produced by exploiting the interaction of high atomic number elements and incoming x-rays. Previous studies have utilized a polychromatic x-ray source to investigate the production of in vivo x-ray fluorescence images for the assessment of concentrations and locations of gold nanoparticles. However, previous efforts have so far been unable to detect low concentrations, such as 0.001% gold by weight, which is an expected concentration accumulated in tumors. We examined the feasibility of a monochromatic synchrotron x-rays implementation of pinhole x-ray fluorescence imaging by Monte Carlo simulations using MCNP5. In the current study, gadolinium (Gd) nanoparticles, which have been widely used as a contrast agent in magnetic resonance imaging and also as a dose enhancer in radiation therapy, were chosen for tumor targeting. Since a monochromatic x-ray source is used, the increased x-ray fluorescence signals allow the detection of low concentrations of Gd. Two different monochromatic x-ray beam energies, 50.5 keV near the Kedge energy (i.e., 50.207 keV) of Gd and 55 keV, were compared by their respective imaging results. Using Monte Carlo simulations the feasibility of imaging low concentrations of Gd nanoparticles (e.g., 0.001 wt%) with x-ray fluorescence using monochromatic synchrotron x-rays of two different energies was shown. In the case of imaging a single Gd column inserted in the center of a water phantom, the fluorescence signals from 0.05 wt% and 0.1 wt% Gd columns irradiated with a 50.5 keV photon beam were higher than those irradiated with 55 keV. Below 0.05 wt% region no significant differences were found.

  10. [Study of early myocardial infarction by nuclear magnetic resonance imaging with gadolinium Dota injection].

    Science.gov (United States)

    Jau, P; Bonnet, J L; Joly, P; Barth, P; Habib, G; Djiane, P; Bory, M; Bernard, P J

    1991-02-01

    Ten patients with acute myocardial infarction were studied by magnetic resonance imaging (MRI) with injection of a paramagnetic contrast agent: Gadolinium-DOTA (Gd-DOTA). The time interval between the onset of symptoms and MRI was 8 to 12 days. The site of infarction was determined in all cases by Thallium 201 scintigraphy (hypofixation) and selective ventriculography (segmental wall anomalies): anterior (6 cases), inferior (4 cases). MRI was performed with a 0.5 Tesla CGR Magniscan by the multiple spin technique. A series of tomographic sections was recorded immediately after intravenous injection of 0.4 mmol/Kg of Gd-DOTA. Recent myocardial infarction with parenchymal oedema gives an enhanced transmural signal: only 3 patients had a sufficiently contrasted image on the 1st spin echo. After Gd-DOTA, 7 patients had significantly increased contrast on this echo and in all excellent contrast between infarcted and healthy myocardium was obtained in 9 of the 10 patients. There was excellent correlation concerning the site of infarction between Thallium scintigraphy and left ventriculography. The intensity of signal and T2 relaxation time of different myocardial segments was studied by the regions of interest technique: the ratio of signal intensity of infarcted/healthy myocardium was 1.3 before and 1.7 after Gd-DOTA on first spin echo images. The mean T2 was 54.1 +/- 9 ms in healthy and 82 +/- 28 ms in infarcted myocardium. After Gd-DOTA, both values decreased and tended to equalize.(ABSTRACT TRUNCATED AT 250 WORDS)

  11. Pinhole X-ray Fluorescence Imaging of Gadolinium Nanoparticles: A Preliminary Monte Carlo Study

    International Nuclear Information System (INIS)

    X-ray fluorescence imaging is a modality for the element-specific imaging of a subject through analysis of characteristic x-rays produced by exploiting the interaction of high atomic number elements and incoming x-rays. Previous studies have utilized a polychromatic x-ray source to investigate the production of in vivo x-ray fluorescence images for the assessment of concentrations and locations of gold nanoparticles. However, previous efforts have so far been unable to detect low concentrations, such as 0.001% gold by weight, which is an expected concentration accumulated in tumors. We examined the feasibility of a monochromatic synchrotron x-rays implementation of pinhole x-ray fluorescence imaging by Monte Carlo simulations using MCNP5. In the current study, gadolinium (Gd) nanoparticles, which have been widely used as a contrast agent in magnetic resonance imaging and also as a dose enhancer in radiation therapy, were chosen for tumor targeting. Since a monochromatic x-ray source is used, the increased x-ray fluorescence signals allow the detection of low concentrations of Gd. Two different monochromatic x-ray beam energies, 50.5 keV near the Kedge energy (i.e., 50.207 keV) of Gd and 55 keV, were compared by their respective imaging results. Using Monte Carlo simulations the feasibility of imaging low concentrations of Gd nanoparticles (e.g., 0.001 wt%) with x-ray fluorescence using monochromatic synchrotron x-rays of two different energies was shown. In the case of imaging a single Gd column inserted in the center of a water phantom, the fluorescence signals from 0.05 wt% and 0.1 wt% Gd columns irradiated with a 50.5 keV photon beam were higher than those irradiated with 55 keV. Below 0.05 wt% region no significant differences were found

  12. Gadolinium-uptake by aquatic and terrestrial organisms-distribution determined by laser ablation inductively coupled plasma mass spectrometry.

    Science.gov (United States)

    Lingott, Jana; Lindner, Uwe; Telgmann, Lena; Esteban-Fernández, Diego; Jakubowski, Norbert; Panne, Ulrich

    2016-02-01

    Gadolinium (Gd) based contrast agents (CA) are used to enhance magnetic resonance imaging. As a consequence of excretion by patients and insufficient elimination in wastewater treatment plants they are detected in high concentrations in surface water. At present, little is known about the uptake of these species by living organisms in aquatic systems. Therefore the uptake of gadolinium containing chelates by plants and animals grown in exposed water or on soil irrigated with exposed water was investigated. For this purpose two types of plants were treated with two different contrast agents. The uptake of the Gd contrast agents was studied by monitoring the elemental distribution with laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS). This technique allows the multi-elemental analysis of solid samples with high resolution and little sample preparation. The analysis of L. minor showed that the uptake of Gd correlated with the concentration of gadodiamide in the water. The higher the concentration in the exposed water, the larger the Gd signal in the LA-ICP-MS acquired image. Exposure time experiments showed saturation within one day. The L. minor had contact with the CAs through roots and fronds, whereas the L. sativum only showed uptake through the roots. These results show that an external absorption of the CA through the leaves of L. sativum was impossible. All the analyzed parts of the plant showed Gd signal from the CA; the highest being at the main vein of the leaf. It is shown that the CAs can be taken up from plants. Furthermore, the uptake and distribution of Gd in Daphnia magna were shown. The exposure via cultivation medium is followed by Gd signals on the skin and in the area of the intestine, while the uptake via exposed nutrition algae causes the significantly highest Gd intensities in the area of the intestine. Because there are hints of negative effects for human organism these findings are important as they show that Gd based

  13. A magnetic x-ray diffraction investigation of gadolinium selenide

    Energy Technology Data Exchange (ETDEWEB)

    Costa, M.M.R.; Almeida, M.J.M. de [Departamento de Fisica, Universidade de Coimbra, Coimbra (Portugal); Nuttall, W.J.; Stirling, W.G. [Department of Physics, Keele University, Keele, Staffs (United Kingdom); Tang, C.C. [Daresbury Laboratory, Warrington, Cheshire (United Kingdom); Forsyth, J.B. [Rutherford Appleton Laboratory, Chilton, Oxon (United Kingdom); Cooper, M.J. [Department of Physics, University of Warwick, Coventry (United Kingdom)

    1996-04-01

    A single-crystal synchrotron radiation study of gadolinium selenide has been made in the temperature range 15-100 K. GdSe has the rocksalt structure and becomes antiferromagnetic below a reported Neel temperature of 65 K. At 15 K, magnetic reflections are observed at G+T with modulation wavevector T={l_brace}1/2:1/2:1/2{r_brace} propagating from reciprocal lattice point G. This is achieved by exploiting the resonant enhancement in the vicinity of the Gd L{sub II} and L{sub III} edges. Similar enhancements are observed at the two edges, with the maximum effect occurring approximately 3 eV above the absorption edge. The temperature dependence of the intensity of the magnetic reflections indicates a Neel temperature of 63(1) K. These measurements, together with high-resolution studies of the fundamental reflections (T=0), contribute further evidence of magnetic or structural changes in the sample at 37(1) K. Our observations are discussed and compared with previous x-ray diffraction and magnetic susceptibility measurements. (author)

  14. Diagnosis of Bell palsy with gadolinium magnetic resonance imaging.

    Science.gov (United States)

    Becelli, R; Perugini, M; Carboni, A; Renzi, G

    2003-01-01

    Bell palsy is a condition resulting from a peripheral edematous compression on the nervous fibers of the facial nerve. This pathological condition often has clinical characteristics of no importance and spontaneously disappears in a short time in a high percentage of cases. Facial palsy concerning cranial nerve VII can also be caused by other conditions such as mastoid fracture, acoustic neurinoma, tumor spread to the temporal lobe (e.g., cholesteatoma), neoformation of the parotid gland, Melkersson-Rosenthal syndrome, and Ramsay-Hunt syndrome. Therefore, it is important to adopt an accurate diagnostic technique allowing the rapid detection of Bell palsy and the exclusion of causes of facial paralysis requiring surgical treatment. Magnetic resonance imaging (MRI) with medium contrast of the skull shows a marked increase in revealing lesions, even of small dimensions, inside the temporal bone and at the cerebellopontine angle. The authors present a clinical case to show the important role played by gadolinium MRI in reaching a diagnosis of Bell palsy in the differential diagnosis of the various conditions that determine paralysis of the facial nerve and in selecting the most suitable treatment or surgery to be adopted.

  15. Electron magnetic resonance of gadolinium-doped calcium fluoride

    Energy Technology Data Exchange (ETDEWEB)

    Biasi, R.S. de, E-mail: rsbiasi@ime.eb.br [Secao de Engenharia Mecanica e de Materiais, Instituto Militar de Engenharia, 22290-270 Rio de Janeiro, RJ (Brazil); Grillo, M.L.N., E-mail: mluciag@uerj.br [Instituto de Fisica, Universidade do Estado do Rio de Janeiro, 20550-013 Rio de Janeiro, RJ (Brazil)

    2012-06-15

    Electron magnetic resonance (EMR) spectra of gadolinium-doped calcium fluoride have been studied at room temperature for Gd concentrations between 0.01 and 2.00 mol%. Gd{sup 3+} ions in sites with two different symmetries were observed. One of the sites, with cubic symmetry, is unstable at room temperature and decays with a time constant of 2.2 day{sup -1}. The other site, with tetragonal symmetry, is stable and is attributed to Gd{sup 3+} ions in substitutional sites next to a charge-compensating F{sup -} interstitial ion. The linewidth and intensity of the EMR spectrum with tetragonal symmetry increase with increasing Gd concentration. A theoretical calculation based on the concentration dependence of the EMR linewidth yields an effective range of the exchange interaction between Gd{sup 3+} ions in CaF{sub 2} of 0.774 nm, of the same order as that of Gd{sup 3+} ions in other cubic ionic compounds.

  16. Design and development of a Gadolinium-doped water Cherenkov detector

    Science.gov (United States)

    Poudyal, Nabin

    This thesis describes a research and development project for neutron capture and detection in Gadolinium doped water. The Sanford Underground Research Facility (SURF) is exploring rare event physics, such as neutrinoless double beta decay (MAJORANA Project) and dark-matter detection (LUX experiment). The success of these experiments requires a careful study and understanding of background radiation, including flux and energy spectrum. The background radiation from surface contamination, radioactive decays of U-238, Th-232, Rn-222 in the surrounding rocks and muon induced neutrons have a large impact on the success of rare-event physics. The main objective of this R&D project is to measure the neutron flux contributing to ongoing experiments at SURF and suppress it by identification and capture method. For this purpose, we first modeled and designed a detector with Geant4 software. The approximate dimension of the detector is determined. The neutron capture percentage of the detector is estimated using Monte Carlo. The energy response of the detector is simulated. Next, we constructed the experimental detector, an acrylic rectangular tank (60cm x 30cm x 30cm), filled with Gadolinium-doped deionized water. The tank is coated with high efficient reflector and then taped with black electrical tape to make it opaque. The voltage dividers attached to PMTs are covered with mu-metal. Two 5-inch Hamamatsu Photomultiplier tubes were attached on both sides facing the tank to collect the Cherenkov light produced in the water. The detector utilizes the principle of Cherenkov light emission by a charged particle moving through a water at a speed higher than the speed of light in the water, hence it has an inherent energy threshold of Cherenkov photon production. This property reduces the lower energy backgrounds. Event data are obtained using the Data Acquisition hardware, Flash Analog to digital converter, along with Multi Instance Data Acquisition software. Post

  17. High-Relaxivity MRI Contrast Agents: Where Coordination Chemistry Meets Medical Imaging

    Energy Technology Data Exchange (ETDEWEB)

    Werner, Eric J.; Datta, Ankona; Jocher, Christoph J.; Raymond, Kenneth N.

    2008-01-15

    The desire to improve and expand the scope of clinical magnetic resonance imaging (MRI) has prompted the search for contrast agents of higher efficiency. The development of better agents requires consideration of the fundamental coordination chemistry of the gadolinium(III) ion and the parameters that affect its efficacy as a proton relaxation agent. In optimizing each parameter, other practical issues such as solubility and in vivo toxicity must also be addressed, making the attainment of safe, high-relaxivity agents a challenging goal. Here we present recent advances in the field, with an emphasis on the hydroxypyridinone family of Gd{sup III} chelates.

  18. Three-dimensional gadolinium-enhanced MR angiography of the intracranial venous system

    International Nuclear Information System (INIS)

    The purpose of this study was to assess the usefulness of three-dimensional (3D) gadolinium-enhanced magnetic resonance (MR) angiography for evaluation of the intracranial venous system. Thirty-three patients underwent 3D dynamic gadolinium-enhanced MR angiography as well as two-dimensional (2D) time-of-flight (TOF) MR venography in transverse and coronal planes and conventional catheter cerebral angiography with digital subtraction. MR venography was displayed using a maximum-intensity-projection (MIP) algorithm. The acquisition time of 3D gadolinium-enhanced MR angiography was 102 seconds, and that of 2D TOF MR venography was about 7 minutes in the transverse plane and about 9 minutes in the coronal plane. Degree of visualization of the intracranial venous system on each MR sequence was compared with that on conventional catheter cerebral angiography as a standard. Superficial cortical veins and the dural sinus were better visualized on 3D gadolinium-enhanced MR angiography than on 2D TOF MR venography. Three-dimensional gadolinium-enhanced MR angiography is noninvasive and very useful for imaging of the intracranial venous system. It can replace 2D TOF MR venography not only because of its short examination time but because it better demonstrates intracranial venous structures. For evaluation of the SSS, lateral sinus, sigmoid sinus and straight sinus in particular, conventional catheter angiography seems to be unnecessary. (author)

  19. Three-dimensional gadolinium-enhanced MR angiography of the intracranial venous system

    Energy Technology Data Exchange (ETDEWEB)

    Daikokuya, Hideo; Inoue, Yuichi; Yamada, Ryusaku [Osaka City Univ. (Japan). Medical School

    2001-12-01

    The purpose of this study was to assess the usefulness of three-dimensional (3D) gadolinium-enhanced magnetic resonance (MR) angiography for evaluation of the intracranial venous system. Thirty-three patients underwent 3D dynamic gadolinium-enhanced MR angiography as well as two-dimensional (2D) time-of-flight (TOF) MR venography in transverse and coronal planes and conventional catheter cerebral angiography with digital subtraction. MR venography was displayed using a maximum-intensity-projection (MIP) algorithm. The acquisition time of 3D gadolinium-enhanced MR angiography was 102 seconds, and that of 2D TOF MR venography was about 7 minutes in the transverse plane and about 9 minutes in the coronal plane. Degree of visualization of the intracranial venous system on each MR sequence was compared with that on conventional catheter cerebral angiography as a standard. Superficial cortical veins and the dural sinus were better visualized on 3D gadolinium-enhanced MR angiography than on 2D TOF MR venography. Three-dimensional gadolinium-enhanced MR angiography is noninvasive and very useful for imaging of the intracranial venous system. It can replace 2D TOF MR venography not only because of its short examination time but because it better demonstrates intracranial venous structures. For evaluation of the SSS, lateral sinus, sigmoid sinus and straight sinus in particular, conventional catheter angiography seems to be unnecessary. (author)

  20. Saline as the Sole Contrast Agent for Successful MRI-guided Epidural Injections

    Energy Technology Data Exchange (ETDEWEB)

    Deli, Martin, E-mail: martin.deli@web.de [University of Witten/Herdecke, Department of Radiology and Microtherapy, Groenemeyer Institute for Microtherapy (GIMT) (Germany); Fritz, Jan, E-mail: jfritz9@jhmi.edu [Johns Hopkins University School of Medicine, Russell H. Morgan Department of Radiology and Radiological Science (United States); Mateiescu, Serban, E-mail: mateiescu@microtherapy.de; Busch, Martin, E-mail: busch@microtherapy.de [University of Witten/Herdecke, Department of Radiology and Microtherapy, Groenemeyer Institute for Microtherapy (GIMT) (Germany); Carrino, John A., E-mail: jcarrin2@jhmi.edu [Johns Hopkins University School of Medicine, Russell H. Morgan Department of Radiology and Radiological Science (United States); Becker, Jan, E-mail: j.becker@microtherapy.de; Garmer, Marietta, E-mail: garmer@microtherapy.de; Groenemeyer, Dietrich, E-mail: dg@microtherapy.de [University of Witten/Herdecke, Department of Radiology and Microtherapy, Groenemeyer Institute for Microtherapy (GIMT) (Germany)

    2013-06-15

    Purpose. To assess the performance of sterile saline solution as the sole contrast agent for percutaneous magnetic resonance imaging (MRI)-guided epidural injections at 1.5 T. Methods. A retrospective analysis of two different techniques of MRI-guided epidural injections was performed with either gadolinium-enhanced saline solution or sterile saline solution for documentation of the epidural location of the needle tip. T1-weighted spoiled gradient echo (FLASH) images or T2-weighted single-shot turbo spin echo (HASTE) images visualized the test injectants. Methods were compared by technical success rate, image quality, table time, and rate of complications. Results. 105 MRI-guided epidural injections (12 of 105 with gadolinium-enhanced saline solution and 93 of 105 with sterile saline solution) were performed successfully and without complications. Visualization of sterile saline solution and gadolinium-enhanced saline solution was sufficient, good, or excellent in all 105 interventions. For either test injectant, quantitative image analysis demonstrated comparable high contrast-to-noise ratios of test injectants to adjacent body substances with reliable statistical significance levels (p < 0.001). The mean table time was 22 {+-} 9 min in the gadolinium-enhanced saline solution group and 22 {+-} 8 min in the saline solution group (p = 0.75). Conclusion. Sterile saline is suitable as the sole contrast agent for successful and safe percutaneous MRI-guided epidural drug delivery at 1.5 T.

  1. Late gadolinium enhancement cardiovascular magnetic resonance predicts clinical worsening in patients with pulmonary hypertension

    Directory of Open Access Journals (Sweden)

    Freed Benjamin H

    2012-02-01

    Full Text Available Abstract Background Late gadolinium enhancement (LGE occurs at the right ventricular (RV insertion point (RVIP in patients with pulmonary hypertension (PH and has been shown to correlate with cardiovascular magnetic resonance (CMR derived RV indices. However, the prognostic role of RVIP-LGE and other CMR-derived parameters of RV function are not well established. Our aim was to evaluate the predictive value of contrast-enhanced CMR in patients with PH. Methods RV size, ejection fraction (RVEF, and the presence of RVIP-LGE were determined in 58 patients with PH referred for CMR. All patients underwent right heart catheterization, exercise testing, and N-terminal pro-brain natriuretic peptide (NT-proBNP evaluation; results of which were included in the final analysis if performed within 4 months of the CMR study. Patients were followed for the primary endpoint of time to clinical worsening (death, decompensated right ventricular heart failure, initiation of prostacyclin, or lung transplantation. Results Overall, 40/58 (69% of patients had RVIP-LGE. Patients with RVIP- LGE had larger right ventricular volume index, lower RVEF, and higher mean pulmonary artery pressure (mPAP, all p Conclusions The presence of RVIP-LGE in patients with PH is a marker for more advanced disease and poor prognosis. In addition, this study reveals for the first time that CMR-derived RVEF is an independent non-invasive imaging predictor of adverse outcomes in this patient population.

  2. An experimental search for the electron Electric Dipole Moment in Gadolinium Gallium Garnet

    Science.gov (United States)

    Kim, Young Jin; Liu, Chen-Yu

    2011-04-01

    A discovery of a permanent electric dipole moment of the electron (eEDM) would provide crucial information about the nature of T-violation and imply new sources of CP-violation beyond the Standard Model. While the leading experimental technique used to measure EDM is based on the nuclear magnetic resonance, we are pursuing research that would improve the present experimental limit of the eEDM using a new technique in solid-state systems at low temperatures. The experiment uses a paramagnetic insulator Gadolinium Gallium Garnet with a large magnetic response. The presence of the eEDM leads to a finite magnetization when the garnet sample is subjected to a strong electric field. The resulting magnetization can be measured using the Superconducting Quantum Interference Device (SQUID) as a sensitive magnetometer. In this talk, we will discuss the progress to control the systematic effects and improve the sensitivity. The major efforts include the design and implementation of a 24-bit data acquisition system with ultra-low level of channel crosstalk, and the control of the high voltage drift from the supply. With these considerable progresses, we report our first background-free experimental limit of the eEDM on the order of 10-24 e.cm.

  3. Environmental behaviour und ecotoxiology of gadolinium-containing MRT contrast media; Umweltverhalten und Oekotoxikologie von gadoliniumhaltigen Magnetresonanztomographie-Kontrastmitteln

    Energy Technology Data Exchange (ETDEWEB)

    Neubert, Claudia

    2008-07-08

    Magnetic resonance imaging (MRI) is an essential tool in noninvasive diagnostics. In order to improve the sensitivity and specificity of diagnoses, several contrast enhancing agents have been developed in the last few decades by various pharmaceutical manufacturers. Gadolinium (Gd), a lanthanide, is the most widely used metal in MRI contrast agents. Its ion has paramagnetic properties (seven unpaired electrons) and a very long electronic relaxation time. Due to the toxicity of free Gd, clinical use is only possible in a complexed form. Commonly used chelating agents are polyamino-polycarboxylic ligands such as DTPA. Due to the exceptional stability of these highly hydrophilic chelates and the lack of human metabolism, the contrast media are quantitatively excreted unchanged after the administration, and are subsequently emitted into the aquatic environment. Several studies have shown notable increases in Gd concentrations in surface or groundwaters receiving sewage effluents, an observation which has been termed ''Gd anomaly''. The Gd anomaly results from the use of MRI contrast agents for which the most significant entry route is the effluent from wastewater treatment works. Relatively little information on the aquatic toxicity of Gd or Gd-chelates has been published up to 2006. Therefore, in a first step, the acute aquatic toxicity of several MRI contrast agents was investigated in fish, daphnia and algae at high concentrations. Furthermore, chronic toxicity tests on fish and daphnia were conducted. The results showed that contrast enhancing agents containing Gd have no toxic effects on the tested organisms at concentrations being of relevance to the environment. At high concentrations growth inhibition of green algae was observed. The environmental fate and the biological degradation of the contrast media was studied in a model wastewater treatment plant and in aquatic sediment systems. The test compounds were neither biodegradable in the

  4. High-technology metals as emerging contaminants: Strong increase of anthropogenic gadolinium levels in tap water of Berlin, Germany, from 2009 to 2012

    International Nuclear Information System (INIS)

    Highlights: • Monitoring study Berlin-2012 confirms tap water contamination with gadolinium. • Contamination confined to western districts of Berlin. • Strong increase of anthropogenic gadolinium from 2009 to 2012. • Anthropogenic gadolinium is tracer for wastewater-derived substances. - Abstract: The distribution of rare earth elements (REE) in tap water sampled in December 2012 in Berlin, Germany, is characterized by anomalously high levels of gadolinium (Gd). While the western districts of the city show strong anthropogenic positive Gd anomalies in REE distribution patterns, the eastern districts are (almost) unaffected. This contamination with anthropogenic Gd results from Gd-based contrast agents used in Magnetic Resonance Imaging, that enter rivers, groundwater and eventually tap water via the clear water effluent from wastewater treatment plants. While the spatial distribution of anthropogenic Gd in 2012 confirms results of an earlier study in 2009 (Kulaksiz and Bau, 2011a), anthropogenic Gd concentrations have increased between 1.5- and 11.5-fold in just three years. This confirms predictions based upon the increase of anthropogenic Gd concentrations in the Havel River over the past two decades and the time it takes the water to migrate from the Havel River to the groundwater production wells. Anomalously high levels of anthropogenic Gd in tap water, which are not confined to Berlin but have also been observed in London, U.K., and in German cities in the Ruhr area and along the Rhine River, reveal that high-technology metals have become emerging contaminants. While non-toxic at the observed concentrations, the anthropogenic Gd is a microcontaminant that may be used as a conservative pseudo-natural tracer for wastewater-derived xenobiotics such as pharmaceuticals, food additives and personal care products. Our results suggest that monitoring the concentrations of such substances in Berlin’s drinking water can be restricted to a few central and

  5. Can unenhanced multiparametric MRI substitute gadolinium-enhanced MRI in the characterization of vertebral marrow infiltrative lesions?

    Directory of Open Access Journals (Sweden)

    Dalia Z. Zidan

    2014-06-01

    Conclusion: Unenhanced-multiparametric MRI is compatible with gadolinium-enhanced MRI in reliable characterization of marrow infiltrative lesions. The routine MRI protocol of cancer patients should be altered to accommodate the evolving MRI technology and cost effectively substitute the need for a gadolinium enhanced scan.

  6. In-Situ Measurement of Relative Attenuation Length of Gadolinium-Loaded Liquid Scintillator Using Source Data at RENO Experiment

    CERN Document Server

    Kim, H S; Choi, J H; Choi, W Q; Choi, Y; Jang, H I; Jang, J S; Joo, K K; Kim, B R; Kim, J Y; Kim, S B; Kim, W; Kwon, E; Lee, D H; Lim, I T; Pac, M Y; Park, I G; Park, J S; Park, R G; Seo, H; Seo, S H; Seon, Y G; Shin, C D; Yeo, I S; Yu, I

    2016-01-01

    We present an in-situ method of measuring the relative attenuation length of gadolinium-loaded liquid scintillator in the RENO detectors using radioactive source calibration data without requiring any PMT performance model. We observed the degradation of the attenuation length of the gadolinium-loaded liquid scintillator in the RENO detectors by ~50% over a period of about 4 years.

  7. Ultrasound guidance to perform intra-articular injection of gadolinium-based contrast material for magnetic resonance arthrography as an alternative to fluoroscopy: the time is now

    International Nuclear Information System (INIS)

    Magnetic resonance (MR) imaging has been definitively established as the reference standard in the evaluation of joints in the body. Similarly, magnetic resonance arthrography has emerged as a technique that has been proven to increase significantly the diagnostic performance if compared with conventional MR imaging, especially when dealing with fibrocartilage and articular cartilage abnormalities. Diluted gadolinium can be injected in the joint space using different approaches: under palpation using anatomic landmarks or using an imaging guidance, such as fluoroscopy, computed tomography, or ultrasound. Fluoroscopy has been traditionally used, but the involvement of ionizing radiation should represent a remarkable limitation of this modality. Conversely, ultrasound has emerged as a feasible, cheap, quick, and radiation-free modality that can be used to inject joints, with comparable accuracy of fluoroscopy. In the present paper, we discuss the advantages and disadvantages of using fluoroscopy or ultrasound in injecting gadolinium-based contrast agents in joints to perform magnetic resonance arthrography, also in view of the new EuroSAFE Imaging initiative promoted by the European Society of Radiology and the recent updates to the European Atomic Energy Community 2013/59 directive on the medical use of ionizing radiation. (orig.)

  8. Ultrasound guidance to perform intra-articular injection of gadolinium-based contrast material for magnetic resonance arthrography as an alternative to fluoroscopy: the time is now

    Energy Technology Data Exchange (ETDEWEB)

    Messina, Carmelo [Universita degli Studi di Milano, Scuola di Specializzazione in Radiodiagnostica, Milano (Italy); Banfi, Giuseppe [IRCCS Istituto Ortopedico Galeazzi, Milano (Italy); Universita Vita-Salute San Raffaele, Milano (Italy); Aliprandi, Alberto [Universita degli Studi di Milano, Dipartimento di Scienze Biomediche per la Salute, Milano (Italy); Mauri, Giovanni [Universita degli Studi di Milano, Dipartimento di Scienze Biomediche per la Salute, Milano (Italy); Istituto Europeo di Oncologia, Unita di Radiologia Interventistica, Milano (Italy); Secchi, Francesco; Sardanelli, Francesco; Sconfienza, Luca Maria [Universita degli Studi di Milano, Dipartimento di Scienze Biomediche per la Salute, Milano (Italy); IRCCS Policlinico San Donato, Servizio di Radiologia, San Donato, Milanese (Italy)

    2016-05-15

    Magnetic resonance (MR) imaging has been definitively established as the reference standard in the evaluation of joints in the body. Similarly, magnetic resonance arthrography has emerged as a technique that has been proven to increase significantly the diagnostic performance if compared with conventional MR imaging, especially when dealing with fibrocartilage and articular cartilage abnormalities. Diluted gadolinium can be injected in the joint space using different approaches: under palpation using anatomic landmarks or using an imaging guidance, such as fluoroscopy, computed tomography, or ultrasound. Fluoroscopy has been traditionally used, but the involvement of ionizing radiation should represent a remarkable limitation of this modality. Conversely, ultrasound has emerged as a feasible, cheap, quick, and radiation-free modality that can be used to inject joints, with comparable accuracy of fluoroscopy. In the present paper, we discuss the advantages and disadvantages of using fluoroscopy or ultrasound in injecting gadolinium-based contrast agents in joints to perform magnetic resonance arthrography, also in view of the new EuroSAFE Imaging initiative promoted by the European Society of Radiology and the recent updates to the European Atomic Energy Community 2013/59 directive on the medical use of ionizing radiation. (orig.)

  9. Gadolinium-enhanced magnetic resonance angiography of right ventricle to pulmonary artery shunts following Norwood 1 palliation in infants

    International Nuclear Information System (INIS)

    The classic Norwood I palliation for the treatment of hypoplastic left-heart disease includes an atrial septectomy, neoaorta creation, and a systemic-to-pulmonary artery shunt. The Norwood I palliation has been modified by the use of a right ventricle-to-pulmonary artery shunt instead of a traditional systemic-to-pulmonary artery shunt. Right ventricle-to-pulmonary artery shunts were non-invasively imaged in four infants using gadolinium-enhanced magnetic resonance angiography. Diagnostic MR angiograms were performed in all infants throughout the length of the shunt and were useful in the detection of shunt patency, stenosis, and aneurysm. Associated surgical conduits and shunts were also evaluated. All findings were verified by subsequent conventional angiography or surgery. (orig.)

  10. Comparison of predicted with observed biokinetics of inhaled plutonium nitrate and gadolinium oxide in humans

    International Nuclear Information System (INIS)

    The absorption kinetics to blood of plutonium and gadolinium after inhalation as nitrate and oxide in humans and animals has been studied. For each material, values describing the time dependence of absorption were derived from the studies in animals and used with the ICRP human respiratory tract model to predict lung retention and cumulative amounts to blood for the volunteers inhaling the same materials. Comparison with the observed behaviour in the volunteers suggests that absorption of plutonium and gadolinium is reasonably species independent, and that data obtained from animal studies can be used to assess their biokinetic behaviour in humans. (author)

  11. Tetrahydrosalen backboned gadolinium complex as initiator for the ring-opening polymerization of ε-caprolactone

    Institute of Scientific and Technical Information of China (English)

    Guang Ming Wu; Xu Feng Ni; Wei Lin Sun; Zhi Quan Shen

    2008-01-01

    Tetrahydrosalen ligand was employed in the synthesis of gadolinium complex. The ligand was deprotoned by LiBu, and the afforded lithium salt was reacted with anhydrous GdCl3 to produce the gadolinium complex through salt metathesis. This complex was successfully used to initiate the ring-opening polymerization of ε-caprolactone. The initiation conditions in different temperature, monomer-to-initiator ratio and time were investigated. Under the condition: [ε-caprolactone]: [catalyst]=600,56℃, toluene: 2ml, poly(ε-caprolactone) (PCL) with Mw=11,2782 and PDI=1.96 was achieved.

  12. Influence of exchange splitting on optical properties in gadolinium and dysprosium single crystals

    International Nuclear Information System (INIS)

    The temperature dependences of optical conductivity in gadolinium and dysprosium single crystals at the light wave vector polarization along a hexagonal axis and in the basis plane are considered. A substantial anisotropy of interzonal absorption has been found. The sample transition into magnetically ordered state is shown to be accompanied by the emergence of resonance absorption peaks in the near infrared spectral region. The manifestation of these peculiarities is associated with quantum electron transitions between the s-, d-f- interaction-split energy bands near the Fermi level. Main peculiarities of the experimental spectrum of gadolinium optical conductivity found their reflection in theoretically calculated dispersion dependence

  13. Misconnections in the Critically Ill: Injection of High-Dose Gadolinium into an External Ventricular Drain.

    Science.gov (United States)

    Singh, Sumit; Rejai, Sepehr; Antongiorgi, Zarah; Gonzalez, Nestor; Stelzner, Matthias

    2016-03-01

    We report an unfortunate case of accidental administration of intrathecal gadolinium through an external ventricular drain in a postcraniotomy patient during magnetic resonance imaging of the brain. The incident occurred after the venous contrast line was connected mistakenly to the ventricular drainage catheter. The patient subsequently developed confusion, aphasia, and right facial droop with new computed tomography evidence of diffuse cerebral edema and stroke. Review of the magnetic resonance image revealed the inappropriate presence of subarachnoid gadolinium. Despite all interventions, the patient developed irreversible neurologic disability. We address the clinical sequelae, management strategies, and factors contributing to the catheter misconnection that led to this event. PMID:26462163

  14. Chemical crowd control agents.

    Science.gov (United States)

    Menezes, Ritesh G; Hussain, Syed Ather; Rameez, Mansoor Ali Merchant; Kharoshah, Magdy A; Madadin, Mohammed; Anwar, Naureen; Senthilkumaran, Subramanian

    2016-03-01

    Chemical crowd control agents are also referred to as riot control agents and are mainly used by civil authorities and government agencies to curtail civil disobedience gatherings or processions by large crowds. Common riot control agents used to disperse large numbers of individuals into smaller, less destructive, and more easily controllable numbers include chloroacetophenone, chlorobenzylidenemalononitrile, dibenzoxazepine, diphenylaminearsine, and oleoresin capsicum. In this paper, we discuss the emergency medical care needed by sufferers of acute chemical agent contamination and raise important issues concerning toxicology, safety and health. PMID:26658556

  15. MRI of osteochontritis dissecans of the knee joint after i. v. gadolinium-DTPA. Magnetresonanztomographie der Osteochondrosis dissecans des Kniegelenkes nach intravenoeser Gadolinium-DTPA-Gabe

    Energy Technology Data Exchange (ETDEWEB)

    Adam, G. (Klinik fuer Radiologische Diagnostik, RWTH Aachen (Germany)); Neuerburg, J. (Klinik fuer Radiologische Diagnostik, RWTH Aachen (Germany)); Peiss, J. (Klinik fuer Radiologische Diagnostik, RWTH Aachen (Germany)); Bohndorf, K. (Klinik fuer Radiologische Diagnostik, RWTH Aachen (Germany)); Guenther, R.W. (Klinik fuer Radiologische Diagnostik, RWTH Aachen (Germany))

    1994-05-01

    20 patients with osteochondritis dissecans were studied by MRI over a period of 3-34 monts in order to observe healing and determine the viability of the loose fragment. After intravenous contrast, there was increased signal intensity at the junction between the fragment and the epiphyseal bed on T[sub 2]-weighted sequences; this was interpreted as fibrous granulation tissue surrounding the fragment. The fragments themselves also showed increased signal intensity after Gadolinium-DTPA. Intravenous Gadolinium allows accurate evaluation of the junctional zone between the fragment and the epiphyseal bed by demonstrating fibrous, vascularised granulation tissue. This can be distinguished from synovial fluid, and it also demonstrates viability of the fragment. (orig.)

  16. Gadolinium and ruthenium red attenuate remote hind limb preconditioning-induced cardioprotection: possible role of TRP and especially TRPV channels.

    Science.gov (United States)

    Randhawa, Puneet Kaur; Jaggi, Amteshwar Singh

    2016-08-01

    Remote ischemic preconditioning is a well reported therapeutic strategy that induces cardioprotective effects but the underlying intracellular mechanisms have not been widely explored. The current study was designed to investigate the involvement of TRP and especially TRPV channels in remote hind limb preconditioning-induced cardioprotection. Remote hind limb preconditioning stimulus (4 alternate cycles of inflation and deflation of 5 min each) was delivered using a blood pressure cuff tied on the hind limb of the anesthetized rat. Using Langendorff's system, the heart was perfused and subjected to 30-min ischemia and 120-min reperfusion. The myocardial injury was assessed by measuring infarct size, lactate dehydrogenase (LDH), creatine kinase (CK), LVDP, +dp/dtmax, -dp/dtmin, heart rate, and coronary flow rate. Gadolinium, TRP blocker, and ruthenium red, TRPV channel blocker, were employed as pharmacological tools. Remote hind limb preconditioning significantly reduced the infarct size, LDH release, CK release and improved coronary flow rate, hemodynamic parameters including LVDP, +dp/dtmax, -dp/dtmin, and heart rate. However, gadolinium (7.5 and 15 mg kg(-1)) and ruthenium red (4 and 8 mg kg(-1)) significantly attenuated the cardioprotective effects suggesting the involvement of TRP especially TRPV channels in mediating remote hind limb preconditioning-induced cardioprotection. Remote hind limb preconditioning stimulus possibly activates TRPV channels on the heart or sensory nerve fibers innervating the heart to induce cardioprotective effects. Alternatively, remote hind limb preconditioning stimulus may also activate the mechanosensitive TRP and especially TRPV channels on the sensory nerve fibers innervating the skeletal muscles to trigger cardioprotective neurogenic signaling cascade. The cardioprotective effects of remote hind limb preconditioning may be mediated via activation of mechanosensitive TRP and especially TRPV channels. PMID:27118661

  17. Antibiotic Agents

    Science.gov (United States)

    ... either as public health or as non-public health antimicrobial agents. What is the difference between bacteriostats, sanitizers, disinfectants ... bacteria, however, there is considerable controversy surrounding their health benefits. The ... producing agents (Table of Antibacterials) have been used for many ...

  18. Clinical impact of gadolinium in the MRI diagnosis of musculoskeletal infection in children

    International Nuclear Information System (INIS)

    The incremental value of gadolinium in the diagnosis of musculoskeletal infection by MRI is controversial. To compare diagnostic utility of noncontrast with contrast MRI in the evaluation of pediatric musculoskeletal infections. We reviewed 90 gadolinium-enhanced MRIs in children with suspected musculoskeletal infection. Noncontrast and contrast MRI scans were evaluated to determine sensitivity and specificity in the diagnosis of musculoskeletal infection and identification of abscesses. Pre- and post-contrast diagnosis of osteomyelitis sensitivity was 89% and 91% (P = 1.00) and specificity was 96% and 96% (P = 1.00), respectively; septic arthritis sensitivity was 50% and 67% (P = 1.00) and specificity was 98% and 98% (P = 1.00), respectively; cellulitis/myositis sensitivity was 100% and 100% (P = 1.00) and specificity was 84% and 88% (P = 0.59), respectively; abscess for the total group was 22 (24.4%) and 42 (46.6%), respectively (P < 0.0001). Abscesses identified only on contrast sequences led to intervention in eight additional children. No child with a final diagnosis of infection had a normal pre-contrast study. Intravenous gadolinium should not be routinely administered in the imaging work-up of nonspinal musculoskeletal infections, particularly when pre-contrast images are normal. However, gadolinium contrast significantly increases the detection of abscesses, particularly small ones that might not require surgical intervention. (orig.)

  19. Research in gadolinium scandium gallium garnet (GSGG) crystal development. Final report, 1 May-31 December 1984

    International Nuclear Information System (INIS)

    The Czochralski growth technique was utilized for the development of a large diameter, laser quality gadolinium, scandium gallium garnet co-doped with neodymium and chromium (Nd:Cr:GSGG). Vary aspects of the development were determinations of raw material purity, foule growth runs, boule composition and lattice parameters, and losses. 8 refs., 13 figs., 10 tabs

  20. Growth, characterization and dielectric studies of gadolinium fumarate heptahydrate single crystals

    Indian Academy of Sciences (India)

    M D Shah; B Want

    2015-02-01

    Gadolinium fumarate heptahydrate single crystals were grown by the single gel diffusion technique using silica gel as a medium of growth. Nucleation rate of these crystals was studied corresponding to the effect of various growth parameters. An attempt was made to relate the experimental results with the classical nucleation theory. The crystals were characterized by different physico-chemical techniques of characterization. Powder X-ray diffraction pattern showed that gadolinium fumarate is a crystalline compound and is isomorphous with samarium fumarate heptahydrate crystals. Fourier transform infrared spectroscopy was performed for the identification of water and other functional groups present in the compound. Elemental analysis sugested the chemical formula of the crystals to be Gd2(C4H2O4)3.7H2O. The presence of seven molecules of water was also supported by the thermogravimetric analysis. The hydrated compound was found to be thermally stable up to a temperature of about 110°C and its anhydrous form up to the temperature of 420°C. The thermal decomposition of the compound in the nitrogen atmosphere leads to the formation of gadolinium oxide as the final product. The dielectric properties and AC conductivity of gadolinium fumarate heptahydrate complex were carried out in the frequency range of 20 Hz–3MHz and over the temperature range of 15–130°C, both showing a hump at about 95°C, which could be attributed to water molecules in the crystal boundary.

  1. Clinical impact of gadolinium in the MRI diagnosis of musculoskeletal infection in children

    Energy Technology Data Exchange (ETDEWEB)

    Kan, J.H.; Young, Robert S.; Hernanz-Schulman, Marta [Vanderbilt University, Department of Radiology and Radiological Sciences, Vanderbilt Children' s Hospital, Nashville, TN (United States); Yu, Chang [Vanderbilt University, Department of Biostatistics, Nashville, TN (United States)

    2010-07-15

    The incremental value of gadolinium in the diagnosis of musculoskeletal infection by MRI is controversial. To compare diagnostic utility of noncontrast with contrast MRI in the evaluation of pediatric musculoskeletal infections. We reviewed 90 gadolinium-enhanced MRIs in children with suspected musculoskeletal infection. Noncontrast and contrast MRI scans were evaluated to determine sensitivity and specificity in the diagnosis of musculoskeletal infection and identification of abscesses. Pre- and post-contrast diagnosis of osteomyelitis sensitivity was 89% and 91% (P = 1.00) and specificity was 96% and 96% (P = 1.00), respectively; septic arthritis sensitivity was 50% and 67% (P = 1.00) and specificity was 98% and 98% (P = 1.00), respectively; cellulitis/myositis sensitivity was 100% and 100% (P = 1.00) and specificity was 84% and 88% (P = 0.59), respectively; abscess for the total group was 22 (24.4%) and 42 (46.6%), respectively (P < 0.0001). Abscesses identified only on contrast sequences led to intervention in eight additional children. No child with a final diagnosis of infection had a normal pre-contrast study. Intravenous gadolinium should not be routinely administered in the imaging work-up of nonspinal musculoskeletal infections, particularly when pre-contrast images are normal. However, gadolinium contrast significantly increases the detection of abscesses, particularly small ones that might not require surgical intervention. (orig.)

  2. Measuring the effect of demagnetization in stacks of gadolinium plates using the magnetocaloric effect

    DEFF Research Database (Denmark)

    Lipsø, Hans Kasper Wigh; Nielsen, Kaspar Kirstein; Christensen, Dennis;

    2011-01-01

    The effect of demagnetization in a stack of gadolinium plates is determined experimentally by using spatially resolved measurements of the adiabatic temperature change due to the magnetocaloric effect. The number of plates in the stack, the spacing between them and the position of the plate...

  3. Colloidal stabilization of cerium-gadolinium oxide (CGO) suspensions via rheology

    DEFF Research Database (Denmark)

    Marani, Debora; Sudireddy, Bhaskar Reddy; Bentzen, Janet Jonna;

    2015-01-01

    colloidally stable state. The method was applied to explore the ability of four commercial dispersants (acidic affine, neutral, basic affine, and polyvinylpyrrolidone (PVP)) to disperse cerium-gadolinium oxide (CGO) in ethanol. Only the acidic affine and the PVP dispersants were found to efficiently disperse...

  4. Gadolinium-enhanced magnetic resonance imaging predicts response to methylprednisolone in multiple sclerosis

    DEFF Research Database (Denmark)

    Sellebjerg, F; Jensen, C.V.; Larsson, H.B.W.;

    2003-01-01

    with attacks of MS were treated with placebo or oral methylprednisolone (500 mg daily for five days with a 10-day tapering period). A gadolinium (Gd)-enhanced magnetic resonance imaging (MRI) scan was obtained at baseline in 66 patients, and 29 patients underwent repeated MRI studies. Seventy-four patients...

  5. MULTIPLET FINE-STRUCTURE IN THE PHOTOEMISSION OF THE GADOLINIUM AND TERBIUM 5P LEVELS

    NARCIS (Netherlands)

    THOLE, BT; WANG, XD; HARMON, BN; LI, DQ; DOWBEN, PA

    1993-01-01

    Fine structure is observed in the photoemission of the gadolinium and terbium 5p levels. The 5p levels are split into multiplets due to spin-orbit splitting and to Coulomb and exchange interactions with the f shell. The calculated theoretical spectra are in good agreement with the experimental resul

  6. Equilibrium and transient conductivity for gadolinium-doped ceria under large perturbations: I. Experiments

    DEFF Research Database (Denmark)

    Ricote, Sandrine; Zhu, Huayang; Coors, W. Grover;

    2014-01-01

    This is the first of a two-part paper that is concerned with measuring and interpreting equilibrium and transient conductivity for 10at.% gadolinium-doped ceria (Ce0.9Gd0.1O1.95-δ, GDC10). AC impedance spectroscopy is used to measure conductivity of slender extruded GDC10 rods at temperatures...

  7. Late gadolinium enhancement cardiovascular magnetic resonance in genotyped hypertrophic cardiomyopathy with normal phenotype

    OpenAIRE

    Jassal Davinder S; Soni Reeni; Ariyarajah Vignendra; Strijack Bradford; Greenberg Cheryl R; McGregor Robert; Morris Andrew

    2008-01-01

    Abstract A 35 year-old asymptomatic Caucasian female with a family history of hypertrophic cardiomyopathy (HCM) was referred for cardiologic evaluation. The electrocardiogram and transthoracic echocardiogram were normal. Cardiovascular magnetic resonance (CMR) was performed for further assessment of myocardial function and presence of myocardial scar. CMR showed normal left ventricular systolic size, measurements and function. However, there was extensive, diffuse late gadolinium enhancement ...

  8. Efficacy of gadolinium enhanced MR imaging for the diagnosis of Legg-Calve-Perthes disease

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jee Eun; Kim, Hyung Sik [Gachon University of Medicine and Science, Gil Medical Center, Incheon (Korea, Republic of); Kim, Ji Hye [Sungkyunkwan University School of Medicine, Seoul (Korea, Republic of)

    2008-04-15

    The purpose of this study was to evaluate the efficacy of gadolinium enhanced MR imaging for making the diagnosis of Legg-Calve-Perthes (LCP) disease. We studied the gadolinium enhanced MR images of 14 hips in 12 children who had the diagnosis of LCP disease. We retrospectively analyzed the extent of necrosis, the epiphyseal revascularization pathways and the metaphyseal changes. The absence of enhancement on gadolinium enhanced MRI was noted in all cases of LCP disease. Diffuse absence of enhancement was observed in 9 femoral epiphyses. Two of them showed normal bone marrow signal intensity on the T1 and T1-weighted images. Focal absence of enhancement was observed in 5 femoral epiphyses. Enhanced MRI showed better epiphyseal revascularization in the lateral column (five cases), in the lateral and medial columns (four cases) and in the transphyseal pathway (three cases). Metaphyseal change was observed in two cases. Gadolinium enhanced MRI allows detection of LCP disease and an accurate analysis of the different revascularization patterns, and this helpful for predicting the prognosis.

  9. Effect of gadolinium on aged hardening behavior,microstructure and mechanical properties of Mg-Nd-Zn-Zr alloy

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Mg-3.4Nd-0.1 Zn-0.40Zr alloy samples with and without containing gadolinium(0.6%,mass fraction)were prepared by sand casting.The aged hardening behavior,solidification microstructures and mechanical properties of the alloys were investigated by using the analysis methods of OM,XRD,TEM,hardness tests and mechanical property tests.The main research results are as follows.1)Compared with the alloy without the addition of gadolinium.the alloys with the addition of gadolinium shows the more remarkable age-hardening response.2) The as-cast microstructure of the alloy with and without containing gadolinium consists of α-Mg grains with Mg12Nd phase on the grain boundary.After solution heat-treatment,Mg12Nd phase of the alloy without containing gadolinium is dissolved in the matrix,however,there iS still discontinued Mg12Nd phase at grain boundary of the alloy with containing gadolinium.The more finely dispersed precipitates in Mg matrix are formed in the alloy with containing gadolinium during age-treatment.3)The room temperature and high temperature mechanical properties ofthe alloy are satisfactory.with σb=280 MPa,σ0.2=165 MPa at RT and aσb=215 MPa,σ0.2=155 MPa at 250℃.The high temperature mechanical properties decrease slightly with the increase of temperature.

  10. Development and in vitro testing of liposomal gadolinium-formulations for neutron capture therapy of glioblastoma multiforme

    International Nuclear Information System (INIS)

    For the improvement of current neutron capture therapy, several liposomal formulations of neutron capture agent gadolinium were developed and tested in a glioma cell model. Formulations were analyzed regarding physicochemical and biological parameters, such as size, zeta potential, uptake into cancer cells and performance under neutron irradiation. The neutron and photon dose derived from intracellular as well as extracellular Gd was calculated via Monte Carlo simulations and set in correlation with the reduction of cell survival after irradiation. To investigate the suitability of Gd as a radiosensitizer for photon radiation, cells were also irradiated with synchrotron radiation in addition to clinically used photons generated by linear accelerator. Irradiation with neutrons led to significantly lower survival for Gd-liposome-treated F98 and LN229 cells, compared to irradiated control cells and cells treated with non-liposomal Gd-DTPA. Correlation between Gd-content and -dose and respective cell survival displayed proportional relationship for most of the applied formulations. Photon irradiation experiments showed the proof-of-principle for the radiosensitizer approach, although the photon spectra currently used have to be optimized for higher efficiency of the radiosensitizer. In conclusion, the newly developed Gd-liposomes show great potential for the improvement of radiation treatment options for highly malignant glioblastoma.

  11. Anthropogenic gadolinium anomalies and rare earth elements in the water of Atibaia River and Anhumas Creek, Southeast Brazil.

    Science.gov (United States)

    de Campos, Francisco Ferreira; Enzweiler, Jacinta

    2016-05-01

    The concentrations of rare earth elements (REE), measured in water samples from Atibaia River and its tributary Anhumas Creek, Brazil, present excess of dissolved gadolinium. Such anthropogenic anomalies of Gd in water, already described in other parts of the world, result from the use of stable and soluble Gd chelates as contrast agents in magnetic resonance imaging. Atibaia River constitutes the main water supply of Campinas Metropolitan area, and its basin receives wastewater effluents. The REE concentrations in water samples were determined in 0.22-μm pore size filtered samples, without and after preconcentration by solid-phase extraction with bis-(2-ethyl-hexyl)-phosphate. This preconcentration method was unable to retain the anthropogenic Gd quantitatively. The probable reason is that the Gd chelates dissociate slowly in acidic media to produce the free ion that is retained by the phosphate ester. Strong correlations between Gd and constituents or parameters associated with effluents confirmed the source of most Gd in water samples as anthropogenic. The shale-normalized REE patterns of Atibaia River and Anhumas Creek water samples showed light and heavy REE enrichment trends, respectively. Also, positive Ce anomalies in many Atibaia River samples, as well as the strong correlations of the REE (except Gd) with terrigenous elements, imply that inorganic colloidal particles contributed to the REE measured values.

  12. Gadolinium(III)-Chelated Silica Nanospheres Integrating Chemotherapy and Photothermal Therapy for Cancer Treatment and Magnetic Resonance Imaging.

    Science.gov (United States)

    Cao, Mingjing; Wang, Pengyang; Kou, Yu; Wang, Jing; Liu, Jing; Li, Yanhui; Li, Jiayang; Wang, Liming; Chen, Chunying

    2015-11-18

    The combination of therapy and diagnosis has been emerging as a promising strategy for cancer treatment. To realize chemotherapy, photothermal therapy, and magnetic resonance imaging (MRI) in one system, we have synthesized a new magnetic nanoparticle (Gd@SiO2-DOX/ICG-PDC) integrating doxorubicin (DOX), indocyanine green (ICG), and gadolinium(III)-chelated silica nanospheres (Gd@SiO2) with a poly(diallyldimethylammonium chloride) (PDC) coating. PDC coating serves as a polymer layer to protect from quick release of drugs from the nanocarriers and increase cellular uptake. The DOX release from Gd@SiO2-DOX/ICG-PDC depends on pH and temperature. The process will be accelerated in the acidic condition than in a neutral pH 7.4. Meanwhile, upon laser irradiation, the photothermal effects promote DOX release and improve the therapeutic efficacy compared to either DOX-loaded Gd@SiO2 or ICG-loaded Gd@SiO2. Moreover, MRI results show that the Gd@SiO2-PDC nanoparticles are safe T1-type MRI contrast agents for imaging. The Gd@SiO2-PDC nanoparticles loaded with DOX and ICG can thus act as a promising theranostic platform for multimodal cancer treatment.

  13. Three-dimensional gadolinium-enhanced MR venography to evaluate central venous steno-occlusive disease in hemodialysis patients

    Energy Technology Data Exchange (ETDEWEB)

    Gao, K.; Jiang, H.; Zhai, R.Y.; Wang, J.F.; Wei, B.J. [Department of Radiology, Beijing Chaoyang Hospital, Capital Medical University, Beijing (China); Huang, Q., E-mail: hq0713@163.com [Department of Radiology, Beijing Chaoyang Hospital, Capital Medical University, Beijing (China)

    2012-06-15

    Aim: To determine the agreement and diagnostic accuracy of three-dimensional gadolinium-enhanced magnetic resonance venography (3D-Gd-MRV) in central venous steno-occlusive disease (CVSD) in haemodialysis patients. Materials and methods: Fourteen consecutive haemodialysis patients underwent interventional procedures to evaluate or treat CVSD. 3D-Gd-MRV was performed before the procedures and the results were compared with digital subtraction angiography (DSA). Results: DSA showed >50% stenosis in all 14 patients, 13 of whom were diagnosed correctly using 3D-Gd-MRV. Moderate stenosis was missed at 3D-Gd-MRV in one case whereby the indwelling dialysis central venous catheter may have caused an artefact on the images and hindered the accuracy of the result. The sensitivity of 3D-Gd-MRV in revealing stenosis was 93% (13/14). No complications caused by contrast agent toxicity occurred in any patient. Conclusion: 3D-Gd-MRV employing a non-breath-hold technique is highly sensitive in the diagnosis of CVSD and may be an alternative technique to DSA for the visualization of central veins.

  14. Anthropogenic gadolinium anomalies and rare earth elements in the water of Atibaia River and Anhumas Creek, Southeast Brazil.

    Science.gov (United States)

    de Campos, Francisco Ferreira; Enzweiler, Jacinta

    2016-05-01

    The concentrations of rare earth elements (REE), measured in water samples from Atibaia River and its tributary Anhumas Creek, Brazil, present excess of dissolved gadolinium. Such anthropogenic anomalies of Gd in water, already described in other parts of the world, result from the use of stable and soluble Gd chelates as contrast agents in magnetic resonance imaging. Atibaia River constitutes the main water supply of Campinas Metropolitan area, and its basin receives wastewater effluents. The REE concentrations in water samples were determined in 0.22-μm pore size filtered samples, without and after preconcentration by solid-phase extraction with bis-(2-ethyl-hexyl)-phosphate. This preconcentration method was unable to retain the anthropogenic Gd quantitatively. The probable reason is that the Gd chelates dissociate slowly in acidic media to produce the free ion that is retained by the phosphate ester. Strong correlations between Gd and constituents or parameters associated with effluents confirmed the source of most Gd in water samples as anthropogenic. The shale-normalized REE patterns of Atibaia River and Anhumas Creek water samples showed light and heavy REE enrichment trends, respectively. Also, positive Ce anomalies in many Atibaia River samples, as well as the strong correlations of the REE (except Gd) with terrigenous elements, imply that inorganic colloidal particles contributed to the REE measured values. PMID:27068533

  15. Criticality experiments with low enriched UO2 fuel rods in water containing dissolved gadolinium

    International Nuclear Information System (INIS)

    The results obtained in a criticality experiments program performed for British Nuclear Fuels, Ltd. (BNFL) under contract with the United States Department of Energy (USDOE) are presented in this report along with a complete description of the experiments. The experiments involved low enriched UO2 and PuO2-UO2 fuel rods in water containing dissolved gadolinium, and are in direct support of BNFL plans to use soluble compounds of the neutron poison gadolinium as a primary criticality safeguard in the reprocessing of low enriched nuclear fuels. The experiments were designed primarily to provide data for validating a calculation method being developed for BNFL design and safety assessments, and to obtain data for the use of gadolinium as a neutron poison in nuclear chemical plant operations - particularly fuel dissolution. The experiments program covers a wide range of neutron moderation (near optimum to very under-moderated) and a wide range of gadolinium concentration (zero to about 2.5 g Gd/l). The measurements provide critical and subcritical k/sub eff/ data (1 greater than or equal to k/sub eff/ greater than or equal to 0.87) on fuel-water assemblies of UO2 rods at two enrichments (2.35 wt % and 4.31 wt % 235U) and on mixed fuel-water assemblies of UO2 and PuO2-UO2 rods containing 4.31 wt % 235U and 2 wt % PuO2 in natural UO2 respectively. Critical size of the lattices was determined with water containing no gadolinium and with water containing dissolved gadolinium nitrate. Pulsed neutron source measurements were performed to determine subcritical k/sub eff/ values as additional amounts of gadolinium were successively dissolved in the water of each critical assembly. Fission rate measurements in 235U using solid state track recorders were made in each of the three unpoisoned critical assemblies, and in the near-optimum moderated and the close-packed poisoned assemblies of this fuel

  16. Ultrasmall superparamagnetic iron oxides (USPIOs): a future alternative magnetic resonance (MR) contrast agent for patients at risk for nephrogenic systemic fibrosis (NSF)?

    OpenAIRE

    Neuwelt, Edward A.; Hamilton, Bronwyn E.; Varallyay, Csanad G; Rooney, William R.; Edelman, Robert D.; Jacobs, Paula M; Watnick, Suzanne G.

    2008-01-01

    Gadolinium (Gd) based contrast agents (GBCAs) in magnetic resonance imaging (MRI) are used in daily clinical practice and appear safe in most patients; however, nephrogenic systemic fibrosis (NSF) is a recently recognized severe complication associated with GBCAs. It affects primarily patients with renal disease, such as stage 4 or 5 chronic kidney disease (CKD; glomerular filtration rate

  17. A new method for the determination of Gadolinium in ppq levels

    Science.gov (United States)

    Brünjes, Robert; Bichler, Andrea; Hofmann, Thilo

    2015-04-01

    The use of Gadolinium (Gd) complexes as a contrast agent in Magnetic Resonance Imaging (MRI) results in an enhanced Gd input in the aquatic environment. Gd-complexes are excreted by humans unmetabolized within 12h after application. Passing the sewage systems with almost no degradation taking place, they successively reach surface waters, which make Gd a capable tracer for surface water/groundwater (SW/GW) interactions. The natural background concentration of Gd and other rare earth elements (REE) occur at ultratrace levels [low ng/L]. Crust-normalized REE patterns show positive Gd-anomalies in surface water, groundwater, and recently also in tap water. The difference between the total concentration and its natural background concentration estimated by the REE pattern is the anthropogenic Gd. Not only densely populated areas are affected by the presence of anthropogenic Gd. Studies have shown that even in rural areas without MRI facilities, anthropogenic Gd can be detected, since people are sent home after treatment. However, low input concentrations and mixing with natural waters lead to a decrease of Gd concentration below the current limit of quantification (LOQ) [1-5ng/L]. Often anthropogenic Gd cannot be calculated, although it is present, because natural background concentration cannot be determined with current methods, in particular in areas with low waste water load (e.g. headwater catchments). A new method using an on-line preconcentration system "SeaFAST" (Elemental Scientific Inc., USA), in combination with a desolvation system "Apex Q" (Elemental Scientific Inc., USA) and a QQQ-ICP-MS instrument (Agilent Technologies, Japan) does lower the LOQ for REE by a factor of 10 to 20. The SeaFAST-system uses a resin with ethylenediaminetriacetic acid and iminodiacetic acid functional groups to preconcentrate specifically REE as they are exclusively trivalent while anions, alkali and alkaline earth cations are washed out. The Apex Q interface is also supposed to

  18. High sensitivity of late gadolinium enhancement for predicting microscopic myocardial scarring in biopsied specimens in hypertrophic cardiomyopathy.

    Directory of Open Access Journals (Sweden)

    Tetsuo Konno

    Full Text Available BACKGROUND: Myocardial scarring can be assessed by cardiac magnetic resonance imaging with late gadolinium enhancement and by endomyocardial biopsy. However, accuracy of late gadolinium enhancement for predicting microscopic myocardial scarring in biopsied specimens remains unknown in hypertrophic cardiomyopathy. We investigated whether late gadolinium enhancement in the whole heart reflects microscopic myocardial scarring in the small biopsied specimens in hypertrophic cardiomyopathy. METHODS AND RESULTS: Twenty-one consecutive patients with hypertrophic cardiomyopathy who were examined both by cardiac magnetic resonance imaging and by endomyocardial biopsy were retrospectively studied. The right interventricular septum was the target site for endomyocardial biopsy in all patients. Late gadolinium enhancement in the ventricular septum had an excellent sensitivity (100% with a low specificity (40% for predicting microscopic myocardial scarring in biopsied specimens. The sensitivity of late gadolinium enhancement in the whole heart remained 100% with a specificity of 27% for predicting microscopic myocardial scarring in biopsied specimens. Quantitative assessments of fibrosis revealed that the extent of late gadolinium enhancement in the whole heart was the only independent variable related to the microscopic collagen fraction in biopsied specimens (β  =  0.59, 95% confident interval: 0.15 - 1.0, p  =  0.012. CONCLUSIONS: Although there was a compromise in the specificity, the sensitivity of late gadolinium enhancement was excellent for prediction of microscopic myocardial scarring in hypertrophic cardiomyopathy. Moreover, the severity of late gadolinium enhancement was independently associated with the quantitative collagen fraction in biopsied specimens in hypertrophic cardiomyopathy. These findings indicate that late gadolinium enhancement can reflect both the presence and the extent of microscopic myocardial scarring in the small

  19. MR imaging of hydrogel filament embolic devices loaded with superparamagnetic iron oxide or gadolinium

    Energy Technology Data Exchange (ETDEWEB)

    Killer, Monika; Schmitt, Anne [Paracelsus Medical University, Neuroscience Institute, Christian Doppler Clinic, Salzburg (Austria); Keeley, Edward M.; Cruise, Gregory M. [MicroVention Terumo, Tustin, CA (United States); McCoy, Mark R. [Paracelsus Medical University, Departments of Radiology and MRI, Christian Doppler Clinic, Salzburg (Austria)

    2011-06-15

    We evaluated hydrogel filaments loaded with barium sulphate and either gadolinium or superparamagnetic iron oxide (SPIO) in an effort to develop an embolic material that is visible with fluoroscopic and magnetic resonance imaging. Hydrogel filaments were prepared with gadolinium and iron concentrations ranging from 1,500 to 7,500 and 500 to 2,500 ppm, respectively. The filaments were encased in agar and imaged using an MR scanner. Embolisation of eight aneurysms (seven bifurcation, one sidewall) in seven rabbits was performed using hydrogel filaments loaded with gadolinium (n = 4) or SPIO (n = 4). Angiographic evaluations occurred immediately post-treatment and at 13 weeks. Magnetic resonance angiography (MRA) evaluations occurred immediately post-treatment or 13 weeks post-treatment. Based on the in vitro results, we selected 4,500 and 2,000 ppm for gadolinium and iron loadings, respectively, for the in vivo experiments. Loading the filaments with gadolinium or SPIO did not affect the angiographic results, as embolic masses were readily evident with some distinguishing of individual filaments. In MRA, the hydrogel filaments loaded with SPIO were hypointense, and the hydrogel filaments loaded with Gd were hyperintense. The hyperintensity of the Gd-loaded filaments confounded the ability to distinguish between flow and the embolic devices. The hypointensity of the hydrogel filaments loaded with SPIO provided sufficient contrast between the embolic devices and the blood flow to allow of aneurysm occlusion evaluation using MRA. Based on these results, we are focusing on loading hydrogel filaments with SPIO in an effort to provide adequate visualisation for use in MR-guided interventions. (orig.)

  20. Paramagnetic Gd2O3 Nanoparticle-Based Targeting Theranostic Agent for C6 Rat Glioma Cell

    Directory of Open Access Journals (Sweden)

    Seong-Pyo Hong

    2016-01-01

    Full Text Available This study aimed to synthesize theranostic agent targeting C6 rat glioma cell, which was based on the dextran coated paramagnetic gadolinium oxide nanoparticles (D-PGONs conjugated with folic acid (FA or paclitaxel (PTX. The D-PGONs were synthesized by the in situ coprecipitation method, and the average value of the size distribution was 2.9 nm. FTIR spectroscopy was fulfilled to confirm the conjugations of FA or PTX with D-PGONs. The bioprotective effects of dextran coating and chemotherapeutic effect of PTX in the C6 glioma cell were evaluated by the MTT assay. The differences in uptakes between the synthesized theranostic agents into C6 cells were observed by confocal laser scanning microscopy. In addition, the magnetic contrast enhancement with different concentration of the synthesized agent was compared by the T1-weighted MRI imaging. It was experimentally shown that the synthesized theranostic agent targets C6 cells due to the ligand-receptor-mediated endocytosis and provides enhancement in MR contrast depending on the concentration due to the paramagnetic property of gadolinium nanoparticle. In addition, it was shown by the results of MTT assay that the synthesized nanocomposites were more effective in reducing cell viability than bare gadolinium nanoparticles. In conclusion, it was shown that FA and PTX conjugated D-PGONs could be used as the theranostic agent with paramagnetism and chemotherapeutic property.

  1. 13 CFR 108.1620 - Functions of agents, including Central Registration Agent, Selling Agent and Fiscal Agent.

    Science.gov (United States)

    2010-01-01

    ... Assistance SMALL BUSINESS ADMINISTRATION NEW MARKETS VENTURE CAPITAL (âNMVCâ) PROGRAM SBA Financial Assistance for NMVC Companies (Leverage) Funding Leverage by Use of Sba Guaranteed Trust Certificates (âtcsâ... financial markets to determine those factors that will minimize or reduce the cost of funding...

  2. A phantom-based feasibility study for detection of gadolinium in bone in-vivo using X-ray fluorescence.

    Science.gov (United States)

    Lord, M L; McNeill, F E; Gräfe, J L; Noseworthy, M D; Chettle, D R

    2016-06-01

    Gadolinium (Gd) based contrast agents have been commonly used over the past three decades to improve contrast in magnetic resonance imaging. These complexes, originally thought to be stable and clear from the body shortly after administration, have been shown to dissociate to a small extent and deposit in organs such as bone. A safe and non-invasive method for measuring Gd in bone is necessary for further exploring Gd retention in the body following the administration of a contrast agent. A feasibility study using a K x-ray fluorescence (K-XRF) system to measure Gd in human tibias was investigated. Bone phantoms mimicking human tibia were created with Gd concentrations ranging from 0 to 120ppm. The minimum detection limit (MDL) was calculated from 20-hour and 7-hour phantom measurements with a source activity of 0.11GBq. All MDL values were scaled to a more realistic measurement time of 30-minutes with a stronger source. Scaling arguments were based on activity ratio, measurement time, and system dead time. The MDL for a 1GBq source was estimated to be 3.60-3.64ppm, for an average range of tissue thicknesses overlaying a human tibia. For a stronger source of 5GBq and a four detector cloverleaf system, the MDL was estimated to be 1.49-1.52ppm. Determined and predicted MDLs are within the range of previous in-vitro Gd measurement data. The K-XRF system shows promising results for detecting Gd in bone and should be seriously considered for in-vivo measurements. PMID:27019028

  3. Biodegradable gadolinium-chelated cationic poly(urethane amide) copolymers for gene transfection and magnetic resonance imaging.

    Science.gov (United States)

    Gao, Xiaolong; Wang, Gangmin; Shi, Ting; Shao, Zhihong; Zhao, Peng; Shi, Donglu; Ren, Jie; Lin, Chao; Wang, Peijun

    2016-08-01

    Theranostic nano-polyplexes containing gene and imaging agents hold a great promise for tumor diagnosis and therapy. In this work, we develop a group of new gadolinium (Gd)-chelated cationic poly(urethane amide)s for gene delivery and T1-weighted magnetic resonance (MR) imaging. Cationic poly(urethane amide)s (denoted as CPUAs) having multiple disulfide bonds, urethane and amide linkages were synthesized by stepwise polycondensation reaction between 1,4-bis(3-aminopropyl)piperazine and a mixture of di(4-nitrophenyl)-2, 2'-dithiodiethanocarbonate (DTDE-PNC) and diethylenetriaminepentaacetic acid (DTPA) dianhydride at varied molar ratios. Then, Gd-chelated CPUAs (denoted as GdCPUAs) were produced by chelating Gd(III) ions with DTPA residues of CPUAs. These GdCPUAs could condense gene into nanosized and positively-charged polyplexes in a physiological condition and, however, liberated gene in an intracellular reductive environment. In vitro transfection experiments revealed that the GdCPUA at a DTDE-PNC/DTPA residue molar ratio of 85/15 induced the highest transfection efficiency in different cancer cells. This efficiency was higher than that yielded with 25kDa branched polyethylenimine as a positive control. GdCPUAs and their polyplexes exhibited low cytotoxicity when an optimal transfection activity was detected. Moreover, GdCPUAs may serve as contrast agents for T1-weighted magnetic resonance imaging. The results of this work indicate that biodegradable Gd-chelated cationic poly(urethane amide) copolymers have high potential for tumor theranostics. PMID:27157741

  4. Following unenhanced MRI assessment for local recurrence after surgical resection of mesenchymal soft tissue tumors, do additional gadolinium-enhanced images change reader confidence or diagnosis?

    Energy Technology Data Exchange (ETDEWEB)

    Diana Afonso, P., E-mail: p.diana.a@gmail.com [Department of Radiology, Duke University Medical Center, 2301 Erwin Road, Durham, NC 27710 (United States); Kosinski, A.S., E-mail: andrzej.kosinski@duke.edu [Department of Biostatistics and Bioinformatics, Duke University Medical Center, 2301 Erwin Road, Durham, NC 27710 (United States); Spritzer, C.E., E-mail: chuck.spritzer@duke.edu [Department of Radiology, Duke University Medical Center, P.O. Box 3808, Duke University Medical Center, Durham, NC (United States)

    2013-05-15

    Highlights: ► Gadolinium enhanced imaging improves reader confidence in detecting soft tissue tumor recurrence. ► Gadolinium enhanced imaging modestly improves inexperienced reader accuracy for detecting tumor recurrence. ► Where possible, gadolinium should be used in the assessment of MSK tumor residual or recurrence. -- Abstract: Purpose: Evaluate if gadolinium enhanced MR imaging (GeMRI) improves confidence, changes the final diagnosis, or improves accuracy in the assessment of musculoskeletal (MSK) tumor residual or recurrence following surgical resection. We also assess if different experience levels change the above results. Methods and materials: Initially, pre-contrast images were independently reviewed by two radiologists, one with 25 years of experience (R1) and one undergoing MSK specialty training (R2). Two questions were answered: (1) Mass present? and (2) Likelihood of malignancy? Subsequently, both pre-contrast and post-contrast images were independently reviewed. The same questions were again answered plus four others including if GeMRI changed mass characterization, better defined cystic versus solid, better defined tumor extent, or improved conspicuity. Lastly, the readers answered whether GeMRI changed confidence, and changed their final diagnosis. Histologic diagnoses were available in 43 cases, with the remaining 44 cases based upon clinical and/or imaging follow-up. Results: GeMRI definitely improved confidence in 8/7 cases, and slightly improved confidence in 20/29 cases and changed the final diagnosis in 11/8 cases for R1 and R2 respectively. Positive and negative predictive values statistically improved for R2 (positive predictive value 36.4% versus 50%, p = 0.02; negative predictive value 75.4% versus 79.1%, p = 0.04) but not for R1. Reader concordance for malignancy improved with GeMRI (κ = 0.44 pre-contrast and κ = 0.71 post-contrast). Conclusion: GeMRI improved reader confidence, improved reader concordance and modestly improved

  5. Following unenhanced MRI assessment for local recurrence after surgical resection of mesenchymal soft tissue tumors, do additional gadolinium-enhanced images change reader confidence or diagnosis?

    International Nuclear Information System (INIS)

    Highlights: ► Gadolinium enhanced imaging improves reader confidence in detecting soft tissue tumor recurrence. ► Gadolinium enhanced imaging modestly improves inexperienced reader accuracy for detecting tumor recurrence. ► Where possible, gadolinium should be used in the assessment of MSK tumor residual or recurrence. -- Abstract: Purpose: Evaluate if gadolinium enhanced MR imaging (GeMRI) improves confidence, changes the final diagnosis, or improves accuracy in the assessment of musculoskeletal (MSK) tumor residual or recurrence following surgical resection. We also assess if different experience levels change the above results. Methods and materials: Initially, pre-contrast images were independently reviewed by two radiologists, one with 25 years of experience (R1) and one undergoing MSK specialty training (R2). Two questions were answered: (1) Mass present? and (2) Likelihood of malignancy? Subsequently, both pre-contrast and post-contrast images were independently reviewed. The same questions were again answered plus four others including if GeMRI changed mass characterization, better defined cystic versus solid, better defined tumor extent, or improved conspicuity. Lastly, the readers answered whether GeMRI changed confidence, and changed their final diagnosis. Histologic diagnoses were available in 43 cases, with the remaining 44 cases based upon clinical and/or imaging follow-up. Results: GeMRI definitely improved confidence in 8/7 cases, and slightly improved confidence in 20/29 cases and changed the final diagnosis in 11/8 cases for R1 and R2 respectively. Positive and negative predictive values statistically improved for R2 (positive predictive value 36.4% versus 50%, p = 0.02; negative predictive value 75.4% versus 79.1%, p = 0.04) but not for R1. Reader concordance for malignancy improved with GeMRI (κ = 0.44 pre-contrast and κ = 0.71 post-contrast). Conclusion: GeMRI improved reader confidence, improved reader concordance and modestly improved

  6. Standard test methods for chemical and mass spectrometric analysis of nuclear-grade gadolinium oxide (Gd2O3) powder

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2006-01-01

    1.1 These test methods cover procedures for the chemical and mass spectrometric analysis of nuclear-grade gadolinium oxide powders to determine compliance with specifications. 1.2 The analytical procedures appear in the following order: Sections Carbon by Direct CombustionThermal Conductivity C1408 Test Method for Carbon (Total) in Uranium Oxide Powders and Pellets By Direct Combustion-Infrared Detection Method Total Chlorine and Fluorine by Pyrohydrolysis Ion Selective Electrode C1502 Test Method for Determination of Total Chlorine and Fluorine in Uranium Dioxide and Gadolinium Oxide Loss of Weight on Ignition 7-13 Sulfur by CombustionIodometric Titration Impurity Elements by a Spark-Source Mass Spectrographic C761 Test Methods for Chemical, Mass Spectrometric, Spectrochemical,Nuclear, and Radiochemical Analysis of Uranium Hexafluoride C1287 Test Method for Determination of Impurities In Uranium Dioxide By Inductively Coupled Plasma Mass Spectrometry Gadolinium Content in Gadolinium Oxid...

  7. Improvement of the LET sensitivity in ESR dosimetry for {gamma}-photons and thermal neutrons through gadolinium addition

    Energy Technology Data Exchange (ETDEWEB)

    Marrale, M. [Dipartimento di Fisica e Tecnologie Relative, Universita di Palermo, Viale delle Scienze, Edificio 18, 90128 Palermo (Italy); Unita CNISM, Palermo and Gruppo V Sezione INFN, Catania (Italy)], E-mail: marrale@difter.unipa.it; Brai, M. [Dipartimento di Fisica e Tecnologie Relative, Universita di Palermo, Viale delle Scienze, Edificio 18, 90128 Palermo (Italy); Unita CNISM, Palermo and Gruppo V Sezione INFN, Catania (Italy); Gennaro, G.; Triolo, A. [Dipartimento di Fisica e Tecnologie Relative, Universita di Palermo, Viale delle Scienze, Edificio 18, 90128 Palermo (Italy); Bartolotta, A. [Dipartimento Farmacochimico Tossicologico e Biologico, Universita di Palermo, Via Archirafi 32, 90123 Palermo (Italy); Unita CNISM, Palermo and Gruppo V Sezione INFN, Catania (Italy)

    2007-07-15

    We investigated the ESR response of new materials, alanine and ammonium tartrate to which gadolinium was added. The addition of gadolinium enhances sensitivity for {sup 60}Co{gamma}-photons because of its high atomic number (Z=64) and an enhancement of sensitivity for thermal neutrons because of its high thermal neutron cross section and high linear energy transfer (LET) secondary particles produced after the reaction with neutrons. In particular, in this paper we analyzed the microwave power saturation properties of dosimeters of alanine and ammonium tartrate with or without gadolinium exposed to different LET beams. The power saturation trends of dosimeters exposed to photons and to thermal neutrons are different. For ammonium tartrate dosimeters the gadolinium addition intensifies significantly these differences and therefore, it improves the ammonium tartrate's ability to discriminate the radiation LET.

  8. Contrast agents for functional and cellular MRI of the kidney

    Energy Technology Data Exchange (ETDEWEB)

    Grenier, Nicolas [ERT CNRS ' Imagerie Moleculaire et Fonctionnelle' , Universite Victor Segalen-Bordeaux 2, Bordeaux (France) and Service d' Imagerie Diagnostique et Interventionnelle de l' Adulte, Groupe Hospitalier Pellegrin, Place Amelie Raba-Leon, 33076 Bordeaux Cedex (France)]. E-mail: nicolas.grenier@chu-bordeaux.fr; Pedersen, Michael [MR Research Center, Aarhus University Hospital, Aarhus (Denmark); Hauger, Olivier [ERT CNRS ' Imagerie Moleculaire et Fonctionnelle' , Universite Victor Segalen-Bordeaux 2, Bordeaux (France); Service d' Imagerie Diagnostique et Interventionnelle de l' Adulte, Groupe Hospitalier Pellegrin, Place Amelie Raba-Leon, 33076 Bordeaux Cedex (France)

    2006-12-15

    Low-molecular-weight gadolinium (Gd) chelates are glomerular tracers but their role in evaluation of renal function with magnetic resonance (MR) imaging is still marginal. Because of their small size, they diffuse freely into the interstitium and the relationship between measured signal intensity and concentration is complex. New categories of contrast agents, such as large Gd-chelates or iron oxide particules, with different pharmacokinetic and magnetic properties have been developed. These large molecules could be useful for both functional (quantification of perfusion, quantification of glomerular filtration rate, estimation of tubular function) and cellular imaging (intrarenal phagocytosis in inflammatory renal diseases). Continuous development of new contrast agents remains worthwhile to get the best adequacy between the physiological phenomenon of interest and the pharmacokinetic of the agent.

  9. Macromolecular and dendrimer-based magnetic resonance contrast agents

    Energy Technology Data Exchange (ETDEWEB)

    Bumb, Ambika; Brechbiel, Martin W. (Radiation Oncology Branch, National Cancer Inst., National Inst. of Health, Bethesda, MD (United States)), e-mail: pchoyke@mail.nih.gov; Choyke, Peter (Molecular Imaging Program, National Cancer Inst., National Inst. of Health, Bethesda, MD (United States))

    2010-09-15

    Magnetic resonance imaging (MRI) is a powerful imaging modality that can provide an assessment of function or molecular expression in tandem with anatomic detail. Over the last 20-25 years, a number of gadolinium-based MR contrast agents have been developed to enhance signal by altering proton relaxation properties. This review explores a range of these agents from small molecule chelates, such as Gd-DTPA and Gd-DOTA, to macromolecular structures composed of albumin, polylysine, polysaccharides (dextran, inulin, starch), poly(ethylene glycol), copolymers of cystamine and cystine with GD-DTPA, and various dendritic structures based on polyamidoamine and polylysine (Gadomers). The synthesis, structure, biodistribution, and targeting of dendrimer-based MR contrast agents are also discussed

  10. Programming Service Oriented Agents

    OpenAIRE

    Hirsch, Benjamin; Konnerth, Thomas; Burkhardt, Michael; Albayrak, Sahin

    2010-01-01

    This paper introduces a programming language for service-oriented agents. JADL++ combines the ease of use of scripting-languages with a state-of-the-art service oriented approach which allows the seamless integration of web-services. Furthermore, the language includes OWL-based ontologies for semantic descriptions of data and services, thus allowing agents to make intelligent decisions about service calls.

  11. The investigation of gadolinium oxide porous structure and refinement of the pore size distribution based on the NLDFT-models

    Science.gov (United States)

    Mashkovtsev, Maxim A.; Botalov, Maxim S.; Smyshlyaev, Denis V.; Kasimova, Renata E.; Bereskina, Polina A.; Vereshchagin, Artem O.

    2016-09-01

    The study focuses on the characterization of gadolinium oxide surface by the method of low-temperature adsorption/desorption of nitrogen. The specific surface area of gadolinium oxide, the average pore diameter and fractal dimensions were determined. The refinement of the pore distribution was performed on the basis of the NLDFT model. It was shown that there were three kinds of pores with average sizes of 150, 300 and 600 Å.

  12. Appearance of microvascular obstruction on high resolution first-pass perfusion, early and late gadolinium enhancement CMR in patients with acute myocardial infarction

    Directory of Open Access Journals (Sweden)

    Redwood Simon

    2009-08-01

    Full Text Available Abstract Background The presence and extent of microvascular obstruction (MO after acute myocardial infarction can be measured by first-pass gadolinium-enhanced perfusion cardiovascular magnetic resonance (CMR or after gadolinium injection with early or late enhancement (EGE/LGE imaging. The volume of MO measured by these three methods may differ because contrast agent diffusion into the MO reduces its apparent extent over time. Theoretically, first-pass perfusion CMR should be the most accurate method to measure MO, but this technique has been limited by lower spatial resolution than EGE and LGE as well as incomplete cardiac coverage. These limitations of perfusion CMR can be overcome using spatio-temporal undersampling methods. The purpose of this study was to compare the extent of MO by high resolution first-pass k-t SENSE accelerated perfusion, EGE and LGE. Methods 34 patients with acute ST elevation myocardial infarction, treated successfully with primary percutaneous coronary intervention (PPCI, underwent CMR within 72 hours of admission. k-t SENSE accelerated first-pass perfusion MR (7 fold acceleration, spatial resolution 1.5 mm × 1.5 mm × 10 mm, 8 slices acquired over 2 RR intervals, 0.1 mmol/kg Gd-DTPA, EGE (1–4 minutes after injection with a fixed TI of 440 ms and LGE images (10–12 minutes after injection, TI determined by a Look-Locker scout were acquired. MO volume was determined for each technique by manual planimetry and summation of discs methodology. Results k-t SENSE first-pass perfusion detected more cases of MO than EGE and LGE (22 vs. 20 vs. 14, respectively. The extent of MO imaged by first-pass perfusion (median mass 4.7 g, IQR 6.7 was greater than by EGE (median mass 2.3 g, IQR 7.1, p = 0.002 and LGE (median mass 0.2 g, IQR 2.4, p = 0.0003. The correlation coefficient between MO mass measured by first-pass perfusion and EGE was 0.91 (p Conclusion The extent of MO following acute myocardial infarction appears larger on

  13. Factors influencing the biosorption of gadolinium by micro-organisms and its mobilisation from sand

    International Nuclear Information System (INIS)

    The present work was devoted to the study of the biosorption capacities of various microbial species (Bacillus subtilis, Pseudomonas aeruginosa, Ralstonia metallidurans CH34 previously Alcaligenes eutrophus CH34, Mycobacterium smegmatis, Saccharomyces cerevisiae) for ions of the lanthanide gadolinium (Gd3+). The uptake by sand of this element was also measured. Saturation curves and Scatchard models were established for all biosorbants used in this work. The results enabled us to determine the binding affinities and the maximum capacities for biosorption of Gd3+, which ranged from 350 μmol g-1 for B. subtilis to 5.1 μmol g-1 for S. cerevisiae. This study demonstrated the usefulness of optimisation of experimental conditions in biosorption investigations. Experimental results showed that bisorption could be influenced by the growth stage and by the composition of the growth medium of microbial cells. Finally, particular attention was given to the transfer of gadolinium ions from a loaded sand to a bacterial suspension. (orig.)

  14. Radiomodifying effect of boron and gadolinium compounds in human peripheral lymphocytes evaluated by the comet assay

    International Nuclear Information System (INIS)

    This study was carried out to investigate the modification of radioresponse due to pretreatment of boron (Borax) and gadolinium compounds (Gd- DTPA) in human peripheral lymphocytes using the comet assay, single cell gel electrophoresis (SCGE) assay. The lymphocytes were treated with boron and gadolinium compounds for 10 minutes right before irradiation. The doses of gamma-ray were 0, 1, 2 and 4 Gy. Pretreatment with 10B (each of 50 nM and 250 nM) gave rise to a dose-dependent reduction in radiosensitivity of lymphocytes. On the other hand, pretreatment of 157 Gd- DTPA (50 nM) resulted in a dose-dependent increase in radiosensitivity, especially in the lymphocytes irradiated with 4 Gy. (P<0.001)

  15. Specific features of the WWER Uranium-Gadolinium fuel behavior at BOL

    International Nuclear Information System (INIS)

    The calculated-experimental analysis of the WWER fuel behavior with 5%wt of gadolinium oxide at the beginning of life (BOL) is presented. The results are based on the data on fuel centerline temperature measurements, gas media pressure inside the cladding and fuel elongation obtained during irradiation of the test fuel rods in HBWR (Halden). Computer analysis of experimental data is performed with TOPRA-2, version 2 code. It is shown that specific features of the uranium-gadolinium fuel behavior at the early of life is due to presence of burnable absorber influencing the average linear heat rating, radial power distribution and lower thermal conductivity. In particular, the analysis of “late” relocation effect on the maximum Gd fuel temperature is presented. (authors)

  16. Out-of-pile researches of modernized Uranium-Gadolinium fuel for WWER reactors

    International Nuclear Information System (INIS)

    Thermal conductivity and creeping characteristics (creep rate) of modernized uranium-gadolinium fuel as a composite - solid solution granules (U,Gd)O2 dispersed into UO2 matrix have been researched in wide temperature range. The main peculiarity of the fuel which is under study is a thin fine-grained zone surrounding each granule (U,Gd)O2. Presence of this zone blocks intergranular diffusion of components preventing decrease of concentration of solid solution (U,Gd)O2. In addition fine-grained zone is the original buffer relaxing both interphase tensions and tensions that can be resulted from radiation-thermal loads during irradiation of fuel. Higher thermal and physical characteristics of describable composite uranium-gadolinium fuel (creep rate, thermal conductivity, peculiarity of microstructure), in comparison with conventional obtained by dry blending of UO2 and Gd2O3 powders, allow consider this fuel as candidate for using in WWER and PWR reactors. (authors)

  17. Frontiers of X-ray spectromicroscopy in biology and medicine: Gadolinium in brain cancer

    Science.gov (United States)

    De Stasio, Gelsomina; Gilbert, B.; Perfetti, P.; Margaritondo, G.; Mercanti, D.; Ciotti, M. T.; Casalbore, P.; Larocca, L. M.; Rinelli, A.; Pallini, R.

    2000-02-01

    We present the first feasibility test of spectromicroscopy on the microlocalization of gadolinium in brain cancer tissue. A gadolinium compound was injected to the patients before the brain tumor was extracted with surgery, and we looked for Gd in the tumor tissue. The goal of the experiment was to understand if Gd Neutron Capture Therapy (GdNCT) is viable for clinical tests, i.e. if there is enough Gd, and it is localized near the nuclei of tumor cells. The experiments were performed using the MEPHISTO X-ray PhotoElectron Emission Microscope (X-PEEM) at the Wisconsin Synchrotron Radiation Center. The present results demonstrate the feasibility of the experiment, and suggest how to improve the sample preparation and data acquisition to achieve the goal.

  18. Synthesis and Crystal Structure of a Binuclear Gadolinium(Ⅲ) Complex Bridged by Cucurbit[6]uril

    Institute of Scientific and Technical Information of China (English)

    Gui Ling ZHANG; Zhi Yong WU; Yan Tuan LI; Da Qi WANG; Jian Min DOU

    2006-01-01

    A new cucurbit[6]uril bridged binuclear complex {[Gd(H2O)6]2[Q6(H2O)]}Cl6·4H2O,where Q6 represents cucurbit[6]uril, has been synthesized and characterized by X-ray diffraction.The crystal structure shows that the complex has an extended cucurbit[6]uril-bridged structure consisting of two gadolinium(Ⅲ) ions, in which each gadolinium(Ⅲ) ion is coordinated with two neighboring carbonylic oxygen atoms of Q6 and six oxygen atoms of water molecules that leans toward one side of the portal. One disordered guest water molecule resides in the Q6 molecule cavity and occupies two different positions. Hydrogen bonds assemble the complex to three-dimensional supramolecular structure.

  19. Impurities especially titanium in the rare earth metal gadolinium-before and after solid state electrotransport

    Institute of Scientific and Technical Information of China (English)

    苗睿瑛; 张小伟; 朱琼; 张志琦; 王志强; 颜世宏; 陈德宏; 周林; 李宗安

    2014-01-01

    Gadolinium was prepared by conventional procedures of fluorination, reduction, distillation and solid state electrotransport (SSE). The electronegativities of the metals were found to have an important influence on the electrotransport process and result of the impurity element. Meanwhile, titanium particles in the distilled gadolinium as major metallic impurities were studied by high resolution transmission electron microscopy (HRTEM) before and after solid state electrotransport. The results showed that impurities especially titanium transported from anode to cathode during SSE. In the metal before SSE, there were impurities of titanium in strip shape or embedded round shape. After SSE processing, titanium particles in the metal smaller than 50 nm in the cathode, but existed 6 to 10 times bigger in the anode.

  20. New High-Resolution Gadolinium-GEM Neutron Detectors for the NMX Instrument at ESS

    CERN Document Server

    Pfeiffer, Dorothea; Birch, Jens; Etxegarai, Maddi; Hall-Wilton, Richard; Höglund, Carina; Hultman, Lars; Llamas-Jansa, Isabel; Oliveri, Eraldo; Oksanen, Esko; Robinson, Linda; Ropelewski, Leszek; Schmidt, Susann; Streli, Christina; Thuiner, Patrik

    2016-01-01

    European Spallation Source instruments like the macromolecular diffractometer, NMX, require an excellent neutron detection efficiency, high-rate capabilities, time resolution, and an unprecedented spatial resolution in the order of a few hundred micrometers over a wide angular range of the incoming neutrons. For these instruments solid converters in combination with Micro Pattern Gaseous Detectors (MPGDs) are a promising option. A GEM detector with gadolinium converter was tested on a cold neutron beam at the IFE research reactor in Norway. The {\\mu}TPC analysis, proven to improve the spatial resolution in the case of $^{10}$B converters, is extended to gadolinium based detectors. For the first time, a Gd-GEM was successfully operated to detect neutrons with an estimated efficiency of 10% at a wavelength of 2 {\\AA} and a position resolution better than 350 {\\mu}m.

  1. Renal function, nephrogenic systemic fibrosis and other adverse reactions associated with gadolinium-based contrast media.

    Science.gov (United States)

    Canga, Ana; Kislikova, Maria; Martínez-Gálvez, María; Arias, Mercedes; Fraga-Rivas, Patricia; Poyatos, Cecilio; de Francisco, Angel L M

    2014-01-01

    Nephrogenic systemic fibrosis is a fibrosing disorder that affects patients with impaired renal function and is associated with the administration of gadolinium-based contrast media used in MRI. Despite being in a group of drugs that were considered safe, report about this potentially serious adverse reaction was a turning point in the administration guidelines of these contrast media. There has been an attempt to establish safety parameters to identify patients with risk factors of renal failure. The close pharmacovigilance and strict observation of current regulations, with special attention being paid to the value of glomerular filtration, have reduced the published cases involving the use of gadolinium-based contrast media. In a meeting between radiologists and nephrologists we reviewed the most relevant aspects currently and recommendations for its prevention.

  2. A new material in the nuclear technology. Gadolinium zirconate pyrochlore prepared by reactive sintering

    International Nuclear Information System (INIS)

    The ability of gadolinium zirconate pyrochlore for actinides incorporation in its lattice makes this material a possible matrix for the immobilization of nuclear wastes. The aim of the presented work was to develop a novel method of gadolinium zirconate synthesis by using a reactive sintering procedure under high pressure based on commercial ZrO2 and Gd2O3 nanopowders. Samples were analyzed using X-ray diffraction and SEM to check their phase composition and microstructure. The obtained sintered pellets demonstrated peaks characteristic for pyrochlore structure for a wide range of preparation temperatures and high density (99.5 % of the theoretical value). It was found that the resulting materials exhibited a homogeneous microstructure and the average grain size dependent on sintering temperature. (author)

  3. Hydrothermal synthesis and characterization of polycrystalline gadolinium aluminum perovskite (GdAlO3, GAP

    Directory of Open Access Journals (Sweden)

    N. Girish H.

    2015-06-01

    Full Text Available Gadolinium aluminum perovskite (GdAlO3, GAP is a promising high temperature ceramic material, known for its wide applications in phosphors. Polycrystalline gadolinium aluminum perovskites were synthesized using a precursor of co-precipitate gel of GdAlO3 by employing hydrothermal supercritical fluid technique under pressure and temperature ranging from 150 to 200 MPa and 600 to 700 °C, respectively. The resulted products of GAP were studied using the characterization techniques, such as powder X-ray diffraction analysis (XRD, infrared spectroscopy (IR, scanning electron microscopy (SEM and energy dispersive analysis of X-ray (EDX. The X-ray diffraction pattern matched well with the reported orthorhombic GAP pattern (JCPDS-46-0395.

  4. Comparison of half-dose and full-dose gadolinium MR contrast on the enhancement of bone and soft tissue tumors

    Energy Technology Data Exchange (ETDEWEB)

    Costelloe, Colleen M. [University of Texas M. D. Anderson Cancer Center, Department of Diagnostic Radiology, Houston, Texas (United States); University of Texas M. D. Anderson Cancer Center, Houston, Texas (United States); Murphy, William A.; Haygood, Tamara M.; Kumar, Rajendra; McEnery, Kevin W.; Madewell, John E. [University of Texas M. D. Anderson Cancer Center, Department of Diagnostic Radiology, Houston, Texas (United States); Stafford, R.J. [University of Texas M. D. Anderson Cancer Center, Department of Imaging Physics, Houston, Texas (United States); Roy, Anjali [Cancer Treatment Centers of America Medical Diagnostic Imaging Group, Arizona (United States); Bassett, Roland L.; Harrell, Robyn K. [University of Texas M. D. Anderson Cancer Center, Department of Biostatistics, Houston, Texas (United States)

    2011-03-15

    To evaluate the effect of half-dose intravenous gadolinium contrast on the enhancement of bone and soft tissue tumors. This study is HIPAA compliant and informed consent was waived by the institutional review board. An institutional database search was performed over a 1-year period for patients with full- and half-dose MR examinations performed for musculoskeletal oncologic indications. Examination pairs that were identical with regard to field strength and presence or absence of fat saturation were included, resulting in 29 paired examinations. When multiple, the lesion that was best delineated and enhanced well on the first examination in the pair was chosen, yielding 17 bone and 12 soft tissue. Five musculoskeletal radiologists blinded to dosages were asked to assess for a difference in enhancement when comparing the lesion on both examinations and to rate the degree of difference on a three-point scale. They were also asked to identify the examination on which the lesion enhanced less (tallied as low dose). Results were analyzed with the exact binomial test. The readers perceived an enhancement difference in 41% (59/145) of studies (p = 0.03) and the majority were rated as ''mild'' (66%, 39/59). The readers did not accurately identify the low-dose examinations (54% correctly identified, 32/59, p = 0.60). Half-dose gadolinium enhancement of lesions could not be accurately distinguished from full-dose enhancement upon review of the same lesion imaged at both concentrations. (orig.)

  5. Comparison of renewable oil, recycled oil, and commercial rejuvenating agent derived from crude oil in paving asphalt modification[Includes the CSCE forum on professional practice and career development : 1. international engineering mechanics and materials specialty conference : 1. international/3. coastal, estuarine and offshore engineering specialty conference : 2. international/8. construction specialty conference

    Energy Technology Data Exchange (ETDEWEB)

    Gordon, C.; Ho, S.; Zanzotto, L. [Calgary Univ., AB (Canada). Schulich School of Engineering

    2009-07-01

    The asphalt industry relies heavily on crude oil. In response to increasing oil prices, there have been efforts to save money on asphalt by taking harder asphalts, such as recycled asphalt pavement (RAP), and softening them with rejuvenating agents. For asphalt that is to be used in cold climates, softer asphalts are preferred because they will perform better under extreme cold conditions without cracking. This study compared the performance, economic benefits, and environmental benefits of renewable materials, recycled oil and a commercially used rejuvenating agent derived from crude oil. Different oily materials including margarine, Cyclogen L (a crude oil-derived material), a vegetable wax, and recycled cooking oil were used to modify paving asphalt. Their effectiveness at improving the superpave low-temperature performance grade was compared. The samples were all tested using the 2008 AASHTO M320 procedures. The high temperature grades were determined using the dynamic shear rheometer test, and the low-temperature grades were determined using the bending beam rheometer test. The 3 varieties of margarine that were tested were able to improve the low-temperature grade, but they caused a greater depreciation of the high-temperature performance grade than the other materials, and were much more expensive. The best candidate for an effective, economic asphalt softening agent was found to be the recycled cooking oil. It out-performed the Cyclogen L oil in terms of improving the low- temperature performance grade, and was less expensive. 12 refs., 4 tabs., 6 figs.

  6. Rotation-vibration structure of even-A samarium and gadolinium isotopes

    International Nuclear Information System (INIS)

    The extended rotation-vibration model, which consists of an asymmetric rotor and breathing mode deformation vibrations, was applied to several even-A samarium and gadolinium isotopes. The comparison between the theoretical and experimental energy levels and the comparison with other model calculations are presented. Also shown are the comparison between the experimental and theoretical B(E2) ratios for the isotopes studied. 1 figure, 2 tables

  7. Gadolinium scandate thin films as an alternative gate dielectric prepared by electron beam evaporation

    OpenAIRE

    Wagner, M.; Heeg, T.; Schubert, J.; Lenk, S.; Mantl, S.; Zhao, C; Caymax, M.; De Gendt, M. A.

    2006-01-01

    Gadolinium scandate thin films deposited on silicon substrates using electron beam evaporation were investigated. Measurements with Rutherford backscattering spectrometry, high temperature x-ray diffraction, x-ray reflectometry, transmission electron microscopy, and atomic force microscopy were performed. A stoichiometric transfer of material from the source to the substrate in high vacuum could be demonstrated. Homogeneous, amorphous, and smooth films (root mean square surface roughness < 1 ...

  8. Pulmonary Vein Inflow Artifact Reduction for Free-Breathing Left Atrium Late Gadolinium Enhancement

    OpenAIRE

    Moghari, Mehdi H; Peters, Dana C; Smink, Jouke; Goepfert, Lois; Kissinger, Kraig V.; Goddu, Beth; Hauser, Thomas H; Josephson, Mark E; Manning, Warren J; Nezafat, Reza

    2011-01-01

    Two-dimensional “pencil-beam” navigator, placed on the right hemidiaphragm (RHD), is used for free-breathing late gadolinium enhancement (LGE) of the left atrium (LA) in patients with atrial fibrillation (AF). The pencil-beam navigator creates an inflow artifact in the right PVs and atrial wall that may obscure local PV and LA scars. To reduce this artifact, we propose a large slab RHD projection navigator that measures the respiratory motion while reducing the associated inflow artifact. Eig...

  9. Study on the effects of gadolinium-based MRI contrast medium on X-ray scanning

    International Nuclear Information System (INIS)

    Gadolinium has a higher atomic mass (64) than iodine (53). The K-edge absorption energy of gadolinium is 50.2 keV, which is in the absorbed wavelength range of the X-rays used by a CT scanner, suggesting that it has a high X-ray absorption ability. This study examined the effects of a gadolinium-based MRI contrast medium on the quality (mAs) and the quality (kVp) of radiation during a X-ray scan. A contrast medium phantom was manufactured after diluting the contrast medium to various concentrations. A CT scanner (Siemens, Somatom Senation 64, Germany) was used to obtain images by changing the quality of radiation from 80 kVp to 100, 120, and 140 kVp. At a constant quality of radiation of 120 kVp, the mAs was changed from 100 mAs to 200 and 300 mAs and images were obtained under each condition. The Hounsfield units (HUs) in a test tube were measured for analysis and comparison. The contrast enhancement by the contrast medium for CT scanning was 100% at a tube voltage of 80 kVp. The contrast enhancements at 100 kVp, 120 kVp, and 140 kVp were 93.8%, 87.7%, and 69.5%, respectively. In addition, although the quantity increased a fixed tube voltage, the HU of the test tube remained relatively constant, indicating that the absorption of the contrast medium had little association with the quantity of X-rays but had some correlation with the quality of radiation. A tube voltage of 80 kVp or lower is recommended when a MRI contrast medium is used CT scanning. When MRI scanning and X-ray scanning are conducted together, X-ray scanning should be performed first or after sufficient gadolinium contrast medium has been excreted.

  10. Gadolinium uptake by brain cancer cells: Quantitative analysis with X-PEEM spectromicroscopy for cancer therapy

    Science.gov (United States)

    De Stasio, Gelsomina; Gilbert, B.; Perfetti, P.; Margaritondo, G.; Mercanti, D.; Ciotti, M. T.; Casalbore, P.; Larocca, L. M.; Rinelli, A.; Pallini, R.

    2000-05-01

    We present the first X-PEEM spectromicroscopy semi-quantitative data, acquired on Gd in glioblastoma cell cultures from human brain cancer. The cells were treated with a Gd compound for the optimization of GdNCT (Gadolinium Neutron Capture Therapy). We analyzed the kinetics of Gd uptake as a function of exposure time, and verified that a quantitative analytical technique gives the same results as our MEPHISTO X-PEEM, demonstrating the feasibility of semi-quantitative spectromicroscopy.

  11. Simulation and Design of Multi-modulars Detector System of Gadolinium-Loaded Liquid Scintillator

    Institute of Scientific and Technical Information of China (English)

    HOU; Long; WANG; Zhao-hui; YU; Guo-liang; WANG; Qi; KANG; Guo-guo; SU; Xiao-bin; ZHANG; Xiao-peng; ZHANG; Kai

    2012-01-01

    <正>The gadolinium-loaded liquid scintillator has the superiority of high detecting efficiency, and it can be used to measure many kinds of nucleus. We improved this technique and construct a 4π liquid scintillator detecting systems which is composed by many liquid scintillators. By coupling with fission chamber, we form a novel research platform which can be used to measure the (n, 2n) and (n, 3n) cross sections of many nuclei.

  12. Dynamic gadolinium-enhanced MR imaging in active and inactive immunoinflammatory gonarthritis

    DEFF Research Database (Denmark)

    Østergaard, Mikkel; Lorenzen, I; Henriksen, O

    1994-01-01

    Dynamic T1-weighted FLASH MR imaging, obtained just after i.v. gadopentetate dimeglumine injection, and pre- and postcontrast T1-weighted spin-echo (T1-SE) MR imaging were performed to compare their information value with respect to inflammatory activity in immunoinflammatory gonarthritis. We exa...... of synovium could differentiate between healthy and arthritic knees. Gadolinium-enhanced dynamic FLASH imaging may provide clinically useful information about the actual inflammatory activity of arthritic joints....

  13. Electron spin resonance absorption spectrum of trivalent gadolinium in the oxide YAIG

    Energy Technology Data Exchange (ETDEWEB)

    Marshall, S.A. (Argonne National Lab., IL); Marshall, T.; Serway, R.A.

    1978-01-01

    The electron spin resonance absorption spectrum of trivalent gadolinium in single crystals of yttrium-aluminium garnet is re-investigated at X-band and Q-band wavelengths. Fine structure spectral parameters deduced from Q-band wavelength measurements are found to predict satisfactorily spectral observations at both wavelengths. A list of spectral parameters deduced from data taken at 77/sup 0/K is given.

  14. Increased blood–brain barrier permeability in type II diabetes demonstrated by gadolinium magnetic resonance imaging

    OpenAIRE

    Starr, J; Wardlaw, J; Ferguson, K; MacLullich, A; Deary, I; Marshall, I

    2003-01-01

    Objectives: Patients with type II diabetes are at increased risk of cognitive impairment. The retinal and renal complications of diabetes follow microvascular damage permitting small arterioles to leak, hence the cerebral damage might also follow loss of blood–brain barrier (BBB) integrity. Magnetic resonance (MR) brain imaging with intravenous gadolinium (Gd) diethylenetriamine pentaacetic acid (Gd-DTPA) was used to identify increased BBB permeability.

  15. Comparison between biokinetics of inhaled plutonium nitrate and gadolinium oxide in humans and animals

    International Nuclear Information System (INIS)

    Due to the paucity of human data after inhalation of different chemical forms of radionuclides, the implications for human exposure are often based on animal studies. Biokinetic studies of plutonium nitrate and gadolinium oxide in human volunteers and rats are described. The results, together with information from other studies with radionuclides, suggests that animal studies can be used with advantage for assessing the biokinetic behavior in humans, and for providing guidance on the assessment of intake and optimal monitoring regimens. (author)

  16. Magnetic moments in a gadolinium iron garnet studied by soft-X-ray magnetic circular dichroism

    NARCIS (Netherlands)

    Rudolf, P.; Sette, F.; Tjeng, L.H.; Meigs, G.; Chen, C.T.

    1992-01-01

    The magnetic moments of Gd and Fe in gadolinium iron garnet (Gd3Fe5O12) were probed at 77 and 300 K by soft-X-ray magnetic circular dichroism (SXMCD) measurements at the GdMa4,5 and at the FeL2,3 absorption edges. The SXMCD signal at each edge allows one to independently determine the magnetic order

  17. Comparison of Lithium Gadolinium Borate Crystal Shards in Scintillating and Nonscintillating Plastic Matrices

    OpenAIRE

    Kazkaz, Kareem; Bowden, Nathaniel S.; Pedretti, Marisa

    2011-01-01

    We present a method for detecting neutrons using scintillating lithium gadolinium borate crystal shards in a plastic matrix while maintaining high gamma rejection. We have procured two cylindrical detectors, 5"\\times5", containing 1% crystal by mass. Crystal shards have a typical dimension of 1 mm. One detector was made with scintillating plastic, and one with nonscintillating plastic. Pulse shape analysis was used to reject gamma ray backgrounds. The scintillating detector was measured to ha...

  18. Agent, autonomous

    OpenAIRE

    Luciani, Annie

    2007-01-01

    The expression autonomous agents, widely used in virtual reality, computer graphics, artificial intelligence and artificial life, corresponds to the simulation of autonomous creatures, virtual (i.e. totally computed by a program), or embodied in a physical envelope, as done in autonomous robots.

  19. Depletion of gadolinium burnable poison in a PWR assembly with high burnup fuel

    International Nuclear Information System (INIS)

    A tendency to increase the discharge burnup of nuclear fuel for Advanced Pressurized Water Reactors (PWR) has been a characteristic of its operation for many years. It will be able to burn at very high burnup of about 70 GWd/t with UO2 fuels. The U-235 enrichment must be higher than 5 %, which leads to the necessity of using an extremely efficient burnable poison like Gadolinium oxide. Using gadolinium isotope is significant due to its particular depletion behavior (''Onion-Skin'' effect). In this paper, the MCNPX2.7 code is used to calculate the important neutronic parameters of the next generation fuels of PWR. K-infinity, local peaking factor and fission rate distributions are calculated for a PWR assembly which burn at very high burnup reaching 70 GWd/t. The calculations are performed using the recently released evaluated Gadolinium cross section data. The results obtained are close to those of a LWR next generation fuel benchmark problem. This demonstrates that the calculation scheme used is able to accurately model a PWR assembly that operates at high burnup values.

  20. Late radiation change in the CNS: MR imaging following gadolinium enhancement

    Energy Technology Data Exchange (ETDEWEB)

    Norris, A.M.; Carrington, B.M.; Slevin, N.J. [Christie Hospital and Holt Radium Inst., Manchester (United Kingdom)

    1997-05-01

    Magnetic resonance imaging is the best imaging technique for the detection of radiotherapy-induced changes in the central nervous system but there are few studies detailing the MRI appearances of radiation effects following enhancement with intravenous gadolinium. In this paper, gadolinium enhanced MR imaging findings were reviewed in seven patients with evidence of late radiation injury following radiotherapy for primary head and neck tumours. On T1-weighted enhanced sequences, abnormal focal areas were present in the anterior temporal lobes and antero-inferior aspects of the frontal lobes. These lesions were well defined and enhanced intensely following intravenous gadolinium. They were present in the white matter in five patients and involved both grey and white matter in two patients. Cystic components were present in larger lesions in three patients and mass effect was present around the enhancing lesions in four patients. All abnormalities occurred within the radiation treatment portals and corresponded to the distribution of increased signal intensity changes in the brain on T2-weighted images. Late radiation-induced injury should be considered in the differential diagnosis of any intensely enhancing lesion occurring within irradiated brain tissue. (author).

  1. Late radiation change in the CNS: MR imaging following gadolinium enhancement

    International Nuclear Information System (INIS)

    Magnetic resonance imaging is the best imaging technique for the detection of radiotherapy-induced changes in the central nervous system but there are few studies detailing the MRI appearances of radiation effects following enhancement with intravenous gadolinium. In this paper, gadolinium enhanced MR imaging findings were reviewed in seven patients with evidence of late radiation injury following radiotherapy for primary head and neck tumours. On T1-weighted enhanced sequences, abnormal focal areas were present in the anterior temporal lobes and antero-inferior aspects of the frontal lobes. These lesions were well defined and enhanced intensely following intravenous gadolinium. They were present in the white matter in five patients and involved both grey and white matter in two patients. Cystic components were present in larger lesions in three patients and mass effect was present around the enhancing lesions in four patients. All abnormalities occurred within the radiation treatment portals and corresponded to the distribution of increased signal intensity changes in the brain on T2-weighted images. Late radiation-induced injury should be considered in the differential diagnosis of any intensely enhancing lesion occurring within irradiated brain tissue. (author)

  2. Gadolinium-chelate nanoparticle entrapped human mesenchymal stem cell via photochemical internalization for cancer diagnosis.

    Science.gov (United States)

    Kim, Kyoung Sub; Park, Wooram; Na, Kun

    2015-01-01

    To improve the gadolinium (Gd) internalization efficiency in stem cells, gadolinium-chelate nanoparticles were prepared from a pullulan derivative (pullulan-deoxycholic acid (DOCA)-diethylene triamine pentaacetic (DTPA)-Gd conjugate; PDDG) and then the PDDG was entrapped into human mesenchymal stem cells (hMSCs) by the photochemical-internalization (PCI) method for cancer diagnosis via the cancer homing property of hMSCs. The internalization efficiency of Gd in hMSCs was significantly increased to 98 ± 4 pg Gd/cell from 32 ± 2 pg Gd/cell via the PCI method. Moreover, the Gd-entrapped hMSCs revealed a low exocytosis ratio of gadolinium-chelate nanoparticles during cell division in vitro and a high cellular labeling efficiency for at least 21 days in vivo. The cancer-targeting and diagnosis effect of the Gd-entrapped hMSCs were confirmed in a small CT26 tumor-bearing mice model. The stem cells detected an early tumor (∼3 mm(3)) within 2 h using 4.7-T MR and optical imaging. The results demonstrated that the PCI-mediated internalization of Gd-incorporated nanoparticles into hMSCs is a promising protocol for efficient cell labeling and tracking.

  3. Optical properties of pure and Ce3+ doped gadolinium gallium garnet crystals and epitaxial layers

    International Nuclear Information System (INIS)

    Results of X-ray diffraction and low temperature optical absorption measurements of cerium doped gadolinium gallium garnet single crystals and epitaxial layers are reported. In the region of intra-configurational 4f–4f transitions the spectra of the bulk crystals exhibit the signatures of several different Ce3+ related centers. Apart from the dominant center, associated with Ce substituting gadolinium, at least three other centers are found, some of them attributed to the so-called antisite locations of rare-earth ions in the garnet host, i.e., in the Ga positions. X-ray diffraction data prove lattice expansion of bulk GGG crystals due to the presence of rare-earth antisites. The concentration of the additional Ce-related centers in epitaxial layers is much lower than in the bulk crystals. However, the Ce-doped layers incorporate a large amount of Pb from flux, which is the most probable source of nonradiative quenching of Ce luminescence, not observed in crystals grown by the Czochralski method. - Highlights: • Ce3+ multicenters found in Gadolinium Gallium Garnet crystals and epitaxial layers. • High quality epitaxial layers of pure and Ce-doped GGG were grown. • Luminescence quenching of Ce3+ by Pb ions from flux detected in GGG epitaxial layers. • X-ray diffraction allows measuring the amount of the rare-earth antisites in GGG

  4. Study of the Photon Strength Functions for Gadolinium Isotopes with the DANCE Array

    International Nuclear Information System (INIS)

    The gadolinium isotopes are interesting for reactor applications as well as for medicine and astrophysics. The gadolinium isotopes have some of the largest neutron capture cross sections. As a consequence they are used in the control rod in reactor fuel assembly. From the basic science point of view, there are seven stable isotopes of gadolinium with varying degrees of deformation. Therefore they provide a good testing ground for the study of deformation dependent structure such as the scissors mode. Decay gamma rays following neutron capture on Gd isotopes are detected by the DANCE array, which is located at flight path 14 at the Lujan Neutron Scattering Center at Los Alamos National Laboratory. The high segmentation and close packing of the detector array enable gamma-ray multiplicity measurements. The calorimetric properties of the DANCE array coupled with the neutron time-of-flight technique enables one to gate on a specific resonance of a specific isotope in the time-of-flight spectrum and obtain the summed energy spectrum for that isotope. The singles gamma-ray spectrum for each multiplicity can be separated by their DANCE cluster multiplicity. Various photon strength function models are used for comparison with experimentally measured DANCE data and provide insight for understanding the statistical decay properties of deformed nuclei.

  5. Depletion of gadolinium burnable poison in a PWR assembly with high burnup fuel

    Energy Technology Data Exchange (ETDEWEB)

    Refeat, Riham Mahmoud [Nuclear and Radiological Regulatory Authority (NRRA), Cairo (Egypt). Safety Engineering Dept.

    2015-12-15

    A tendency to increase the discharge burnup of nuclear fuel for Advanced Pressurized Water Reactors (PWR) has been a characteristic of its operation for many years. It will be able to burn at very high burnup of about 70 GWd/t with UO{sub 2} fuels. The U-235 enrichment must be higher than 5 %, which leads to the necessity of using an extremely efficient burnable poison like Gadolinium oxide. Using gadolinium isotope is significant due to its particular depletion behavior (''Onion-Skin'' effect). In this paper, the MCNPX2.7 code is used to calculate the important neutronic parameters of the next generation fuels of PWR. K-infinity, local peaking factor and fission rate distributions are calculated for a PWR assembly which burn at very high burnup reaching 70 GWd/t. The calculations are performed using the recently released evaluated Gadolinium cross section data. The results obtained are close to those of a LWR next generation fuel benchmark problem. This demonstrates that the calculation scheme used is able to accurately model a PWR assembly that operates at high burnup values.

  6. Removal of lanthanum and gadolinium from nitrate medium using Aliquat-336 impregnated onto Amberlite XAD-4

    International Nuclear Information System (INIS)

    Aliquat-336 in benzene was supported on Amberlite XAD-4 crosslinked polystyrene resin. The use of XAD-4 impregnated with Aliquat-336 resin for removal of lanthanum(III) and gadolinium(III) from nitrate medium was carried out using batch technique. Various parameters affecting the uptake of these metal ions such as contact time, metal ion concentrations, V/m and pH value were separately studied. Effect of temperature on the equilibrium distribution values has been studied to evaluate the changes in standard thermodynamic quantities. A comparison of kinetic models applied to the adsorption rate data was evaluated for Lagergren first order, the pseudo second order and Morris-Weber kinetic models. From the results, both pseudo second order and intraparticle diffusion models were found to best correlate the experimental rate data. The capacity of the impregnated resin for both lanthanum(III) and gadolinium(III) was found to be 4.73 and 4.44 mg/g. From the results, impregnation of Aliquat-336 onto Amberlite XAD-4 provides an efficient impregnated resin for the removal of lanthanum(III) and gadolinium(III) from 0.1 M nitrate aqueous solution

  7. Influence of gadolinium concentration on the EMR spectrum of Gd{sup 3+} in zircon

    Energy Technology Data Exchange (ETDEWEB)

    Biasi, R.S. de, E-mail: rsbiasi@ime.eb.b [Secao de Engenharia Mecanica e de Materiais, Instituto Militar de Engenharia, 22290-270 Rio de Janeiro, RJ (Brazil); Grillo, M.L.N., E-mail: mluciag@uerj.b [Instituto de Fisica, Universidade do Estado do Rio de Janeiro, 20550-013 Rio de Janeiro, RJ (Brazil)

    2009-11-01

    Electron magnetic resonance (EMR) spectra of gadolinium-doped zircon (ZrSiO{sub 4}) powders have been studied at room temperature for gadolinium concentrations between 0.20 and 1.0 mol%. The results suggest that Gd{sup 3+} ions occupy substitutional sites in the zircon lattice, that the electron magnetic resonance linewidth increases with increasing gadolinium concentration and that the range of the exchange interaction between Gd{sup 3+} ions is about 1.17 nm, larger than that of the same ion in other host lattices, such as ceria (CeO{sub 2}), strontium oxide (SrO) and calcium oxide (CaO). The fact that the electron magnetic resonance linewidth of the Gd{sup 3+} ion in polycrystalline zircon increases, regularly and predictably, with Gd concentration, shows that the Gd{sup 3+} ion can be used as a probe to study, rapidly and non-destructively, the crystallinity and degradation of ZrSiO{sub 4}.

  8. Selective Filtration of Gadolinium Trichloride for Use in Neutron Detection in Large Water Cherenkov Detectors

    Energy Technology Data Exchange (ETDEWEB)

    Vagins, Mark R.

    2013-04-10

    Water Cherenkov detectors have been used for many years as inexpensive, effective detectors for neutrino interactions and nucleon decay searches. While many important measurements have been made with these detectors a major drawback has been their inability to detect the absorption of thermal neutrons. We believe an inexpensive, effective technique could be developed to overcome this situation via the addition to water of a solute with a large neutron cross section and energetic gamma daughters which would make neutrons detectable. Gadolinium seems an excellent candidate especially since in recent years it has become very inexpensive, now less than $8 per kilogram in the form of commercially-available gadolinium trichloride, GdCl{sub 3}. This non-toxic, non-reactive substance is highly soluble in water. Neutron capture on gadolinium yields a gamma cascade which would be easily seen in detectors like Super-Kamiokande. We have been investigating the use of GdCl{sub 3} as a possible upgrade for the Super-Kamiokande detector with a view toward improving its performance as a detector for atmospheric neutrinos, supernova neutrinos, wrong-sign solar neutrinos, reactor neutrinos, proton decay, and also as a target for the coming T2K long-baseline neutrino experiment. This focused study of selective water filtration and GdCl{sub 3} extraction techniques, conducted at UC Irvine, followed up on highly promising benchtop-scale and kiloton-scale work previously carried out with the assistance of 2003 and 2005 Advanced Detector Research Program grants.

  9. Technical requirements, biophysical considerations and protocol optimization with magnetic resonance angiography using blood-pool agents

    International Nuclear Information System (INIS)

    In order to maximize the potential benefits of contrast-enhanced magnetic resonance angiography, careful attention must be paid to the choice of hardware, data acquisition and processing, and to the choice of contrast agent. Typically, contrast-enhanced magnetic resonance angiography uses parallel-imaging techniques, which shorten the acquisition time, enhance spatial resolution and reduce artefacts. The timing of data acquisition is crucial for maximal enhancement of the arteries: for optimal arterial depiction, the centre of k-space should be acquired at the time of peak concentration of contrast agent in the arterial bed being investigated, and a number of k-space acquisition techniques are available to achieve this. SENSE or GRAPPA techniques can be used to facilitate parallel-imaging reconstruction of either the image data or k-space data, respectively. Gadolinium contrast agents shorten the proton relaxation times (most importantly T1) of blood, thereby increasing the signal-to-noise ratio and enhancing differentiation between blood vessels and other tissues. The blood-pool (intravascular) contrast agent gadofosveset trisodium (Vasovist, Bayer Schering Pharma AG, Berlin, Germany) is reversibly protein-bound in human plasma. This results in a marked increase in relaxivity, and hence a strong T1 shortening effect compared with other gadolinium-based contrast agents. Furthermore, the blood retention time of gadofosveset trisodium is substantially prolonged compared with conventional contrast agents. As a result, gadofosveset trisodium permits both first-pass and steady-state imaging. (orig.)

  10. Agent-Based Modeling and Mapping of Manufacturing System

    Institute of Scientific and Technical Information of China (English)

    Z; Zhang

    2002-01-01

    Considering the agent-based modeling and mapping i n manufacturing system, some system models are described in this paper, which are included: Domain Based Hierarchical Structure (DBHS), Cascading Agent Structure (CAS), Proximity Relation Structure (PRS), and Bus-based Network Structure (BNS ). In DBHS, one sort of agents, called static agents, individually acts as Domai n Agents, Resources Agents, UserInterface Agents and Gateway Agents. And the oth ers, named mobile agents, are the brokers of task and ...

  11. Fat-suppressed MRI of musculoskeletal infection: fast T2-weighted techniques versus gadolinium-enhanced T1-weighted images

    Energy Technology Data Exchange (ETDEWEB)

    Miller, T.T. [Department of Radiology, North Shore University Hospital, 300 Community Drive, Manhasset, NY 11030 (United States)]|[Department of Radiology, Columbia-Presbyterian Medical Center MHB 2-121, 177 Fort Washington Ave., New York, NY 10032 (United States); Randolph, D.A. Jr.; Staron, R.B.; Feldman, F.; Cushin, S. [Department of Radiology, Columbia-Presbyterian Medical Center MHB 2-121, 177 Fort Washington Ave., New York, NY 10032 (United States)

    1997-11-01

    Purpose. To investigate gadolinium`s role in imaging musculoskeletal infection by comparing the conspicuity and extent of inflammatory changes demonstrated on gadolinium-enhanced fat-suppressed T1-weighted images versus fat-suppressed fast T2-weighted sequences. Design. Eighteen patients with infection were imaged in a 1.5-T unit, using frequency-selective and/or inversion recovery fat-suppressed fast T2-weighted images (T2WI) and gadolinium-enhanced frequency-selective fat-suppressed T1-weighted images (T1WI). Thirty-four imaging planes with both a fat-suppressed gadolinium-enhanced T1-weighted sequence and a fat-suppressed T2-weighted sequence were obtained. Comparison of the extent and conspicuity of signal intensity changes was made for both bone and soft tissue in each plane. Results. In bone, inflammatory change was equal in extent and conspicuity on fat-suppressed T2WI and fat-suppressed T1WI with gadolinium in 19 planes, more extensive or conspicuous on T2WI in three planes, and less so on T2WI in two planes. Marrow was normal on all three sequences in 10 cases. In soft tissue, inflammatory change was seen equally well in 20 instances, more extensively or conspicuously on the T2WI in 11 instances, and less so on T2WI in 2 instances. One case had no soft tissue involvement on any of the sequences. Five abscesses and three joint effusions were present, all more conspicuously delineated from surrounding inflammatory change on the fat-saturated T1WI with gadolinium. The average imaging time for the fat-saturated T1WI with gadolinium was 6.75 min, while that of the T2-weighted sequences was 5.75 min. Conclusion. Routine use of gadolinium is not warranted. Instead, gadolinium should be reserved for clinically suspected infection in or around a joint, and in cases refractory to medical or surgical treatment due to possible abscess formation. (orig.) With 3 figs., 1 tab., 10 refs.

  12. Comparison between a linear versus a macrocyclic contrast agent for whole body MR angiography in a clinical routine setting

    OpenAIRE

    Rittig Kilian; Tepe Gunnar; Klumpp Bernhard; Döring Jörg; Bretschneider Christiane; Grimm Florian; Fenchel Michael; Kramer Ulrich; Seeger Achim; Seidensticker Peter R; Claussen Claus D; Miller Stephan

    2008-01-01

    Abstract Background Previous experiences of whole body MR angiography are predominantly available in linear 0.5 M gadolinium-containing contrast agents. The aim of this study was to compare image quality on a four-point scale (range 1–4) and diagnostic accuracy of a 1.0 M macrocyclic contrast agent (gadobutrol, n = 80 patients) with a 0.5 M linear contrast agent (gadopentetate dimeglumine, n = 85 patients) on a 1.5 T whole body MR system. Digital subtraction angiography served as standard of ...

  13. Incorporation of Integral Fuel Burnable Absorbers Boron and Gadolinium into Zirconium-Alloy Fuel Clad Material

    Energy Technology Data Exchange (ETDEWEB)

    Sridharan, K.; Renk, T.J.; Lahoda, E.J.; Corradini, M.L

    2004-12-14

    Long-lived fuels require the use of higher enrichments of 235U or other fissile materials. Such high levels of fissile material lead to excessive fuel activity at the beginning of life. To counteract this excessive activity, integral fuel burnable absorbers (IFBA) are added to some rods in the fuel assembly. The two commonly used IFBA elements are gadolinium, which is added as gadolinium-oxide to the UO2 powder, and boron, which is applied as a zirconium-diboride coating on the UO2 pellets using plasma spraying or chemical vapor deposition techniques. The incorporation of IFBA into the fuel has to be performed in a nuclear-regulated facility that is physically separated from the main plant. These operations tend to be very costly because of their small volume and can add from 20 to 30% to the manufacturing cost of the fuel. Other manufacturing issues that impact cost and performance are maintaining the correct levels of dosing, the reduction in fuel melting point due to gadolinium-oxide additions, and parasitic neutron absorption at fuel's end-of-life. The goal of the proposed research is to develop an alternative approach that involves incorporation of boron or gadolinium into the outer surface of the fuel cladding material rather than as an additive to the fuel pellets. This paradigm shift will allow for the introduction of the IFBA in a non-nuclear regulated environment and will obviate the necessity of additional handling and processing of the fuel pellets. This could represent significant cost savings and potentially lead to greater reproducibility and control of the burnable fuel in the early stages of the reactor operation. The surface alloying is being performed using the IBEST (Ion Beam Surface Treatment) process developed at Sandia National Laboratories. IBEST involves the delivery of energetic ion beam pulses onto the surface of a material, near-surface melting, and rapid solidification. The non-equilibrium nature of such processing allows for

  14. Distribution of late gadolinium enhancement in various types of cardiomyopathies:Significance in differential diagnosis, clinical features and prognosis

    Institute of Scientific and Technical Information of China (English)

    Hiroshi; Satoh; Makoto; Sano; Kenichiro; Suwa; Takeji; Saitoh; Mamoru; Nobuhara; Masao; Saotome; Tsuyoshi; Urushida; Hideki; Katoh; Hideharu; Hayashi

    2014-01-01

    The recent development of cardiac magnetic resonance(CMR)techniques has allowed detailed analyses of cardiac function and tissue characterization with high spatial resolution.We review characteristic CMR features in ischemic and non-ischemic cardiomyopathies(ICM and NICM),especially in terms of the location and distribution of late gadolinium enhancement(LGE).CMR in ICM shows segmental wall motion abnormalities or wall thinning in a particular coronary arterial territory,and the subendocardial or transmural LGE.LGE in NICM generally does not correspond to any particular coronary artery distribution and is located mostly in the mid-wall to subepicardial layer.The analysis of LGE distribution is valuable to differentiate NICM with diffusely impaired systolic function,including dilated cardiomyopathy,end-stage hypertrophic cardiomyopathy(HCM),cardiac sarcoidosis,and myocarditis,and those with diffuse left ventricular(LV)hypertrophy including HCM,cardiac amyloidosis and Anderson-Fabry disease.A transient low signal intensity LGE in regions of severe LV dysfunction is a particular feature of stress cardiomyopathy.In arrhythmogenic right ventricular cardiomyopathy/dysplasia,an enhancement of right ventricular(RV)wall with functional and morphological changes of RV becomes apparent.Finally,the analyses of LGE distribution have potentials to predict cardiac outcomes and response to treatments.

  15. Enhanced production of reactive oxygen species by gadolinium oxide nanoparticles under core-inner-shell excitation by proton or monochromatic X-ray irradiation: implication of the contribution from the interatomic de-excitation-mediated nanoradiator effect to dose enhancement.

    Science.gov (United States)

    Seo, Seung-Jun; Han, Sung-Mi; Cho, Jae-Hoon; Hyodo, Kazuyuki; Zaboronok, Alexander; You, He; Peach, Ken; Hill, Mark A; Kim, Jong-Ki

    2015-11-01

    Core-inner-valence ionization of high-Z nanoparticle atomic clusters can de-excite electrons through various interatomic de-excitation processes, thereby leading to the ionization of both directly exposed atoms and adjacent neutral atoms within the nanoparticles, and to an enhancement in photon-electron emission, which is termed the nanoradiator effect. To investigate the nanoradiator-mediated dose enhancement in the radio-sensitizing of high-Z nanoparticles, the production of reactive oxygen species (ROS) was measured in a gadolinium oxide nanoparticle (Gd-oxide NP) solution under core-inner-valence excitation of Gd with either 50 keV monochromatic synchrotron X-rays or 45 MeV protons. This measurement was compared with either a radiation-only control or a gadolinium-chelate magnetic resonance imaging contrast agent solution containing equal amounts of gadolinium as the separate atomic species in which Gd-Gd interatomic de-excitations are absent. Ionization excitations followed by ROS measurements were performed on nanoparticle-loaded cells or aqueous solutions. Both photoexcitation and proton impact produced a dose-dependent enhancement in the production of ROS by a range of factors from 1.6 to 1.94 compared with the radiation-only control. Enhanced production of ROS, by a factor of 1.83, was observed from Gd-oxide NP atomic clusters compared with the Gd-chelate molecule, with a Gd concentration of 48 μg/mL in the core-level photon excitation, or by a factor of 1.82 under a Gd concentration of 12 μg/mL for the proton impact at 10 Gy (p < 0.02). The enhanced production of ROS in the irradiated nanoparticles suggests the potential for additional therapeutic dose enhancements in radiation treatment via the potent Gd-Gd interatomic de-excitation-driven nanoradiator effect.

  16. Enthesitis of lumbar spinal ligaments in clinically suspected spondyloarthritis: value of gadolinium-enhanced MR images in comparison to STIR

    Energy Technology Data Exchange (ETDEWEB)

    Agten, Christoph A.; Zubler, Veronika; Rosskopf, Andrea B.; Pfirrmann, Christian W.A. [Balgrist University Hospital, Radiology, Zurich (Switzerland); University of Zurich, Faculty of Medicine, Zurich (Switzerland); Weiss, Bettina [Balgrist University Hospital, Rheumatology, Zurich (Switzerland); University of Zurich, Faculty of Medicine, Zurich (Switzerland)

    2016-02-15

    To compare detection of spinal ligament enthesitis between gadolinium-enhanced fat-saturated T1-weighted gadolinium-enhanced fat-saturated T1-weighted (T1+Gd) and STIR sequences in patients with suspected spondyloarthritis. Sixty-eight patients (37 males, 42 ± 14 years) with a sacroiliac-joint (SIJ) and lumbar spine MRI for suspected spondyloarthritis were prospectively included. Sagittal T1+Gd and STIR images of the lumbar spine were assessed by two readers for enthesitis of interspinous/supraspinous ligaments, and for capsulitis of facet-joints between T12-S1. Patients' MRI were grouped according to ASAS (Assessment of SpondyloArthritis international Society) criteria in positive (group A) or negative (group B) SIJs. Enthesitis/capsulitis were compared between groups. Interreader agreement was assessed. Enthesitis/capsulitis per patient was statistically significantly more frequent with T1+Gd compared to STIR (p ≤ 0.007), except for interspinous ligaments for reader 1 (p = 0.455). Interspinous enthesitis, supraspinous enthesitis, and capsulitis were present with T1+Gd(STIR) in 64.7 %(72.1 %), 60.3 %(17.7 %), and 61.8 %(29.4 %) for reader 1, and 51.5 %(41.2 %), 45.6 %(7.4 %), and 91.2 %(45.5 %) for reader 2. There were 76.5 %(52/68) patients in group A and 23.5 %(16/68) in group B. Total number of enthesitis/capsulitis on T1+Gd was statistically significantly higher in group A than B (4.96 vs. 2.94, p = 0.026; 8.12 vs. 5.25, p = 0.041 for reader 1 and 2, respectively). Interreader agreement showed mixed results for interspinous/supraspinous/capsulitis but was higher on T1+Gd (ICC = 0.838/0.783/0.367; p ≤ 0.001) compared to STIR (ICC = 0.652/0.298/0.224; p ≤ 0.032). In patients with suspected spondyloarthritis, enthesitis/capsulitis in the lumbar spine are common findings and more frequently/reliably detected with T1+Gd than STIR. In patients with positive SIJ-MRI, the total number of enthesitis/capsulitis in T1+Gd was higher compared to patients with

  17. MoS2-Gd Chelate Magnetic Nanomaterials with Core-Shell Structure Used as Contrast Agents in in Vivo Magnetic Resonance Imaging.

    Science.gov (United States)

    Anbazhagan, Rajeshkumar; Su, Yu-An; Tsai, Hsieh-Chih; Jeng, Ru-Jong

    2016-01-27

    Despite their frequent usages as contrast agents for in vivo MRI imaging, paramagnetic molecules continue to suffer from low resolution, physicochemical instability, and high toxicity. Herein, we present a molybdenum disulfide and gadolinium complex, as an alternative core-shell magnetic nanomaterial that exhibits enhanced paramagnetic property; 4.5-times longer water proton spin-lattice relaxation time (T1) when compared to commercial gadolinium contrast agents; as well as lowered toxicity, extended blood circulation time, increased stability, and desirable excretion characteristic. Transmission electron microscopy (TEM) revealed smooth core-shell nanoparticles 100 nm in size with a shell width of approximately 10 nm. These findings suggest that the synthesized nanomaterial possesses high potential as a positive contrast agent for the enhancement of MRI imaging.

  18. Comparison of Delayed Gadolinium-Enhanced MRI with Magnetization Transfer after Injection of Single-Dose and Immediate Image without MT after Injection of Double Dose Gadolinium Chelates for Detecting

    Directory of Open Access Journals (Sweden)

    Ahmad Alizadeh

    2010-05-01

    Full Text Available Background/Objective: To determine whether the use of single dose gadolinium chelate in combination of MTC and delay of 20-30 minute brain imaging is useful in detecting MS lesions."nPatients and Methods: T1W spin echo images with and without MTC were obtained before contrast administration followed by T1W images with MTC starting and 20-30 minutes after contrast administration. After 24-72 hours T1W images without MTC were obtained immediately after injection of 0.2 mmol/Kg contrast material. All images were evaluated in a blinded route by two readers. Outcome parameters included the number of enhancing lesions."nResults: Single dose in combination with MTC and delay of 20-30 minutes showed 16 enhancing lesions and double dose showed 44. Differences between the two methods were significant (p=0.003. Thirteen lesions enhanced with both methods."nConclusion: The use of single dose in combination with MTC and delay of 20-30 minutes enables us to detect an increase of enhancing lesions."nKeywords: Magnetic Resonance, Magnetization Transfer, Multiple Sclerosis, Delay

  19. Gadolinium-enhanced magnetic resonance angiography of the abdominal vessels

    International Nuclear Information System (INIS)

    Contrast enhanced (CE) magnetic resonance angiography (MRA) provides high resolution angiograms within 20-40 sec. The technique is based on the acquisition of heavily T1-weighted threedimensional (3D) gradient-echo data sets (FISP) with ultrashort echo-(<2 ms) and repetition times (<5 ms) during the arterial phase of an intravenously injected bolus of a T1-shortening agent such as Gd-DTPA. For MR-angiography of abdominal vessels CE-MRA is better suited than 'time-of-flight' (TOF) and phase-contrast (PC) MRA because motional artifacts can be obviated with breath-held acquisitions. We have optimised the technique and evaluated its potential for angiography of the abdominal aorta and its branches as well as the portal vein and its tributaries. Whilst CE-MRA provides reliable diagnostic accuracy in the aorta and the proximal sections of its branches, small peripheral arteries cannot be assessed accurately. The portal vein and its tributaries can often be depicted better with CE-MRA than with conventional angiography but, like conventional angiography, CE-MRA is hampered by slow and reversed flow, conditions under which TOF or 'true FISP' MRA may perform bst. We have also investigated FLASH-echo-planar imaging (EPI) hybrid techniques, a further technical development which due to shorter acquisition times of 12-15 sec. allows semi-dynamic imaging of the arterial and venous phase and provide better vessel contrast due to the use of fat-suppression. (orig.)

  20. Meniscal tears of the knee : diagnosis with fast spin-echo MR imaging and role of gadolinium-enhancement

    Energy Technology Data Exchange (ETDEWEB)

    Moon, Kyung Mi; Jee, Won Hee; Choe, Bo Young; Rhim, Soo A.; Lee, Jung Whee; Ku, Young Mi; Yoon, Young Hyun; Choi, Si Young; Choi, Kyu Ho; Shinn, Kyung Sub [Catholic Univ., Seoul (Korea, Republic of). Medical Coll.

    1998-01-01

    The usefulness of fast spin-echo MR imaging for the diagnosis of meniscal tear to the knee is a matter of debate. The purpose of this study was to evaluate the accuracy of diagnosis of meniscal tears by fast spin-echo MR imaging and the role of gadolinium enhancement. In 68 cases of arthroscopically-proven meniscal tears, MR sensitivity to tear was 93% (63/68) for spin-echo alone and 96% (40/41) for combined fast spin-echo and fat-suppressed gadolinium-enhanced T1-weighted MR images. MR sensitivity to medial meniscus tear was 98% (40/41) for fast spin-echo alone and 98% (40/41) for combined fast spin-echo and fat-suppressed gadolinium-enhanced T1-weighted MR images. MR sensitivity to lateral meniscus tear was 85 % (23/27) for fast spin-echo alone and 93% (25/27) for combined fast spin-echo and fat-suppressed gadolinium-enhanced T1-weighted MR images. Fast spin-echo MR imaging with adequate imaging parameters is suitable for the diagnosis of meniscal tears, and additional fat-suppressed gadolinium-enhanced T1-weighted MR imaging may increase diagnostic sensitivity to such tears. (author). 13 refs., 1 tab., 3 figs.

  1. Does gadolinium-based contrast material improve diagnostic accuracy of local invasion in rectal cancer MRI? A multireader study.

    Science.gov (United States)

    Gollub, Marc J; Lakhman, Yulia; McGinty, Katrina; Weiser, Martin R; Sohn, Michael; Zheng, Junting; Shia, Jinru

    2015-02-01

    OBJECTIVE. The purpose of this study was to compare reader accuracy and agreement on rectal MRI with and without gadolinium administration in the detection of T4 rectal cancer. MATERIALS AND METHODS. In this study, two radiologists and one fellow independently interpreted all posttreatment MRI studies for patients with locally advanced or recurrent rectal cancer using unenhanced images alone or combined with contrast-enhanced images, with a minimum interval of 4 weeks. Readers evaluated involvement of surrounding structures on a 5-point scale and were blinded to pathology and disease stage. Sensitivity, specificity, negative predictive value, positive predictive value, and AUC were calculated and kappa statistics were used to describe interreader agreement. RESULTS. Seventy-two patients (38 men and 34 women) with a mean age of 61 years (range, 32-86 years) were evaluated. Fifteen patients had 32 organs invaded. Global AUCs without and with gadolinium administration were 0.79 and 0.77, 0.91 and 0.86, and 0.83 and 0.78 for readers 1, 2, and 3, respectively. AUCs before and after gadolinium administration were similar. Kappa values before and after gadolinium administration for pairs of readers ranged from 0.5 to 0.7. CONCLUSION. On the basis of pathology as a reference standard, the use of gadolinium during rectal MRI did not significantly improve radiologists' agreement or ability to detect T4 disease.

  2. Trading Agents

    CERN Document Server

    Wellman, Michael

    2011-01-01

    Automated trading in electronic markets is one of the most common and consequential applications of autonomous software agents. Design of effective trading strategies requires thorough understanding of how market mechanisms operate, and appreciation of strategic issues that commonly manifest in trading scenarios. Drawing on research in auction theory and artificial intelligence, this book presents core principles of strategic reasoning that apply to market situations. The author illustrates trading strategy choices through examples of concrete market environments, such as eBay, as well as abst

  3. Agents of Change

    DEFF Research Database (Denmark)

    Hansen, Jens Aage; Lehmann, Martin

    2004-01-01

    at large, it emphasises universities as key change agents and providers in new learning, including tools such as project based and problem oriented learning (PBL) as well as information and communication technology (ICT); as providers of competent and motivated graduates to fill key positions in society...

  4. Early detection of cardiac involvement in Miyoshi myopathy: 2D strain echocardiography and late gadolinium enhancement cardiovascular magnetic resonance

    Directory of Open Access Journals (Sweden)

    Kim Byoung

    2010-05-01

    Full Text Available Abstract Background Miyoshi myopathy (MM is an autosomal recessive distal myopathy characterized by early adult onset. Cardiomyopathy is a major clinical manifestation in other muscular dystrophies and an important prognostic factor. Although dysferlin is highly expressed in cardiac muscle, the effect of dysferlin deficiency in cardiac muscle has not been studied. We hypothesized that early myocardial dysfunction could be detected by 2D strain echocardiography and late gadolinium enhancement (LGE cardiovascular magnetic resonance (CMR. Method Five consecutive MM patients (3 male in whom we detected the DYSF gene mutation and age-matched healthy control subjects were included. None of the patients had history of cardiac disease or signs and symptoms of overt heart failure. Patients were studied using 2D strain echocardiography and CMR, with 2D strain being obtained using the Automated Function Imaging technique. Results All patients had preserved left ventricular systolic function. However, segmental Peak Systolic Longitudinal Strain (PSLS was decreased in 3 patients. Global PSLS was significantly lower in patients with MM than in control subjects (p = 0.005. Basal anterior septum, basal inferior septum, mid anterior, and mid inferior septum PSLS were significantly lower in patients with MM than in control subjects (P Conclusions Patients with MM showed subclinical involvement of the heart. 2D strain and LGE are sensitive methods for detecting myocardial dysfunction prior to the development of cardiovascular symptoms. The prognostic significance of these findings warrants further longitudinal follow-up.

  5. MR imaging in recurrent pain after back surgery. A comparative study using standard and high doses of gadolinium contrast agents

    Energy Technology Data Exchange (ETDEWEB)

    Aakeson, P. [Univ. Hospital, Lund (Sweden). Dept. of Radiology; Annertz, M. [Univ. Hospital, Lund (Sweden). Dept. of Radiology; Kristoffersen, D.T. [Nycomed Imaging AS, Oslo (Norway); Jonsson, E. [Nycomed AB, Stockholm (Sweden); Holtaas, S. [Univ. Hospital, Lund (Sweden). Dept. of Radiology

    1996-11-01

    Purpose: To compare the diagnostic results following injection of (a) a high dose (0.3 mmol/kg b.w.) of gadodiamide injection and (b) the standard dose (0.1 mmol/kg b.w.) of Gd-DTPA, in patients with recurrent symptoms after surgery for lumbar disc herniation. Material and Methods: Twenty patients with recurrent or sustained symptoms after surgery for lumbar disc herniations were examined. MR imaging (0.3 T) was first performed before and after Gd-DTPA at 0.1 mmol/kg b.w., and then within one month (17 patients) or within 3 months (3 patients) before and after gadodiamide injection at 0.3 mmol/kg b.w. The examinations were first evaluated by 2 neuroradiologists blinded to dose but not to patient as the images were presented in pairs. Six months later the same investigators evaluated the examinations again, this time blinded to both dose and patient. Results: At the evaluation in pairs (with the investigators blinded to dose only) the high-dose examinations were considered the most informative (p=0.05). However, at the later evaluation (with the investigators blinded both to dose and patient) no significant difference between high and standard dose was found regarding diagnosis or diagnostic certainty. Conclusion: In this study the high-dose contrast enhancement of MR imaging at 0.3 T did not increase the diagnostic information for differentiating between scar and recurrent hernia. The high-dose images were considered more informative when evaluated in pairs, but gave no additional or different information when evaluated separately. The study also indicated that comparisons in pairs should be interpreted with caution. (orig.).

  6. First clinical results of ultrafast, gadolinium-enhanced dual-phase 3D MR-angiography in the abdomen

    International Nuclear Information System (INIS)

    To assess the utility of breath-hold abdominal ultrafast three-dimensional (3D) gadolinium-enhanced dual-phase magnetic resonance angiography (MRA). Material and methods: 125 patients with various abdominal pathologies were imaged using a breath-hold ultrafast gadolinium-enhanced dual-phase 3D-MRA technique. Results: 119 (95%) of 125 MRA's were of good or excellent quality. The sensitivity in the detection of renal artery stenoses as well as stenoses of the celiac trunk and the superior mesenteric artery was 100%. Accessory renal arteries (n=9) and replaced hepatic arteries (n=4) were reliably detected by MRA. In 24 (71%) of 34 cases MR-angiographic delineation of the spleno-portal system and hepatic veins was superior compared to conventional angiography. Conclusion: Breath-hold gadolinium-enhanced dual-phase 3D-MRA has the potential to replace conventional angiography in the abdomen. (orig.)

  7. Prominent porto-systemic collateral pathways in patients with portal hypertension: demonstration by gadolinium-enhanced magnetic resonance angiography

    International Nuclear Information System (INIS)

    To demonstrate the usefulness of gadolinium-enhanced magnetic resonance angiography in the evaluation of prominent porto-systemic collateral pathways. We reviewed the images from 40 patients with portal hypertension studied with gadolinium-enhanced magnetic resonance angiography and selected illustrative cases of prominent porto-systemic collateral pathways. The scans were performed using high field equipment (1.5 Tesla) and a 3 D volume technique. Image were obtained after intravenous injection of paramagnetic contrast media using a power injector. Magnetic resonance angiography demonstrated with precision the porto-systemic collateral pathways, particularly when investigating extensive territories or large vessels. The cases presented show the potential of this method in the investigation of patients with portal hypertension. Gadolinium-enhanced magnetic resonance angiography is a useful method for the evaluation of patients with portal hypertension and prominent collateral pathways. (author)

  8. Silica nanoparticles containing 159-Gadolinium as potential system for cancer treatment

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, Andre Felipe de; Ferreira, Tiago Hilario; Sousa, Edesia Martins Barros de, E-mail: andrefelipe.oliveira88@gmail.com [Centro de Desenvolvimento da Tecnologia Nuclear (SENAN/CDTN/CNEN-MG), Belo Horizonte, MG (Brazil). Servico de Nanotecnologia; Lacerda, Marco Aurelio [Centro de Desenvolvimento da Tecnologia Nuclear (SERAS/CDTN/CNEN-MG), Belo Horizonte, MG (Brazil). Servico das Radiacoes Aplicadas a Saude

    2013-07-01

    Ordered silica nanoparticles are compounds highly organized which have very interesting textural characteristics, such as high thermal stability, well defined pore size, narrow size distribution and high area surface. Among the various types of nano materials ordered, the SBA-16 have a meso structure that can be considered very interesting due to the fact of the arrangement of mesoporous (tri dimensional as a cage) and spherical morphology, which make it in a promising material for a range of bioapplications such as incorporation of drugs and radioisotopes. In this study Gadodiamide® (Omniscan-General Electric Healthcare Company), a frequently non-ionic gadolinium complex contrasting used in MRI's was incorporated in the silica matrix SBA-16 as a carrier. From this gadolinium it is possible to obtain the isotope {sup 159}Gd by neutron irradiation, wherein the isotope {sup 158}Gd captures a neutron and becomes {sup 159}Gd [{sup 15}'8Gd(n,c){sup 1}'5{sup 9}Gd]. The {sup 159}Gd is a beta (endpoint energy of 970.6 keV) and gamma (main energy: 363.54 keV) emitter with a half-life of 18.59 hours. These characteristics are similar to that of other isotopes already used in nuclear medicine such as {sup 90}Y. In this work, the {sup 158}Gd incorporated in the Gd-silica was activated by the neutron flux generated by the cyclotron located in the Centro de Desenvolvimento da Tecnologia Nuclear (CDTN) during the production of the {sup 18}FDG. Atomic emission spectroscopy (ICP-AES) and infrared spectroscopy (FTIR) were used to confirm the presence of the gadolinium complex in the silica matrix. The antitumor activity of the complex after the irradiation was evaluated through cytotoxicity assay with T98 cell lines derived from a human glioblastoma multiform tumor. (author)

  9. Relaxometric studies of gadolinium-functionalized perfluorocarbon nanoparticles for MR imaging.

    Science.gov (United States)

    de Vries, Anke; Moonen, Rik; Yildirim, Muhammed; Langereis, Sander; Lamerichs, Rolf; Pikkemaat, Jeroen A; Baroni, Simona; Terreno, Enzo; Nicolay, Klaas; Strijkers, Gustav J; Grüll, Holger

    2014-01-01

    Fluorine MRI ((19) F MRI) is receiving an increasing attention as a viable alternative to proton-based MRI ((1) H MRI) for dedicated application in molecular imaging. The (19) F nucleus has a high gyromagnetic ratio, a 100% natural abundance and is furthermore hardly present in human tissues allowing for hot spot MR imaging. The applicability of (19) F MRI as a molecular and cellular imaging technique has been exploited, ranging from cell tracking to detection and imaging of tumors in preclinical studies. In addition to applications, developing new contrast materials with improved relaxation properties has also been a core research topic in the field, since the inherently low longitudinal relaxation rates of perfluorocarbon compounds result in relatively low imaging efficiency. Borrowed from (1) H MRI, the incorporation of lanthanides, specifically Gd(III) complexes, as signal modulating ingredients in the nanoparticle formulation has emerged as a promising approach to improvement of the fluorine signal. Three different perfluorocarbon emulsions were investigated at five different magnetic field strengths. Perfluoro-15-crown-5-ether was used as the core material and Gd(III)DOTA-DSPE, Gd(III)DOTA-C6-DSPE and Gd(III)DTPA-BSA as the relaxation altering components. While Gd(III)DOTA-DSPE and Gd(III)DOTA-C6-DSPE were favorable constructs for (1) H NMR, Gd(III)DTPA-BSA showed the strongest increase in (19F) R(1). These results show the potential of the use of paramagnetic lipids to increase (19F) R(1) at clinical field strengths (1.5-3 T). At higher field strengths (6.3-14 T), gadolinium does not lead to an increase in (19F) R(1) compared with emulsions without gadolinium, but leads to an significant increase in (19F) R(2). Our data therefore suggest that the most favorable situation for fluorine measurements is at high magnetic fields without the inclusion of gadolinium constructs.

  10. UTBot: A Virtual Agent Platform for Teaching Agent System Design

    Directory of Open Access Journals (Sweden)

    In-Cheol Kim

    2007-02-01

    Full Text Available We introduce UTBot, a virtual agent platform for teaching agent system design. UTBot implements a client for the Unreal Tournament game server and Gamebots system. It provides students with the basic functionality required to start developing their own intelligent virtual agents to play autonomously UT games. UTBot includes a generic agent architecture, CAA (Context-sensitive Agent Architecture, a domain-specific world model, a visualization tool, several basic strategies (represented by internal modes and internal behaviors, and skills (represented by external behaviors. The CAA architecture can support complex long-term behaviors as well as reactive short-term behaviors. It also realizes high context-sensitivity of behaviors. We also discuss our experience using UTBot as a pedagogical tool for teaching agent system design in undergraduate Artificial Intelligence course.

  11. Radioprotective Agents

    Directory of Open Access Journals (Sweden)

    Ilker Kelle

    2008-01-01

    Full Text Available Since1949, a great deal of research has been carried out on the radioprotective activity of various chemical substances. Thiol compounds, compounds which contain –SH radical, different classes of pharmacological agents and other compounds such as vitamine C and WR-2721 have been shown to reduce mortality when administered prior to exposure to a lethal dose of radiation. Recently, honey bee venom as well as that of its components melittin and histamine have shown to be valuable in reduction of radiation-induced damage and also provide prophylactic alternative treatment for serious side effects related with radiotherapy. It has been suggested that the radioprotective activity of bee venom components is related with the stimulation of the hematopoetic system.

  12. Caustic Precipitation of Plutonium Using Gadolinium as the Neutron Poison for Disposition to High Level Waste

    International Nuclear Information System (INIS)

    Nuclear Materials Management Division (NMMD) has proposed that up to 100 kg of the plutonium (Pu) solutions stored in H-Canyon be precipitated with a nuclear poison and dispositioned to H-Area Tank Farm. The use of gadolinium (Gd) as the poison would greatly reduce the number of additional glass logs resulting from this disposition. This report summarizes the characteristics of the precipitation process and addresses criticality concerns in the Nuclear Criticality Safety Evaluation. No problems were found with the nature of the precipitate or the neutralization process

  13. Separate spectrophotometric determination of gadolinium and dysprosium in binary mixtures by phthalexones using nomogram

    International Nuclear Information System (INIS)

    The possibility has been shown of using different-ligand complexes of rare earths with phthalexones and cetylpyridinium for differential spectrophotometric determination of rare earths in mixtures. The molar absorptivities of individual components of a mixture are not constant values if the total mixture concentration changes. The application of an equation for calculation of mixture absorbances makes it possible to change concentration of the components in mixtures over a wide range (the limit Me1:Me2 ratio is 1:50). Simultaneous nomographic determinations of gadolinium and dysprosium in their mixtures were carried out

  14. Controlled manipulation of gadolinium-coordinated supramolecules by low-temperature scanning tunneling microscopy.

    Science.gov (United States)

    Urgel, José I; Ecija, David; Auwärter, Willi; Barth, Johannes V

    2014-03-12

    Coordination bonding between para-quarterphenyl-dicarbonitrile linkers and gadolinium on Ag(111) has been exploited to construct pentameric mononuclear supramolecules, consisting of a rare-earth center surrounded by five molecular linkers. By employing a scanning tunneling microscope tip, a manipulation protocol was developed to position individual pentamers on the surface. In addition, the tip was used to extract and replace individual linkers yielding tetrameric, pentameric, nonameric, and dodecameric metallosupramolecular arrangements. These results open new avenues toward advanced nanofabrication methods and rare-earth nanochemistry by combining the versatility of metal-ligand interactions and atomistic manipulation capabilities.

  15. Peculiarities of gadolinium molybdate change-over using alternating electric field

    International Nuclear Information System (INIS)

    Experimental investigation into processes of total repolarization of a gadolinium molybdate monocrystal Gd(MoO4)3-GMO following alternating electric effects is conduced. The process of total change-over of the GMO monocrystal with a capillar layer of weak-conductive liquid deposited on its polar surfaces at application of alternating stationary electric field is shown to proceed through sidewise traverse of the single plane domain boundary of one and the same crystallographical orientation (110) in the coordinate system of monodomain state being changed-over

  16. Controllable Fabrication and Optical Properties of Uniform Gadolinium Oxysulfate Hollow Spheres

    OpenAIRE

    Fashen Chen; Gen Chen; Tao Liu; Ning Zhang; Xiaohe Liu; Hongmei Luo; Junhui Li; Limiao Chen; Renzhi Ma; Guanzhou Qiu

    2015-01-01

    Uniform gadolinium oxysulfate (Gd2O2SO4) hollow spheres were successfully fabricated by calcination of corresponding Gd-organic precursor obtained via a facile hydrothermal process. The Gd2O2SO4 hollow spheres have a mean diameter of approximately 550 nm and shell thickness in the range of 30–70 nm. The sizes and morphologies of as-prepared Gd2O2SO4 hollow spheres could be deliberately controlled by adjusting the experimental parameters. Eu-doped Gd2O2SO4 hollow spheres have also been prepare...

  17. Vascular changes caused by deep brain stimulation using double-dose gadolinium-enhanced brain MRI

    Institute of Scientific and Technical Information of China (English)

    Byeong Sam Choi; Yong Hwan Kim; Sang Ryong Jeon

    2014-01-01

    We retrospectively analyzed the clinical data of 32 patients with medically intractable idiopathic Parkinson’s disease who had undergone staged bilateral deep brain stimulation of the subtha-lamic nuclei from January 2007 to May 2011. The vascularture of the patients who received two deep brain stimulations was detected using double-dose gadolinium-enhanced brain MRI. The dimensions of straight sinus, superior sagittal sinus, ipsilateral internal cerebral vein in the tha-lamic branch and ipsilateral anterior caudate vein were reduced. These ifndings demonstrate that bilateral deep brain stimulation of the subthalamic nuclei affects cerebral venous blood lfow.

  18. Production of Gadolinium-loaded Liquid Scintillator for the Daya Bay Reactor Neutrino Experiment

    CERN Document Server

    Beriguete, Wanda; Ding, Yayun; Hans, Sunej; Heeger, Karsten M; Hu, Liangming; Huang, Aizhong; Luk, Kam-Biu; Nemchenok, Igor; Qi, Ming; Rosero, Richard; Sun, Hansheng; Wang, Ruiguang; Wang, Yifang; Wen, Liangjian; Yang, Yi; Yeh, Minfang; Zhang, Zhiyong; Zhou, Li

    2014-01-01

    We report on the production and characterization of liquid scintillators for the detection of electron antineutrinos by the Daya Bay Reactor Neutrino Experiment. One hundred eighty-five tons of gadolinium-loaded (0.1% by mass) liquid scintillator (Gd-LS) and two hundred tons of unloaded liquid scintillator (LS) were successfully produced from a linear-alkylbenzene (LAB) solvent in six months. The scintillator properties, the production and purification systems, and the quality assurance and control (QA/QC) procedures are described.

  19. Radicals as EPR probes of magnetization of gadolinium stearate Langmuir-Blodgett film

    DEFF Research Database (Denmark)

    Koksharov, Y.A.; Bykov, I.V.; Malakho, A.P.;

    2002-01-01

    In the present work we have applied the method of the EPR spin probes which allows performing simultaneously EPR and magnetization measurements to the investigation of magnetism of the Cid stearate Langmuir-Blodgett (LB) films. For this purpose we have prepared and studied by the EPR technique th...... corresponded to the magnetization of the film along the field direction. Such effect has not been observed for the Y stearate LB film. The data obtained give an experimental proof for the room temperature. magnetic ordering in the! gadolinium stearate LB film....

  20. Gadolinium(III) texaphyrin: a tumor selective radiation sensitizer that is detectable by MRI.

    OpenAIRE

    Young, S W; Qing, F; Harriman, A; Sessler, J.L.; Dow, W C; Mody, T D; Hemmi, G W; Hao, Y.; Miller, R. A.

    1996-01-01

    Gadolinium(III) texaphyrin (Gd-tex2+) is representative of a new class of radiation sensitizers detectable by magnetic resonance imaging (MRI). This porphyrin-like complex has a high electron affinity [E1/2 (red.) approximately = -0.08 V versus normal hydrogen electrode] and forms a long-lived pi-radical cation upon exposure to hydrated electrons, reducing ketyl radicals, or superoxide ions. Consistent with these chemical findings, Gd-tex2+ was found to be an efficient radiation sensitizer in...

  1. Separation of gadolinium(III) and lanthanum(III) by nanofiltration-complexation in aqueous medium

    International Nuclear Information System (INIS)

    A new method is proposed for the separation of gadolinium(III) and lanthanum(III) in aqueous medium by nanofiltration combined with a complexation step. First DTPA was chosen as ligand for a selective Gd(III)/La(III) complexation. Having investigated the influence of three factors (pH, temperature and amount of ligand) for the selective complexation of DTPA towards Gd(III) and La(III), the system is then combined with a nanofiltration separation process to remove 92% of initial Gd(III) and only 12% of initial La. (author)

  2. High-resolution, three-step resonance ionization mass spectrometry of gadolinium

    Science.gov (United States)

    Blaum, K.; Bushaw, B. A.; Nörtershäuser, W.; Wendt, K.

    2001-08-01

    High-resolution resonance ionization mass spectrometry has been used to measure triple-resonance autoionization (AI) spectra of gadolinium. Al resonances as narrow as 10 MHz have been observed and isotope shifts and hyperfine structure have been measured in selected AI states. The strongest AI state observed at 49663.576 cm-1 with a photoionization cross section of >3.6×10-15 cm2 was found to have an overall detection efficiency of >3×10-5, allowing application to a number of ultratrace determination problems. Analytical measurements with a diode-laser-based system have been successfully performed on bio-medical tissue samples.

  3. High-resolution, three-step resonance ionization mass spectrometry of gadolinium

    International Nuclear Information System (INIS)

    High-resolution resonance ionization mass spectrometry has been used to measure triple-resonance autoionization (AI) spectra of gadolinium. Al resonances as narrow as 10 MHz have been observed and isotope shifts and hyperfine structure have been measured in selected AI states. The strongest AI state observed at 49663.576 cm-1 with a photoionization cross section of >3.6x10-15 cm2 was found to have an overall detection efficiency of >3x10-5, allowing application to a number of ultratrace determination problems. Analytical measurements with a diode-laser-based system have been successfully performed on bio-medical tissue samples

  4. Anchor Toolkit - a secure mobile agent system

    OpenAIRE

    Mudumbai, Srilekha S.; Johnston, William; Essiari, Abdelilah

    2008-01-01

    Mobile agent technology facilitates intelligent operation in software systems with less human interaction. Major challenge to deployment of mobile agents include secure transmission of agents and preventing unauthorized access to resources between interacting systems, as either hosts, or agents, or both can act maliciously. The Anchor toolkit, designed by LBNL, handles the transmission and secure management of mobile agents in a heterogeneous distributed computing environment. It provide...

  5. Importance of timing of post-contrast MRI in rheumatoid arthritis: what happens during the first 60 minutes after IV gadolinium-DTPA?

    DEFF Research Database (Denmark)

    Østergaard, Mikkel; Klarlund, Mette

    2001-01-01

    BACKGROUND: Volumes of inflamed synovial membrane determined by magnetic resonance imaging (MRI) are closely related to histopathological synovitis and may predict erosive progression in rheumatoid arthritis (RA). However, after IV injection, leakage of MRI contrast from the synovium gradually...... compromises the differentiation of synovium from joint fluid. OBJECTIVE: To determine the time period after IV MRI contrast (gadolinium-DTPA (Gd)) injection in which synovial membrane volume determination is reliable. METHODS: MRI of five RA knees with clinical synovitis was carried out, with axial, T(1......) weighted, spin echo images before IV Gd injection and every 1.75 minutes for 60 minutes post-Gd. By a semiautomated "signal enhancement threshold" method, including voxels with >35% or >45% relative post-Gd enhancement, synovial membrane volumes were estimated at each time point. At 4.25 minutes post...

  6. Pharmacologic Agents for Chronic Diarrhea

    OpenAIRE

    Lee, Kwang Jae

    2015-01-01

    Chronic diarrhea is usually associated with a number of non-infectious causes. When definitive treatment is unavailable, symptomatic drug therapy is indicated. Pharmacologic agents for chronic diarrhea include loperamide, 5-hydroxytryptamine type 3 (5-HT3) receptor antagonists, diosmectite, cholestyramine, probiotics, antispasmodics, rifaximin, and anti-inflammatory agents. Loperamide, a synthetic opiate agonist, decreases peristaltic activity and inhibits secretion, resulting in the reductio...

  7. Stability of Evolving Agent Populations

    CERN Document Server

    Briscoe, G

    2007-01-01

    Stability is perhaps the most desired feature in the systems that we design. It is important for us to be able to predict the response of a Multi-Agent System (MAS) to various environmental conditions prior to its actual deployment. The Chli-DeWilde agent stability measure views a MAS as a discrete time Markov chain with a potentially unknown transition probabilities. A MAS is considered to be stable when its state, a stochastic process, has converged to an equilibrium distribution. We investigate an extension of their agent stability definition to include MASs with evolutionary dynamics, focusing on evolving agent populations. Additionally, using our extended agent stability measure, we construct an entropy-based definition for the degree of instability. An example system, the Digital Ecosystem, is considered in detail to investigate the stability of an evolving agent population through simulations. The results are consistent with the original Chli-DeWilde measure.

  8. Odor Classification using Agent Technology

    Directory of Open Access Journals (Sweden)

    Sigeru OMATU

    2014-03-01

    Full Text Available In order to measure and classify odors, Quartz Crystal Microbalance (QCM can be used. In the present study, seven QCM sensors and three different odors are used. The system has been developed as a virtual organization of agents using an agent platform called PANGEA (Platform for Automatic coNstruction of orGanizations of intElligent Agents. This is a platform for developing open multi-agent systems, specifically those including organizational aspects. The main reason for the use of agents is the scalability of the platform, i.e. the way in which it models the services. The system models functionalities as services inside the agents, or as Service Oriented Approach (SOA architecture compliant services using Web Services. This way the adaptation of the odor classification systems with new algorithms, tools and classification techniques is allowed.

  9. An agent framework for dynamic agent retraining: Agent academy

    OpenAIRE

    Mitkas, P.; A. Symeonidis; Kechagias, D.; Athanasiadis, I.N.; Laleci, G.; KURT, G.; Kabak, Y.; Acar, A.; Dogac, A.

    2004-01-01

    Agent Academy (AA) aims to develop a multi-agent society that can train new agents for specific or general tasks, while constantly retraining existing agents in a recursive mode. The system is based on collecting information both from the environment and the behaviors of the acting agents and their related successes/failures to generate a body of data, stored in the Agent Use Repository, which is mined by the Data Miner module, in order to generate useful knowledge about the application domai...

  10. First-principles study of 2D electride : Gadolinium carbide

    Science.gov (United States)

    Nandadasa, Chandani; Kim, Seong-Gon; Kim, Sungho; Kim, Sung Wng

    Electrides are an exclusive class of ionic compounds in which some electrons are occupying crystal voids instead of attaching to specific atoms or bonds. Using first-principles density functional theory calculations, we study structural, electronic and magnetic properties of Gd2C. The theoretically predicted structure of Gd2C is in good agreement with the available experimental data. Energy band diagram of Gd2C shows that they are crossing the Fermi level. Projected electronic density of states plots indicate that the interstitial sites are the main contributor to the density of states at the Fermi level. Charge of individual atoms including interstitial site are obtained using Bader analysis. Magnetic properties of Gd2C is determined from magnetization density plots. Work functions of Gd2C are determined for (001) and (100) surfaces with the technique of macroscopic average of electrostatic potential with the Fermi energy of bulk.

  11. Biocompatible and high-performance amino acids-capped MnWO4 nanocasting as a novel non-lanthanide contrast agent for X-ray computed tomography and T1-weighted magnetic resonance imaging

    Science.gov (United States)

    Dong, Kai; Liu, Zhen; Liu, Jianhua; Huang, Sa; Li, Zhenhua; Yuan, Qinghai; Ren, Jinsong; Qu, Xiaogang

    2014-01-01

    -weighted MR imaging capabilities. As an alternative to T2-weighted MRI and CT dual-modality contrast agents, the nanoprobes can provide a positive contrast signal, which prevents confusion with the dark signals from hemorrhage and blood clots. To the best of our knowledge, this is the first report that a non-lanthanide imaging nanoprobe is applied for CT and T1-weighted MRI simultaneously. Moreover, comparing with gadolinium-based T1-weighted MRI and CT dual-modality contrast agents that were associated with nephrogenic systemic fibrosis (NSF), our contrast agents have superior biocompatibility, which is proved by a detailed study of the pharmacokinetics, biodistribution, and in vivo toxicology. Together with excellent dispersibility, high biocompatibility and superior contrast efficacy, these nanoprobes provide detailed and complementary information from dual-modality imaging over traditional single-mode imaging and bring more opportunities to the new generation of non-lanthanide nanoparticulate-based contrast agents. Electronic supplementary information (ESI) available: TEM images of MnWO4 nanoparticles synthesized at pH = 7, 180 °C pH = 9, 180 °C pH = 6, 200 °C with various amino acid molecules as capped agents, survey XPS spectra, FTIR spectrum of glycine capped MnWO4 nanorods, photos of glycine capped MnWO4 nanorods in various solutions including PBS, DMEM cell medium, and FBS, in vivo coronal view CT images of a rat before and after intravenous injection of iobitridol at different timed intervals, in vivo CT imaging of the rat one month after intravenous injection of MnWO4 nanorods, CT values of the heart, liver, spleen and kidney of a rat before and after intravenous administration of MnWO4 nanorods and iobitridol at different time intervals, hematology analysis and blood biochemical assay. See DOI: 10.1039/c3nr05455a

  12. Gadolinium-enhanced magnetic resonance angiography with ultra-short echo times. Initial experience

    International Nuclear Information System (INIS)

    Magnetic resonance angiography (MRA) using three-dimensional (3D) gradient-echo sequences with ultra-short echotimes (USTE; 2 ms) and luminal enhancement of vessels with a gadolinium bolus affords the depiction of extended vascular territories with high spatial resolution within 20-60 s. Because of the ultra-short echo and repetition times, filling of the vascular lumen with gadolinium is depicted; the latter is relatively independent of the complex flow effects on which conventional MRA is based. MRA typical flow voids caused by turbulence or slow flow are thus significantly reduced and allow more reliable depiction of stenoses. After implementing the sequences on our scanner, we evaluated the potential of USTE-MRA for the delineation of various vascular territories in 56 patients. A total of 70 vascular territories were depicted and evaluated by two independent radiologists for image quality and obscuring the arteries because of the contrast of veins. Out of the 56 (4%) diagnostic angiographic quality could not be obtained in only 2 cases. In 13 patients (23%) the studies were judged suboptimal, but diagnostic. In only 3 cases (5%) was venous filling judged to obscure the arteries completely on MIPs (maximum intensity reconstructions), although the studies were diagnostic when evaluated with MRPs (multiplanar reconstructions). Venous superimposition occurred significantly more frequently in the neck than elsewhere. The greatest improvement over conventional MRA was obtained in the abdomen and thorax where USTE-MRAs can be obtained within a breath-hold without motional artifact. (orig.)

  13. Tracing the spatial propagation of river inlet water into an agricultural polder area using anthropogenic gadolinium

    Directory of Open Access Journals (Sweden)

    J. Rozemeijer

    2012-08-01

    Full Text Available Diverting river water into agricultural areas or nature reserves is a frequently applied management strategy to prevent fresh water shortage. However, the river water might have negative consequences for chemical and ecological water quality in the receiving water bodies. This study aimed to obtain a spatial image of the diverted river water propagation into a hydrologically complex polder area, the polder Quarles van Ufford in The Netherlands. We used anthropogenic gadolinium (Gd-anomaly as a tracer for river water that was diverted into the polder. A clear reduction in the river water contribution was found between very dry conditions on 5 August 2010 and very wet conditions on 22 October. Despite the large river water impact on 5 August, the diverted river water did not propagate up into the small agricultural headwater ditches. Gadolinium proved to be an effective tracer for diverted river water in a polder system. We applied our results to upgrade the interpretation of water quality monitoring data and to validate an integrated nutrient transport model.

  14. Gadolinium-148 And Other Spallation Production Cross Section Measurements For Accelerator Target Facilities

    CERN Document Server

    Kelley, K C

    2004-01-01

    At the Los Alamos Neutron Science Center accelerator complex, protons are accelerated to 800 MeV and directed to two tungsten targets, Target 4 at the Weapons Neutron Research facility and the 1L target at the Lujan Center. The Department of Energy requires hazard classification analyses to be performed on these targets and places limits on certain radionuclide inventories in the targets to avoid characterizing the facilities as “nuclear facilities.” Gadolinium-148 is a radionuclide created from the spallation of tungsten. Allowed isotopic inventories are particularly low for this isotope because it is an alpha-particle emitter with a 75-year half-life. The activity level of Gadolinium-148 is low, but it encompasses almost two-thirds of the total dose burden for the two tungsten targets based on present yield estimates. From a hazard classification standpoint, this severely limits the lifetime of these tungsten targets. The cross section is not well-established experimentally and this is t...

  15. Effect of solid-phase amorphization on the spectral characteristics of europium-doped gadolinium molybdate

    Science.gov (United States)

    Shmurak, S. Z.; Kiselev, A. P.; Kurmasheva, D. M.; Red'Kin, B. S.; Sinitsyn, V. V.

    2010-05-01

    A method is proposed for detecting spectral characteristics of optically inactive molybdates of rare-earth elements by their doping with rare-earth ions whose luminescence lies in the transparency region of all structural modifications of the sample. Gadolinium molybdate is chosen as the object of investigations, while europium ions are used as an optically active and structurally sensitive admixture. It is shown that after the action of a high pressure under which gadolinium molybdate passes to the amorphous state, the spectral characteristics of Gd1.99Eu0.01(MoO4)3 (GMO:Eu) change radically; namely, considerable line broadening is observed in the luminescence spectra and the luminescence excitation spectra, while the long-wave threshold of optical absorption is shifted considerably (by approximately 1.1 eV) towards lower energies. It is found that by changing the structural state of GMO:Eu by solid-state amorphization followed by annealing, the spectral characteristics of the sample can be purposefully changed. This is extremely important for solving the urgent problem of designing high-efficiency light-emitting diodes producing “white” light.

  16. Development of a gadolinium-loaded liquid scintillator for the Hanaro short baseline prototype detector

    Science.gov (United States)

    Yeo, In Sung; Joo, Kyung Kwang; So, Sun Heang; Song, Sook Hyung; Kim, Hong Joo; So, Jung Ho; Park, Kang Soon; Ma, Kyung Ju; Jeon, Eun Ju; Kim, Jin Yu; Kim, Young Duk; Lee, Jason; Lee, Jeong-Yeon; Sun, Gwang-Min

    2014-02-01

    We propose a new experiment on the site of the Korea Atomic Energy Research Institute (KAERI) located at Daejeon, Korea. The Hanaro short baseline (SBL) nuclear reactor with a thermal power output 30 MW is used to investigate a reactor neutrino anomaly. A Hanaro SBL prototype detector having a 60- l volume has been constructed ˜6 m away from the reactor core. A gadolinium (Gd)-loaded liquid scintillator (LS) is used as an active material to trigger events. The selection of the LS is guided by physical and technical requirements, as well as safety considerations. A linear alkyl benzene (LAB) is used as a base solvent of the Hanaro SBL prototype detector. Three g/ l of PPO and 30 mg/ l of bis-MSB are dissolved to formulate the LAB-based LS. Then, a 0.5% gadolinium (Gd) complex with carboxylic acid is loaded into the LAB-based LS by using the liquidliquid extraction method. In this paper, we will summarize all the characteristics of the Gd-loaded LAB-based LS for the Hanaro prototype detector.

  17. Effect of solid-phase amorphization on the spectral characteristics of europium-doped gadolinium molybdate

    International Nuclear Information System (INIS)

    A method is proposed for detecting spectral characteristics of optically inactive molybdates of rare-earth elements by their doping with rare-earth ions whose luminescence lies in the transparency region of all structural modifications of the sample. Gadolinium molybdate is chosen as the object of investigations, while europium ions are used as an optically active and structurally sensitive admixture. It is shown that after the action of a high pressure under which gadolinium molybdate passes to the amorphous state, the spectral characteristics of Gd1.99Eu0.01(MoO4)3 (GMO:Eu) change radically; namely, considerable line broadening is observed in the luminescence spectra and the luminescence excitation spectra, while the long-wave threshold of optical absorption is shifted considerably (by approximately 1.1 eV) towards lower energies. It is found that by changing the structural state of GMO:Eu by solid-state amorphization followed by annealing, the spectral characteristics of the sample can be purposefully changed. This is extremely important for solving the urgent problem of designing high-efficiency light-emitting diodes producing 'white' light.

  18. Investigation of Plutonium and Uranium Precipitation Behavior with Gadolinium as a Neutron Poison

    CERN Document Server

    Visser, A E

    2003-01-01

    The caustic precipitation of plutonium (Pu)-containing solutions has been investigated to determine whether the presence of 3:1 uranium (U):Pu in solutions stored in the H-Canyon Facility at the U.S. Department of Energy's (DOE) Savannah River Site (SRS) would adversely impact the use of gadolinium nitrate (Gd(NO3)3) as a neutron poison. In the past, this disposition strategy has been successfully used to discard solutions containing approximately 100 kg of Pu to the SRS high level waste (HLW) system. In the current experiments, gadolinium (as Gd(NO3)3) was added to samples of a 3:1 U:Pu solution, a surrogate 3 g/L U solution, and a surrogate 3 g/L U with 1 g/L Pu solution. A series of experiments was then performed to observe and characterize the precipitate at selected pH values. Solids formed at pH 4.5 and were found to contain at least 50 percent of the U and 94 percent of the Pu, but only 6 percent of the Gd. As the pH of the solution increased (e.g., pH greater than 14 with 1.2 or 3.6 M sodium hydroxide...

  19. Hydrogen in-situ refining method for preparing high purity gadolinium

    Energy Technology Data Exchange (ETDEWEB)

    Li, Guoling [Beijing National Laboratory of Molecular Sciences, State Key Laboratory of Rare Earth Materials Chemistry and Applications, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871 (China); Department of Materials Physics and Chemistry, University of Science and Technology Beijing, NO. 30, Xueyuan Road, Beijing 100083 (China); Li, Li [Beijing National Laboratory of Molecular Sciences, State Key Laboratory of Rare Earth Materials Chemistry and Applications, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871 (China); Fu, Kai [Beijing National Laboratory of Molecular Sciences, State Key Laboratory of Rare Earth Materials Chemistry and Applications, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871 (China); Department of Materials Physics and Chemistry, University of Science and Technology Beijing, NO. 30, Xueyuan Road, Beijing 100083 (China); Wang, Chongyun [Department of Materials Physics and Chemistry, University of Science and Technology Beijing, NO. 30, Xueyuan Road, Beijing 100083 (China); Zheng, Jie [Beijing National Laboratory of Molecular Sciences, State Key Laboratory of Rare Earth Materials Chemistry and Applications, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871 (China); Xu, Li [State Grid Smart Grid Research Institute, Future Science& Technology Park, Changping, Beijing 102211 (China); Tian, Wenhuai [Department of Materials Physics and Chemistry, University of Science and Technology Beijing, NO. 30, Xueyuan Road, Beijing 100083 (China); Li, Xingguo, E-mail: xgli@pku.edu.cn [Beijing National Laboratory of Molecular Sciences, State Key Laboratory of Rare Earth Materials Chemistry and Applications, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871 (China)

    2015-11-05

    The removal of non-metallic impurities, especially oxygen and nitrogen, from the rare-earth metal gadolinium (Gd) is challenging, due to their strong affinity to Gd metal. Herein we present an effective approach to prepare high purity Gd via a novel hydrogen in-situ refining method. The final concentrations of oxygen and nitrogen could be reduced to 30 and 19 mass ppm, respectively. The changes of lattice parameters were derived from XRD; enthalpy values and gaseous speciation associated with the gas–solid physiochemical reactions were determined through a combination of DSC/MS measurements and thermodynamic calculations. The results show that oxygen and nitrogen can be efficiently removed by degassing Gd with dissolved hydrogen. The underlying mechanism for the refinement is discussed systematically in this paper. - Highlights: • Hydrogen can shuttle gadolinium freely at high temperature. • The concentration of O and N dropped to 30 ppm and 19 ppm, respectively. • The hydrogen content could finally decrease to 17 ppm. • Hydrogen, water and ammonia signals can be detected successfully. • This method is environment friendly and no other recontaminations.

  20. Biochemical effects of gadolinium chloride in rats liver and kidney studied by 1H NMR metabolomics

    Institute of Scientific and Technical Information of China (English)

    LIAO Peiqiu; WEI Lai; Wu Huifeng; LI Weisheng; WU Yijie; LI Xiaojing; NI Jiazuan; PEI Fengkui

    2009-01-01

    The biochemical effects of gadolinium chloride were studied using high-resolution IH nuclear magnetic resonance (NMR) spec-troscopy to investigate the biochemical composition of tissue (liver and kidney) aqueous extracts obtained from control and gadolinium chlo-ride (GdCl3) (10 and 50 mg/kg body weight, intraperitoneal injection, i.p.) treated rats. Tissue samples were collected at 48, 96 and 168 h p.d. after exposure to GdCl3, and extracted using methanol/chloroform solvent system. 1H NMR spectra of tissue extracts were analyzed by pat-tern recognition using principal components analysis. The liver damages caused by GdCl3 were characterized by increased succinate and de-creased glycogen level and elevated lactate, alanine and betaine concentration in liver. Furthermore, the increase of creatine and lactate, and decrease of glutamate, alanine, phosphocholine, glycophosphocholine (GPC), betaine, myo-inositoi and trimethylamine N-oxide (TMAO)levels in kidney illustrated kidney disturbance induced by GdCl3.

  1. Implementation of a Gadolinium Burnable Absorber in the Carbide LEU-NTR

    Energy Technology Data Exchange (ETDEWEB)

    Venneria, Paolo; Kim, Yonghee [Korea Advanced Institute of Science and Technology, Daejeon (Korea, Republic of)

    2015-05-15

    Among the most crucial are the rapid reactivity depletion during full-power operation and the positive reactivity insertion during the full-submersion criticality accident. In previous work, it has been suggested that both challenges can be mitigated through the successful implementation of a burnable absorber in the active core. Of the poisons previously surveyed, one of the most promising is Gadolinium in the form of Gadolina (Gd2O4). This paper explores the possibility of different methods by which the Gadolinia can be implemented in the core and makes a preliminary study of its effect on the full submersion criticality accident and the reactivity depletion during operation. The application of a Gadolinium neutron absorber in the active core region of the LEU-NTR has been shown to be neutronically feasible. It can be introduced into the core in various locations without resulting in core performance loss. The utility of the poison in terms of mitigating the full-submersion reactivity accident and the rapid change in reactivity during full-power operation have been preliminarily shown and the first steps towards eventual implementation made. Future work will consist of determining the maximum poison content in the core and tailoring the self-shielding effect in order to determine a specific Gd depletion rate.

  2. Acute and chronic tears of anterior cruciate ligament : role of gadolinium-enhanced MR imaging

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Eun Jung; Jee, Won Hee; Im, Soo A; Chun, Ho Jong; Jung, Hyun Seouk; Kim, Soo Young; Kwon, Tae An; Song, Sun Wha; Choi, Kyu Ho [Catholic Univ. Medical College. Kangnam St. Mary' s Hospital, Seoul (Korea, Republic of)

    1998-07-01

    To evaluate the efficacy of fat-suppressed gadolinium-enhanced MR imaging in differentiating acute from chronic ligament tears of anterior cruciate ligament. Materials and Methods : MR images of 22 patients with arthroscopically proven complete tear of the anterior cruciate ligament were retrospectively reviewed. The interval between injury and MR examination was one day to seven years. When ligament tear was detected on MR image with three months of injury, the case was considered acute;if detected after three months had elapsed, it was judged to be chronic. The extent of contrast enhancement was graded as 1, 2 or 3; grade 1, enhancement was confined to the expected ligament region; grade 2, enhancement extended to the joint capsule; grade 3, enhancement extended beyond the joint capsule. The grades of contrast enhancement correlated with the acute and chronic stages of ligament tears. Associated bone bruise and/or adjacent soft tissue edema were also evaluated. Results : Among 15 patients with acute ligament tear, nine (60%) showed grade 3 enhancement; among seven in whom tearing was chronic, four (57%) showed grade 1 enhancement. Bone bruising was present in 100% of acute tears (15/15) and 29 % of chronic tears (2/7). Soft tissue edema was associated in 87% of acute tears (13/15) and 29% of chronic tears(2/7). Conclusion : Fat-suppressed gadolinium-enhanced MR imaging could help differentiate acute from chronic tears of anterior cruciate ligament, as well as bone bruising and tissue edema.

  3. Acute and chronic tears of anterior cruciate ligament : role of gadolinium-enhanced MR imaging

    International Nuclear Information System (INIS)

    To evaluate the efficacy of fat-suppressed gadolinium-enhanced MR imaging in differentiating acute from chronic ligament tears of anterior cruciate ligament. Materials and Methods : MR images of 22 patients with arthroscopically proven complete tear of the anterior cruciate ligament were retrospectively reviewed. The interval between injury and MR examination was one day to seven years. When ligament tear was detected on MR image with three months of injury, the case was considered acute;if detected after three months had elapsed, it was judged to be chronic. The extent of contrast enhancement was graded as 1, 2 or 3; grade 1, enhancement was confined to the expected ligament region; grade 2, enhancement extended to the joint capsule; grade 3, enhancement extended beyond the joint capsule. The grades of contrast enhancement correlated with the acute and chronic stages of ligament tears. Associated bone bruise and/or adjacent soft tissue edema were also evaluated. Results : Among 15 patients with acute ligament tear, nine (60%) showed grade 3 enhancement; among seven in whom tearing was chronic, four (57%) showed grade 1 enhancement. Bone bruising was present in 100% of acute tears (15/15) and 29 % of chronic tears (2/7). Soft tissue edema was associated in 87% of acute tears (13/15) and 29% of chronic tears(2/7). Conclusion : Fat-suppressed gadolinium-enhanced MR imaging could help differentiate acute from chronic tears of anterior cruciate ligament, as well as bone bruising and tissue edema

  4. Density functional calculations for structural, electronic, and magnetic properties of gadolinium-oxide clusters

    Energy Technology Data Exchange (ETDEWEB)

    Yuan, H. K.; Chen, H., E-mail: chenh@swu.edu.cn; Tian, C. L.; Kuang, A. L.; Wang, J. Z. [School of Physical Science and Technology, Southwest University, Chongqing 400715 (China)

    2014-04-21

    Gadolinium-oxide clusters in various sizes and stoichiometries have been systematically studied by employing the density functional theory with the generalized gradient approximation. The clusters in bulk stoichiometry are relatively more stable and their binding energies increase with the increasing size. Stoichiometric (Gd{sub 2}O{sub 3}){sub n} clusters of n = 1–3 prefer cage-like structures, whereas the clusters of n = 4–30 prefer compact structures layered by wedge-like units and exhibit a rough feature toward the bulk-like arrangement with small disorders of atomic positions. The polyhedral-cages analogous to carbon-fullerenes are stable isomers yet not the minimum energy configurations. Their stabilities can be improved by embedding one oxygen atom or a suitable cage to form core-shell configurations. The mostly favored antiferromagnetic couplings between adjacent Gd atoms are nearly degenerated in energy with their ferromagnetic couplings, resulting in super-paramagnetic characters of gadolinium-oxide clusters. The Ruderman-Kittel-Kasuya-Yosida (RKKY)-type mechanism together with the superexchange-type mechanism plays cooperation role for the magnetic interactions in clusters. We present, as a function of n, calculated binding energies, ionization potential, electron affinity, and electronic dipole moment.

  5. Injection of gadolinium contrast through pediatric central venous catheters: a safety study

    Energy Technology Data Exchange (ETDEWEB)

    Moriarty, John M.; Ramos, Yanerys; Finn, J.P. [University of California, Department of Radiological Sciences, David Geffen School of Medicine, Los Angeles, CA (United States); Kung, Geoffrey L. [University of California, Department of Radiological Sciences, David Geffen School of Medicine, Los Angeles, CA (United States); University of California, Biomedical Engineering Interdepartmental Program, Los Angeles, CA (United States); Moghaddam, Abbas N. [University of California, Department of Radiological Sciences, David Geffen School of Medicine, Los Angeles, CA (United States); Amirkabir University of Technology (Tehran Polytechnic), Department of Biomedical Engineering, Tehran (Iran, Islamic Republic of); Ennis, Daniel B. [University of California, Department of Radiological Sciences, David Geffen School of Medicine, Los Angeles, CA (United States); University of California, Biomedical Engineering Interdepartmental Program, Los Angeles, CA (United States); University of California, Biomedical Physics Interdepartmental Program, Los Angeles, CA (United States)

    2012-09-15

    Catheter rupture during CT angiography has prompted policies prohibiting the use of electronic injectors with peripherally inserted central venous catheters (PICCs) not only for CT but also for MRI. Consequently, many institutions mandate hand injection for MR angiography, limiting precision of infusion rates and durations of delivery. To determine whether electronic injection of gadolinium-based contrast media through a range of small-caliber, single-lumen PICCs would be safe without risk of catheter rupture over the range of clinical protocols and determine whether programmed flow rates and volumes were realized when using PICCs for contrast delivery. Experiments were performed and recorded using the Medrad Spectris Solaris EP MR Injection System. PICC sizes, contrast media and flow rates were based on common institutional protocols. No catheters were damaged during any experiments. Mean difference between programmed and delivered volume was 0.07 {+-} 0.10 mL for all experiments. Reduced flow rates and prolonged injection durations were observed when the injector's pressure-limiting algorithm was triggered, only in protocols outside the clinical range. PICCs commonly used in children can withstand in vitro power injection of gadolinium-based contrast media at protocols significantly above clinical levels. (orig.)

  6. Development of a gadolinium-loaded liquid scintillator for the Hanaro short baseline prototype detector

    International Nuclear Information System (INIS)

    We propose a new experiment on the site of the Korea Atomic Energy Research Institute (KAERI) located at Daejeon, Korea. The Hanaro short baseline (SBL) nuclear reactor with a thermal power output 30 MW is used to investigate a reactor neutrino anomaly. A Hanaro SBL prototype detector having a 60-l volume has been constructed ∼6 m away from the reactor core. A gadolinium (Gd)-loaded liquid scintillator (LS) is used as an active material to trigger events. The selection of the LS is guided by physical and technical requirements, as well as safety considerations. A linear alkyl benzene (LAB) is used as a base solvent of the Hanaro SBL prototype detector. Three g/l of PPO and 30 mg/l of bis-MSB are dissolved to formulate the LAB-based LS. Then, a 0.5% gadolinium (Gd) complex with carboxylic acid is loaded into the LAB-based LS by using the liquid - liquid extraction method. In this paper, we will summarize all the characteristics of the Gd-loaded LAB-based LS for the Hanaro prototype detector.

  7. Gamma ray induced thermoluminescence studies of yttrium (III oxide nanopowders doped with gadolinium

    Directory of Open Access Journals (Sweden)

    Raunak Kumar Tamrakar

    2014-10-01

    Full Text Available Y2O3:Gd3+ nanophosphor was prepared by the solid state reaction method. Systematic studies have been done to investigate the structural and optical properties of the gadolinium doped Y2O3 phosphor. The prepared phosphor was characterized by using X-ray diffractometer (XRD, scanning electron microscopy (SEM, transmission electron microscopy and UV–VIS–NIR spectrophotometer. The XRD patterns reveal that these prepared phosphors have cubic phase crystal structure. SEM and TEM images showed uniform doping of the material over the entire materials. The energy band gap for gadolinium doped Y2O3 phosphor was revealed from the optical studies and was found to 5.1 eV. The prepared phosphors were also examined by thermoluminescence technique. The kinetic parameters like trap depth, frequency factor were calculated by using the Peak shape method, which are discussed in details. The TL Glow curves were fitted in CGCD (computerized glow curve convolution deconvolution technique & trapping parameters calculated. The TL parameters such as activation energy for deconvoluted peak were found in the range of 0.82–2.24 eV. The frequency factor is of the order of between of 1.78 × 1012 and 9.84 × 1020 s−1.

  8. Synthesis and characterization of gadolinium-doped nanotubular titania for enhanced photocatalysis

    Energy Technology Data Exchange (ETDEWEB)

    Shi, Liang [College of Chemistry and Chemical Engineering, Ocean University of China, Qingdao 266100 (China); Cao, Lixin, E-mail: caolixin@ouc.edu.cn [College of Chemistry and Chemical Engineering, Ocean University of China, Qingdao 266100 (China); Institute of Materials Science and Engineering, Ocean University of China, Qingdao 266100 (China); Gao, Rongjie; Zhao, Yanling [Institute of Materials Science and Engineering, Ocean University of China, Qingdao 266100 (China); Zhang, Huibin; Xia, Chenghui [College of Chemistry and Chemical Engineering, Ocean University of China, Qingdao 266100 (China)

    2014-12-25

    Graphical abstract: The Gd-doped titania nanotubes showed an increase in photocatalytic activity together with Gd/Ti ratio increase up 0.5%, followed by a rapid fall above 1.0%. - Highlights: • Enhanced Gd-doped titania nanotube photocatalysts have been synthesized. • Uniform Gd-doped titania nanoparticles were employed as raw materials. • Actual gadolinium contents in titania were precisely characterized by ICP-AES. • The distribution of Gd dopant was marked using element mapping. - Abstract: Gadolinium-doped titanium dioxide nanotubes were fabricated with a facile two-step route. Precursors Gd-doped titania nanoparticles were synthesized by a traditional sol–gel method. Hydrothermal process and acid treatment were employed afterwards, and Gd-doped titania nanotubes were finally obtained after calcination. The nominal doping concentration was expressed by Gd/Ti atomic ratio, ranged from 0% to 5.0%. Both the precursors and nanotubes were characterized by X-ray photoelectron spectra, inductively coupled plasma-atomic emission spectrometry, transmission electron microscopy, scanning electron microscopy, X-ray diffraction, energy dispersive X-ray spectrometer, UV–vis diffusion reflection spectra and N{sub 2} absorption–desorption experiment. The photocatalytic activities were investigated using methyl orange as the model pollutant. The results indicated that Gd-doped titania nanotubes with nominal Gd/Ti of 0.5% possessed the optimal photocatalytic activity in our study.

  9. Gadolinium(III) ion selective sensor using a new synthesized Schiff's base as a sensing material

    International Nuclear Information System (INIS)

    According to a solution study which showed a selective complexation between N,N′-bis(methylsalicylidene)-2-aminobenzylamine (MSAB) and gadolinium ions, MSAB was used as a sensing element in construction of a gadolinium(III) ion selective electrode. Acetophenon (AP) was used as solvent mediator and sodium tetraphenyl borate (NaTPB) as an anion excluder. The electrode showed a good selectivity towards Gd(III) ions over a wide variety of cations tested. The constructed sensor displayed a Nernstian behavior (19.7 ± 0.3 mV/decade) in the concentration range of 1.0 × 10−6 to 1.0 × 10−2 mol L−1 with detection limit of 5.0 × 10−7 mol L−1 and a short response time (3+–PVC membrane sensor based on an ion carrier as sensing material is introduced. ► This technique is very simple and it's not necessary to use sophisticated equipment. ► This sensor shows good selectivity against other metal ions.

  10. Single crystal Processing and magnetic properties of gadolinium nickel

    Energy Technology Data Exchange (ETDEWEB)

    Shreve, Andrew John [Iowa State Univ., Ames, IA (United States)

    2012-01-01

    GdNi is a rare earth intermetallic material that exhibits very interesting magnetic properties. Spontaneous magnetostriction occurs in GdNi at T{sub C}, on the order of 8000ppm strain along the c-axis and only until very recently the mechanism causing this giant magnetostriction was not understood. In order to learn more about the electronic and magnetic structure of GdNi, single crystals are required for anisotropic magnetic property measurements. Single crystal processing is quite challenging for GdNi though since the rare-earth transition-metal composition yields a very reactive intermetallic compound. Many crystal growth methods are pursued in this study including crucible free methods, precipitation growths, and specially developed Bridgman crucibles. A plasma-sprayed Gd2O3 W-backed Bridgman crucible was found to be the best means of GdNi single crystal processing. With a source of high-quality single crystals, many magnetization measurements were collected to reveal the magnetic structure of GdNi. Heat capacity and the magnetocaloric effect are also measured on a single crystal sample. The result is a thorough report on high quality single crystal processing and the magnetic properties of GdNi.

  11. Ultra low-dose of gadobenate dimeglumine for late gadolinium enhancement (LGE) imaging in acute myocardial infarction: A feasibility study

    Energy Technology Data Exchange (ETDEWEB)

    Galea, Nicola, E-mail: nicola.galea@uniroma1.it [Department of Radiological Sciences, Pathology and Oncology, Policlinico Umberto I, “Sapienza” University of Rome, Viale Regina Elena 315, 00161 Rome (Italy); Francone, Marco, E-mail: marco.francone@uniroma1.it [Department of Radiological Sciences, Pathology and Oncology, Policlinico Umberto I, “Sapienza” University of Rome, Viale Regina Elena 315, 00161 Rome (Italy); Zaccagna, Fulvio, E-mail: f.zaccagna@gmail.com [Department of Radiological Sciences, Pathology and Oncology, Policlinico Umberto I, “Sapienza” University of Rome, Viale Regina Elena 315, 00161 Rome (Italy); Ciolina, Federica, E-mail: federica.ciolina@gmail.com [Department of Radiological Sciences, Pathology and Oncology, Policlinico Umberto I, “Sapienza” University of Rome, Viale Regina Elena 315, 00161 Rome (Italy); Cannata, David, E-mail: davidrum@yahoo.it [Department of Radiological Sciences, Pathology and Oncology, Policlinico Umberto I, “Sapienza” University of Rome, Viale Regina Elena 315, 00161 Rome (Italy); Algeri, Emanuela, E-mail: emanuela_algeri@yahoo.com [Service de Radiologie et Imagerie Cardiovasculaire, Hôpital Cardiologique, Centre Hospitalier Régional et Universitaire de Lille, Avenue Oscar Lambret, 59037 Lille Cedex (France); Agati, Luciano, E-mail: luciano.agati@uniroma1.it [Department of Cardiovascular, Respiratory, Nephrologic, Anestesiologic and Geriatric Sciences, Sapienza University of Rome, Policlinico Umberto I, Via del Policlinico 165, 00161 Rome, Rome (Italy); and others

    2014-12-15

    Highlights: • We compared two gadolinium dose for late enhancement imaging in acute infarction. • We evaluated image quality both qualitatively and quantitatively. • Low dose regimen is feasible and provides better image quality at 5–10 min delay. • Standard dose warrants better image quality and should be routinely preferred. - Abstract: Purpose: To assess the feasibility of using an ultra-low dose (0.05 mmol/kg of body weight [BW]) of high relaxivity contrast agent for late gadolinium enhancement (LGE) imaging in patients with acute myocardial infarction (AMI). Materials and methods: 17 consecutive patients (mean age, 60.1 ± 10.3 years) with ST-segment elevation AMI underwent two randomized cardiac magnetic resonance studies (exam intervals between 24 and 48 h) on a 1.5 T unit during the first week after the event using gadobenate dimeglumine (Gd-BOPTA) at the dose of 0.1 mmol/kg BW (standard dose or SD group) and 0.05 mmol/kg BW (half dose or HD group). Image quality was qualitatively assessed. Quantitative analysis of LGE were performed by measuring signal intensity (SI), signal-to-noise ratio (SNR) in the infarcted myocardium (IM), non-infarcted myocardium (N-IM) and left ventricular cavity (LVC) in images acquired at 1, 3, 5, 10, 15 and 20 min after administration of Gd-BOPTA using both contrast media protocol. Contrast-to-noise ratio (CNR) between IM and N-IM (CNR IM/N-IM) and between IM and LVC (CNR IM/LVC) were also quantified for each time point. Moreover the extent of infarcted myocardium was measured. Results: 102 LGE images were evaluated for each dose group. Quality score was significantly higher for SD at 1, 15 and 20 min (0.002 < p < 0.046) and for HD at 5 min (p = 0.013). SNR has been higher in the SD group compared to the HD group even though not statistically significant at any time-point for both IM (SD vs. HD: 87.7 ± 73 vs. 65 ± 66; 0.15 < p < 0.38) and N-IM (SD vs. HD: 22 ± 61 vs. 9.9 ± 6.5; 0.09 < p < 0.43). LVC SNR was

  12. Free-breathing motion-corrected late-gadolinium-enhancement imaging improves image quality in children

    Energy Technology Data Exchange (ETDEWEB)

    Olivieri, Laura; O' Brien, Kendall J. [Children' s National Health System, Division of Cardiology, Washington, DC (United States); National Heart, Lung and Blood Institute, National Institutes of Health, Bethesda, MD (United States); Cross, Russell [Children' s National Health System, Division of Cardiology, Washington, DC (United States); Xue, Hui; Kellman, Peter; Hansen, Michael S. [National Heart, Lung and Blood Institute, National Institutes of Health, Bethesda, MD (United States)

    2016-06-15

    The value of late-gadolinium-enhancement (LGE) imaging in the diagnosis and management of pediatric and congenital heart disease is clear; however current acquisition techniques are susceptible to error and artifacts when performed in children because of children's higher heart rates, higher prevalence of sinus arrhythmia, and inability to breath-hold. Commonly used techniques in pediatric LGE imaging include breath-held segmented FLASH (segFLASH) and steady-state free precession-based (segSSFP) imaging. More recently, single-shot SSFP techniques with respiratory motion-corrected averaging have emerged. This study tested and compared single-shot free-breathing LGE techniques with standard segmented breath-held techniques in children undergoing LGE imaging. Thirty-two consecutive children underwent clinically indicated late-enhancement imaging using intravenous gadobutrol 0.15 mmol/kg. Breath-held segSSFP, breath-held segFLASH, and free-breathing single-shot SSFP LGE sequences were performed in consecutive series in each child. Two blinded reviewers evaluated the quality of the images and rated them on a scale of 1-5 (1 = poor, 5 = superior) based on blood pool-myocardial definition, presence of cardiac motion, presence of respiratory motion artifacts, and image acquisition artifact. We used analysis of variance (ANOVA) to compare groups. Patients ranged in age from 9 months to 18 years, with a mean +/- standard deviation (SD) of 13.3 +/- 4.8 years. R-R interval at the time of acquisition ranged 366-1,265 milliseconds (ms) (47-164 beats per minute [bpm]), mean +/- SD of 843+/-231 ms (72+/-21 bpm). Mean +/- SD quality ratings for long-axis imaging for segFLASH, segSSFP and single-shot SSFP were 3.1+/-0.9, 3.4+/-0.9 and 4.0+/-0.9, respectively (P < 0.01 by ANOVA). Mean +/- SD quality ratings for short-axis imaging for segFLASH, segSSFP and single-shot SSFP were 3.4+/-1, 3.8+/-0.9 and 4.3+/-0.7, respectively (P < 0.01 by ANOVA). Single-shot late

  13. Delayed gadolinium-enhanced magnetic resonance imaging of cartilage (dGEMRIC), after slipped capital femoral epiphysis

    International Nuclear Information System (INIS)

    Objective: The aim of this study was to assess the glycosaminoglycan (GAG) content in hip joint cartilage in mature hips with a history of slipped capital femoral epiphysis (SCFE) using delayed gadolinium-enhanced MRI of cartilage (dGEMRIC). Methods: 28 young-adult subjects (32 hips) with a mean age of 23.8 ± 4.0 years (range: 18.1-30.5 years) who were treated for mild or moderate SCFE in adolescence were included into the study. Hip function and clinical symptoms were evaluated with the Harris hip score (HHS) system at the time of MRI. Plain radiographic evaluation included Tonnis grading, measurement of the minimal joint space width (JSW) and alpha-angle measurement. The alpha-angle values were used to classify three sub-groups: group 1 = subjects with normal femoral head-neck offset (alpha-angle o), group 2 = subjects with mild offset decrease (alpha-angle 50o-60o), and group 3 = subjects with severe offset decrease (alpha-angle >60o). Results: There was statistically significant difference noted for the T1Gd values, lateral and central, between group 1 and group 3 (p-values = 0.038 and 0.041). The T1Gd values measured within the lateral portion were slightly lower compared with the T1Gd values measured within the central portion that was at a statistically significance level (p-value <0.001). HHS, Tonnis grades and JSW revealed no statistically significant difference. Conclusion: By using dGEMRIC in the mid-term follow-up of SCFE we were able to reveal degenerative changes even in the absence of joint space narrowing that seem to be related to the degree of offset pathology. The dGEMRIC technique may be a potential diagnostic modality in the follow-up evaluation of SCFE.

  14. Delayed gadolinium-enhanced magnetic resonance imaging of cartilage (dGEMRIC), after slipped capital femoral epiphysis

    Energy Technology Data Exchange (ETDEWEB)

    Zilkens, Christoph, E-mail: Christoph.Zilkens@med.uni-duesseldorf.de [Department of Orthopaedics, Heinrich-Heine University Medical School, Moorenstrasse 5, 40225 Duesseldorf (Germany); Miese, Falk [Department of Radiology, Heinrich-Heine University Medical School, Moorenstrasse 5, 40225 Duesseldorf (Germany); Bittersohl, Bernd; Jaeger, Marcus; Schultz, Johannes [Department of Orthopaedics, Heinrich-Heine University Medical School, Moorenstrasse 5, 40225 Duesseldorf (Germany); Holstein, Arne [Department of Radiology, Heinrich-Heine University Medical School, Moorenstrasse 5, 40225 Duesseldorf (Germany); Kim, Young-jo; Millis, Michael B. [Department of Orthopaedic Surgery, Childrens Hospital Boston, Harvard Medical, School, 300 Longwood Avenue, Boston, MA 02115 (United States); Mamisch, Tallal C. [Department of Orthopaedic Surgery, Inselspital Bern, University Hospital, Bern (Switzerland); Krauspe, Ruediger [Department of Orthopaedics, Heinrich-Heine University Medical School, Moorenstrasse 5, 40225 Duesseldorf (Germany)

    2011-09-15

    Objective: The aim of this study was to assess the glycosaminoglycan (GAG) content in hip joint cartilage in mature hips with a history of slipped capital femoral epiphysis (SCFE) using delayed gadolinium-enhanced MRI of cartilage (dGEMRIC). Methods: 28 young-adult subjects (32 hips) with a mean age of 23.8 {+-} 4.0 years (range: 18.1-30.5 years) who were treated for mild or moderate SCFE in adolescence were included into the study. Hip function and clinical symptoms were evaluated with the Harris hip score (HHS) system at the time of MRI. Plain radiographic evaluation included Tonnis grading, measurement of the minimal joint space width (JSW) and alpha-angle measurement. The alpha-angle values were used to classify three sub-groups: group 1 = subjects with normal femoral head-neck offset (alpha-angle <50{sup o}), group 2 = subjects with mild offset decrease (alpha-angle 50{sup o}-60{sup o}), and group 3 = subjects with severe offset decrease (alpha-angle >60{sup o}). Results: There was statistically significant difference noted for the T1{sub Gd} values, lateral and central, between group 1 and group 3 (p-values = 0.038 and 0.041). The T1{sub Gd} values measured within the lateral portion were slightly lower compared with the T1{sub Gd} values measured within the central portion that was at a statistically significance level (p-value <0.001). HHS, Tonnis grades and JSW revealed no statistically significant difference. Conclusion: By using dGEMRIC in the mid-term follow-up of SCFE we were able to reveal degenerative changes even in the absence of joint space narrowing that seem to be related to the degree of offset pathology. The dGEMRIC technique may be a potential diagnostic modality in the follow-up evaluation of SCFE.

  15. SECOND BUYING AGENT

    CERN Multimedia

    SPL - SERVICES ACHATS

    2000-01-01

    Last year the buying agent LOGITRADE started operations on the CERN site, processing purchasing requests for well-defined families of products up to a certain value. It was planned from the outset that a second buying agent would be brought in to handle the remaining product families. So, according to that plan, the company CHARLES KENDALL will be commencing operations at CERN on 8 May 2000 in Building 73, 1st floor, offices 31 and 35 (phone and fax numbers to be announced).Each buying agent will have its own specific list of product families and will handle purchasing requests up to 10'000 CHF.Whenever possible they will provide the requested supplies at a price (including the cost of their own services) which must be equivalent to or lower than the price mentioned on the purchasing request, changing the supplier if necessary. If a lower price cannot be obtained, agents will provide the necessary administrative support free of charge.To ensure that all orders are processed in the best possible conditions, us...

  16. Cardiac-synchronized gadolinium-enhanced MR angiography: preliminary experience for the evaluation of the thoracic aorta.

    NARCIS (Netherlands)

    Goldfarb, J.W.; Holland, A.E.; Heijstraten, F.M.J.; Skotnicki, S.H.; Barentsz, J.O.

    2006-01-01

    Gadolinium (Gd)-enhanced three-dimensional breath-hold magnetic resonance cardiac-synchronized angiography was performed in 13 patients suspected or known to have thoracic aortic disease. High-quality angiograms of the ascending/descending thoracic aorta and coronary arteries were obtained with this

  17. Gadolinium-enhanced MRI features of acute gouty arthritis on top of chronic gouty involvement in different joints

    NARCIS (Netherlands)

    Emad, Yasser; Ragab, Yasser; El-Naggar, Ahmed; El-Shaarawy, Nashwa; Abd-Allah, Mayada A.; Gamal, Rania M.; Fathy, Ahmed; Hawass, Mona; Rasker, Hans

    2015-01-01

    The aims of the current study are to describe gadolinium-enhanced MRI features of an acute flare of established gouty arthritis in different joints and to examine a possible association between serum uric acid and MRI signs indicative of ongoing inflammation and/or structural joint damage as well as

  18. Neutron and Charged-Particle Induced Cross Sections for Radiochemistry in the Region of Samarium, Europium, and Gadolinium

    Energy Technology Data Exchange (ETDEWEB)

    Hoffman, R D; Kelley, K; Dietrich, F S; Bauer, R; Mustafa, M

    2004-11-30

    We have developed a set of modeled nuclear reaction cross sections for use in radiochemical diagnostics. Systematics for the input parameters required by the Hauser-Feshbach statistical model were developed and used to calculate neutron and proton induced nuclear reaction cross sections in the mass region of samarium, europium and gadolinium (62 {le} Z {le} 64, 82 {le} N {le} 96).

  19. Differentiation between benign and malignant colon tumors using fast dynamic gadolinium-enhanced MR colonography; a feasibility study

    DEFF Research Database (Denmark)

    Achiam, M P; Andersen, L P H; Klein, M;

    2010-01-01

    Colorectal cancer will present itself as a bowel obstruction in 16-23% of all cases. However, not all obstructing tumors are malignant and the differentiation between a benign and a malignant tumor can be difficult. The purpose of our study was to determine whether fast dynamic gadolinium...

  20. Influence of hydroxyl content of binders on rheological properties of cerium-gadolinium oxide (CGO) screen printing inks

    DEFF Research Database (Denmark)

    Marani, Debora; Gadea, Christophe; Hjelm, Johan;

    2015-01-01

    vinyl resins) were selected and characterized in solution via viscosimetry method. A high degree of hyper-entanglement was observed for ethyl cellulose polymers, whereas a mitigated effect characterized the two vinyl resins. Cerium-gadolinium oxides (CGO)-based inks, prepared using the selected binders...

  1. Early Reversible Ischemia of Femoral Head Epiphysis in Piglets on Gadolinium-enhanced MRI: An experimental study

    Institute of Scientific and Technical Information of China (English)

    LI Xiaoming; HU Junwu; ZHEN Hongwei; TANG Lihua; XU Anhui

    2006-01-01

    The purpose of this study is to demonstrate if Gadolinium-enhanced MRI can detect early reversible ischemia of the femoral head epiphysis caused by hip hyper-abduction in piglets. Between 3 and 6 h consistent hyper-abduction, gadolinium-enhanced MRI was performed in 20 femoral heads of 10 piglets. After completion of MRI scan, the piglets were allowed to ambulate freely for 1 or 7 days and re-imaged. The enhanced-MRI results of epiphyseal and physeal cartilage and the secondary center of ossification were observed. MRI appearances and histological findings were compared. On Gadolinium-enhanced MRI, decreased or absent enhancement was seen in 14 cartilaginous epiphyses of all 20 femoral heads. Reperfusion was completed in 10 of 14 femoral heads after one day of ambulation and in the rest 4 after 7 days of ambulation. Gadolinium-enhanced MRI can identify early ischemia and its reversal of the capital femoral epiphysis induced by hip hyper-abduction.

  2. Feasibility of synchrotron radiation computed tomography on rats bearing glioma after iodine or gadolinium injection. Jeune Equipe RSRM-UJF.

    Science.gov (United States)

    Le Duc, G; Corde, S; Elleaume, H; Estève, F; Charvet, A M; Brochard, T; Fiedler, S; Collomb, A; Le Bas, J F

    2000-01-01

    The purpose of this work was to demonstrate the feasibility of a new imaging technique called synchrotron radiation computed tomography (SRCT). This technique leads to a direct assessment of the in vivo concentration of an iodine- or gadolinium-labeled compound. Rats bearing C6 glioma were imaged by MRI prior to the SRCT experiment. The SRCT experiments were performed after a 1.3 g I/kg (n = 5) or a 0.4 g Gd/kg (n = 5) injection. Finally, brains were sampled for histology. The SRCT images exhibited contrast enhancement at the tumor location. Ten minutes after injection, iodine and gadolinium tissular concentrations were equal to 0.80 ( +/- 0.40) mg/cm3 and 0.50 ( +/- 0.10) mg/cm3, respectively in the peripheral area of the tumor (respective background value: 0.20 +/- 0.02 to 0.10 +/- 0.01). Correlation to MRI and histology revealed that the contrast uptake occurred in the most vascularized area of the tumor. The present study summarizes the feasibility of in vivo SRCT to obtain quantitative information about iodine and gadolinium-labeled compounds. Beyond brain tumor pathology, the SRCT appears as a complementary approach to MRI and CT, for studying iodine- and gadolinium-labeled compounds by the direct achievement of the tissular concentration value in the tissue.

  3. Focal sparing in fatty liver : Mimicking hypervascular tumor on gadolinium-enhanced opposed-phase gradient-echo images

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Dal Mo; Kim, Hak Soo; Kim, Hyung Sik; Jin, Wook; Cho, Seung Whi [Gachon Medical College, Incheon (Korea, Republic of)

    2001-12-01

    We describe the magnetic resonance imaging findings in a case of focal sparing in fatty liver that showed homogeneous hyperintensity on gadolinium-enhanced opposed-phase gradient-echo images and mimicked a hypervascular mass due to paradoxical suppression of signal intensity of surrounding liver parenchyma with fatty infiltration.

  4. Late gadolinium enhancement in cardiovascular magnetic resonance in patients with hypertrophic cardiomyopathy complicated by life-threatening ventricular tachyarrhythmia

    NARCIS (Netherlands)

    Petkow-Dimitrow, Pawel; Klimeczek, Piotr; Vliegenthart, Rozemarijn; Pasowicz, Mieczyslaw; Miszalski-Jamka, Tomasz; Oudkerk, Matthijs; Podolec, Piotr; Dubiel, Jacek S.; Tracz, Wieslawa

    2009-01-01

    Background: Late gadolinium enhancement (LGE) on cardiac magnetic resonance imaging (CMR) has been shown to be associated with ventricular arrhythmias, however, its prognostic role in predicting sudden cardiac death has not yet been established. Aim: To explore a potential relationship between LGE v

  5. The application of Anthropogenic Gadolinium as a tracer in ground and surface water: examples from France and the Netherlands

    Science.gov (United States)

    Klaver, G.; Verheul, M.; Petelet-Giraud, E.; Negrel, P. J.

    2011-12-01

    Gadolinium chelates have been used since 1988 as contrasts agents in medical imaging (MRI) and produce positive anthropogenic Gd anomalies in rare element shale normalized patterns (REEnasc) of river and lake waters. Both in the Netherlands and France the presence of a positive Gd anomaly in surface and groundwater is used as a common tool in complex surface-surface and surface-groundwater studies. In this poster 3 examples of this common practice are given. The "Ile du Chambon" catchment (100 ha) is located in the Allier Valley, within Oligocene alluvial formations (sand and gravel). The nitrate content in the wells of the drinking water supply is ≥ 50 mg/l and two sources for the origin of the nitrates are hypothesized: agriculture or wastewater from a waste water treatment plant. Widory et al. (2005), using a coupled chemical (Cl and NO3) and isotopic (nitrogen and boron) approach, could show that the wastewater was the main source of the nitrate pollution. The presence of a Gd anomaly in the shale normalized rare earth patterns of wells contaminated by the waste water confirms the findings of Widory et al. (2005). In the second case the Gd anomaly is used to follow the infiltration of river water into a small lake in the Netherlands. During dry periods in this small river, Meuse water with a distinct Gd anomaly is fed into this river. The REE were monitored in the river, in a piezometer installed in the dike between the river and the lake and in the lake before, during and after the Meuse water was fed into this river. With the time series analyses the infiltration of the Meuse water into the dike and the small lake could be clearly followed. In a third case, in the center of the Netherlands, the flow of inlet Meuse water with a distinct Gd anomaly into a polder and subsequently from the larger into the smaller ditches of this polder were followed by analyzing the REEs. In such dry periods the ditches in the polder are also fed by groundwater that does not

  6. Agent-based Modeling and Mapping of Manufacturing System

    Institute of Scientific and Technical Information of China (English)

    Z; Zhang

    2002-01-01

    Considering the gent-based modeling and mapping in m anufacturing system, in this paper, some system models are described, which are including: Domain Based Hierarchical Structure (DBHS), Cascading Agent Struc ture (CAS), Proximity Relation structure (PRS), and Bus-based network structure (BNS). In DBHS, one sort of agent individually delegates Domain Agents, Res ources Agents, UserInterface Agents and Gateway Agents and the other one is a br oker of tasks and process flow. Static agents representing...

  7. Tolerance and long-term MRI imaging of gadolinium-modified meshes used in soft organ repair.

    Directory of Open Access Journals (Sweden)

    Vincent Letouzey

    Full Text Available Synthetic meshes are frequently used to reinforce soft tissues. The aim of this translational study is to evaluate tolerance and long-term MRI visibility of two recently developed Gadolinium-modified meshes in a rat animal model.Gadolinium-poly-ε-caprolactone (Gd-PCL and Gadolinium-polymethylacrylate (Gd-PMA modified meshes were implanted in Wistar rats and their tolerance was assessed daily. Inflammation and biocompatibility of the implants were assessed by histology and immunohistochemistry after 30 days post implantation. Implants were visualised by 7T and 3T MRI at day 30 and at day 90. Diffusion of Gadolinium in the tissues of the implanted animals was assessed by Inductively Coupled Plasma Mass Spectrometry.Overall Gd-PMA coated implants were better tolerated as compared to those coated with Gd-PCL. In fact, Gd-PMA implants were characterised by a high ratio collagen I/III and good vascularisation of the integration tissues. High resolution images of the coated mesh were obtained in vivo with experimental 7T as well as 3T clinical MRI. Mass spectrometry analyses showed that levels of Gadolinium in animals implanted with coated mesh were similar to those of the control group.Meshes coated with Gd-PMA are better tolerated as compared to those coated with Gd-PCL as no signs of erosion or significant inflammation were detected at 30 days post implantation. Also, Gd-PMA coated meshes were clearly visualised with both 7T and 3T MRI devices. This new technique of mesh optimisation may represent a valuable tool in soft tissue repair and management.

  8. TSPO imaging in glioblastoma multiforme: A direct comparison between 123ICLINDE-SPECT, 18F-FET PET and gadolinium-enhanced MRI.

    OpenAIRE

    Jensen, Per; Feng, Li; Law, Ian; Svarer, Claus; Knudsen, Gitte M; Mikkelsen, Jens D.; de Nijs, Robin; Larsen, Vibeke A; Dyssegaard, Agnete; Thomsen, Gerda; Fischer, Walter; GUILLOTEAU, Denis; Pinborg, Lars H.

    2015-01-01

    Here we compare TSPO imaging using 123 I-CLINDE and amino acid transport imaging using 18 F-FET and investigate if 123 I-CLINDE is superior to 18 F-FET in predictingprogression of glioblastoma multiforme (GBM) at follow up. Methods  Three patients with WHO grade IV GBM were scanned with 123 I-CLINDE SPECT, 18 F-FET PET and Gadolinium enhanced magnetic resonance imaging (gadolinium-MRI). Molecular imaging data were compared to follow-up gadolinium-MRI or contrast enhanc...

  9. Investigation of Plutonium and Uranium Precipitation Behavior with Gadolinium as a Neutron Poison

    International Nuclear Information System (INIS)

    The caustic precipitation of plutonium (Pu)-containing solutions has been investigated to determine whether the presence of 3:1 uranium (U):Pu in solutions stored in the H-Canyon Facility at the U.S. Department of Energy's (DOE) Savannah River Site (SRS) would adversely impact the use of gadolinium nitrate (Gd(NO3)3) as a neutron poison. In the past, this disposition strategy has been successfully used to discard solutions containing approximately 100 kg of Pu to the SRS high level waste (HLW) system. In the current experiments, gadolinium (as Gd(NO3)3) was added to samples of a 3:1 U:Pu solution, a surrogate 3 g/L U solution, and a surrogate 3 g/L U with 1 g/L Pu solution. A series of experiments was then performed to observe and characterize the precipitate at selected pH values. Solids formed at pH 4.5 and were found to contain at least 50 percent of the U and 94 percent of the Pu, but only 6 percent of the Gd. As the pH of the solution increased (e.g., pH greater than 14 with 1.2 or 3.6 M sodium hydroxide (NaOH) excess), the precipitate contained greater than 99 percent of the Pu, U, and Gd. After the pH greater than 14 systems were undisturbed for one week, no significant changes were found in the composition of the solid or supernate for each sample. The solids were characterized by X-ray diffraction (XRD) which found sodium diuranate (Na2U2O7) and gadolinium hydroxide (Gd(OH)3) at pH 14. Thermal gravimetric analysis (TGA) indicated sufficient water molecules were present in the solids to thermalize the neutrons, a requirement for the use of Gd as a neutron poison. Scanning electron microscopy (SEM) was also performed and the accompanying back-scattering electron analysis (BSE) found Pu, U, and Gd compounds in all pH greater than 14 precipitate samples. The rheological properties of the slurries at pH greater than 14 were also investigated by performing precipitate settling rate studies and measuring the viscosity and density of the materials. Based on the

  10. Gadolinium contrast media are more nephrotoxic than iodine media. The importance of osmolality in direct renal artery injections

    Energy Technology Data Exchange (ETDEWEB)

    Elmstaahl, Barbara; Leander, Peter; Almen, Torsten [Malmoe University Hospital, Lund University, Department of Diagnostic Radiology, Malmoe (Sweden); Nyman, Ulf [Lasarettet Trelleborg, Department of Radiology, Trelleborg (Sweden); Chai, Chun-Ming [Malmoe University Hospital, Lund University, Department of Experimental Research, Malmoe (Sweden); Golman, Klaes [Biosciences, GE Health, Malmoe (Sweden); Bjoerk, Jonas [University Hospital, Lund University, Competence Center for Clinical Research, Lund (Sweden)

    2006-12-15

    A study was undertaken of the role of osmotoxicity in gadolinium (Gd) and iodine contrast media (CM) nephrotoxicity in ischemic porcine kidneys. Test solutions: mannitol iso-osmotic to 0.5 M gadopentetate (1.96 Osm/kg H{sub 2}O), 0.5 M gadodiamide (0.78 Osm/kg H{sub 2}O) and 0.5 M iohexol (190 mg I/ml, 0.42 Osm/kg H{sub 2}O). Each solution was injected [3 ml/kg body weight (BW)] into the balloon-occluded (10 min) renal artery of eight left-sided nephrectomized pigs. The plasma half-life of a glomerular filtration rate (GFR) marker was used to compare their effects on GFR 1-3 h post-injection. The median half-lives of the GFR marker after injection of gadopentetate (1,730 min) and mannitol 1.96 Osm/kg H{sub 2}O (2,782 min) did not differ statistically (P=0.28), but were significantly longer than after all other solutions (P<0.001). There was no significant difference (P=0.06) between gadodiamide (218 min) and mannitol 0.82 Osm/kg H{sub 2}O (169 min), while there was (P=0.03) between iohexol (181 min) and mannitol 0.43 Osm/kg H{sub 2}O (148 min). The difference between gadodiamide and iohexol was significant (P=0.01). Reduction in GFR, as a marker of nephrotoxicity, induced by gadopentetate correlated with its high osmolality, while the effect of gadodiamide and iohexol may include chemotoxicity. Iohexol molecules were less nephrotoxic than the Gd-CM molecules and contain three-times the number of attenuating atoms per molecule. (orig.)

  11. Multiwalled carbon nanotube hybrids as MRI contrast agents

    Science.gov (United States)

    Tomczyk, Mateusz Michał

    2016-01-01

    Summary Magnetic resonance imaging (MRI) is one of the most commonly used tomography techniques in medical diagnosis due to the non-invasive character, the high spatial resolution and the possibility of soft tissue imaging. Contrast agents, such as gadolinium complexes and superparamagnetic iron oxides, are administered to spotlight certain organs and their pathologies. Many new models have been proposed that reduce side effects and required doses of these already clinically approved contrast agents. These new candidates often possess additional functionalities, e.g., the possibility of bioactivation upon action of particular stimuli, thus serving as smart molecular probes, or the coupling with therapeutic agents and therefore combining both a diagnostic and therapeutic role. Nanomaterials have been found to be an excellent scaffold for contrast agents, among which carbon nanotubes offer vast possibilities. The morphology of multiwalled carbon nanotubes (MWCNTs), their magnetic and electronic properties, the possibility of different functionalization and the potential to penetrate cell membranes result in a unique and very attractive candidate for a new MRI contrast agent. In this review we describe the different issues connected with MWCNT hybrids designed for MRI contrast agents, i.e., their synthesis and magnetic and dispersion properties, as well as both in vitro and in vivo behavior, which is important for diagnostic purposes. An introduction to MRI contrast agent theory is elaborated here in order to point to the specific expectations regarding nanomaterials. Finally, we propose a promising, general model of MWCNTs as MRI contrast agent candidates based on the studies presented here and supported by appropriate theories. PMID:27547627

  12. Multiwalled carbon nanotube hybrids as MRI contrast agents.

    Science.gov (United States)

    Kuźnik, Nikodem; Tomczyk, Mateusz Michał

    2016-01-01

    Magnetic resonance imaging (MRI) is one of the most commonly used tomography techniques in medical diagnosis due to the non-invasive character, the high spatial resolution and the possibility of soft tissue imaging. Contrast agents, such as gadolinium complexes and superparamagnetic iron oxides, are administered to spotlight certain organs and their pathologies. Many new models have been proposed that reduce side effects and required doses of these already clinically approved contrast agents. These new candidates often possess additional functionalities, e.g., the possibility of bioactivation upon action of particular stimuli, thus serving as smart molecular probes, or the coupling with therapeutic agents and therefore combining both a diagnostic and therapeutic role. Nanomaterials have been found to be an excellent scaffold for contrast agents, among which carbon nanotubes offer vast possibilities. The morphology of multiwalled carbon nanotubes (MWCNTs), their magnetic and electronic properties, the possibility of different functionalization and the potential to penetrate cell membranes result in a unique and very attractive candidate for a new MRI contrast agent. In this review we describe the different issues connected with MWCNT hybrids designed for MRI contrast agents, i.e., their synthesis and magnetic and dispersion properties, as well as both in vitro and in vivo behavior, which is important for diagnostic purposes. An introduction to MRI contrast agent theory is elaborated here in order to point to the specific expectations regarding nanomaterials. Finally, we propose a promising, general model of MWCNTs as MRI contrast agent candidates based on the studies presented here and supported by appropriate theories. PMID:27547627

  13. Gd-doped BNNTs as T2-weighted MRI contrast agents

    International Nuclear Information System (INIS)

    This work describes, for the first time, doping of boron nitride nanotubes (BNNTs) with gadolinium (Gd-BNNTs), a stable functionalization that permits non-invasive BNNT tracking via magnetic resonance imaging (MRI). We report the structure, Gd loading, and relaxometric properties in water suspension at 7 T of Gd-BNNTs, and show the behaviour of these nanostructures as promising T2-weighted contrast agents. Finally, we demonstrate their complete biocompatibility in vitro on human neuroblastoma cells, together with their ability to effectively label and affect contrast in MRI images at 7 T. (paper)

  14. Antagonistic formation motion of cooperative agents

    Institute of Scientific and Technical Information of China (English)

    卢婉婷; 代明香; 薛方正

    2015-01-01

    This paper investigates a new formation motion problem of a class of first-order multi-agent systems with antagonis-tic interactions. A distributed formation control algorithm is proposed for each agent to realize the antagonistic formation motion. A sufficient condition is derived to ensure that all agents make an antagonistic formation motion in a distributed manner. It is shown that all agents can be spontaneously divided into several groups, and agents in the same group collab-orate while agents in different groups compete. Finally, a numerical simulation is included to demonstrate our theoretical results.

  15. Agent planning in AgScala

    Science.gov (United States)

    Tošić, Saša; Mitrović, Dejan; Ivanović, Mirjana

    2013-10-01

    Agent-oriented programming languages are designed to simplify the development of software agents, especially those that exhibit complex, intelligent behavior. This paper presents recent improvements of AgScala, an agent-oriented programming language based on Scala. AgScala includes declarative constructs for managing beliefs, actions and goals of intelligent agents. Combined with object-oriented and functional programming paradigms offered by Scala, it aims to be an efficient framework for developing both purely reactive, and more complex, deliberate agents. Instead of the Prolog back-end used initially, the new version of AgScala relies on Agent Planning Package, a more advanced system for automated planning and reasoning.

  16. Agent Chameleons: Virtual Agents Real Intelligence

    OpenAIRE

    O'Hare, Gregory; Duffy, Brian; Schoen-Phelan, Bianca; Martin, Alan; Bradley, John

    2003-01-01

    Agent Chameleons provides virtual agents powered by real intelligence, delivering next generation autonomic entities that can seamlessly migrate, mutate and evolve on their journey between and within physical and digital information spaces.

  17. Web Search Agents: "One-Stop Shopping" for Researchers.

    Science.gov (United States)

    Perez, Ernest

    2002-01-01

    Explains Web search agents as tools that apply intelligent agent software technology for the purpose of automating, improving, and speeding up online search operations. Topics include intelligent desktop agents; search agent marketplace; comparing Web search agents; subjective evaluations; and use by researchers. (LRW)

  18. Catechin tuned magnetism of Gd-doped orthovanadate through morphology as T1-T2 MRI contrast agents

    Science.gov (United States)

    Vairapperumal, Tamilmani; Saraswathy, Ariya; Ramapurath, Jayasree S.; Kalarical Janardhanan, Sreeram; Balachandran Unni, Nair

    2016-01-01

    Tetragonal (t)-LaVO4 has turned out to be a potential host for luminescent materials. Synthesis of t-LaVO4 till date has been based on chelating effect of EDTA making it not ideal for bioimaging applications. An alternative was proposed by us through the use of catechin. In recent times there is interest for new MRI contrast agents that can through appropriate doping function both as MRI contrast and optical/upconversion materials. It is generally believed that under appropriate doping, t-LaVO4 would be a better upconversion material than monoclinic (m)-LaVO4. Based on these postulations, this work explores the use of gadolinium doped t-LaVO4 as an MRI contrast agent. From literature, gadolinium oxide is a good T1 contrast agent. Through this work, using catechin as a template for the synthesis of Gd doped t-LaVO4, we demonstrate the possible use as a T1 contrast agent. Interestingly, as the catechin concentration changes, morphology changes from nanorods to square nanoplates and spheres. In this process, a switch from T1 to T2 contrast agent was also observed. Under optimal concentration of catechin, with a rod shaped Gd doped t-LaVO4 an r2/r1 value of 21.30 was observed. Similarly, with a spherical shape had an r2/r1 value of 1.48 was observed. PMID:27752038

  19. Optical modulator including grapene

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Ming; Yin, Xiaobo; Zhang, Xiang

    2016-06-07

    The present invention provides for a one or more layer graphene optical modulator. In a first exemplary embodiment the optical modulator includes an optical waveguide, a nanoscale oxide spacer adjacent to a working region of the waveguide, and a monolayer graphene sheet adjacent to the spacer. In a second exemplary embodiment, the optical modulator includes at least one pair of active media, where the pair includes an oxide spacer, a first monolayer graphene sheet adjacent to a first side of the spacer, and a second monolayer graphene sheet adjacent to a second side of the spacer, and at least one optical waveguide adjacent to the pair.

  20. Chitosan oligosaccharide based Gd-DTPA complex as a potential bimodal magnetic resonance imaging contrast agent.

    Science.gov (United States)

    Huang, Yan; Cao, Juan; Zhang, Qi; Lu, Zheng-rong; Hua, Ming-qing; Zhang, Xiao-yan; Gao, Hu

    2016-01-01

    A new gadolinium diethylenetriamine pentaacetic acid (DTPA) complex (Gd-DTPA-DMABA-CS11) as a potential bimodal magnetic resonance imaging (MRI) contrast agent with fluorescence was synthesized. It was synthesized by the incorporation of 4-dimethylaminobenzaldehyde (DMABA) and chitosan oligosaccharide (CSn; n=11) with low polydispersity index to DTPA anhydride and then chelated with gadolinium chloride. The structure was characterized by Fourier transform infrared (FTIR), (1)H NMR, elemental analysis and size exclusion chromatography (SEC). MRI measurements in vitro were evaluated. The results indicated that Gd-DTPA-DMABA-CS11 provided higher molar longitudinal relaxivity (r1) (12.95mM(-1)·s(-1)) than that of commercial Gd-DTPA (3.63mM(-1)·s(-1)) at 0.5T. Gd-DTPA-DMABA-CS11 also emitted fluorescence, and the intensity was much stronger than that of Gd-DTPA. Therefore, it can be meanwhile used in fluorescent imaging for improving the sensitivity in clinic diagnosis. Gd-DTPA-DMABA-CS11 as a potential contrast agent is preliminarily stable in vitro. The results of thermodynamic action between Gd-DTPA-DMABA-CS11 and bovine serum albumin (BSA) illustrated that the binding process was exothermic and spontaneous, and the main force was van der Waals' interaction and hydrogen bond. The preliminary study suggested that Gd-DTPA-DMABA-CS11 could be used in both magnetic resonance and fluorescent imaging as a promising bimodal contrast agent.