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Sample records for gadolinium oxysulfide screen-film

  1. Screen-film mammography

    International Nuclear Information System (INIS)

    Logan, W.W.; Janus, J.A.

    1987-01-01

    The development of screen-film mammography has resulted in the re-emergence of confidence, rather than fear, in mammography. When screen-film mammography is performed with state-of-the-art dedicated equipment utilizing vigorous breast compression and a ''soft'' x-ray beam for improved contrast, screen-film images are equivalent or superior to those of reduced-dose xeromammography and superior to those of nonscreen film mammography. Technological aids for conversion from xeromammographic or nonscreen film mammographic techniques to screen-film techniques have been described. Screen-film mammography should not be attempted until dedicated equipment has been obtained and the importance of vigorous compression has been understood

  2. Guided design of copper oxysulfide superconductors

    Energy Technology Data Exchange (ETDEWEB)

    Yee, Chuck-Hou; Birol, Turan; Kotliar, Gabriel

    2015-07-01

    We describe a framework for designing novel materials, combining modern first-principles electronic-structure tools, materials databases, and evolutionary algorithms capable of exploring large configurational spaces. Guided by the chemical principles introduced by Antipov et al., for the design and synthesis of the Hg-based high-temperature superconductors, we apply our framework to screen 333 proposed compositions to design a new layered copper oxysulfide, Hg(CaS)2CuO2. We evaluate the prospects of superconductivity in this oxysulfide using theories based on charge-transfer energies, orbital distillation and uniaxial strain.

  3. Improving screen-film chest radiography

    International Nuclear Information System (INIS)

    Shaikh, N.; Baker, R.A.

    1996-01-01

    Traditionally symmetric screens and double emulsion symmetric films with medium to wide latitutde are used for radiography of the chest. Beacuse of mismatch of transmitted exposure through the chest with limited latitude of the film, most of the dense areas of the chest are underexposed. Kodak's recent innovation of a unique asymmetry screen-film system (InSight) alleviates this problem. Our phantom measurement indicates that the InSight system offers wider recording range, and the flexible grid permits more positional latitude than conventional grids. Our five-year extensive clinical experience indicates that dense anatomic structures, such as mediastinum, retrocardiac and subdiaphragmatic, are more visible in the InSight system than in the conventional symmetric system. Similarly, a substantial improvement in image quality in portable chest imaging is realized by use of flexible grids because of scatter rejection and invisible grid lines. (author)

  4. Bismuth Oxysulfide and Its Polymer Nanocomposites for Efficient Purification

    Directory of Open Access Journals (Sweden)

    Yidong Luo

    2018-03-01

    Full Text Available The danger of toxic organic pollutants in both aquatic and air environments calls for high-efficiency purification material. Herein, layered bismuth copper oxychalcogenides, BiCuSO, nanosheets of high photocatalytic activity were introduced to the PVDF (Polyvinylidene Fluoride. The fibrous membranes provide an easy, efficient, and recyclable way to purify organic pollutant. The physical and photophysical properties of the BiCuSO and its polymer composite were characterized by scanning electron microscopy (SEM, X-ray diffraction (XRD, ultraviolet-visible diffuse reflection spectroscopy (DRS, X-ray photoelectron spectroscopy (XPS, electron spin resonance (EPR. Photocatalysis of Congo Red reveals that the BiCuSO/PVDF shows a superior photocatalytic activity of a 55% degradation rate in 70 min at visible light. The high photocatalytic activity is attributed to the exposed active {101} facets and the triple vacant associates V B i ‴ V O • • V B i ‴ . By engineering the intrinsic defects on the surface of bismuth oxysulfide, high solar-driven photocatalytic activity can be approached. The successful fabrication of the bismuth oxysulfide and its polymer nanocomposites provides an easy and general approach for high-performance purification materials for various applications.

  5. Bismuth Silver Oxysulfide for Photoconversion Applications: Structural and Optoelectronic Properties

    KAUST Repository

    Baqais, Amal Ali Abdulallh

    2017-09-18

    Single-phase bismuth silver oxysulfide, BiAgOS, was prepared by a hydrothermal method. Its structural, morphological and optoelectronic properties were investigated and compared with bismuth copper oxysulfide (BiCuOS). Rietveld refinement of the powder X-ray diffraction (XRD) measurements revealed that the BiAgOS and BiCuOS crystals have the same structure as ZrSiCuAs: the tetragonal space group P4/nmm. X-ray photoelectron spectroscopy (XPS) analyses confirmed that the BiAgOS has a high purity, in contrast with BiCuOS, which tends to have Cu vacancies. The Ag has a monovalent oxidation state, whereas Cu is present in the oxidation states of +1 and +2 in the BiCuOS system. Combined with experimental measurements, density functional theory calculations employing the range-separated hybrid HSE06 exchange-correlation functional with spin-orbit coupling quantitatively elucidated photophysical properties such as ab-sorption coefficients, effective masses and dielectric constants. BiCuOS and BiAgOS were found to have indirect bandgaps of 1.1 and 1.5 eV, respectively. Both possess high dielectric constants and low electron and hole effective masses. Therefore, these materials are expected to have high exciton dissociation capabilities and excellent carrier diffusion properties. This study reveals that BiAgOS is a promising candidate for photoconversion applications.

  6. A neutron spectroscopy study of magnetic excitations in uranium oxysulfide

    International Nuclear Information System (INIS)

    Amoretti, G.; Larroque, J.; Osborn, R.

    1988-12-01

    A neutron spectroscopy experiment has been performed to observe the position of the crystal field levels in both the paramagnetic and antiferromagnetic phases of UOS (uranium oxysulfide). The J = 4 ground manifold undergoes an overall splitting of about 100 meV in agreement with the predictions of a crystal field model used to analyze specific heat data. Above T N , two main peaks are observed at 74 and 82 meV with a shoulder at about 87 meV. Below T N there is a redistribution of intensity together with a shift of the peak positions to 76, 84 and 92 meV at T = 30K. The experimental observations are interpreted in the framework of a refined crystal field model. (author)

  7. Gadolinium neutron capture therapy

    International Nuclear Information System (INIS)

    Akine, Yasuyuki; Tokita, Nobuhiko; Tokuuye, Koichi; Satoh, Michinao; Churei, Hisahiko

    1993-01-01

    Gadolinium neutron capture therapy makes use of photons and electrons produced by nuclear reactions between gadolinium and lower-energy neutrons which occur within the tumor. The results of our studies have shown that its radiation effect is mostly of low LET and that the electrons are the significant component in the over-all dose. The dose from gadolinium neutron capture reactions does not seem to increase in proportion to the gadolinium concentration, and the Gd-157 concentration of about 100 μg/ml appears most optimal for therapy. Close contact between gadolinium and the cell is not necessarily required for cell inactivation, however, the effect of electrons released from intracellular gadolinium may be significant. Experimental studies on tumor-bearing mice and rabbits have shown that this is a very promising modality though further improvements in gadolinium delivery to tumors are needed. (author)

  8. The BiCu{sub 1−x}OS oxysulfide: Copper deficiency and electronic properties

    Energy Technology Data Exchange (ETDEWEB)

    Berthebaud, D.; Guilmeau, E.; Lebedev, O.I. [Laboratoire CRISMAT, UMR 6508 CNRS/ENSICAEN/UCBN, 6 bd du Maréchal Juin, F-14050 CAEN Cedex 4 (France); Maignan, A., E-mail: antoine.maignan@ensicaen.fr [Laboratoire CRISMAT, UMR 6508 CNRS/ENSICAEN/UCBN, 6 bd du Maréchal Juin, F-14050 CAEN Cedex 4 (France); Gamon, J.; Barboux, P. [Institut de Recherche de Chimie de Paris, Ecole Nationale Supérieure de Chimie de Paris, 11 rue Pierre et Marie Curie, 75231 Paris Cedex 09 France (France)

    2016-05-15

    An oxysulfide series of nominal compositions BiCu{sub 1−x}OS with x<0.20 has been prepared and its structural properties characterized by combining powder X-ray diffraction and transmission electron microscopy techniques. It is found that this oxysulfide, crystallizing in the P4/nmm space group, tends to adopt a constant amount of copper vacancy corresponding to x=0.05 in the BiCu{sub 1−x}OS formula. The presence of Cu vacancies is confirmed by HAADF-STEM analysis showing, in the Cu atomic columns, alternating peaks of different intensities in some very localized regions. For larger Cu deficiencies (x>0.05 in the nominal composition), other types of structural nanodefects are evidenced such as bismuth oxysulfides of the “BiOS” ternary system which might explain the report of superconductivity for the BiCu{sub 1−x}OS oxysulfide. Local epitaxial growth of the BiCuOS oxysulfide on top of CuO is also observed. In marked contrast to the BiCu{sub 1−x}OSe oxyselenide, these results give an explanation to the limited impact of Cu deficiency on the Seebeck coefficient in BiCu{sub 1−x}OS compounds. - Graphical abstract: High resolution TEM image showing a Bi(Cu)OS/Bi{sub 2}O{sub 2}S interface and corresponding dislocation region. The Bi(Cu)OS structure adopts a rather constant Cu content (near 0.95); starting from BiCuOS leads to the formation of defects such as the Bi{sub 2}O{sub 2}S oxysulfide.

  9. Lanthanum and yttrium oxysulfides activated by europium: (Ln1-x Eux)2 O2 S - Synthesis and characterization

    International Nuclear Information System (INIS)

    Luiz, J.M.

    1989-01-01

    The synthesis of lanthanum and yttrium oxysulfides activated by europium were obtained by thermal decomposition of lanthanum and yttrium oxalates doped with europium, under an argon and sulphur atmosphere. The thermal decomposition of these compounds is studied by differential thermal analysis (DTA). The characterization of these oxysulfides were made by chemical analyses, infrared spectroscopy, X-ray diffraction, scanning electron microscopy and emission spectroscopy. (M.V.M.)

  10. [Comparison of screens and screen-film-systems (author's transl)].

    Science.gov (United States)

    Maurer, H J; Goos, F

    1979-06-01

    Important details are to be payed attention in comparison of different scrreens resp. screen-film-systems: 1. Physical characteristics of different groups of luminescent materials: f.i. calcium tung-state, rare-earths compounds, double halogenides. - 2. Different types of screens: highest details up to highest speed intensifying screens, have to be defined more specifically and differentiated against to each other too. - 3. Besides intensification, resolution has to be included into consideration since one of these dates alone does not allow any statement on the total function of a screen or a screen-film-system. - 4. The technical methodological conditions of apparatuses, object and its positioning have to be defined, f.i. X-ray quality, distances, grid, and in automatically controlled exposition, if necessary, position of ionization chamber as well as absorption of cassetts and screen. - 5. Considering these points gradation curves have to include the whole necessary or interesting diagnostic range. - 6. Due to functional correlation between intensification and resolution, the resolution has to be taken in consideration due to application; its interdependence of density and object (f.i. scattered radiation) is often not taken enough in consideration.

  11. Gadolinium-153 line sources

    Energy Technology Data Exchange (ETDEWEB)

    Lebedev, V.M. E-mail: kar@orip.niiar.simbirsk.su; Gordeev, J.N.; Karelin, E.A.; Gavrilov, V.D

    2000-11-15

    The technology for Gd-153 line source production has been developed at SSC RIAR. The source active core is made of Al-Gd{sub 2}O{sub 3} composition by means of one of the following ways: either collecting pressed pellets or filling the source body with the composition followed by sintering. The composition is prepared by gadolinium salt thermal destruction on aluminium particles. The method allows setting gadolinium mass fraction (from 0.02 to 6%) with high accuracy and uniformity of distribution in the composition volume of more than 95%.

  12. Performance comparison of full-field digital mammography to screen-film mammography in clinical practice

    International Nuclear Information System (INIS)

    Berns, Eric A.; Hendrick, R. Edward; Cutter, Gary R.

    2002-01-01

    Results of acceptance testing 18 full-field digital mammography systems for clinical use and of conducting annual physics surveys of 38 screen-film mammography systems were compared in terms of exposure times, mean glandular breast doses, and image quality. These evaluations were made using the same test tools on all systems, with emphasis on assessing automatic exposure control performance and image quality on both digital and screen-film systems using clinical techniques. Survey results indicated that digital mammography systems performed similarly to screen-film systems in terms of exposure times and mean glandular doses for thin to intermediate breasts, but that digital mammography systems selected shorter exposure times and lower mean glandular doses for thicker breasts. For all breast thicknesses, digital mammography systems yielded mean contrast-detail scores higher than those for screen-film systems. For all breast thicknesses, the 18 digital mammography systems demonstrated less variance in terms of exposure times, mean glandular doses, and contrast-detail scores than did the 38 screen-film systems tested. These results indicate that the clinical use of digital mammography may generally improve image quality for equal or lower breast doses, while providing tighter control on exposures and image quality than screen-film mammography

  13. Structural, physical and electrochemical characteristics of a vanadium oxysulfide, a cathode material for lithium batteries

    Science.gov (United States)

    Ouvrard, G.; Tchangbédji, G.; Deniard, P.; Prouzet, E.

    A vanadium oxysulfide is obtained by a reaction between water solutions of a vanadyl salt and sodium sulfide at room temperature. After drying under mild conditions, the formulation of this phase is V 2O 3S·3H 2O. Thermogravimetric analyses show that it is not possible to remove completely water without losing sulfur. This is in agreement with proton nuclear magnetic resonance experiments which prove that water molecules are tightly bonded to vanadium. Magnetic susceptibility and X-ray absorption spectroscopy measurements allow to define the oxidation states of vanadium and sulfur, (IV) and (-II) respectively. From extended X-ray absorption fine structure spectroscopy at the vanadium K edge and infrared spectroscopy, the local structure around vanadium can be defined as a distorted octahedron, with a vanadyl bond and an opposite sulfur atom. Magnetic susceptibility and X-ray absorption spectroscopy measurements on chemically lithiated compounds show a complex charge transfer from lithium to the host structure upon lithium intercalation. If it appears that vanadium atoms are reduced, a possible role of sulfur atoms in the redox process has to be considered. Cycling tests of lithium batteries whose positive consists of oxysulfide are promising with 70 cycles under a regime of {C}/{8}, without noticeable loss in capacity of 120 Ah/kg.

  14. A new continuous two-step molecular precursor route to rare-earth oxysulfides Ln2O2S

    International Nuclear Information System (INIS)

    De Crom, N.; Devillers, M.

    2012-01-01

    A continuous two-step molecular precursor pathway is designed for the preparation of rare-earth oxysulfides Ln 2 O 2 S (Ln=Y, La, Pr, Nd, Sm–Lu). This new route involves a first oxidation step leading to the rare-earth oxysulfate Ln 2 O 2 SO 4 which is subsequently reduced to the rare-earth oxysulfide Ln 2 O 2 S by switching to a H 2 –Ar atmosphere. The whole process occurs at a temperature significantly lower than usual solid state synthesis (T≤650 °C) and avoids the use of dangerous sulfur-based gases, providing a convenient route to the synthesis of the entire series of Ln 2 O 2 S. The molecular precursors consist in heteroleptic dithiocarbamate complexes [Ln(Et 2 dtc) 3 (phen)] and [Ln(Et 2 dtc) 3 (bipy)] (Et 2 dtc=N,N-diethyldithiocarbamate; phen=1,10-phenanthroline; bipy=2,2′-bipyridine) and were synthesized by a new high yield and high purity synthesis route. The nature of the molecular precursor determines the minimum synthesis temperature and influences therefore the purity of the final Ln 2 O 2 S crystalline phase. - Graphical abstract: A continuous two-step molecular precursor pathway was designed for the preparation of rare-earth oxysulfides Ln 2 O 2 S (Ln=Y, La, Pr, Nd, Sm–Lu), starting from heteroleptic dithiocarbamate complexes. The influence of the nature of the molecular precursor on the minimum synthesis temperature and on the purity of the final Ln 2 O 2 S crystalline phase is discussed. Highlights: ► A new high yield and high purity synthesis route of rare earth dithiocarbamates is described. ► These compounds are used as precursors in a continuous process leading to rare-earth oxysulfides. ► The oxysulfides are obtained under much more moderate conditions than previously described.

  15. Quality Imaging - Comparison of CR Mammography with Screen-Film Mammography

    International Nuclear Information System (INIS)

    Gaona, E.; Azorin Nieto, J.; Iran Diaz Gongora, J. A.; Arreola, M.; Casian Castellanos, G.; Perdigon Castaneda, G. M.; Franco Enriquez, J. G.

    2006-01-01

    The aim of this work is a quality imaging comparison of CR mammography images printed to film by a laser printer with screen-film mammography. A Giotto and Elscintec dedicated mammography units with fully automatic exposure and a nominal large focal spot size of 0.3 mm were used for the image acquisition of phantoms in screen-film mammography. Four CR mammography units from two different manufacturers and three dedicated x-ray mammography units with fully automatic exposure and a nominal large focal spot size of 0.3 mm were used for the image acquisition of phantoms in CR mammography. The tests quality image included an assessment of system resolution, scoring phantom images, Artifacts, mean optical density and density difference (contrast). In this study, screen-film mammography with a quality control program offers a significantly greater level of quality image relative to CR mammography images printed on film

  16. Proximal surface caries detection with direct-exposure and rare earth screen/film imaging

    International Nuclear Information System (INIS)

    Lundeen, R.C.; McDavid, W.D.; Barnwell, G.M.

    1988-01-01

    This laboratory study compared five imaging systems for their diagnostic accuracy in detection of proximal surface dental caries. Ten viewers provided data on radiographic detectability of carious lesions. The diagnostic accuracy of each system was determined with receiver operating characteristic (ROC) curves by comparing viewer data with the true state of the teeth as determined microscopically. D-speed film marginally outperformed the other four systems, but the three screen/film systems matched the diagnostic accuracy of E-speed film. Radiation reductions between 62% and 92% were achieved with the screen/film systems when compared to the two conventional dental films. The feasibility of designing a screen/film bite-wing cassette was shown, but the poor diagnostic accuracy of the present bite-wing system indicated a need for a new technology in caries detection

  17. Proximal surface caries detection with direct-exposure and rare earth screen/film imaging

    Energy Technology Data Exchange (ETDEWEB)

    Lundeen, R.C.; McDavid, W.D.; Barnwell, G.M.

    1988-12-01

    This laboratory study compared five imaging systems for their diagnostic accuracy in detection of proximal surface dental caries. Ten viewers provided data on radiographic detectability of carious lesions. The diagnostic accuracy of each system was determined with receiver operating characteristic (ROC) curves by comparing viewer data with the true state of the teeth as determined microscopically. D-speed film marginally outperformed the other four systems, but the three screen/film systems matched the diagnostic accuracy of E-speed film. Radiation reductions between 62% and 92% were achieved with the screen/film systems when compared to the two conventional dental films. The feasibility of designing a screen/film bite-wing cassette was shown, but the poor diagnostic accuracy of the present bite-wing system indicated a need for a new technology in caries detection.

  18. A clinical trial of a rare earth screen/film system in a periapical cassette

    Energy Technology Data Exchange (ETDEWEB)

    Kogon, S.L.; Stephens, R.G.; Reid, J.A.; Lubus, N.J.

    1984-04-01

    In a clinical trial, a slow rare earth screen/film system (Siemens Titan 2D/Kodak XG) was used to obtain intraoral radiographs at conventional monitoring stages in endodontic treatment. The screen film image proved to be an effective substitute for the direct-exposure Ultraspeed periapical film. The intraoral cassettes, designed and fabricated for the study, were an adaptation of the flexible, vacuum-sealed cassettes used in mammography. It is believed that when a practicable periapical cassette is manufactured, many additional indications for the system are probable. Major reductions in patient exposure of at least 85% to 90% per periapical film would be effected.

  19. A clinical trial of a rare earth screen/film system in a periapical cassette

    International Nuclear Information System (INIS)

    Kogon, S.L.; Stephens, R.G.; Reid, J.A.; Lubus, N.J.

    1984-01-01

    In a clinical trial, a slow rare earth screen/film system (Siemens Titan 2D/Kodak XG) was used to obtain intraoral radiographs at conventional monitoring stages in endodontic treatment. The screen film image proved to be an effective substitute for the direct-exposure Ultraspeed periapical film. The intraoral cassettes, designed and fabricated for the study, were an adaptation of the flexible, vacuum-sealed cassettes used in mammography. It is believed that when a practicable periapical cassette is manufactured, many additional indications for the system are probable. Major reductions in patient exposure of at least 85% to 90% per periapical film would be effected

  20. Europium determination in oxide and oxysulfide luminophors and their wastes by the method of direct and derivative spectrophotometry

    International Nuclear Information System (INIS)

    Mishchenko, V.T.; Aleksandrova, N.N.

    1989-01-01

    Spectrophotometric methods for europium determination in luminophors are proposed. Application of standard and derivative spectrophotometry allows one to determine europium in oxide and oxysulfide luminophors, their wastes and raffinates produced during waste reprocessing quite accurately and reliably. When determining Eu 2 O 3 (Eu 2 O 2 S) mass shares within 4-8 % limits absolute deviation from the mean result makes up to more than ± 0.2 %, relative standard deviation does not exceed 0.02

  1. [Follow up of total hip prothesis: storage phosphor versus screen-film radiography].

    Science.gov (United States)

    Polet, K; de La Selle, H; Leroux, J; Ludig, T; Girard, F; Coudane, H; Blum, A

    2003-03-01

    Digital radiography may lead to interpretation difficulties in patients with hip prosthesis, especially when initial evaluation was performed using screen film radiography. The purpose of this study was to evaluate inter-observer and inter-technique reproducibility comparing digital and screen-film radiography. Twenty-eight patients with unilateral (n=24) or bilateral (n=4) hip prosthesis (total=32 prostheses) underwent screen-film and digital (storage phosphor) radiography. The bone-cement and metal-cement interfaces were evaluated for the presence of a lucent line in 14 different sectors reclassified into 3 regions. This evaluation was performed by two independent readers. Inter-observer and inter-technique reproducibility were calculated using kappa values. The inter-observer reproducibility was negligible, poor or average with Kappa values ranging from 0.07 to 0.47. The degree of agreement between the two methods was poor, average or good for both observers with Kappa values ranging from 0.10 to 0.66. Although inter-technique agreement is not high, it is better than inter-observer agreement. Therefore, storage phosphor technique should not be rejected for total hip prosthesis follow-up, even though previous films were screen-film radiographs.

  2. The LSF and MTF of rare-earth oxysulfide intensifying screens.

    Science.gov (United States)

    Arnold, B A; Eisenberg, H; Bjärngard, B E

    1976-11-01

    The line spread function (LSF) and modulation transfer function (MTF) of 9 rare-earth screen/film systems were measured and compared with those of two fast calcium tungstate systems, using double-emulsion films sandwiched between two screens and mounted in regular cassettes. The LSFs were found to fit exponential functions. These results indicate that the increased sensitivity of rare-earth phosphors over calcium tungstate can be used to construct screens with a higher MTF or increased speed. The fast rare-earth systems allow the use of smaller focal spots for increased resolution while reducing the radiation dose to the patient.

  3. Cast Iron Inoculation Enhanced by Supplementary Oxy-sulfides Forming Elements

    Science.gov (United States)

    Riposan, Iulian; Stan, Stelian; Uta, Valentin; Stefan, Ion

    2017-09-01

    Inoculation is one of the most important metallurgical treatments applied to the molten cast iron immediately prior to casting, to promote solidification without excessive eutectic undercooling, which favors carbides formation usually with undesirable graphite morphologies. The paper focused on the separate addition of an inoculant enhancer alloy [S, O, oxy-sulfides forming elements] with a conventional Ca-FeSi alloy, in the production of gray and ductile cast irons. Carbides formation tendency decreased with improved graphite characteristics as an effect of the [Ca-FeSi + Enhancer] inoculation combination, when compared to other Ca/Ca, Ba/Ca, RE-FeSi alloy treatments. Adding an inoculant enhancer greatly enhances inoculation, lowers inoculant consumption up to 50% or more and avoids the need to use more costly inoculants, such as a rare earth bearing alloy. The Inoculation Specific Factor [ISF] was developed as a means to more realistically measure inoculant treatment efficiency. It compares the ratio between the improved characteristic level and total inoculant consumption for this effect. Addition of any of the commercial inoculants plus the inoculant enhancer offered outstanding inoculation power [increased ISF] even at higher solidification cooling rates, even though the total enhancer addition was at a small fraction of the amount of commercial inoculant used.

  4. Silicon Oxysulfide, OSiS: Rotational Spectrum, Quantum-Chemical Calculations, and Equilibrium Structure.

    Science.gov (United States)

    Thorwirth, Sven; Mück, Leonie Anna; Gauss, Jürgen; Tamassia, Filippo; Lattanzi, Valerio; McCarthy, Michael C

    2011-06-02

    Silicon oxysulfide, OSiS, and seven of its minor isotopic species have been characterized for the first time in the gas phase at high spectral resolution by means of Fourier transform microwave spectroscopy. The equilibrium structure of OSiS has been determined from the experimental data using calculated vibration-rotation interaction constants. The structural parameters (rO-Si = 1.5064 Å and rSi-S = 1.9133 Å) are in very good agreement with values from high-level quantum chemical calculations using coupled-cluster techniques together with sophisticated additivity and extrapolation schemes. The bond distances in OSiS are very short in comparison with those in SiO and SiS. This unexpected finding is explained by the partial charges calculated for OSiS via a natural population analysis. The results suggest that electrostatic effects rather than multiple bonding are the key factors in determining bonding in this triatomic molecule. The data presented provide the spectroscopic information needed for radio astronomical searches for OSiS.

  5. Oxysulfide LiAlSO: A Lithium Superionic Conductor from First Principles

    Science.gov (United States)

    Wang, Xuelong; Xiao, Ruijuan; Li, Hong; Chen, Liquan

    2017-05-01

    Through first-principles calculations and crystal structure prediction techniques, we identify a new layered oxysulfide LiAlSO in orthorhombic structure as a novel lithium superionic conductor. Two kinds of stacking sequences of layers of AlS2O2 are found in different temperature ranges. Phonon and molecular dynamics simulations verify their dynamic stabilities, and wide band gaps up to 5.6 eV are found by electronic structure calculations. The lithium migration energy barrier simulations reveal the collective interstitial-host ion "kick-off" hopping mode with barriers lower than 50 meV as the dominating conduction mechanism for LiAlSO, indicating it to be a promising solid-state electrolyte in lithium secondary batteries with fast ionic conductivity and a wide electrochemical window. This is a first attempt in which the lithium superionic conductors are designed by the crystal structure prediction method and may help explore other mixed-anion battery materials.

  6. Magnification mammography versus grid techniques comparative experimental and clinical studies with D screen-film systems

    International Nuclear Information System (INIS)

    Teubner, J.; Wentz, K.U.; Lenk, J.Z.

    1986-01-01

    The diagnostic efficiency of 0.1-mm microfocus magnification mammography and 0.3-mm grid mammography measured with respect to detail detectability and the breast dome on different screen-film systems. The experimental tests were formed with a lead bar test pattern and a biologic pattern for grid mammography and for magnification mammography with different magnifications. In 50 patients the authors compared the diagnostic efficiency of 2X magnification mammography with high-speed screen-film system and grid mammography with photosensitized industrial film. Both mammographic systems require the same skin entrance radiation dose. They analyze detectability of microcalcifications and the assessment of margins. For the same organ radiation dose, grid mammography and magnification mammography yielded comparable detectability. The essential advantages of magnification mammography are faster processing, easier visual evaluation, and the ability of further information due to different projections

  7. Diagnostic value of digital radiography compared to conventional screen-film system combinations

    International Nuclear Information System (INIS)

    Krug, B.; Zaehringer, M.; Lackner, K.

    1997-01-01

    Digital projection radiography provides digital data in X-ray examinations, which used to be carried out by examinations screen-film system combinations. The technological basis and clinical performances of digital luminescent radiography (DLR) and digital radiography are reviewed. Digital projection radiography does not allow to reduce selenium exposure significantly, compared to screen-film system combinations. Digital luminescent radiography can be used for the entire spectrum of analogous projection radiography the only exception being extremely subtile structural changes. The clinical experiences with digital selenium radiography achieved so far in chest X-rays are promising and the technique is expected to be increasing used in other anatomic regions as well. (orig.) [de

  8. Diagnostic imaging and biopsy pathways following abnormal screen-film and digital screening mammography

    Science.gov (United States)

    Hubbard, Rebecca A.; Zhu, Weiwei; Horblyuk, Ruslan; Karliner, Leah; Sprague, Brian L.; Henderson, Louise; Lee, David; Onega, Tracy; Buist, Diana SM.; Sweet, Alison

    2013-01-01

    Objective The transition from screen-film to digital mammography may have altered diagnostic evaluation of women following a positive screening examination. This study compared use and timeliness of diagnostic imaging and biopsy for women screened with screen-film or digital mammography. Materials and Methods Data were from 35,321 positive screening mammograms on 32,087 women aged 40–89 years, from 22 Breast Cancer Surveillance Consortium facilities in 2005–2008. Diagnostic pathways were classified by their inclusion of diagnostic mammography, ultrasound, magnetic resonance imaging (MRI), and biopsy. We compared time to resolution and frequency of diagnostic pathways by patient characteristics, screening exam modality, and radiology facility. Between-facility differences were evaluated by computing the proportion of mammograms receiving follow-up with a particular pathway for each facility and examining variation in these proportions across facilities. Multinomial logistic regression adjusting for age, calendar year, and facility compared odds of follow-up with each pathway. Results The median time to resolution of a positive screening mammogram was 10 days. Compared to screen-film mammograms, digital mammograms were more frequently followed by only a single diagnostic mammogram (46% vs. 36%). Pathways following digital screening mammography were also less likely to include biopsy (16% vs. 20%). However, in adjusted analyses most differences were not statistically significant (p = 0.857 for mammography only; p = 0.03 for biopsy). Substantial variability in diagnostic pathway frequency was seen across facilities. For instance, the frequency of evaluation with diagnostic mammography alone ranged from 23% to 55% across facilities. Conclusion Differences in evaluation of positive digital and screen-film screening mammograms were minor, and appeared to be largely attributable to substantial variation between radiology facilities. To guide health systems in their

  9. Dose reduction by x-ray beam filtration in screen-film radiography

    International Nuclear Information System (INIS)

    Koedooder, C.

    1986-01-01

    This thesis describes experimental and theoretical aspects of dose reduction by x-ray beam filtration in screen-film radiography. The thesis deals mainly with dose reduction under the constraint of constant image quality; an analytical approach is chosen. Therefore, part of the thesis deals with the development of an algorithm to calculate patient dose and exposure for different filter materials and different tube load conditions, under the constraint of constant contrast and constant optical density. (Auth.)

  10. Image quality and breast dose of 24 screen-film combinations for mammography.

    Science.gov (United States)

    Dimakopoulou, A D; Tsalafoutas, I A; Georgiou, E K; Yakoumakis, E N

    2006-02-01

    In this study the effect of different mammographic screen-film combinations on image quality and breast dose, and the correlation between the various image quality parameters, breast dose and the sensitometric parameters of a film were investigated. Three Agfa (MR5-II, HDR, HT), two Kodak (Min-R M, Min-R 2000), one Fuji (AD-M), one Konica (CM-H) and one Ferrania (HM plus) single emulsion mammographic films were combined with three intensifying screens (Agfa HDS, Kodak Min-R 2190 and Fuji AD-MA). The film characteristics were determined by sensitometry, while the image quality and the dose to the breast of the resulting 24 screen-film combinations were assessed using a mammography quality control phantom. For each combination, three images of the phantom were acquired with optical density within three different ranges. Two observers assessed the quality of the 72 phantom images obtained, while the breast dose was calculated from the exposure data required for each image. Large differences among screen-film combinations in terms of image quality and breast dose were identified however, that, could not be correlated with the film's sensitometric characteristics. All films presented the best resolution when combined with the HDS screen at the expense of speed, and the largest speed when combined with the AD-MA screen, without degradation of the overall image quality. However, an ideal screen-film combination presenting the best image quality with the least dose was not identified. It is also worth mentioning that the best performance for a film was not necessarily obtained when this was combined with the screen provided by the same manufacturer. The results of this study clearly demonstrate that comparison of films based on their sensitometric characteristics are of limited value for clinical practice, as their performance is strongly affected by the screens with which they are combined.

  11. Technology assessment: observer study directly compares screen/film to CR mammography

    Science.gov (United States)

    Fletcher-Heath, Lynn; Richards, Anne; Ryan-Kron, Susan

    2007-03-01

    A new study supports and expands upon a previous reporting that computed radiography (CR) mammography offers as good, or better, image quality than state-of-the-art screen/film mammography. The suitability of CR mammography is explored through qualitative and quantitative study components: feature comparison and cancer detection rates of each modality. Images were collected from 150 normal and 50 biopsy-confirmed subjects representing a range of breast and pathology types. Comparison views were collected without releasing compression, using automatic exposure control on Kodak MIN-R films, followed by CR. Digital images were displayed as both softcopy (S/C) and hardcopy (H/C) for the feature comparison, and S/C for the cancer detection task. The qualitative assessment used preference scores from five board-certified radiologists obtained while viewing 100 screen/film-CR pairs from the cancer subjects for S/C and H/C CR output. Fifteen general image-quality features were rated, and up to 12 additional features were rated for each pair, based on the pathology present. Results demonstrate that CR is equivalent or preferred to conventional mammography for overall image quality (89% S/C, 95% H/C), image contrast (95% S/C, 98% H/C), sharpness (86% S/C, 93% H/C), and noise (94% S/C, 91% H/C). The quantitative objective was satisfied by asking 10 board-certified radiologists to provide a BI-RADS TM score and probability of malignancy per breast for each modality of the 200 cases. At least 28 days passed between observations of the same case. Average sensitivity and specificity was 0.89 and 0.82 for CR and 0.91 and 0.82 for screen/film, respectively.

  12. Development and exploitation of the slit method for the characterization of x-ray screen-film combinations

    International Nuclear Information System (INIS)

    Hoeschen, D.

    1987-01-01

    For the determination of the modulation transfer function (MTF) of screen-film combinations which are used in medical x-ray diagnostics a measuring method has been developed: the screen-film combination is exposed to x-rays behind a thin slit and the modulation transfer function is calculated from the resulting rather broad slit images on the film. After solving many technical and photographic problems, the slit method provides high precision in the MTF determination. The only objection against this method is the necessary high dose variation which has to be provided by the x-ray machine

  13. Magnetic order and phase transition in the iron oxysulfide La2O2Fe2OS2

    Science.gov (United States)

    Oogarah, Reeya K.; Suard, Emmanuelle; McCabe, Emma E.

    2018-01-01

    The Mott-insulating iron oxychalcogenides exhibit complex magnetic behaviour and we report here a neutron diffraction investigation into the magnetic ordering in La2O2Fe2OS2. This quaternary oxysulfide adopts the anti-Sr2MnO2Mn2Sb2-type structure (described by space group I4/mmm) and orders antiferromagnetically below TN = 105 K. We consider both its long-range magnetic structure and its magnetic microstructure, and the onset of magnetic order. It adopts the multi-k vector "2k" magnetic structure (k = (1/2 0 1/2) and k = (0 1/2 1/2) and has similarities with related iron oxychalcogenides, illustrating the robust nature of the "2k" magnetic structure.

  14. Quality control: comparison of images quality with screen film system and digital mammography CR

    International Nuclear Information System (INIS)

    Alvarenga, Frederico L.; Nogueira, Maria do Socorro

    2008-01-01

    The mammography screen film system should be used as part of processing chemicals, revelation process, equipment and this system has have a progressive replacing by the digital technology Full Field Digital Mammography FFDM, Computed Radiography (CR) Mammography and hardcopy. This new acquisition process of medical images has improved radiology section; however it is necessary efficient means for evaluating of the quality parameters. It should be considered taking into account the adaptation of the existent equipment and that procedures adopted for the exam, as well the adaptation of the new mammography films, the radiologist view box constitutes a part of the quality control program. This program aims at obtaining radiography with good quality that allows obtaining more information for the diagnosis and decreases the patient dose. For evaluation the quality image, this article is focused on presenting the differences regarding the acquired images through simulator mammography radiographic PMMA (Poly methyl methacrylate) in CR Mammography system and screen film system. The tests were accomplished at the same equipment of Mammography with the Automatic Exposure Control using a tension of 28 kV for both systems. The quality tests evaluated the spatial resolution, the own structures of the phantom, artifacts, optical density and contrast with conventional and laser films by mammography system. The installation for the accomplishment of the test has a quality control program. The evaluation was based on the pattern developed by the competent organ of the State of Minas Gerais. In this study, it was verified that the suitable Phantom Mama used by the Brazilian School of Radiology for conventional mammography did not obtain satisfactory result for Spatial Resolution in the digital mammography system CR. The final aim of this work is to obtain parameters to characterize the reference phantom quality image in an objective way. These parameters will be used to compare

  15. Radiative lifetimes of neutral gadolinium

    International Nuclear Information System (INIS)

    Den Hartog, E A; Bilty, K A; Lawler, J E

    2011-01-01

    The current work is part of an ongoing study of radiative properties of rare earth neutral atoms motivated by research needs in several disparate fields including astrophysics, laser chemistry and lighting technology. Time-resolved laser-induced fluorescence on a slow atomic beam has been used to measure radiative lifetimes, accurate to ±5%, for 136 levels of neutral gadolinium. Of the 136 levels, 6 are odd parity ranging in energy from 32 929 to 36 654 cm -1 , and the remaining 130 are even parity ranging from 17 750 to 34 175 cm -1 . This set of Gd i lifetimes represents a significant extension to the available published data, with 93 of the 136 level lifetimes measured for the first time. These lifetimes will provide the absolute normalization for a large set of measured Gd i transition probabilities.

  16. Screen-film versus full-field digital mammography: Radiation dose and image quality in a large teaching hospital

    Directory of Open Access Journals (Sweden)

    Stantić Tomislav J.

    2013-01-01

    Full Text Available The objective of this paper is to measure the radiation dose and image quality in conventional screen-film mammography and full-field digital mammography in women referred to mammography examination. Participants underwent bilateral, two-view screen-film mammography or full-field digital mammography. The visibility of anatomical regions and overall clinical image quality was rated by experienced radiologists. Total of 387 women and 1548 mammograms were enrolled in the study. Image quality was assessed in terms of image quality score, whereas patient dose assessment was performed in terms of mean glandular dose. Average mean glandular dose for cranio-caudal projection was 1.5 mGy and 2.1 mGy in full-field digital mammography and screen-film mammography, respectively. For medio-lateral oblique projection, corresponding values were 2.3 and 2.1 mGy. Overall image quality criteria scoring was 0.82 and 0.99 for screen-film and digital systems, respectively. The scores were in the range from 0.11 to 1.0 for different anatomical structures. Overall, full-field digital mammography was superior both in terms of image quality and dose over the screen-film mammography. The results have indicated that phantom dose values can assist in setting the optimisation activities in mammography and for comparison between mammography units. To obtain accurate diagnostic information with an acceptable radiation dose to breast, it is necessary to periodically perform patient dose and image quality surveys in all mammography units.

  17. FBFC's gadolinium fuel assembly manufacturing experience

    International Nuclear Information System (INIS)

    Van Den Eynde, M.; Belvegue, P.

    1999-01-01

    The burnable poison used by Framatome is gadolinium oxide integrated in the pellet by blending with UO 2 . This is the integrated poison which provides the largest experience feedback world-wide. Its main advantages are design flexibility and its well-known rod in reactor behaviour. FBFC's manufacturing experience with gadolinium is extensive. The first pellets were produced in 1986, present production averages 10 tons/year and cumulated experience reaches 47 tons. In parallel Framatome acquired gadolinium irradiation experience with more then 2 000 fuel assemblies in 33 reactors in 5 countries. Taking into account the increasing needs, a new gadolinium shop has been implemented in the FBFC Dessel plant. This shop, with a production capacity of 30 tU/yr is to be commissioned in the second quarter of 1999. It implements the most recent technological developments to achieve top product quality, safety and environment protection. (authors)

  18. Gadolinium sheet converter for neutron radiography

    Energy Technology Data Exchange (ETDEWEB)

    Lima, C.T.S. [Laboratorio de Neutrongrafia em Tempo Real (LNRTR/PEN/COPPE), Universidade Federal do Rio de Janeiro, Ilha do Fundao, Caixa Postal 68509, 21941-972 Rio de Janeiro, RJ (Brazil); Crispim, V.R. [Laboratorio de Neutrongrafia em Tempo Real (LNRTR/PEN/COPPE), Universidade Federal do Rio de Janeiro, Ilha do Fundao, Caixa Postal 68509, 21941-972 Rio de Janeiro, RJ (Brazil); PEN/COPPE-DNC/Escola Politecnica CT, Universidade Federal do Rio de Janeiro, Ilha do Fundao, Caixa Postal 68509, 21941-972 Rio de Janeiro, RJ (Brazil)], E-mail: verginia@con.ufrj.br; Santos, W.M.S. [Laboratorio de Colisao Atomica e Molecular (LACAM/IF), Universidade Federal do Rio de Janeiro, Ilha do Fundao, Caixa Postal 68528, 21941-972 Rio de Janeiro, RJ (Brazil)

    2007-12-15

    This work describes a methodology developed for the confection of gadolinium sheet converter for neutron radiography using the gadolinium chloride (GdCl{sub 3}) as material converter. Though manufactured at a relatively low cost, they are as good as the sheet converter on the market. Here, we present neutron radiography of the penetrameter, the edge spread function, the modulation transfer function and characteristic curves for each set sheet-AA400 Kodak film.

  19. Impact of a CAD system in a screen-film mammography screening program: A prospective study

    International Nuclear Information System (INIS)

    Sanchez Gómez, S.; Torres Tabanera, M.; Vega Bolivar, A.; Sainz Miranda, M.; Baroja Mazo, A.; Ruiz Diaz, M.; Martinez Miravete, P.; Lag Asturiano, E.; Muñoz Cacho, P.; Delgado Macias, T.

    2011-01-01

    Objective: The purpose of our study was to perform a prospective assessment of the impact of a CAD system in a screen-film mammography screening program during a period of 3 years. Materials and methods: Our study was carried out on a population of 21,855 asymptomatic women (45–65 years). Mammograms were processed in a CAD system and independently interpreted by one of six radiologists. We analyzed the following parameters: sensitivity of radiologist's interpretation (without and with CAD), detection increase, recall rate and positive predictive value of biopsy, CAD's marks, radiologist's false negatives and comparative analysis of carcinomas detected and non-detected by CAD. Results: Detection rate was 4.3‰. CAD supposed an increase of 0.1‰ in detection rate and 1% in the total number of cases (p < 0.005). The impact on recall rate was not significant (0.4%) and PPV of percutaneous biopsy was unchanged by CAD (20.23%). CAD's marks were 2.7 per case and 0.7 per view. Radiologist's false negatives were 13 lesions which were initially considered as CAD's false positives. Conclusions: CAD supposed a significant increase in detection, without modifications in recall rates and PPV of biopsy. However, better results could have been achieved if radiologists had considered actionable those cases marked by CAD but initially misinterpreted.

  20. High-resolution storage phosphor imaging of the chest: Comparison with conventional screen-film systems

    International Nuclear Information System (INIS)

    Fuhrman, C.R.; Good, B.; Feist, J.; Gur, D.; Darby, J.

    1987-01-01

    An experimental high-resolution storage phosphor imaging system (Eastman Kodak) has been used to evaluate the image quality and impact on diagnostic interpretation of storage phosphor images relative to conventional screen-film images of the same patients. The elements of the system include a high-resolution laser scanner (4K X 5K X 12 bit); an image processing system; and a high-resolution (4K X 5K X 12 bit) laser printer. Each case was digitally printed onto film in two different formats: a full-size (14 X 14-inch) and a half-size format of four processed, minified images (7 X 7-inches each). The multiformat image includes an original, an unsharp-masked, a reversed (black bone) unsharp-masked, and a high-contrast unsharp-masked image. The results of this preliminary study (11 cases, eight readers) clearly indicate that after minimal adjustment, radiologists do not object to making diagnoses from minified images. Unsharp masked images were considered preferable to unprocessed images, and processed storage phosphor images were rated significantly better than conventional film images

  1. Influence of Upconversion Processes in the Optically-Induced Inhomogeneous Thermal Behavior of Erbium-Doped Lanthanum Oxysulfide Powders

    Directory of Open Access Journals (Sweden)

    Rolindes Balda

    2016-05-01

    Full Text Available The efficient infrared-to-visible upconversion emission present in Er-doped lanthanum oxysulfide crystal powders is used as a fine thermal sensor to determine the influence of upconversion processes on the laser-induced thermal load produced by the pump laser and to assess the potentialities of this material in order to obtain anti-Stokes laser-induced cooling. The analysis of the upconversion emission and excitation spectra as well as the decay curves indicates that energy transfer upconversion is the main mechanism responsible for the green (4S3/2 and red (4F9/2 upconversion luminescence. The dependence on temperature of the intensity ratio of upconversion emission from thermally-coupled 2H11/2 and 4S3/2 levels of Er3+ in the 240–300 K temperature range has been used to estimate a relative sensitivity of 1.09 × 10−2 K−1. Thermal measurements performed on the powder samples by using a thermal infrared camera exhibit a very inhomogeneous heat distribution at the sample surface due to the random distribution of the pumping energy inside the sample as well as to the random properties of the thermal field. The analysis of both spectroscopic and thermal measurements show that after a transient heating induced by the background absorption, cooling of discrete regions by means of anti-Stokes processes can be observed.

  2. Digital versus screen-film mammography: impact of mammographic density and hormone therapy on breast cancer detection.

    Science.gov (United States)

    Chiarelli, Anna M; Prummel, Maegan V; Muradali, Derek; Shumak, Rene S; Majpruz, Vicky; Brown, Patrick; Jiang, Hedy; Done, Susan J; Yaffe, Martin J

    2015-11-01

    Most studies that have examined the effects of mammographic density and hormone therapy use on breast cancer detection have included screen-film mammography. This study further examines this association in post-menopausal women screened by digital mammography. Approved by the University of Toronto Research Ethics Board, this study identified 688,418 women of age 50-74 years screened with digital or screen-film mammography from 2008 to 2009 within the Ontario Breast Screening Program. Of 2993 eligible women with invasive breast cancer, 2450 were contacted and 1421 participated (847 screen-film mammography, 574 digital direct radiography). Mammographic density was measured by study radiologists using the standard BI-RADS classification system and by a computer-assisted method. Information on hormone therapy use was collected by a telephone-administered questionnaire. Logistic regression and two-tailed tests for significance evaluated associations between factors and detection method by mammography type. Women with >75 % radiologist-measured mammographic density compared to those with mammography (OR = 2.41, 95 % CI 0.67-8.58) and aged 50-64 years screened with screen-film mammography (OR = 10.86, 95 % CI 2.96-39.57). Recent former hormone therapy users were also at an increased risk of having an interval cancer with the association being significant for women screened with digital mammography (OR = 2.08, 95 % CI 1.17-3.71). Breast screening using digital mammography lowers the risk of having an interval cancer for post-menopausal women aged 50-64 with greater mammographic density.

  3. Incidental MRI findings of acute gadolinium hypersensitivity.

    Science.gov (United States)

    Amene, C; Yeh-Nayre, L A; Dory, C E; Crawford, J R

    2012-01-01

    A 13-year-old girl with a remote history of juvenile pilocytic astrocytoma developed acute onset flushing, tachycardia and shortness of breath immediately following administration of gadopentetate dimeglumine during routine brain MRI that subsided following intravenous diphenhydramine. A retrospective review of the MRI results revealed multiple areas of contrast enhancement of the face, consistent with observed urticaria. The patient received pretreatment medications prior to subsequent gadolinium injections without incident. Gadolinium allergy is extremely rare and has been reported in less than 0.1% of injections. However, in patients who undergo anesthesia for MRI studies, similar subtle extracranial MRI findings should alert the neuroradiologist to possible gadolinium allergy that may warrant premedication prior to future injections.

  4. A toxicological study of gadolinium nitrate

    Energy Technology Data Exchange (ETDEWEB)

    London, J.E.

    1988-05-01

    The sensitization study in the guinea pig did not show gadolinium nitrate to have potential sensitizing properties. Skin application studies in the rabbit demonstrated that it was cutaneously a severe irritant. This material was considered an irritant in the rabbit eye application studies. 3 refs., 1 tab.

  5. Growth, characterization and dielectric studies of gadolinium ...

    Indian Academy of Sciences (India)

    Abstract. 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 ...

  6. Reduction of radiation dose by using digital luminescence radiography compared to conventional screen film system with grid cassette

    International Nuclear Information System (INIS)

    Heyne, J.P.; Merbold, H.; Neumann, R.; Freesmeyer, M.; Jonetz-Mentzel, L.; Kaiser, W.A.; Sehner, J.

    1999-01-01

    Purpose: How much can the radiation dose be reduced for skull radiography by using digital luminescence radiography (DLR) compared to a conventional screen film system with a grid cassette? Methods and Materials: A skull phantom (3M) was X-rayed in anterior-posterior orientation using both a conventional screen film system with grid cassette and DLR (ADC-70, Agfa). The tube current time product (mAs) was diminished gradually while keeping the voltage constant. The surface entrance dose was measured by a sensor of Dosimax (Wellhoefer). Five investigators evaluated the images by characteristic and critical features, spatial resolution and contrast. Results: The surface entrance dose at 73 kV/22 mAs was 0,432 mGy in conventional screen film system and 0,435 mGy in DLR. The images could be evaluated very well down to an average dose of 71% (0,308 mGy; SD 0,050); sufficient images were obtained down to an average dose of 31% (0,136 mGy; SD 0,065). The resolution of the line pairs were reduced down to a 2 levels depending on the investigator. Contrast was assessed as being very good to sufficient. The acceptance of the postprocessed images (MUSICA-software) was individually different and resultde in an improvement of the assessment of bone structures an contrast in higher dose ranges only. Conclusion: For the sufficient assessment of a possible fracture/of paranasal sinuses/of measurement the skull the dose can be reduced to at least 56% (31%; SD 14,9%)/40% (27%; SD 9,3%)/18% (14%; SD 4,4%). Digital radiography allows question-referred exposure parameters with clearly reduced dose, so e.g. for fracture exclusion 73 kV/12,5 mAs and to skull measurement 73 kV/4 mAs. (orig.) [de

  7. Light deflection in gadolinium molybdate ferroelastic crystals

    International Nuclear Information System (INIS)

    Staniorowski, Piotr; Bornarel, Jean

    2000-01-01

    The deflection of a He-Ne light beam by polydomain gadolinium molybdate (GMO) crystals has been studied with respect to incidence angle α i on the sample at room temperature. The A and B deflected beams do not cross each other during the α 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. (author)

  8. Room temperature ferromagnetic gadolinium silicide nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Hadimani, Magundappa Ravi L.; Gupta, Shalabh; Harstad, Shane; Pecharsky, Vitalij; Jiles, David C.

    2018-03-06

    A particle usable as T1 and T2 contrast agents is provided. The particle is a gadolinium silicide (Gd5Si4) particle that is ferromagnetic at temperatures up to 290 K and is less than 2 .mu.m in diameter. An MRI contrast agent that includes a plurality of gadolinium silicide (Gd.sub.5Si.sub.4) particles that are less than 1 .mu.m in diameter is also provided. A method for creating gadolinium silicide (Gd5Si4) particles is also provided. The method includes the steps of providing a Gd5Si4 bulk alloy; grinding the Gd5Si4 bulk alloy into a powder; and milling the Gd5Si4 bulk alloy powder for a time of approximately 20 minutes or less.

  9. Determination of gadolinium by the method of derivative spectrophotometry

    International Nuclear Information System (INIS)

    Aleksandrova, N.N.; Mishchenko, V.T.; Poluehktov, N.S.; Mukomel', V.L.

    1988-01-01

    Technique for gadolinium determination at the presence of interfering rare earth elements, which is based on the derivative spectrophotometry method, is suggested. The technique is of increased selectivity and allows to determine gadolinium in the mixtures with elements, which presence in solution makes impossible to determine gadolinium directly. At binary mixtures analysis Sr relative standard deviation does not exceed 0.03, while at the analysis of more complex mixtures Sr increases up to 0.06

  10. Calculation qualification of gadolinium burnable poisons in water reactors

    International Nuclear Information System (INIS)

    Chaucheprat, P.

    1988-01-01

    The work presented in this thesis constitutes the qualification on the one end of Appolo-Neptune scheme for the gadolinium burnable poison in a pressurized water reactor, and on the other end of basis nuclear data on natural gadolinium. This study has permitted to reduce by a factor 3 the actual incertitude on the gadolinium poison comparatively at precisions cited in international benchmarks calculations [fr

  11. Contrast opacification for CT from iodine, gadolinium and ytterbium

    International Nuclear Information System (INIS)

    Zwicker, C.; Langer, M.; Ullrich, V.; Felix, R.

    1993-01-01

    The absorption of the elements iodine, gadolinium und ytterbium in various dilutions was studied in relation to CT. Regression analysis and specific CT density measurements showed that absorption decreases from gadolinium to ytterbium and iodine. These results were confirmed by experiments using ten dogs. Boli of 0.5 molar gadolinium used for angio-CT without table movement showed the largest increase in density in the aorta and liver with an average of 190 HU and 21 HU respectively compared with iodine which gave 157 HU and 12 HU respectively. The animal experimental studies suggest that gadolinium and ytterbium are suitable contrast media for dynamic CT investigations. (orig.) [de

  12. Thermal diffusivity of samarium-gadolinium zirconate solid solutions

    International Nuclear Information System (INIS)

    Pan, W.; Wan, C.L.; Xu, Q.; Wang, J.D.; Qu, Z.X.

    2007-01-01

    We synthesized samarium-gadolinium zirconate solid solutions and determined their thermal diffusivities, Young's moduli and thermal expansion coefficients, which are very important for their application in thermal barrier coatings. Samarium-gadolinium zirconate solid solutions have extremely low thermal diffusivity between 20 and 600 deg. C. The solid solutions have lower Young's moduli and higher thermal expansion coefficients than those of pure samarium and gadolinium zirconates. This combination of characteristics is promising for the application of samarium and gadolinium zirconates in gas turbines. The mechanism of phonon scattering by point defects is discussed

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

    International Nuclear Information System (INIS)

    Klepper, O.H.

    1985-06-01

    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

  14. Comparison between a digital scanning system and a conventional screen film system in the full spine radiological procedure in pediatrics

    International Nuclear Information System (INIS)

    Espana, M. L.; Gomez, G.; Romero, A.; Minambres, A.; Albi, G.; Floriano, A.; Rodirguez, A.; Lopez Franco, P.

    2004-01-01

    To compare from both dosimetry and image quality standpoints, a digital scanning system with a conventional screen film system, in the full spine radiological procedure. The standard patient is considered to be 12 years old, and a sample of forty patients referred for full spine radiological procedure has been studied. Gonad shielding has been used in all the patients, and its efficiency has been evaluated. Dosimetric study includes Kerma-area product, and thorax and gonad entrance surface dose. Kerma area product has been measured using a transmission camera, and for entrance surface dose estimation both thermoluminescent dosemeter LiF: Mg, Cu, P and LiF: Mg, Ti have been utilized. Three radiologists have evaluated the image quality according to the degree of fulfilment of the image quality criteria. (Author) 22 refs

  15. Comparison of Digital Screening Mammography and Screen-Film Mammography in the Early Detection of Clinically Relevant Cancers: A Multicenter Study

    NARCIS (Netherlands)

    Bluekens, Adriana M. J.; Holland, Roland; Karssemeijer, Nico; Broeders, Mireille J. M.; den Heeten, Gerard J.

    2012-01-01

    Purpose: To compare screen-film mammography with digital mammography in a breast cancer screening program, with a focus on the clinical relevance of detected cancers. Materials and Methods: The study was approved by the regional medical ethics review board. Informed consent was not required. Before

  16. Comparison of digital screening mammography and screen-film mammography in the early detection of clinically relevant cancers: a multicenter study

    NARCIS (Netherlands)

    Bluekens, A.M.; Holland, R.; Karssemeijer, N.; Broeders, M.J.M.; Heeten, G.J. den

    2012-01-01

    Purpose: To compare screen-film mammography with digital mammography in a breast cancer screening program, with a focus on the clinical relevance of detected cancers. Materials and Methods: The study was approved by the regional medical ethics review board. Informed consent was not required. Before

  17. Mammographic density assessed on paired raw and processed digital images and on paired screen-film and digital images across three mammography systems

    NARCIS (Netherlands)

    Burton, Anya; Byrnes, Graham; Stone, Jennifer; Tamimi, Rulla M; Heine, John; Vachon, Celine; Ozmen, Vahit; Pereira, Ana; Garmendia, Maria Luisa; Scott, Christopher; Hipwell, John H; Dickens, Caroline; Schüz, Joachim; Aribal, Mustafa Erkin; Bertrand, Kimberly; Kwong, Ava; Giles, Graham G; Hopper, John; Pérez Gómez, Beatriz; Pollán, Marina; Teo, Soo-Hwang; Mariapun, Shivaani; Taib, Nur Aishah Mohd; Lajous, Martín; Lopez-Riduara, Ruy; Rice, Megan; Romieu, Isabelle; Flugelman, Anath Arzee; Ursin, Giske; Qureshi, Samera; Ma, Huiyan; Lee, Eunjung; Sirous, Reza; Sirous, Mehri; Lee, Jong Won; Kim, Jisun; Salem, Dorria; Kamal, Rasha; Hartman, Mikael; Miao, Hui; Chia, Kee-Seng; Nagata, Chisato; Vinayak, Sudhir; Ndumia, Rose; van Gils, Carla H; Wanders, Johanna O P; Peplonska, Beata; Bukowska, Agnieszka; Allen, Steve; Vinnicombe, Sarah; Moss, Sue; Chiarelli, Anna M; Linton, Linda; Maskarinec, Gertraud; Yaffe, Martin J; Boyd, Norman F; Dos-Santos-Silva, Isabel; McCormack, Valerie A

    2016-01-01

    BACKGROUND: Inter-women and intra-women comparisons of mammographic density (MD) are needed in research, clinical and screening applications; however, MD measurements are influenced by mammography modality (screen film/digital) and digital image format (raw/processed). We aimed to examine

  18. Impact of the transition from screen-film to digital screening mammography on interval cancer characteristics and treatment : A population based study from the Netherlands

    NARCIS (Netherlands)

    Nederend, J.; Duijm, L.E.; Louwman, M.W.J.; Coebergh, J.W.; Roumen, R.M.H.; Lohle, P.N.; Roukema, J.A.; Rutten, M.J.; van Steenbergen, L.N.; Ernst, M.F.; Jansen, F.H.; Plaisier, M.L.; Hooijen, M.J.H.H.; Voogd, A.C.

    2014-01-01

    Introduction In most breast screening programmes screen-film mammography (SFM) has been replaced by full-field digital mammography (FFDM). We compared interval cancer characteristics at SFM and FFDM screening mammography. Patients and methods We included all 297 screen-detected and 104 interval

  19. Gadolinium-enhanced magnetic resonance imaging in acute myocardial infarction

    International Nuclear Information System (INIS)

    Dijkman, P.R.M. van; Wall, E.E. van der; Roos, A. de; Doornbos, J.; Laarse, A. van der; Voorthuisen, A.E. van; Bruschke, A.V.G.; Rossum, A.C. van

    1990-01-01

    To evaluate he usefulness of the paramagnetic contrast agent Gadolinium-DTPA (diethylenetriaminepentaacetic acid) in Magnetic Resonance. Imaging of acute myocardial infarction, we studied a total of 45 patients with a first acute myocardial infarction by ECG-gated magnetic resonance imaging before and after intravenous administration of 0.1 mmol/kg Gadolinium-DTPA. All patients received thrombolytic treatment by intravenous streptokinase. The magnetic resonance imaging studies were preformed after a meam of 88 h (range 15-241) after the acute onset of acute myocardial infarction. Five patients without evidence of cardiac disease served as controls. Spin-echo measurements (TE 30 ms) were made using a Philips Gyroscan (0.5 Tesla) or a Teslacon II (0.6 Tesla). The 45 patients were divided into four groups of patients. In Group I( patients) Gadolinium-DTPA improved the detection of myocardial infarction by Gadolinium-DTPA. In Group II (20 patients) the magnetic resonance imaging procedure was repeated every 10 min for up to 40 min following administration of Gadolinium-DTPA. Optimal contrast enhancement was obtained 20-25 min after Gadolinium-DTPA. In Group III (27 patients) signal intensities were significantly higher in the patients who underwent the magnetic resonance imaging study more than 72 h (mean 120) after the acute event, suggesting increased acculumation of Gadolinium-DTPA in a more advanced stage of the infarction process. In Group IV (45 patients) Gadolinium-DTPA was administered in an attempt to distinguish between reperfused and nonreperfused myocardial areas after thrombolytic treatment for acute myocardial infarction. The signal intensities did not differ, but reperfused areas showed a more homogeneous aspect whereas nonreperfused areas were visualized as a more heterogeneous contrast enhancement. It is concluded that magnetic resonance imaging using the contrast agent Gadolinium-DTPA significantly improves the detection of infarcted myocardial areas

  20. 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).

  1. Effect of organic bases on extraction of gadolinium carboxylates

    International Nuclear Information System (INIS)

    Sukhan, V.V.; Frankovskij, V.A.

    1982-01-01

    The effect of pyridine, 2-aminopyridine, benzylamine, antipyrine and o-phenanthroline on the extraction of capronates and bromocapronates of gadolinium with chloroform is studied. Out of the studied organic bases benzylamine produces the highest synergetic effect. In the absence of organic bases gadolinium carboxylates, solvated by three molecules of carbonic acids, are extracted into organic phase. A possihility of extractional separation of gadolinium from comparable amounts of iron with the mixture of 1 M solutions of caproic or bromocaproic acids with 1 M benzylamine from 0.1 M solution of tartaric acids is shown [ru

  2. Alkali metal and alkali earth metal gadolinium halide scintillators

    Science.gov (United States)

    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. Gadolinium recovery from aqueous pharmaceutical residuals by pulsed electrical discharge; Rueckgewinnung von Gadolinium aus pharmazeutischen Abwaessern mittels gepulster elektrischer Entladung

    Energy Technology Data Exchange (ETDEWEB)

    Lorenz, Tom; Froehlich, Peter [TU Bergakademie Freiberg (Germany); Seifert, Martin; Jacob-Seifert, Karin [FNE Entsorgungsdienste GmbH, Freiberg (Germany)

    2017-02-15

    Advanced oxidation process (AOP) is an oxidation step releasing reactive oxygen species by pulsed electrical discharge in aqueous systems. In contrast to processes generating ozone by external UV radiation this method is feasible for turbid liquids with solid particles. This method is currently used in particular in the field of purification of chemically polluted waste waters. In the present application AOP is applied for partial degradation of the organic ligand system of a gadolinium X-ray contrast agent to separate gadolinium subsequently by adding caustic soda to precipitate > 99% of gadolinium.

  4. Studies Comparing Screen-Film Mammography and Full-Field Digital Mammography in Breast Cancer Screening: Updated Review

    International Nuclear Information System (INIS)

    Skaane, P.

    2009-01-01

    Full-field digital mammography (FFDM) has several potential benefits as compared with screen-film mammography (SFM) in mammography screening. Digital technology also opens for implementation of advanced applications, including computer-aided detection (CAD) and tomosynthesis. Phantom studies and experimental clinical studies have shown that FFDM is equal or slightly superior to SFM for detection and characterization of mammographic abnormalities. Despite obvious advantages, the conversion to digital mammography has been slower than anticipated, and not only due to higher costs. Until very recently, some countries did not even permit the use of digital mammography in breast cancer screening. The reason for this reluctant attitude was concern about lower spatial resolution and about using soft-copy reading. Furthermore, there was a lack of data supporting improved diagnostic accuracy using FFDM in a screening setting, since two pioneer trials both showed nonsignificantly lower cancer detection rate at FFDM. The 10 studies comparing FFDM and SFM in mammography screening published so far have shown divergent and rather conflicting results. Nevertheless, there is a rapid conversion to digital mammography in breast cancer screening in many western countries. The aim of this article is to give an updated review of these studies, discuss the conflicting findings, and draw some conclusions from the results

  5. Observer variability in screen-film mammography versus full-field digital mammography with soft-copy reading

    Energy Technology Data Exchange (ETDEWEB)

    Skaane, Per; Young, Kari [Ullevaal University Hospital, Department of Radiology, Breast Imaging Center, Oslo (Norway); Diekmann, Felix; Diekmann, Susanne [University Charite, Department of Diagnostic Radiology, Berlin (Germany); Balleyguier, Corinne [Institut Gustave Roussy, Villejuif (France); Piguet, Jean-Charles [Institut Imagerive, Geneva (Switzerland); Abdelnoor, Michael [Ullevaal University Hospital, Center for Clinical Research, Section of Epidemiology and Biostatistics, Oslo (Norway); Niklason, Loren [Hologic Inc., Hillsborough, NC (United States)

    2008-06-15

    Full-field digital mammography (FFDM) with soft-copy reading is more complex than screen-film mammography (SFM) with hard-copy reading. The aim of this study was to compare inter- and intraobserver variability in SFM versus FFDM of paired mammograms from a breast cancer screening program. Six radiologists interpreted mammograms of 232 cases obtained with both techniques, including 46 cancers, 88 benign lesions, and 98 normals. Image interpretation included BI-RADS categories. A case consisted of standard two-view mammograms of one breast. Images were scored in two sessions separated by 5 weeks. Observer variability was substantial for SFM as well as for FFDM, but overall there was no significant difference between the observer variability at SFM and FFDM. Mean kappa values were lower, indicating less agreement, for microcalcifications compared with masses. The lower observer agreement for microcalcifications, and especially the low intraobserver concordance between the two imaging techniques for three readers, was noticeable. The level of observer agreement might be an indicator of radiologist performance and could confound studies designed to separate diagnostic differences between the two imaging techniques. The results of our study confirm the need for proper training for radiologists starting FFDM with soft-copy reading in breast cancer screening. (orig.)

  6. Computer-aided detection of masses in full-field digital mammography using screen-film mammograms for training

    International Nuclear Information System (INIS)

    Kallenberg, Michiel; Karssemeijer, Nico

    2008-01-01

    It would be of great value when available databases of screen-film mammography (SFM) images can be used to train full-field digital mammography (FFDM) computer-aided detection (CAD) systems, as compilation of new databases is costly. In this paper, we investigate this possibility. Firstly, we develop a method that converts an FFDM image into an SFM-like representation. In this conversion method, we establish a relation between exposure and optical density by simulation of an automatic exposure control unit. Secondly, we investigate the effects of using the SFM images as training samples compared to training with FFDM images. Our FFDM database consisted of 266 cases, of which 102 were biopsy-proven malignant masses and 164 normals. The images were acquired with systems of two different manufacturers. We found that, when we trained our FFDM CAD system with a small number of images, training with FFDM images, using a five-fold crossvalidation procedure, outperformed training with SFM images. However, when the full SFM database, consisting of 348 abnormal cases (including 204 priors) and 810 normal cases, was used for training, SFM training outperformed FFDMA training. These results show that an existing CAD system for detection of masses in SFM can be used for FFDM images without retraining.

  7. 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...

  8. 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...

  9. Extraction of gadolinium from high flux isotope reactor control plates

    International Nuclear Information System (INIS)

    Kohring, M.W.

    1987-04-01

    Gadolinium-153 is an important radioisotope used in the diagnosis of various bone disorders. Recent medical and technical developments in the detection and cure of osteoporosis, a bone disease affecting an estimated 50 million people, have greatly increased the demand for this isotope. The Oak Ridge National Laboratory (ORNL) has produced 153 Gd since 1980 primarily through the irradiation of a natural europium-oxide powder followed by the chemical separation of the gadolinium fraction from the europium material. Due to the higher demand for 153 Gd, an alternative production method to supplement this process has been investigated. This process involves the extraction of gadolinium from the europium-bearing region of highly radioactive, spent control plates used at the High Flux Isotope Reactor (HFIR) with a subsequent re-irradiation of the extracted material for the production of the 153 Gd. Based on the results of experimental and calculational analyses, up to 25 grams of valuable gadolinium (≥60% enriched in 152 Gd) resides in the europium-bearing region of the HFIR control components of which 70% is recoverable. At a specific activity yield of 40 curies of 153 Gd for each gram of gadolinium re-irradiated, 700 one-curie sources can be produced from each control plate assayed

  10. Selective photoionization of gadolinium isotopes with a polarized laser

    International Nuclear Information System (INIS)

    Le Guyadec, E.

    1990-06-01

    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 [fr

  11. Use of gadolinium as neutron poison in 540 MWe PHWR

    International Nuclear Information System (INIS)

    Nag, P.K.; Fernando, M.P.S.; Kumar, A.N.

    2006-01-01

    In Pressurised heavy water reactors (PHWRs), neutron poison in the moderator is used to compensate the excess reactivity present in the core on different occasions such as xenon decay during synchronization just after poison out period or start ups from xenon free conditions. It is also used in secondary shutdown system (SDS-2), where required amount of neutron poison is injected directly into the moderator within 2.5 seconds. Further, it is also used for over poisoning the moderator to achieve the guaranteed shutdown state when the regular shutdown systems are taken for maintenance. Generally, two types of moderator poisons are used in power reactors to balance the reactivity of the core and they are boron and gadolinium. Gadolinium is used in the form of gadolinium nitrate (Gd(NO 3 ) 3 .6H 2 O). The paper gives the details of estimation of reactivity coefficients of gadolinium for 540 MWe PHWR for different operating conditions. These neutron poisons are converted into non-absorbing elements and therefore their effective worth will decrease as reactor operation proceeds. The rate of burning of neutron absorbing isotopes depends on its magnitude of absorption cross-section and thermal flux seen by them. The present study discusses the burning characteristics of gadolinium during power operation in 540 MWe PHWR. It is established by detailed analysis that the rate of positive reactivity realized due to burning of neutron absorbing Gd isotopes almost match with the build up rate of xenon. The burning half lives of boron and gadolinium is worked out for different power levels. (author)

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

    DEFF Research Database (Denmark)

    Bahl, Christian Robert Haffenden; Nielsen, Kaspar Kirstein

    2009-01-01

    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...... for by the demagnetization factor. Also, the temperature dependence of DeltaTad has been measured experimentally and modeled by mean field theory. Corrections to mean field theory modeling due to the demagnetization field are proposed and discussed. ©2009 American Institute of Physics...

  13. The obtaining a high-grade gadolinium concentrate

    International Nuclear Information System (INIS)

    Soltysiak, I.; Ozga, W.

    1982-01-01

    Gadolinium concentrates obtained by the fractional precipitation of lanthanon-potassium double chromates were separated by ion exchange with 0,4 M lactic acid solution in the presence of 0,1 M ammonium nitrate at pH of the medium 2,95-3,4. It was found out, that using the fractional precipitation of lanthanon-potassium double chromates (as the fast and cheap method that does not need special equipment) together with ion exchange separation with lactic acid solution as the eluent gave a highgrade gadolinium concentrate in a quick and economical way. (author)

  14. Gadolinium-based contrast agents in pediatric magnetic resonance imaging

    Energy Technology Data Exchange (ETDEWEB)

    Gale, Eric M.; Caravan, Peter [Massachusetts General Hospital, Harvard Medical School, Department of Radiology, The Martinos Center for Biomedical Imaging, Boston, MA (United States); Rao, Anil G. [Medical University of South Carolina, Department of Radiology and Radiological Science, Charleston, SC (United States); McDonald, Robert J. [College of Medicine, Mayo Clinic, Department of Radiology, Rochester, MN (United States); Winfeld, Matthew [University of Pennsylvania Perelman School of Medicine, Philadelphia, PA (United States); Fleck, Robert J. [Cincinnati Children' s Hospital Medical Center, Department of Pediatric Radiology, Cincinnati, OH (United States); Gee, Michael S. [MassGeneral Hospital for Children, Harvard Medical School, Division of Pediatric Imaging, Department of Radiology, Boston, MA (United States)

    2017-05-15

    Gadolinium-based contrast agents can increase the accuracy and expediency of an MRI examination. However the benefits of a contrast-enhanced scan must be carefully weighed against the well-documented risks associated with administration of exogenous contrast media. The purpose of this review is to discuss commercially available gadolinium-based contrast agents (GBCAs) in the context of pediatric radiology. We discuss the chemistry, regulatory status, safety and clinical applications, with particular emphasis on imaging of the blood vessels, heart, hepatobiliary tree and central nervous system. We also discuss non-GBCA MRI contrast agents that are less frequently used or not commercially available. (orig.)

  15. Gadolinium-based contrast agents in pediatric magnetic resonance imaging

    International Nuclear Information System (INIS)

    Gale, Eric M.; Caravan, Peter; Rao, Anil G.; McDonald, Robert J.; Winfeld, Matthew; Fleck, Robert J.; Gee, Michael S.

    2017-01-01

    Gadolinium-based contrast agents can increase the accuracy and expediency of an MRI examination. However the benefits of a contrast-enhanced scan must be carefully weighed against the well-documented risks associated with administration of exogenous contrast media. The purpose of this review is to discuss commercially available gadolinium-based contrast agents (GBCAs) in the context of pediatric radiology. We discuss the chemistry, regulatory status, safety and clinical applications, with particular emphasis on imaging of the blood vessels, heart, hepatobiliary tree and central nervous system. We also discuss non-GBCA MRI contrast agents that are less frequently used or not commercially available. (orig.)

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

    International Nuclear Information System (INIS)

    Mercanti, D.; Casalbore, P.; Sanita, F.; Rosi, F.; Festinesi, A.; Pallini, R.; Gilbert, B.; Stasio, G. de

    2000-01-01

    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)

  17. Thermal expansion studies on dysprosium and gadolinium titanates

    International Nuclear Information System (INIS)

    Panneerselvam, G.; Antony, M.P.; Vasudeva Rao, P.R.

    2002-01-01

    Lanthanides and their oxides are considered potential candidates for the use in nuclear reactors as control rod. Dysprosium (Dy) and gadolinium (Gd) have very high absorption cross-section for neutrons. Dysprosium and gadolinium titanates were prepared by ceramic route as well as wet chemical route. The compounds were characterized chemically by using inductively coupled plasma mass spectrometric (ICPMS) technique and by x-ray diffraction (XRD) technique. Thermal expansion coefficient was measured in the temperature range 573 to 1573 K by using high temperature x-ray diffraction technique. (author)

  18. Use of gadolinium-based magnetic resonance imaging contrast agents and awareness of brain gadolinium deposition among pediatric providers in North America

    Energy Technology Data Exchange (ETDEWEB)

    Mithal, Leena B. [Northwestern University, Feinberg School of Medicine, Ann and Robert H. Lurie Children' s Hospital of Chicago, Department of Pediatrics, Chicago, IL (United States); Patel, Payal S. [University of Arizona College of Medicine, Department of Pediatrics, Phoenix, AZ (United States); Mithal, Divakar [Northwestern University, Feinberg School of Medicine, Ann and Robert H. Lurie Children' s Hospital of Chicago, Department of Pediatric Neurology, Chicago, IL (United States); Palac, Hannah L. [Northwestern University, Biostatistics, Feinberg School of Medicine, Ann and Robert H. Lurie Children' s Hospital of Chicago, Chicago, IL (United States); Rozenfeld, Michael N. [University of Arizona College of Medicine, Department of Radiology, Phoenix, AZ (United States)

    2017-05-15

    Numerous recent articles have reported brain gadolinium deposition when using linear but not macrocyclic gadolinium-based contrast agents (GBCAs). To determine the current landscape of gadolinium use among pediatric institutions and the knowledge base of radiologists and referring providers with regard to GBCAs and brain gadolinium deposition. We e-mailed voluntary closed surveys to 5,390 physicians in various pediatric professional societies between January 2016 and March 2016. We used chi-square and Fisher exact tests to compare response distributions among specialties. We found that 80% of surveyed pediatric hospitals use macrocyclic contrast agents. In the last year, 58% switched their agent, most commonly to gadoterate meglumine, with the most common reason being brain gadolinium deposition. Furthermore, surveys indicated that 23% of hospitals are considering switching, and, of these, 83% would switch to gadoterate meglumine; the most common reasons were brain gadolinium deposition and safety. Radiologists were more aware of brain gadolinium deposition than non-radiologist physicians (87% vs. 26%; P<0.0001). Radiologists and referring providers expressed similar levels of concern (95% and 89%). Twelve percent of radiologists and 2% of referring providers reported patients asking about brain gadolinium deposition. Radiologists were significantly more comfortable addressing patient inquiries than referring pediatric physicians (48% vs. 6%; P<0.0001). The number of MRIs requested by referring pediatric physicians correlated with their knowledge of brain gadolinium deposition, contrast agent used by their hospital, and comfort discussing brain gadolinium deposition with patients (P<0.0001). Since the discovery of brain gadolinium deposition, many pediatric hospitals have switched to or plan to switch to a more stable macrocyclic MR contrast agent, most commonly gadoterate meglumine. Despite this, there is need for substantial further education of radiologists and

  19. 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...

  20. Burnup calculation and analysis of burnable poison gadolinium

    International Nuclear Information System (INIS)

    Zhao Wei

    1989-01-01

    The analysis and calculation of thermal group parameters of gadolinium oxide as burnable poison, and characteristics of energy spectrum with change of burnup are presented. At the same time the theoretical problems of this new type of burnable poison which is used in PWR design is discussed

  1. Low-lying (K ) states of gadolinium isotopes

    Indian Academy of Sciences (India)

    model can be identified with the fully symmetric states in the sdf interacting boson approxima- tion model. A systematic study of the sdf-IBA .... those found for other nuclei in this region. Again, the model is capable only of accounting .... π = 0+. ) states of gadolinium isotopes. A useful measure of collectivity is the R4/2 = E4. +.

  2. Nephrogenic systemic fibrosis (NSF) and gadolinium-based contrast ...

    African Journals Online (AJOL)

    Nephrogenic systemic fibrosis (NSF), unknown before March 1997 and first described in 2000, is a systemic disorder characterised by widespread tissue fibrosis. The first known case occurred in 1997, after the use of gadolinium-based contrast agents (GBCAs) at high doses in patients with renal failure had become routine.

  3. 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.

  4. 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.

  5. Kinetics of zigzag domain boundaries in gadolinium molybdate

    International Nuclear Information System (INIS)

    Alekseev, A.N.; Proklov, A.L.; Tikhomirova, N.A.; Shuvalov, L.A.; AN SSSR, Moscow. Inst. Kristallografii)

    1987-01-01

    Kinetics of zigzag domain boundaries (3DB) in ferroelectric gadolinium molybdate (GMO) crystal was investigated at different amplitude, duration and growth rate of external electric field. The results verify the difference between shifting rates of two 3DB constituents of wedge-shaped systems, growing with field change rate increase

  6. Development of gadolinium based nanoparticles having an affinity towards melanin

    Science.gov (United States)

    Morlieras, Jessica; Chezal, Jean-Michel; Miot-Noirault, Elisabeth; Roux, Amandine; Heinrich-Balard, Laurence; Cohen, Richard; Tarrit, Sébastien; Truillet, Charles; Mignot, Anna; Hachani, Roxanne; Kryza, David; Antoine, Rodolphe; Dugourd, Philippe; Perriat, Pascal; Janier, Marc; Sancey, Lucie; Lux, François; Tillement, Olivier

    2013-01-01

    Small Rigid Platforms (SRPs) are sub-5 nanometre gadolinium based nanoparticles that have been developed for multimodal imaging and theranostic applications. They are composed of a polysiloxane network surrounded by gadolinium chelates. A covalent coupling with quinoxaline derivatives has been performed. Such derivatives have proven their affinity for melanin frequently expressed in primary melanoma cases. Three different quinoxaline derivatives have been synthesised and coupled to the nanoparticles. The affinity of the grafted nanoparticles for melanin has then been shown in vitro by surface plasmon resonance on a homemade melanin grafted gold chip.Small Rigid Platforms (SRPs) are sub-5 nanometre gadolinium based nanoparticles that have been developed for multimodal imaging and theranostic applications. They are composed of a polysiloxane network surrounded by gadolinium chelates. A covalent coupling with quinoxaline derivatives has been performed. Such derivatives have proven their affinity for melanin frequently expressed in primary melanoma cases. Three different quinoxaline derivatives have been synthesised and coupled to the nanoparticles. The affinity of the grafted nanoparticles for melanin has then been shown in vitro by surface plasmon resonance on a homemade melanin grafted gold chip. Electronic supplementary information (ESI) available. See DOI: 10.1039/c2nr33457g

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

    International Nuclear Information System (INIS)

    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.

    1997-01-01

    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

  8. Importance of the use of gadolinium in neurocysticercosis diagnosis

    International Nuclear Information System (INIS)

    Machado Junior, M.A.; Costa, G.; Barbosa, V.A.; Rubin, J.C.

    1994-01-01

    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)

  9. In vitro uptake of 153gadolinium and gadolinium complexes by hyaline articular cartilage

    International Nuclear Information System (INIS)

    Engel, A.; Fleischmann, D.; Hamilton, G.; Hajek, P.

    1990-01-01

    This in vitro study evaluated whether Gadolinium (Gd) penetrates into hyaline cartilage and would be incorporated into vital chondrocytes. Hyaline joint cartilage of rabbits was exposed to radioactive 153 GdCl 3 and to a radioactive 153 Gd-DTPA-BSA-complex (DTPA, diethylene-triaminepentaacetic acid; BSA, bovine serum albumine). In addition an exchange experiment with radioactive 153 GdCl 3 versus Gd-DTPA-di-N-methylglucamine (Magnevist) was performed. Incorporation of 153 GdCl 3 into neuroblastoma cells, connective tissue cells and chondrocytes was tested. The results showed that the depth and extent of incorporation of Gd depends on the molecular mass and time of exposure. 153 Gd-DTPA-BSA complexes exhibited an incorporation rate of maximal 11 per cent ± 2.8 per cent up to the middle third of the cartilage within 24 h with almost no incorporation (2 ± 1.9 per cent) for the deep layer. The exchange experiment revealed no uptake of Gd for the deep layer. The maximal incorporation rate of 153 GdCl 3 into vital chondrocytes was 6.3 per cent. These data indicate that under the condition of MR-arthrography, Gd-DTPA-di-N-methylglucamine will not be absorbed into the deep layers of hyaline cartilage and will not be incorporated into vital chondrocytes. (author). 8 refs.; 3 tabs

  10. Mammographic density assessed on paired raw and processed digital images and on paired screen-film and digital images across three mammography systems.

    Science.gov (United States)

    Burton, Anya; Byrnes, Graham; Stone, Jennifer; Tamimi, Rulla M; Heine, John; Vachon, Celine; Ozmen, Vahit; Pereira, Ana; Garmendia, Maria Luisa; Scott, Christopher; Hipwell, John H; Dickens, Caroline; Schüz, Joachim; Aribal, Mustafa Erkin; Bertrand, Kimberly; Kwong, Ava; Giles, Graham G; Hopper, John; Pérez Gómez, Beatriz; Pollán, Marina; Teo, Soo-Hwang; Mariapun, Shivaani; Taib, Nur Aishah Mohd; Lajous, Martín; Lopez-Riduara, Ruy; Rice, Megan; Romieu, Isabelle; Flugelman, Anath Arzee; Ursin, Giske; Qureshi, Samera; Ma, Huiyan; Lee, Eunjung; Sirous, Reza; Sirous, Mehri; Lee, Jong Won; Kim, Jisun; Salem, Dorria; Kamal, Rasha; Hartman, Mikael; Miao, Hui; Chia, Kee-Seng; Nagata, Chisato; Vinayak, Sudhir; Ndumia, Rose; van Gils, Carla H; Wanders, Johanna O P; Peplonska, Beata; Bukowska, Agnieszka; Allen, Steve; Vinnicombe, Sarah; Moss, Sue; Chiarelli, Anna M; Linton, Linda; Maskarinec, Gertraud; Yaffe, Martin J; Boyd, Norman F; Dos-Santos-Silva, Isabel; McCormack, Valerie A

    2016-12-19

    Inter-women and intra-women comparisons of mammographic density (MD) are needed in research, clinical and screening applications; however, MD measurements are influenced by mammography modality (screen film/digital) and digital image format (raw/processed). We aimed to examine differences in MD assessed on these image types. We obtained 1294 pairs of images saved in both raw and processed formats from Hologic and General Electric (GE) direct digital systems and a Fuji computed radiography (CR) system, and 128 screen-film and processed CR-digital pairs from consecutive screening rounds. Four readers performed Cumulus-based MD measurements (n = 3441), with each image pair read by the same reader. Multi-level models of square-root percent MD were fitted, with a random intercept for woman, to estimate processed-raw MD differences. Breast area did not differ in processed images compared with that in raw images, but the percent MD was higher, due to a larger dense area (median 28.5 and 25.4 cm 2 respectively, mean √dense area difference 0.44 cm (95% CI: 0.36, 0.52)). This difference in √dense area was significant for direct digital systems (Hologic 0.50 cm (95% CI: 0.39, 0.61), GE 0.56 cm (95% CI: 0.42, 0.69)) but not for Fuji CR (0.06 cm (95% CI: -0.10, 0.23)). Additionally, within each system, reader-specific differences varied in magnitude and direction (p < 0.001). Conversion equations revealed differences converged to zero with increasing dense area. MD differences between screen-film and processed digital on the subsequent screening round were consistent with expected time-related MD declines. MD was slightly higher when measured on processed than on raw direct digital mammograms. Comparisons of MD on these image formats should ideally control for this non-constant and reader-specific difference.

  11. Behavior of gadolinium-based diagnostics in water treatment

    Energy Technology Data Exchange (ETDEWEB)

    Cyris, Maike

    2013-04-25

    Wastewater treatment plants throughout Europe are retrofitted for a sufficient removal of micropollutants. Most target compounds are eliminated efficiently at reasonable costs by oxidation. Sorption processes, on the other hand, are favored as no transformation products are formed. For oxidation, ozone is preferred presently. Its action is divided in two main reaction pathways: Via ozone and via hydroxyl radicals formed by ozone-matrix reactions. Oxidation efficiency strongly depends on reaction rate constants. Sorption processes are usually characterized, including sorption strength, by determination of isotherms. Also, for description of filtration processes isotherm data are necessary. So far, gadolinium chelates, used as contrast agents in magnetic resonance imaging, have not been investigated in both advanced wastewater treatment processes. The stable chelates are excreted without metabolization. Conventional wastewater treatment does not remove them substantially. They remain intact and no free Gd(III) is released. This may be changed due to oxidative treatment which potentially destroys the chelates, and Gd(III) ions which are toxic, contrary to the chelated form, may be liberated. Monitoring campaigns in wastewater and drinking water have been performed to demonstrate the relevance of gadolinium in such treatment steps. In a European monitoring campaign an average concentration of 118 ng L{sup -1} gadolinium has been determined for 75 wastewater treatment plants effluents, corresponding to a non-geogenic gadolinium concentration of 116 ng L{sup -1}. In drinking water in the Ruhr area, a densely populated region in Germany, gadolinium and the anomaly were measurable by a factor of five lower than the average in the investigated wastewater samples. The determined concentrations in drinking water are lower than acute toxic effect concentration. The speciation of gadolinium in the investigated samples is unknown, as only total element concentration has been

  12. Behavior of gadolinium-based diagnostics in water treatment

    International Nuclear Information System (INIS)

    Cyris, Maike

    2013-01-01

    Wastewater treatment plants throughout Europe are retrofitted for a sufficient removal of micropollutants. Most target compounds are eliminated efficiently at reasonable costs by oxidation. Sorption processes, on the other hand, are favored as no transformation products are formed. For oxidation, ozone is preferred presently. Its action is divided in two main reaction pathways: Via ozone and via hydroxyl radicals formed by ozone-matrix reactions. Oxidation efficiency strongly depends on reaction rate constants. Sorption processes are usually characterized, including sorption strength, by determination of isotherms. Also, for description of filtration processes isotherm data are necessary. So far, gadolinium chelates, used as contrast agents in magnetic resonance imaging, have not been investigated in both advanced wastewater treatment processes. The stable chelates are excreted without metabolization. Conventional wastewater treatment does not remove them substantially. They remain intact and no free Gd(III) is released. This may be changed due to oxidative treatment which potentially destroys the chelates, and Gd(III) ions which are toxic, contrary to the chelated form, may be liberated. Monitoring campaigns in wastewater and drinking water have been performed to demonstrate the relevance of gadolinium in such treatment steps. In a European monitoring campaign an average concentration of 118 ng L -1 gadolinium has been determined for 75 wastewater treatment plants effluents, corresponding to a non-geogenic gadolinium concentration of 116 ng L -1 . In drinking water in the Ruhr area, a densely populated region in Germany, gadolinium and the anomaly were measurable by a factor of five lower than the average in the investigated wastewater samples. The determined concentrations in drinking water are lower than acute toxic effect concentration. The speciation of gadolinium in the investigated samples is unknown, as only total element concentration has been determined

  13. Laser spectroscopy and laser isotope separation of atomic gadolinium

    International Nuclear Information System (INIS)

    Chen, Y. W.; Yamanaka, C.; Nomaru, K.; Kou, K.; Niki, H.; Izawa, Y.; Nakai, S.

    1994-01-01

    Atomic vapor laser isotope separation (AVLIS) is a process which uses intense pulsed lasers to selectively photoionize one isotopic species of a chemical element, after which these ions are extracted electromagnetically. The AVLIS has several advantages over the traditional methods based on the mass difference, such as high selectivity, low energy consumption, short starting time and versatility to any atoms. The efforts for atomic vapor laser isotope separation at ILT and ILE, Osaka University have been concentrated into the following items: 1) studies on laser spectroscopy and laser isotope separation of atomic gadolinium, 2) studies on interaction processes including coherent dynamics, propagation effects and atom-ion collision in AVLIS system, 3) development of laser systems for AVLIS. In this paper, we present experimental results on the laser spectroscopy and laser isotope separation of atomic gadolinium.

  14. Microwave and optical diagnostics in a gadolinium plasma

    International Nuclear Information System (INIS)

    Larousse, B.

    1997-01-01

    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 -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 10 cm -3 . In the spectral range between 380 and 400 nm, two lines are observed, issue from the fundamental and metastable (633 cm -1 ) levels. The density of metastable level of gadolinium ions is about 10 10 cm -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)

  15. Process for the manufacture of nuclear fuels containing gadolinium

    International Nuclear Information System (INIS)

    Sondermann, T.

    1980-01-01

    A uranyl nitrate solution containing the required gadolinium CO 2 gas and NH 3 gas is taken to a precipitator with an aqueous condensate containing ammonium carbonate with a pH value of 9. A pump circulates the suspension. The salt is precipitated by reducing the pH value to 8.2. After filtration and drying these crystals together with AUC are changed to the oxide form, which can be sintered. (RW) [de

  16. Laser ablation of Bi-substituted gadolinium iron garnet films

    International Nuclear Information System (INIS)

    Watanabe, N.; Hayashida, K.; Kawano, K.; Higuchi, K.; Ohkoshi, M.; Tsushima, K.

    1995-01-01

    Bi-substituted gadolinium iron garnet films were deposited by laser ablation. The composition, the structure and the magnetic properties of the films were found to be strongly dependent both on the compositions of the targets and on the pressure of oxygen. The highest values of Bi-substitution up to x=1.44 with uniform composition were obtained, after annealing in air. ((orig.))

  17. Growth and scintillation properties of gadolinium and yttrium orthovanadate crystals

    International Nuclear Information System (INIS)

    Voloshina, O.V.; Baumer, V.N.; Bondar, V.G.; Kurtsev, D.A.; Gorbacheva, T.E.; Zenya, I.M.; Zhukov, A.V.; Sidletskiy, O.Ts.

    2012-01-01

    Aiming to explore the possibility of using the undoped rare-earth orthovanadates as scintillation materials, we developed the procedure for growth of gadolinium (GdVO 4 ) and yttrium (YVO 4 ) orthovanadate single crystals by Czochralski method, and determined the optimal conditions of their after-growth annealing. Optical, luminescent, and scintillation properties of YVO 4 and GdVO 4 were discussed versus known literature data. Scintillation characteristics of GdVO 4 were determined for the first time.

  18. A study of reduction of patient's radiation exposure by using the new ortho screen film systems (4). A study of the possibility of higher developing temperature by observation of chest phantom radiographs

    International Nuclear Information System (INIS)

    Yagi, Hirofumi; Fukui, Toshihito; Yasutomo, Motokatsu; Takashima, Koosuke; Kuroda, Tokue; Nishitani, Hiromu.

    1995-01-01

    Recently, some new ortho screen-film systems (Konica EX system, Fuji AD system and Kodak IEF system) are being developed. The granulalities of these systems have been greatly improved and gross fogs are lower than those of traditional ortho screen-film systems. Even if the radiographs with the new ortho screen-film are processed at higher temperature than with the old ortho system such as Lanex Medium/TMC-RA (Eastman Kodak), the deterioration in the image quality is negligible. Furthermore, the speed of the screen-film systems increases as the developing temperature rises. Therefore, there may be the potential to reduce patients' radiation exposure without greatly decreasing the image quality. At that time, the problem arises how to determine the appropriate developing temperature. The limit of developing temperature for the new ortho system was determined as the temperature for getting the same gross fog in old ortho-system. In this report, phantom radiographs were made at various developing temperatures and the comments about the higher limit of the developing temperature were solicited from medical doctors who evaluated them. Consequently, it has been confirmed there are sufficient image quality in the radiographs which were developed at the higher developing temperature than at the temperature used in many faculties now. (author)

  19. The cation-deficient Ruddlesden-Popper oxysulfide Y2Ti2O5S2 as a layered sulfide: topotactic potassium intercalation to form KY2Ti2O5S2.

    Science.gov (United States)

    Rutt, Oliver J; Hill, Timothy L; Gál, Zoltán A; Hayward, Michael A; Clarke, Simon J

    2003-12-01

    Potassium intercalation into the cation-deficient n = 2 Ruddlesden-Popper oxysulfide Y(2)Ti(2)O(5)S(2) to form KY(2)Ti(2)O(5)S(2) has been carried out by reaction of the oxysulfide with potassium vapor in sealed metal tubes at 400 degrees C, potassium naphthalide in THF at 50 degrees C, or potassium in liquid ammonia at temperatures as low as -78 degrees C. Insertion of potassium is topotactic, and although a site 12-coordinate by oxide ions is vacant in the perovskite-type oxide slabs of the structure, potassium is too large to enter this site via the 4-coordinate window, and instead enters the rock-salt-type sulfide layers of the structure which necessitates a 30% increase in the lattice parameter c normal to the layers. In contrast with one of the sodium intercalates of Y(2)Ti(2)O(5)S(2) (beta-NaY(2)Ti(2)O(5)S(2)) in which sodium occupies a tetrahedral site in the sulfide layers, potassium favors an 8-coordinate site which necessitates a relative translation of adjacent oxide slabs. KY(2)Ti(2)O(5)S(2) is tetragonal: P4/mmm, a = 3.71563(4) A, c = 14.8682(2) A (at 298 K), Z = 1. Although the resistivity (3.4(1) x 10(3) Omega cm) is larger than would be expected for a metal, temperature independent paramagnetism dominates the magnetic susceptibility, and the material is electronically very similar to the analogous sodium intercalate beta-NaY(2)Ti(2)O(5)S(2) which features reduced-titanium-containing oxide layers of very similar geometry and electron count.

  20. 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.

  1. Utilization of gadolinium burnable poison for reactivity control of pressurized water reactors

    International Nuclear Information System (INIS)

    Galperin, A.; Segev, M.

    1985-01-01

    Summarized here is an attempt to utilize gadolinium as a burnable poison for total reactivity control of a PWR core equilibrium cycle, i.e., control without a soluble poison system. In the course of the research, a few design guidelines evolved: 1) gadolinium can be utilized well in the form of a lumped poison rod; 2) the optimal gadolinium rod is an annulus of gadolinium immersed in water; 3) BP rods are inserted into vacant thimble guide tubes; and 4) only fresh fuel assemblies are loaded with BP rods, thus avoiding insertion of the BP clusters into irradiated fuel assemblies

  2. Femtosecond laser excitation drives ferromagnetic gadolinium out of magnetic equilibrium.

    Science.gov (United States)

    Carley, Robert; Döbrich, Kristian; Frietsch, Björn; Gahl, Cornelius; Teichmann, Martin; Schwarzkopf, Olaf; Wernet, Philippe; Weinelt, Martin

    2012-08-03

    The temporal evolution of the exchange-split Δ(2)-like Σ valence bands of the 4f-ferromagnet gadolinium after femtosecond laser excitation has been studied using angle-resolved photoelectron spectroscopy based on high-order harmonic generation. The ultrafast drop of the exchange splitting reflects the magnetic response seen in femtosecond magnetic dichroism experiments. However, while the minority valence band reacts immediately, the response of the majority counterpart is delayed by 1 picosecond and is only half as fast. These findings demonstrate that laser excitation drives the valence band structure out of magnetic equilibrium.

  3. Gadolinium-enhanced MR imaging in evaluation of Bell palsy

    International Nuclear Information System (INIS)

    Wang, A.M.; Wesolowski, D.P.; Bojrab, D.I.; Ernstoff, R.M.; Farah, J.

    1989-01-01

    Eight patients with Bell palsy were evaluated with Gd-DTPA (Magnevist)-enhanced MR imaging in a 1.0-T Siemen's Magnetom unit. Axial pre-and postcontrast and coronal postcontrast T1-weighted MR images of facial nerves were studied. Significant unilateral enhancement of the facial nerve within the internal auditory canal, with or without involvement of the geniculate ganglia, was found in six patients. Three of these patients without satisfactory response to medical treatment underwent surgical decompression, with excellent recovery of facial nerve function. The authors believe that gadolinium-enhanced MR imaging is valuable in the evaluation and management of Bell palsy

  4. Production and characterization of quality gadolinium oxide nanoparticles

    International Nuclear Information System (INIS)

    Hazarika, Samiran; Mohanta, Dambarudhar

    2013-01-01

    Rare earth system Gadolinium (Gd), in either pure form or oxide form, is highly stable against environmental attack. It has immense potential as a contrast agent in magnetic resonance imaging (MRI) devices. Being mechanically and thermally stable it is always difficult to obtain Gd 2 O 3 nanopowders directly from its bulk counterpart using conventional top-down approach. Recently, we have reported production of Gd 2 O 3 nanopowders by first converting bulk Gd 2 O 3 into a nitrate compound and subsequently reduced into a hydroxide product and finally to the oxide product (nanopowder form)

  5. Gadolinium enhances the sensitivity of SW-1573 cells for thermal neutron irradiation

    NARCIS (Netherlands)

    Franken, N. A. P.; Bergs, J. W. J.; Kok, T. T.; Kuperus, R. R. N.; Stecher-Rasmussen, F.; Haveman, J.; van Bree, C.; Stalpers, L. J. A.

    2006-01-01

    Gadolinium neutron capture therapy (Gd-NCT) is an experimental cancer treatment based on the physical principal that neutron capture by gadolinium-157 ensures the release of focal high-dose radiation, such as gamma-rays and electrons. Survival and induction of chromosomal aberrations of human

  6. Studies on deposition of gadolinium from its nitrate solution of zircaloy-2 surfaces

    International Nuclear Information System (INIS)

    Shah, G.C.; Unny, V.K.P.; Vartak, D.G.

    1981-01-01

    Gadolinium nitrate solution (25000 ppm) is proposed as a neutron poison in tertiary shut down system of R-5 reactor at Trombay, Bombay. The gadolinium nitrate solution when in contact with the zircaloy tube can get deposited and thus, affect the reactivity of the reactor during operation. Experiments were conducted to evaluate the rate of deposition of gadolinium on zircaloy-2 surfaces at various temperatures and at different periods of time. Studies were also conducted to determine the deposition of gadolinium when exposed to various 60 Co γ-ray irradiation doses. The studies indicated that deposition of gadolinium increases with increase in temperature while there was no increase in rate of deposition by 60 Co γ-ray irradiation upto 440 Mrads. (author)

  7. Psa study of ETRR-2 Gadolinium injection system

    International Nuclear Information System (INIS)

    El-Messiry, A.M.; Moustafa, A.M.

    1999-01-01

    one of the main safety feature of ETRR-2, egypt test and reactor 3 2 (new reactor), is the use of a redundant and diverse shutdown systems, called second shutdown system SSS. This system operates through injection of a high absorbing material, gadolinium Gd solution, into four rectangular chambers surrounding the reactor core. In view of the fact that the core is super-moderated, the injected neutron poison between the core and the reflector will cause an immediate reactor shutdown. The SSS triggers due to: manual, seismic, fails of actuation of the first shutdown system FSS, or high power neutron flux signal. Because of safety importance of this new system design, the present probabilistic safety assessment PDA study is initiated. The study carried ou in view of the system acceptable unavailability together with the effects of failure probabilities of relevant parameters and basic events. The effect of system design modifications (remove of high power signal and addition of nitrogen filtering line) on reactor safety and system unavailability is analyzed. A new proposed PSA model which take into consideration all possible failure modes of the system components is developed. The results show that the modification done on the system improves its unavailability while increases the minimal cut sets. The proposed model unavailability is greater (bad) than the designer model (That contains many hypothesis). human error contribution on system unavailability is reflected on failure type of gadolinium concentration. The IAEA psa pack IV code is utilized for calculation purposes

  8. Computer-aided detection system for clustered microcalcifications: comparison of performance on full-field digital mammograms and digitized screen-film mammograms

    International Nuclear Information System (INIS)

    Ge Jun; Hadjiiski, Lubomir M; Sahiner, Berkman; Wei Jun; Helvie, Mark A; Zhou Chuan; Chan Heangping

    2007-01-01

    We have developed a computer-aided detection (CAD) system to detect clustered microcalcifications automatically on full-field digital mammograms (FFDMs) and a CAD system for screen-film mammograms (SFMs). The two systems used the same computer vision algorithms but their false positive (FP) classifiers were trained separately with sample images of each modality. In this study, we compared the performance of the CAD systems for detection of clustered microcalcifications on pairs of FFDM and SFM obtained from the same patient. For case-based performance evaluation, the FFDM CAD system achieved detection sensitivities of 70%, 80% and 90% at an average FP cluster rate of 0.07, 0.16 and 0.63 per image, compared with an average FP cluster rate of 0.15, 0.38 and 2.02 per image for the SFM CAD system. The difference was statistically significant with the alternative free-response receiver operating characteristic (AFROC) analysis. When evaluated on data sets negative for microcalcification clusters, the average FP cluster rates of the FFDM CAD system were 0.04, 0.11 and 0.33 per image at detection sensitivity level of 70%, 80% and 90% compared with an average FP cluster rate of 0.08, 0.14 and 0.50 per image for the SFM CAD system. When evaluated for malignant cases only, the difference of the performance of the two CAD systems was not statistically significant with AFROC analysis

  9. Differences in radiological patterns, tumour characteristics and diagnostic precision between digital mammography and screen-film mammography in four breast cancer screening programmes in Spain

    Energy Technology Data Exchange (ETDEWEB)

    Domingo, Laia; Sala, Maria [IMIM-Hospital del Mar, Department of Epidemiology and Evaluation, Barcelona (Spain); CIBER de Epidemiologia y Salud Publica (CIBERESP), Barcelona (Spain); Universitat Autonoma de Barcelona (UAB), EHEA Doctoral Program in Public Health. Department of Pediatrics, Obstetrics and Gynecology, Preventive Medicine and Public Health, Barcelona (Spain); Romero, Anabel; Belvis, Francesc; Macia, Francesc; Castells, Xavier [IMIM-Hospital del Mar, Department of Epidemiology and Evaluation, Barcelona (Spain); CIBER de Epidemiologia y Salud Publica (CIBERESP), Barcelona (Spain); Sanchez, Mar [Government of Cantabria, General Directorate of Public Health, Department of Health, Santander (Spain); Ferrer, Joana [Radiology Unit. Hospital Santa Caterina, Girona (Spain); Salas, Dolores; Ibanez, Josefa [General Directorate Public Health and Centre for Public Health Research (CSISP), Valencia (Spain); Vega, Alfonso [Hospital Universitario Marques de Valdecilla, Radiology Unit, Santander (Spain); Ferrer, Francesc [Hospital del Mar, Radiology and Nuclear Medicine Service, Barcelona (Spain); Laso, M.S. [Breast Cancer Screening Unit Burjassot, Valencia (Spain)

    2011-09-15

    To compare tumour characteristics between cancers detected with screen-film mammography (SFM) and digital mammography (DM) and to evaluate changes in positive predictive values (PPVs) for further assessments, for invasive procedures and for distinct radiological patterns in recalled women. 242,838 screening mammograms (171,191 SFM and 71,647 DM) from 103,613 women aged 45-69 years, performed in four population-based breast cancer screening programmes in Spain, were included. The tumour characteristics and PPVs of each group were compared. Radiological patterns (masses, calcifications, distortions and asymmetries) among recalled women were described and PPVs were evaluated. The percentages of ductal carcinoma in situ (DCIS) were higher in DM than in SFM both in the first [18.5% vs. 15.8%(p = 0.580)] and in successive screenings [23.2% vs. 15.7%(p = 0.115)]. PPVs for masses, asymmetries and calcifications were higher in DM, being statistically significant in masses (5.3% vs. 3.9%; proportion ratio: 1.37 95%CI: 1.08-1.72). Among cancers detected by calcifications, the percentage of DCIS was higher in DM (60.3% vs. 46.4%, p = 0.060). PPVs were higher when DM was used, both for further assessments and for invasive procedures, with similar cancer detection rates and no statistically significant differences in tumour characteristics. The greatest improvements in PPVs were found for masses. (orig.)

  10. Differences in radiological patterns, tumour characteristics and diagnostic precision between digital mammography and screen-film mammography in four breast cancer screening programmes in Spain

    International Nuclear Information System (INIS)

    Domingo, Laia; Sala, Maria; Romero, Anabel; Belvis, Francesc; Macia, Francesc; Castells, Xavier; Sanchez, Mar; Ferrer, Joana; Salas, Dolores; Ibanez, Josefa; Vega, Alfonso; Ferrer, Francesc; Laso, M.S.

    2011-01-01

    To compare tumour characteristics between cancers detected with screen-film mammography (SFM) and digital mammography (DM) and to evaluate changes in positive predictive values (PPVs) for further assessments, for invasive procedures and for distinct radiological patterns in recalled women. 242,838 screening mammograms (171,191 SFM and 71,647 DM) from 103,613 women aged 45-69 years, performed in four population-based breast cancer screening programmes in Spain, were included. The tumour characteristics and PPVs of each group were compared. Radiological patterns (masses, calcifications, distortions and asymmetries) among recalled women were described and PPVs were evaluated. The percentages of ductal carcinoma in situ (DCIS) were higher in DM than in SFM both in the first [18.5% vs. 15.8%(p = 0.580)] and in successive screenings [23.2% vs. 15.7%(p = 0.115)]. PPVs for masses, asymmetries and calcifications were higher in DM, being statistically significant in masses (5.3% vs. 3.9%; proportion ratio: 1.37 95%CI: 1.08-1.72). Among cancers detected by calcifications, the percentage of DCIS was higher in DM (60.3% vs. 46.4%, p = 0.060). PPVs were higher when DM was used, both for further assessments and for invasive procedures, with similar cancer detection rates and no statistically significant differences in tumour characteristics. The greatest improvements in PPVs were found for masses. (orig.)

  11. Establishing daily quality control (QC) in screen-film mammography using leeds tor (max) phantom at the breast imaging unit of USTH-Benavides Cancer Institute

    Science.gov (United States)

    Acaba, K. J. C.; Cinco, L. D.; Melchor, J. N.

    2016-03-01

    Daily QC tests performed on screen film mammography (SFM) equipment are essential to ensure that both SFM unit and film processor are working in a consistent manner. The Breast Imaging Unit of USTH-Benavides Cancer Institute has been conducting QC following the test protocols in the IAEA Human Health Series No.2 manual. However, the availability of Leeds breast phantom (CRP E13039) in the facility made the task easier. Instead of carrying out separate tests on AEC constancy and light sensitometry, only one exposure of the phantom is done to accomplish the two tests. It was observed that measurements made on mAs output and optical densities (ODs) using the Leeds TOR (MAX) phantom are comparable with that obtained from the usual conduct of tests, taking into account the attenuation characteristic of the phantom. Image quality parameters such as low contrast and high contrast details were also evaluated from the phantom image. The authors recognize the usefulness of the phantom in determining technical factors that will help improve detection of smallest pathological details on breast images. The phantom is also convenient for daily QC monitoring and economical since less number of films is expended.

  12. Influence of the addition of gadolinium on the microstructure and mechanical properties of duplex stainless steel

    International Nuclear Information System (INIS)

    Ahn, Ji-Ho; Jung, Hyun-Do; Im, Jae-Han; Jung, Ki Ho; Moon, Byung-Moon

    2016-01-01

    The aim of this study is to investigate the effects of gadolinium addition on the microstructure and mechanical properties of duplex stainless steel (DSS) fabricated using a normal casting method. The oxygen content in the cast DSS alloy with gadolinium decreased because of the high reactivity of gadolinium with oxygen. The area fraction and size of non-intermetallic inclusions in the alloy decreased from 0.80±0.12% to 0.58±0.04% and from 6.9±0.7 to 5.8±0.4 μm upon gadolinium addition, respectively. Notably, the ultimate tensile strength and strain at break of the cast alloy significantly increased with the addition of gadolinium from 919±25 to 969±8 MPa and from 24.8±1.9% to 28.4±1.1%, respectively. The hardness of the cast alloy with gadolinium increased from 23.6±1.3 to 25.0±1.2 HRC. A significant increase in the impact energy of the cast alloy was observed and the brittle-to-ductile transition temperature slightly decreased by approximately 10 °C with the addition of gadolinium.

  13. 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.

  14. Self-consistent, relativistic, ferromagnetic band structure of gadolinium

    International Nuclear Information System (INIS)

    Harmon, B.N.; Schirber, J.; Koelling, D.D.

    1977-01-01

    An initial self-consistent calculation of the ground state magnetic band structure of gadolinium is described. A linearized APW method was used which included all single particle relativistic effects except spin-orbit coupling. The spin polarized potential was obtained in the muffin-tin form using the local spin density approximation for exchange and correlation. The most striking and unorthodox aspect of the results is the position of the 4f spin-down ''bands'' which are required to float just on top of the Fermi level in order to obtain convergence. If the 4f states (l = 3 resonance) are removed from the occupied region of the conduction bands the magnetic moment is approximately .75 μ/sub B//atom; however, as the 4f spin-down states are allowed to find their own position they hybridize with the conduction bands at the Fermi level and the moment becomes smaller. Means of improving the calculation are discussed

  15. First results on study of gadolinium as burnable absorber

    International Nuclear Information System (INIS)

    Abbate, Maximo J.; Sbaffoni, Maria M.

    2000-01-01

    Following on with the work included in the 'Burnable absorbers research plan' several experiments were carried out oriented to determine Ga 2 O 3 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)

  16. Nuclear orientation of 149Pm in gadolinium host

    International Nuclear Information System (INIS)

    Badzhelidze, N.G.; Ehn, L.; Janout, Z.; Finger, M.; Lebedev, N.A.; Pavlov, V.N.; Prochazka, I.; Simecek, P.

    1983-01-01

    The temperature dependence of the anisotropy of the 285.9 keV gamma-ray following the decay of oriented 149 Pm was measured. The 149 Pm parent nuclei were oriented at low temperatures between 14 and 80 mK in a gadolinium host containing 1 At.% of neodymium admixture. The external magnetic field of 1.2 T was applied to polarize the domains of the host. Limits of experimental values of gamma-ray angular distribution coefficient A 2 varies in the region 0.097 2 (γ 285.9 keV) 2 =1.53 and the deorientation factor U 2 =0.925 were used. The result yields multipole mixing ratio, delta (E2/M1) lying in intervals 0.0 < delta < +0.11 or -19 < delta < -5.7

  17. Early Gadolinium Enhancement for Determination of Area at Risk

    DEFF Research Database (Denmark)

    Hammer-Hansen, Sophia; Leung, Steve W; Hsu, Li-Yueh

    2017-01-01

    between 10 and 15 min after contrast injection. AAR was defined as myocardium with blood flow difference in the size...... requires pathological validation. METHODS: Eleven dogs underwent 2 h of coronary artery occlusion and 48 h of reperfusion before imaging at 1.5-T. EGE imaging was performed 3 min after contrast administration with coverage of the entire left ventricle. Late gadolinium enhancement imaging was performed...... of enhancement by EGE compared with the size of AAR by microspheres (44.1 ± 15.8% vs. 42.7 ± 9.2%; p = 0.61), with good correlation (r = 0.88; p difference in the size of enhancement by EGE compared with enhancement...

  18. Role of gadolinium in MR imaging of sinonasal masses

    International Nuclear Information System (INIS)

    Lanzieri, C.F.; Shah, M.; Smith, A.S.; Tarr, R.; Van Dyke, C.; Kaufman, B.; Krauss, D.; Lavertu, P.

    1990-01-01

    This paper determines whether additional clinically useful information can be obtained with the use of contrast-enhanced MR imaging, compared with nonenhanced MR imaging and enhanced CT, in the evaluation of patients with sinonasal masses. Twenty-one patients with CT evidence of a sinonasal mass were imaged at 1.5 T with T1 and T2 weighting and without and with gadolinium injection. The studies were interpreted independently and correlated with the surgical and pathologic findings. The contrast-enhanced MR images yielded additional clinically useful information in 13 of 21 cases. It was the only way to separate tumor from a mucocele in four of 13 cases. In two of 13 instances, it was the only modality that identified encephalocele as distinct from a tumor. In the remaining seven cases, more accurate delineation of the tumor margins was obtained

  19. SWI enhances vein detection using gadolinium in multiple sclerosis

    International Nuclear Information System (INIS)

    Maggi, Pietro; Mazzoni, Lorenzo N; Moretti, Marco; Grammatico, Matteo; Chiti, Stefano; Massacesi, Luca

    2015-01-01

    Susceptibility weighted imaging (SWI) combined with the FLAIR sequence provides the ability to depict in vivo the perivenous location of inflammatory demyelinating lesions – one of the most specific pathologic features of multiple sclerosis (MS). In addition, in MS white matter (WM) lesions, gadolinium-based contrast media (CM) can increase vein signal loss on SWI. This report focuses on two cases of WM inflammatory lesions enhancing on SWI images after CM injection. In these lesions in fact the CM increased the contrast between the parenchyma and the central vein allowing as well, in one of the two cases, the detection of a vein not visible on the same SWI sequence acquired before CM injection

  20. Temperature profiles on the gadolinium surface during electron beam evaporation

    International Nuclear Information System (INIS)

    Ohba, Hironori; Shibata, Takemasa

    1995-01-01

    The distributions of surface temperature of gadolinium in a water-cooled copper crucible during electron beam evaporation were measured by optical pyrometry. The surface temperatures were obtained from the radiation intensity ratio of the evaporating surface and a reference light source using Planck's law of radiation. The emitted radiation from the evaporating surface and a reference source was detected by a CCD sensor through a band pass filter of 650 nm. The measured surface temperature generally agreed with those estimated from the deposition rate and the data of the saturated vapor pressure. At high input powers, it was found that the measured value had small difference with the estimated one due to variation of the surface condition. (author)

  1. Gadolinium ring enhancement and mass effect in acute disseminated encephalomyelitis

    Energy Technology Data Exchange (ETDEWEB)

    Meyden, C.H. van der (Dept. of Neurology, Univ. of the Orange Free State, Bloemfontein (South Africa)); Villiers, J.F.K. de (Dept. of Radiology, Univ. of the Orange Free State, Bloemfontein (South Africa)); Middlecote, B.D. (Dept. of Anatomical Pathology, Univ. of the Orange Free State, Bloemfontein (South Africa)); Terblanche, J. (Dept. of Neurology, Univ. of the Orange Free State, Bloemfontein (South Africa))

    1994-04-01

    A 9-year-old boy presented with a subacute history of optic neuritis followed by brainstem involvement, with fever and a lymphocytic pleocytosis in the cerebrospinal fluid. Gadolinium-enhancing ring lesions were demonstrated in the white matter of the cerebrum, brainstem and cerebellum on day 17 of the illness, all appearing simultaneously as part of a monophasic illmess. A parietal lesion exerted mass effect. Needling and biopsy yielded no evidence of a pyogenic lesion, tumour or tuberculosis and showed vasculitis. There was insufficient material for myelin staining. Dexamethasone therapy lead to rapid improvement of the radiological lesions: MRI and CT on day 34 of the illness showed complete clearing of the lesions except for residual abnormality at the biopsy site. (orig.)

  2. 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.)

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

    International Nuclear Information System (INIS)

    Mendichovszky, Iosif A.; Marks, Stephen D.; Simcock, Clare M.; Olsen, Oeystein E.

    2008-01-01

    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.)

  4. Effect of hydrostatic pressure on magnetic phase transitions and magnetization in gadolinium monocrystal

    International Nuclear Information System (INIS)

    Nikitin, S.A.; Bezdushnyj, R.V.

    1989-01-01

    Effect of hydrostatic pressure on magnetization in gadolinium monocrystal (Δσ-effect) was investigated. Dependences of spesific magnetization, Δσ-effect and bulk magnetostriction of gadolinium monocrystal on temperatures were studied. Results of conducted investigation have shown that in gadolinium the change of specific magnetization under the hydrostatic pressure effect is caused in general case by three effects: a)change of spontaneous magnetization under the effect of hydrostatic pressure; b)change of magnetization within technical magnetization range due to the effect of hydrostatic pressure on magnetic anisotropy constants; c)change of magnetization due to the effect of hydrostatic pressure on temperature of spin-reoriented transition

  5. Immediate hypersensitivity reaction to gadolinium-based MR contrast media.

    Science.gov (United States)

    Jung, Jae-Woo; Kang, Hye-Ryun; Kim, Min-Hye; Lee, Whal; Min, Kyung-Up; Han, Moon-Hee; Cho, Sang-Heon

    2012-08-01

    To determine the incidence and risk factors of immediate hypersensitivity reactions to gadolinium-based magnetic resonance (MR) contrast agents. Institutional review board approval and a waiver of informed consent were obtained. A retrospective study of patients who had been given gadolinium-based MR contrast media between August 2004 and July 2010 was performed by reviewing their electronic medical records. In addition to data on immediate hypersensitivity reaction, the kinds of MR contrast media and demographic data including age, sex, and comorbidity were collected. To compare the groups, the χ(2) test, Fisher exact test, χ(2) test for trend, Student t test, analysis of variance test, and multiple logistic regression test were performed. A total of 112 immediate hypersensitivity reactions (0.079% of 141 623 total doses) were identified in 102 patients (0.121% of 84 367 total patients). Among the six evaluated MR contrast media, gadodiamide had the lowest rate (0.013%) of immediate hypersensitivity reactions, while gadobenate dimeglumine had the highest rate (0.22%). The rate for immediate hypersensitivity reactions was significantly higher in female patients (odds ratio = 1.687; 95% confidence interval: 1.143, 2.491) and in patients with allergies and asthma (odds ratio = 2.829; 95% confidence interval: 1.427, 5.610). Patients with a previous history of immediate hypersensitivity reactions had a higher rate of recurrence after reexposure to MR contrast media (30%) compared with the incidence rate in total patients (P immediate hypersensitivity reactions increased depending on the number of times patients were exposed to MR contrast media (P for trend = .036). The most common symptom was urticaria (91.1%), and anaphylaxis occurred in 11 cases (9.8%). The mortality rate was 0.0007% because of one fatality. The incidence of immediate hypersensitivity reactions to MR contrast media was 0.079%, and the recurrence rate of hypersensitivity reactions was 30% in

  6. A methodology to evaluate differential costs of full field digital as compared to conventional screen film mammography in a clinical setting

    International Nuclear Information System (INIS)

    Ciatto, S.; Brancato, B.; Baglioni, R.; Turci, M.

    2006-01-01

    Purpose: The use of full field digital mammography (FFDM) in alternative to conventional screen film mammography (SFM) in the current practice is delayed by the high costs of FFDM. The present study, performed at the Centro per lo Studio e la Prevenzione Oncologica of Florence, using both FFDM and SFM, was aimed at estimating the impact of introducing the new FFDM technique on overall mammography costs. Material and methods: We estimated the differential costs of both methods, based on real expenditures, as provided by the administrative department, and on radiologists, radiographers and other staff's working time. Two different workload scenarios (5000 and 10,000 tests/year per mammography equipment) were considered. Common costs of both techniques were censored for study purpose. Results: Beside a higher cost due to purchase and hire/leasing costs of equipment, FFDM implies a greater workload for radiologists (reading time almost doubled). SFM implies a greater workload for the administrative staff to run the archive and for loading/unloading films of the roller viewer, whereas no different workload has been observed for radiographers. Overall FFDM costs Euro 24.22-26.46 for examination more than SFM for the 5000 tests scenario and Euro 9.91-12.15 more for the 10,000 tests scenario. Discussion: Although present study estimates cannot easily be generalised to any local setting, the model for cost calculation is easy to be exported to another scenario by applying different local parameters. The advantages made available by FFDM (computerised data recording, tele-transmission, tele-reporting, tele-consulting, automatic display on monitor of previous exams and use of CAD) may justify the higher cost, but a limited reduction in purchase and assistance costs could easily allow a turnover, with FFDM being more convenient than SFM even on the cost side

  7. Interval breast cancer characteristics before, during and after the transition from screen-film to full-field digital screening mammography.

    Science.gov (United States)

    van Bommel, Rob M G; Weber, Roy; Voogd, Adri C; Nederend, Joost; Louwman, Marieke W J; Venderink, Dick; Strobbe, Luc J A; Rutten, Matthieu J C; Plaisier, Menno L; Lohle, Paul N; Hooijen, Marianne J H; Tjan-Heijnen, Vivianne C G; Duijm, Lucien E M

    2017-05-05

    To determine the proportion of "true" interval cancers and tumor characteristics of interval breast cancers prior to, during and after the transition from screen-film mammography screening (SFM) to full-field digital mammography screening (FFDM). We included all women with interval cancers detected between January 2006 and January 2014. Breast imaging reports, biopsy results and breast surgery reports of all women recalled at screening mammography and of all women with interval breast cancers were collected. Two experienced screening radiologists reviewed the diagnostic mammograms, on which the interval cancers were diagnosed, as well as the prior screening mammograms and determined whether or not the interval cancer had been missed on the most recent screening mammogram. If not missed, the cancer was considered an occult ("true") interval cancer. A total of 442 interval cancers had been diagnosed, of which 144 at SFM with a prior SFM (SFM-SFM), 159 at FFDM with a prior SFM (FFDM-SFM) and 139 at FFDM with a prior FFDM (FFDM-FFDM). The transition from SFM to FFDM screening resulted in the diagnosis of more occult ("true") interval cancers at FFDM-SFM than at SFM-SFM (65.4% (104/159) versus 49.3% (71/144), P mammography. However, this increase seems temporary and is no longer detectable after the second round of digital screening. Tumor characteristics and type of surgery are comparable for interval cancers detected prior to, during and after the transition from SFM to FFDM screening mammography, except of a lower proportion of invasive ductal cancers after the transition.

  8. Luminescence study on Eu or Tb doped lanthanum-gadolinium pyrosilicate crystal

    Czech Academy of Sciences Publication Activity Database

    Kurosawa, S.; Shishido, T.; Sugawara, T.; Nomura, A.; Yubuta, K.; Pejchal, Jan; Murakami, R.; Yokota, Y.; Shoji, Y.; Ohashi, Y.; Kamada, K.; Yoshikawa, A.

    2015-01-01

    Roč. 41, Mar (2015), s. 80-83 ISSN 0925-3467 Institutional support: RVO:68378271 Keywords : scintillator * gadolinium pyrosilicate Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 2.183, year: 2015

  9. Gadolinium EUV Multilayers for Solar Imaging Near 60 nm, Phase I

    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...

  10. 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...

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

    International Nuclear Information System (INIS)

    Thomsen, Henrik S.; Almen, Torsten; Morcos, Sameh K.

    2002-01-01

    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.)

  12. Screen-film specimen radiography

    International Nuclear Information System (INIS)

    Shepard, S.J.; Hogan, J.; Schreck, B.

    1990-01-01

    This paper reports on the reproducibility and quality of biopsy specimen radiographs, a unique phototimed cabinet x-ray system is being developed. The system utilizes specially modified Kodal Min-R cassettes and will be compatible with current mammographic films. Tube voltages are in the 14-20-kVp range with 0.1-1.0-second exposure times. A top-hat type compression device is used (1) to compress the specimen to uniform thickness, (2) to measure the specimen thickness and determine optimum kVp, and (3) to superimpose a grid over the specimen for identification of objects of radiographic interest. The phototiming circuit developed specifically for this purpose will be described along with the modified Min-R cassette. Characteristics of the generator and cabinet will also be described. Tests will be performed on phantoms to evaluate the system limitations

  13. 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+) Eu(3+) 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-N distances.

  14. Liver nodules. MR imaging using extracellular gadolinium agent

    International Nuclear Information System (INIS)

    Yoshimitsu, Kengo; Honda, Hiroshi

    2009-01-01

    Extracellular gadolinium (Gd)-containing contrast medium, including gadopentetate dimeglumine (Gd-DTPA), has been playing a main role in the diagnostic MR imaging of the liver. Its significance is two-fold: assessment of the degree of neovascularity or angiogenesis in its early dynamic phase, and that of bulk of interstitium in its equilibrium phase. With the advent of gadolinium ethoxybenzyl diethylenetriamine-pentaacetic acid (Gd-EOB-DTPA), which can be used as a dynamic study agent by bolus injection in addition to its original use as a tissue-specific agent, some possibility has been suggested that extracellular Gd agent would be no longer available in the near future in the field of liver MR imaging. Neovascularity or arterial supply of a lesion may well be assessed by Gd-EOB-DTPA, when carefully selected pulse sequence and well designed injection protocol are used, as well as by Gd-DTPA. However, the pertinent assessment of interstitium or stroma can never be achieved by Gd-EOB-DTPA or any other contrast medium present. The interstitium of neoplasm, typically called as stromal fibrosis, is generated through the interaction between the neoplasm per se and its host, and its clinicopathological significance related to disease prognosis has well been established in some disease entities. Extracellular Gd agent is the only contrast medium that can provide information regarding the tumor stroma in a simple, easy, safe and non-invasive fashion, when properly used. This review article discusses, dynamic MR imaging features of representative liver diseases, including several recent topics. From technical point of view, 3D gradient-echo sequence with fat suppression should be used for dynamic studies along with tailored injection protocol using autoinjector and saline flush. Vascularity of hepatocellular carcinoma (HCC) can now be properly assessed by dynamic MR with approximately 90% concordance with CT during hepatic arteriography. Portal phase images can be used to

  15. MCNP analysis of the nine-cell LWR gadolinium benchmark

    International Nuclear Information System (INIS)

    Arkuszewski, J.J.

    1988-01-01

    The Monte Carlo results for a 9-cell fragment of the light water reactor square lattice with a central gadolinium-loaded pin are presented. The calculations are performed with the code MCNP-3A and the ENDF-B/5 library and compared with the results obtained from the BOXER code system and the JEF-1 library. The objective of this exercise is to study the feasibility of BOXER for the analysis of a Gd-loaded LWR lattice in the broader framework of GAP International Benchmark Analysis. A comparison of results indicates that, apart from unavoidable discrepancies originating from different data evaluations, the BOXER code overestimates the multiplication factor by 1.4 % and underestimates the power release in a Gd cell by 4.66 %. It is hoped that further similar studies with use of the JEF-1 library for both BOXER and MCNP will help to isolate and explain these discrepancies in a cleaner way. (author) 4 refs., 9 figs., 10 tabs

  16. Gadolinium Magnetic resonance with a diagnosis of Bell's facial palsy

    International Nuclear Information System (INIS)

    Rovira Canellas, A.; Sanchez Torres, C.; Navarrete, M.; Grive Isern, E.; Capellades Font, J.; Navarrete, M.

    1993-01-01

    The intratemporal pathway of the facial nerve has been prospectively studied by means of gadolinium MR in 12 patients with a diagnosis of Bell's facial palsy. All the cases presented total facial paralysis and were studied in the acute phase of the disease. With MR, the intratemporal pathway of the facial nerve has been viewed before and after the administration of a paramagnetic contrast medium, revealing uptake involving mainly the labyrinthine segment and the geniculate ganglion in every case. In no case did the MR findings influence the therapeutic approach, nor did they provide information of prognostic value. Therefore, this exploration is not considered necessary in the assessment of typical facial paralyses. The possible advantages of an MR study with contrast medium in facial paralysis specially apply to those cases with atypical clinical presentation, making it possible to establish a positive diagnosis, ruling out other lesions that may have a similar clinical presentantion. Thus, for the time being, a diagnosis of Bell's paralysis is not necessarily an exclusion diagnosis. (Author)

  17. Gadolinium neutron capture therapy for brain tumors. Biological aspects

    International Nuclear Information System (INIS)

    Takagaki, Masao; Oda, Yoshifumi; Matsumoto, Masato; Kikuchi, Haruhiko; Kobayashi, Tooru; Kanda, Keiji; Ujeno, Yowri.

    1994-01-01

    This study investigated the tumoricidal effect of gadolinium neutron capture therapy (Gd-NCT) in in vitro and in vivo systems using Gd-DTPA. In in vitro study, a certain amount of Gd-DTPA, yielding 5000 ppm Gd-n, was added to human glioma cells, T98G, upon which thermal neutrons were exposed. After irradiation, the cells were incubated and the colonies were counted 10 days later. In in vivo study, Fisher-344 rats with experimentally induced gliosarcoma cells (9L) were exposed to thermal neutrons at a fluence rate of 3E+9/s for 1 h immediately after iv injection of Gd-DTPA. Two weeks after irradiation, brain samples were histologically examined. Tumor clearance of Gd-DTPA was also determined. In vitro analysis showed that a 1% survival level was obtained at 3.75E+12 (n/cm 2 ) for the Gd (+) medium and 2.50E+13 (n/cm 2 ) for the Gd (-) medium. In in vivo analysis, the concentration of Gd in 9L-rat brain tumor after iv injection of 0.2 mg/kg Gd-DTPA was found to be less than 100 ppm, but Gd-NCT on 9L-rat brain tumor administered with a ten-fold dose showed a substantial killing effect on tumor without serious injury to the normal brain structure. The killing effect of Gd-NCT was confirmed in in vitro and in vivo systems. (N.K.)

  18. Ordered structures of defect clusters in gadolinium-doped ceria

    Science.gov (United States)

    Li, Zhi-Peng; Mori, Toshiyuki; Ye, Fei; Ou, Dingrong; Zou, Jin; Drennan, John

    2011-06-01

    The nano-domain, with short-range ordered structure, has been widely observed in rare-earth-doped ceria. Atomistic simulation has been employed to investigate the ordering structure of the nano-domain, as a result of aggregation and segregation of dopant cations and the associated oxygen vacancies in gadolinium-doped ceria. It is found that the binding energy of defect cluster increases as a function of cluster size, which provides the intrinsic driving force for the defect cluster growth. However, the ordered structures of the defect clusters are different from the chain model as previously reported. Adjacent oxygen vacancies prefer to locate along /2 lattice vector, which results in a unique stable structure (isosceles triangle) formation. Such isosceles triangle structure can act as the smallest unit of cluster growth to form a symmetric dumbbell structure. This unique dumbbell structure is hence considered as a building block for the development of larger defect clusters, leading to nano-domain formation in rare-earth-doped ceria.

  19. Magnetocaloric effect at cryogenic temperature in gadolinium oxide nanotubes

    Energy Technology Data Exchange (ETDEWEB)

    Paul, Rima, E-mail: rima.paul@saha.ac.in [Saha Institute of Nuclear Physics, 1/AF Bidhannagar, Kolkata 700064 (India); Paramanik, Tapas; Das, Kalipada [Saha Institute of Nuclear Physics, 1/AF Bidhannagar, Kolkata 700064 (India); Sen, Pintu [Variable Energy Cyclotron Centre, 1/AF Bidhannagar, Kolkata 700064 (India); Satpati, B.; Das, I. [Saha Institute of Nuclear Physics, 1/AF Bidhannagar, Kolkata 700064 (India)

    2016-11-01

    We have synthesized fascinating nano-structure of Gadolinium oxide (Gd{sub 2}O{sub 3}) using controlled template-assisted electrochemical deposition technique which showed interesting anisotropic magnetic behavior. The nanotubes of Gd{sub 2}O{sub 3} 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 Gd{sub 2}O{sub 3} nanotubes have been performed for both parallel and perpendicular magnetic field orientations with respect to the axis of the Gd{sub 2}O{sub 3} 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 Gd{sub 2}O{sub 3} nanotubes, has been observed in the cryogenic temperature regime that shows anisotropic behavior. - Highlights: • Gd{sub 2}O{sub 3} nanotubes of diameter ~200 nm synthesized through electrochemical technique. • The nanotubes are superparamagnetic in nature. • At cryogenic temperature, the nanotubes exhibit large magnetocaloric anisotropic effect.

  20. Thermal stability of neodymium, samarium, europium and gadolinium thiocarbamide compounds

    International Nuclear Information System (INIS)

    Sakharova, Yu.G.; Borisova, G.M.

    1976-01-01

    The behaviour of thiocarbamide complexes of the composition Me(C 3 H 5 O 2 ) 3 x Cs(NH 2 ) 2 x 3H 2 O, where Me is Nd, Sm, Eu or Gd, has been studied in the process of heating by thermographic, thermogravimetric, and chemical analyses and by infrared spectroscopy. It has been established that thermolysis of complexes is accompanied by thermal effects which point to the fact that the processes take place both with absorption liberation of heat. Above 100 deg C dehydration of compounds begins. The weight of neodymium, samarium, europium, and gadolinium decreases by 11.43, 12.57, 12.57, and 11.48% which corresponds to the loss of water entering into the compounds. It has been proved experimentally that complete removal of water from complexes proceeds at 110 deg C. As main products of thermolysis of thiocarbomide compounds at 230 deg C, oxypropionates of the corresponding rare-earth elements are formed. The highest rate of decomposition of thiocarbamide complexes of rare-earth elements has been attained at 320 and 360 deg C. Qualitative and quantitative analyses as well as IR spectroscopy have shown that the main products of thermolysis at these temperatures are oxysulphates of rare-earth elements with a small impurity of oxysulphides and adsorbed ammonia

  1. Immunomodulation by gadolinium chloride-induced Kupffer cell phagocytosis blockade

    International Nuclear Information System (INIS)

    Lazar, G.; Husztik, E.; Kiss, I.; Szakacs, J.; Olah, J.

    1998-01-01

    Gadolinium chloride (GdCl 3 ), a rare earth metal salt, depresses macrophage activity, and is commonly used to study the physiology of the reticuloendothelial system. In the present work, the effect of GdCl 3 -induced Kupffer cell blockade on the humoral immune response in mice to sheep red blood cells (SRBC) was investigated. Kupffer cell phagocytosis blockade was found to increase both the primary and secondary immune responses to SRBC. The primary immune response was significantly augmented in animals injected intravenously with GdCl 3 2, 3 or 4 days before injection of the cellular antigen, but GdCl 3 injected 7 days before the antigen did not modify the immune response. Increased secondary humoral immune responses were also observed. When GdCl 3 was injected 2 days before the second dose of antigen, the numbers of both IgM and IgG-producing plaque forming cells were augmented. GdCl 3 injected 2 days before the first dose of SRBC did not modify the humoral immune response. Earlier studies with 51 Cr-labelled foreign red blood cells suggested that the augmentation of the humoral immune response in GdCl 3 -pretreated mice is a consequence of the spillover of the antigen from the liver into the spleen and other extrahepatic reticuloendothelial organs. (orig.)

  2. Reverse microemulsion synthesis of layered gadolinium hydroxide nanoparticles

    Science.gov (United States)

    Xu, Yadong; Suthar, Jugal; Egbu, Raphael; Weston, Andrew J.; Fogg, Andrew M.; Williams, Gareth R.

    2018-02-01

    A reverse microemulsion approach has been explored for the synthesis of layered gadolinium hydroxide (LGdH) nanoparticles in this work. This method uses oleylamine as a multifunctional agent, acting as surfactant, oil phase and base. 1-butanol is additionally used as a co-surfactant. A systematic study of the key reaction parameters was undertaken, including the volume ratio of surfactant (oleylamine) to water, the reaction time, synthesis temperature, and the amount of co-surfactant (1-butanol) added. It proved possible to obtain pristine LGdH materials at temperatures of 120 °C or below with an oleylamine: water ratio of 1:4. Using larger amounts of surfactant or higher temperatures caused the formation of Gd(OH)3, either as the sole product or as a major impurity phase. The LGdH particles produced have sizes of ca. 200 nm, with this size being largely independent of temperature or reaction time. Adjusting the amount of 1-butanol co-surfactant added permits the size to be varied between 200 and 300 nm.

  3. Gadolinium-loaded gel scintillators for neutron and antineutrino detection

    Energy Technology Data Exchange (ETDEWEB)

    Riddle, Catherine Lynn; Akers, Douglas William; Demmer, Ricky Lynn; Paviet, Patricia Denise; Drigert, Mark William

    2016-11-29

    A gadolinium (Gd) loaded scintillation gel (Gd-ScintGel) compound allows for neutron and gamma-ray detection. The unique gel scintillator encompasses some of the best features of both liquid and solid scintillators, yet without many of the disadvantages associated therewith. Preferably, the gel scintillator is a water soluble Gd-DTPA compound and water soluble fluorophores such as: CdSe/ZnS (or ZnS) quantum dot (Q-dot) nanoparticles, coumarin derivatives 7-hydroxy-4-methylcoumarin, 7-hydroxy-4-methylcoumarin-3-acetic acid, 7-hydroxycoumarin-3-carboxylic acid, and Alexa Fluor 350 as well as a carbostyril compound, carbostyril 124 in a stable water-based gel, such as methylcellulose or polyacrylamide polymers. The Gd-loaded ScintGel allows for a homogenious distribution of the Gd-DTPA and the fluorophores, and yields clean fluorescent emission peaks. A moderator, such as deuterium or a water-based clear polymer, can be incorporated in the Gd-ScintGel. The gel scintillators can be used in compact detectors, including neutron and antineutrino detectors.

  4. Gadolinium-containing magnetic resonance imaging contrast and nephrogenic systemic fibrosis: a case-control study.

    Science.gov (United States)

    Kallen, Alexander J; Jhung, Michael A; Cheng, Steven; Hess, Theresa; Turabelidze, George; Abramova, Liana; Arduino, Matthew; Guarner, Jeannette; Pollack, Brian; Saab, Georges; Patel, Priti R

    2008-06-01

    Nephrogenic systemic fibrosis (NSF) is a newly described disorder occurring in persons with renal failure. Gadolinium-based contrast used in magnetic resonance imaging (MRI) has been suggested as a cause. A cluster of patients with NSF was investigated to identify risk factors. Limited preliminary findings from this investigation were presented in the Morbidity and Mortality Weekly Report. Matched case-control. Dialysis patients with and without a diagnosis of NSF treated at an academic medical center. Exposure to gadolinium-based contrast. Laboratory and clinical characteristics of NSF. 19 of 28 cases identified at the hospital from December 2002 to August 2006 met inclusion criteria and were matched to 57 controls. In univariate analysis, receipt of gadolinium-containing MRI contrast in the preceding year (odds ratio [OR], 7.99; 95% confidence interval, 2.22 to 28.8) was associated with NSF; the measure of association increased as cumulative dose increased. Gadodiamide exposure (OR, 9.83; 95% confidence interval, 2.09 to 46.2) was associated more strongly with NSF than gadoversetamide (OR, 1.82; 95% confidence interval, 0.33 to 10.2). Although not statistically significant, cases were more likely than controls to have undergone primarily peritoneal dialysis in the preceding 6 months. There was no significant difference in receipt of high-dose recombinant erythropoietin between cases and controls. In multivariable analysis, gadolinium contrast exposure (OR, 8.97; 95% confidence interval, 1.28 to 63.0) remained significantly associated with NSF. Retrospective design, small sample size, inability to completely evaluate erythropoietin. Receipt of gadolinium-containing MRI contrast is associated with NSF in a dose-dependent manner. The risk associated with gadolinium may differ by contrast agent and dialysis modality. Use of gadolinium-based contrast agents should be avoided when possible in patients with renal failure.

  5. The presence of the gadolinium-based contrast agent depositions in the brain and symptoms of gadolinium neurotoxicity - A systematic review.

    Directory of Open Access Journals (Sweden)

    Cyprian Olchowy

    Full Text Available Gadolinium based contrast agents (GBCAs are widely used in magnetic resonance imaging, but recently, high signal intensity in the cerebellum structures was reported after repeated administrations of contrast- enhanced magnetic resonance images. The aim of this systematic review was to investigate the association between increased signal intensity in the dentate nucleus and globus pallidus in the brain and repeated administrations of GBCAs. Additionally, we focused on possible short- and long-term consequences of gadolinium use in those patients.Systematic review of retrospective investigations in PubMed and Medline was performed in July 2016. Primary outcomes included the presence of increased signal intensity within the dentate nucleus and globus pallidus on unenhanced T1-weighted MR images in patients following administrations of GBCAs. Two independent reviewers were responsible for search and data extraction.25 publications satisfied inclusion criteria (19 magnetic resonance images analyses, 3 case reports; 3 autopsy studies. Magnetic resonance images of 1247 patients with increased signal intensity on unenhanced T1-weighted MR images were analyzed as well as tissue specimens from 27 patients. Signal intensity correlated positively with the exposure to GBCAs and was greater after serial administrations of linear nonionic than cyclic contrast agents. Gadolinium was detected in all tissue examinations.High signal intensity in the dentate nucleus and globus pallidus on unenhanced T1-weighted magnetic resonance images were associated with previous administration of GBCAs. Signal intensity correlated negatively with stability of contrast agents. Clinical significance of gadolinium deposition in the brain remains unclear. There is a strong need for further research to identify type of gadolinium deposited in the brain as well as to gather knowledge about long-term consequences.

  6. 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.)

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

    International Nuclear Information System (INIS)

    Webb, Judith A.W.; Thomsen, Henrik S.; Morcos, Sameh K.

    2005-01-01

    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.)

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

    International Nuclear Information System (INIS)

    Nasr, Mohamed.

    1981-09-01

    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 [fr

  9. Compensated gadolinium-loaded plastic scintillators for thermal neutron detection (and counting)

    Energy Technology Data Exchange (ETDEWEB)

    Dumazert, Jonathan; Coulon, Romain; Bertrand, Guillaume H. V.; Hamel, Matthieu; Sguerra, Fabien; Dehe-Pittance, Chrystele; Normand, Stephane [CEA, LIST, Laboratoire Capteurs Architectures Electroniques, 99 Gif-sur-Yvette, (France); Mechin, Laurence [CNRS, UCBN, Groupe de Recherche en Informatique, Image, Automatique et Instrumentation de Caen, 4050 Caen, (France)

    2015-07-01

    Plastic scintillator loading with gadolinium-rich organometallic complexes shows a high potential for the deployment of efficient and cost-effective neutron detectors. Due to the low-energy photon and electron signature of thermal neutron capture by gadolinium-155 and gadolinium-157, alternative treatment to Pulse Shape Discrimination has to be proposed in order to display a trustable count rate. This paper discloses the principle of a compensation method applied to a two-scintillator system: a detection scintillator interacts with photon radiation and is loaded with gadolinium organometallic compound to become a thermal neutron absorber, while a non-gadolinium loaded compensation scintillator solely interacts with the photon part of the incident radiation. Posterior to the nonlinear smoothing of the counting signals, a hypothesis test determines whether the resulting count rate after photon response compensation falls into statistical fluctuations or provides a robust image of a neutron activity. A laboratory prototype is tested under both photon and neutron irradiations, allowing us to investigate the performance of the overall compensation system in terms of neutron detection, especially with regards to a commercial helium-3 counter. The study reveals satisfactory results in terms of sensitivity and orientates future investigation toward promising axes. (authors)

  10. Radio response of human lymphocytes pretreated with boron and gadoliniums assessed by the, comet assay

    International Nuclear Information System (INIS)

    Kim, J. K.; Park, T. W.; Cebulska-Wasiewska, A.; Nili, M.

    2009-01-01

    Boron and gadolinium are among the nuclides that hold a unique property of being a neutron capture therapy agent. Neutron beams have often a considerable portion of gamma rays with fast neutrons. Gamma rays, as beam contaminants, can cause considerable damage to normal tissues even if such tissues do contain high boron concentrations. Materials and Methods: The modification of radio response in human lymphocytes pretreated with boron or gadolinium compound was studied by assessing the DNA damage using single cell gel electrophoresis, the comet assay. The lymphocytes from the human peripheral blood were irradiated with 0, 1, 2 and 4 Gy of gamma rays from a 60 Co isotopic source with or without pretreatment of boron or gadolinium compound for 10 minutes at 4 d egree C . Post-irradiation procedures included slide preparation, cell-lysing, unwinding and electrophoresis, neutralization, staining, and analytic steps, gel electrophoresis. Results: The results indicate that pretreatment with boron compound (50 n M or 250 n M of 10 B) is effective in reducing the radiosensitivity of the lymphocyte DNA. Conversely, pretreatment with gadolinium compound (50 n M) led to a dose-dependent increase in the radiosensitivity, most prominently with a dose of 4 Gy (P<0.001). Furthermore, when the lymphocytes were pretreated with a Combined mixture (1:1) of boron (250 n M) and gadolinium (50 n M) compounds, the reduced radiosensitivity was also observed.

  11. Utility of late gadolinium enhancement in pediatric cardiac MRI.

    Science.gov (United States)

    Etesami, Maryam; Gilkeson, Robert C; Rajiah, Prabhakar

    2016-07-01

    Late gadolinium enhancement (LGE) cardiac magnetic resonance (MR) imaging sequence is increasingly used in the evaluation of pediatric cardiovascular disorders, and although LGE might be a normal feature at the sites of previous surgeries, it is pathologically seen as a result of extracellular space expansion, either from acute cell damage or chronic scarring or fibrosis. LGE is broadly divided into ischemic and non-ischemic patterns. LGE caused by myocardial infarction occurs in a vascular distribution and always involves the subendocardial portion, progressively involving the outer regions in a waveform pattern. Non-ischemic cardiomyopathies can have a mid-myocardial (either linear or patchy), subepicardial or diffuse subendocardial distribution. Idiopathic dilated cardiomyopathy can have a linear mid-myocardial pattern, while hypertrophic cardiomyopathy can have fine, patchy enhancement in hypertrophied and non-hypertrophied segments as well as right ventricular insertion points. Myocarditis and sarcoidosis have a mid-myocardial or subepicardial pattern of LGE. Fabry disease typically affects the basal inferolateral segment while Danon disease typically spares the septum. Pericarditis is characterized by diffuse or focal pericardial thickening and enhancement. Thrombus, the most common non-neoplastic cardiac mass, is characterized by absence of enhancement in all sequences, while neoplastic masses show at least some contrast enhancement, depending on the pathology. Regardless of the etiology, presence of LGE is associated with a poor prognosis. In this review, we describe the technical modifications required for performing LGE cardiac MR sequence in children, review and illustrate the patterns of LGE in children, and discuss their clinical significance.

  12. Utility of late gadolinium enhancement in pediatric cardiac MRI

    International Nuclear Information System (INIS)

    Etesami, Maryam; Gilkeson, Robert C.; Rajiah, Prabhakar

    2016-01-01

    Late gadolinium enhancement (LGE) cardiac magnetic resonance (MR) imaging sequence is increasingly used in the evaluation of pediatric cardiovascular disorders, and although LGE might be a normal feature at the sites of previous surgeries, it is pathologically seen as a result of extracellular space expansion, either from acute cell damage or chronic scarring or fibrosis. LGE is broadly divided into ischemic and non-ischemic patterns. LGE caused by myocardial infarction occurs in a vascular distribution and always involves the subendocardial portion, progressively involving the outer regions in a waveform pattern. Non-ischemic cardiomyopathies can have a mid-myocardial (either linear or patchy), subepicardial or diffuse subendocardial distribution. Idiopathic dilated cardiomyopathy can have a linear mid-myocardial pattern, while hypertrophic cardiomyopathy can have fine, patchy enhancement in hypertrophied and non-hypertrophied segments as well as right ventricular insertion points. Myocarditis and sarcoidosis have a mid-myocardial or subepicardial pattern of LGE. Fabry disease typically affects the basal inferolateral segment while Danon disease typically spares the septum. Pericarditis is characterized by diffuse or focal pericardial thickening and enhancement. Thrombus, the most common non-neoplastic cardiac mass, is characterized by absence of enhancement in all sequences, while neoplastic masses show at least some contrast enhancement, depending on the pathology. Regardless of the etiology, presence of LGE is associated with a poor prognosis. In this review, we describe the technical modifications required for performing LGE cardiac MR sequence in children, review and illustrate the patterns of LGE in children, and discuss their clinical significance. (orig.)

  13. Fabrication and evaluation of a Gd{sub 2}O{sub 2}S:Tb phosphor screen film for development of a CMOS-based X-ray imaging detector

    Energy Technology Data Exchange (ETDEWEB)

    Park, Ji Koon; Choi, Su Rim; Noh, Si Cheol; Jung, Bong Jae; Choi, Il Hong; Kang, Sang Sik [International University of Korea, Jinju (Korea, Republic of)

    2014-08-15

    In this study, Gd{sub 2}O{sub 2}S:Tb phosphor screen films were fabricated by using a special particle-inbinder sedimentation method. The phosphor particles used in this study were manufactured in two sizes, 2.5-μm and 5-μm. To evaluate luminescence efficiency and the spatial resolution according to the thickness, we fabricated screen films with thicknesses of 120, 150, 170, and 210-μm. The spatial resolution of the fabricated films was assessed by using an edge method to measure the modulation transfer function (MTF). From the experimental results, the spatial resolution of the mammography exposures (low-energy X-ray quality) was better than that of dental radiography (high-energy X-ray quality). Also, with the same film thickness, the screen with 2.5-μm particles had better resolution than the screen with 5.0-μm particles, but it showed about 20% lower resolution than a commercial Gd{sub 2}O{sub 2}S:Tb screen. In the evaluation of the results for the dependence of the spatial resolution on the film's thickness, the 120-μm-thick screen showed the highest resolution, which was similar to that of a commercial screen.

  14. Follow-up and Final Results of the Oslo I Study Comparing Screen-Film Mammography and Full-field Digital Mammography with Soft-Copy Reading

    Energy Technology Data Exchange (ETDEWEB)

    Skaane, P.; Skjennald, A.; Young, K. [Ullevaal Univ. Hospital, Oslo (Norway). Dept. of Radiology] [and others

    2005-11-01

    Purpose: To compare cancer detection rates of screen-film (SFM) and full-field digital mammography (FFDM) with soft-copy reading in a screening program including the initial positive scores for interval cancers and cancers in the subsequent screening round, and to analyze the false-negative FFDM interpretations. Material and Methods: Using a paired study design, 3683 women underwent SFM and FFDM in a population-based screening program. Two standard views of each breast were acquired. The images were interpreted without previous films for comparison. Independent double reading using a 5-point rating scale for probability of cancer was used for each modality. An examination was defined as positive if at least one of the two independent readers scored 2 or higher on the 5-point rating scale. SFM-positive cases were discussed in a SFM consensus meeting and FFDM-positive cases in a separate FFDM consensus meeting before recall. The study population was followed for more than 2 years so that interval cancers and screen-detected cancers in the subsequent screening round could be included. Cancer detection rates were compared using the McNemar test for paired proportions. The kappa statistic and Wilcoxon signed-rank test for matched pairs were used for comparing rating scores. The reading time was recorded for all FFDM interpretations. Results: A total of 31 cancers (detection rate 0.84%) were diagnosed initially, of which SFM detected 28 and FFDM 23 (McNemar test P 0.23, discordant pair 8 and 3). Two cancers with a positive score at initial SFM reading and three with a positive score at initial FFDM reading were dismissed at SFM and FFDM consensus meetings, respectively. The difference in cancer detection after recall (discordant pair 11 and 5) was not significant (McNemar test, P = 0.21). Of the 10 interval cancers and 16 screen-detected cancers in the subsequent round, 3 had true-positive SFM scores while 4 had true-positive FFDM scores in the initial reading session. A

  15. Characterization of composite metal-ceramic of nickel-oxide cerium doped gadolinium

    International Nuclear Information System (INIS)

    Silva, M.L.A. da; Varela, M.C.R.S.

    2016-01-01

    Composite nickel doped cerium oxide are used in SOFC anode materials. In this study we evaluated the effect of the presence of gadolinium on the properties of composite nickel and ceria and. The supports were synthesized by sol-gel method. The impregnation with nickel nitrate was taken sequentially, followed by calcination. The materials were characterized by X-ray diffraction, measurement of specific surface area, temperature programmed reduction, Raman spectroscopy. The presence of gadolinium retained the fluorite structure of ceria by forming a solid solution, also not influencing significantly on the specific surface area of the support. On the other hand, there was a decrease in the area catalysts, which can be attributed to sintering of nickel. Furthermore, addition of gadolinium favored the formation of intrinsic and extrinsic vacancies in cerium oxide, which leads to an increase in the ionic conductivity of the solid, desirable property for an SOFC anode catalyst. (author)

  16. 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.

  17. The network formers role of gadolinium(III) ions in some zinc-borate glass ceramics

    Science.gov (United States)

    Bosca, Maria; Pop, Lidia; Pascuta, Petru

    2017-12-01

    EPR and magnetic susceptibility measurements were performed on glass ceramics from the (Gd2O3)x.(B2O3)(60-x).(ZnO)40 system, with 0 ≤ x ≤ 15 mol%, in order to determine the role of gadolinium ions on structural and magnetic properties. At low Gd2O3 contents (x ≤ 1 mol%) the EPR spectra show four resonance lines with effective g-values of ˜ 6, 4.8, 2.8 and 2, typical for Gd3+ ions uniformly distributed in the glass and glass ceramic samples. For higher contents of gadolinium ions (x ≥ 3 mol%) the EPR spectra are dominated by a single broad line centered at g ˜ 2, which can be due to the magnetic clusters containing Gd3+ ions. The magnetic susceptibility data show that the gadolinium ions are involved in superexchange interactions in all the investigated glass ceramics, being antiferromagnetically coupled.

  18. 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.

  19. 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.)

  20. Detection of anthropogenic gadolinium in the Brisbane River plume in Moreton Bay, Queensland, Australia

    International Nuclear Information System (INIS)

    Lawrence, Michael G.

    2010-01-01

    Wastewater effluent is known to contain macro and micropollutants, which may be deleterious to environmental health. One such class of micropollutants is chelated gadolinium, which are used as MRI contrast agents. As these MRI contrast agents can be assumed to behave conservatively during estuarine mixing, it is possible to calculate how much wastewater is represented in any particular sample. In this study, the percentage contribution of wastewater at specific locations in Moreton Bay, Qld, were determined by calculating the additional anthropogenic gadolinium contribution to the total rare earth element concentrations. Wastewater contributions were measured at concentrations as low as 0.2%, demonstrating the applicability of this technique for wastewater effluent plume mapping.

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

    International Nuclear Information System (INIS)

    Hodgson, A.; Shutt, A.L.; Etherington, G.; Hodgson, S.A.; Rance, E.; Stradling, G.N.; Youngman, M.J.; Ziesenis, A.; Kreyling, W.G.

    2003-01-01

    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)

  2. Structural, morphological and optical investigations on Sm{sup 3+} doped gadolinium oxide nanorods

    Energy Technology Data Exchange (ETDEWEB)

    Boopathi, G.; Mohan, R. [Department of Physics, Presidency College, Chennai - 600005 (India); Raj, S. Gokul [Materials Science Research Lab, Department of Physics, VEL TECH UNIVERSITY, Avadi, Chennai - 600062 (India); Kumar, G. Ramesh, E-mail: rameshvandhai@yahoo.co.in [Department of Physics, University College of Engineering Arni, Anna University Chennai, Arni-632317 (India)

    2014-04-24

    One dimensional uniform Sm{sup 3+} doped gadolinium hydroxide nanorods have been prepared via simple co– precipitation technique at 60 °C temperature for 1 hour. The samples were calcinated at 750 °C to obtain Sm{sup 3+} doped gadolinium oxide nanorods. The 1D nanorods were then subjected to different characterization techniques to ascertain its structural stability and its morphology were investigated using high–resolution transmission electron microscopy. Photoluminescence (PL) spectrophotometry was investigated and the obtained results were discussed in detail.

  3. Structural and optical properties of Nd{sup 3+} doped gadolinium oxide 1D nanorods

    Energy Technology Data Exchange (ETDEWEB)

    Boopathi, G., E-mail: psixboopathi@gmail.com; Mohan, R. [Department of Physics, Presidency College, Chennai - 600 005 (India); Raj, S. Gokul [Materials Science Research Lab, Department of Physics, Vel Tech University, Avadi, Chennai -62 (India); Kumar, G. Ramesh [Department of Physics, University College of Engineering Arni, Anna University Chennai, Arni - 632 317 (India)

    2014-04-24

    Neodymium doped gadolinium hydroxide [Nd:Gd(OH)3] nanorods were successfully synthesized at 60 °C through co-precipitation method. The dopant percentage was maintained at 5% and calcination was done at 750 °C temperature for 1 hour to form the respective neodymium doped gadolinium oxide [Nd:Gd{sub 2}O{sub 3}] nanorods. The as-formed and annealed products were investigated in detail by using powder X-ray diffraction (XRD) pattern, scanning electron microscopy (SEM) with an energy dispersive X-ray spectrum (EDX), high-resolution transmission electron microscopy (HRTEM) and photoluminescence (PL) spectrophotometry.

  4. Gadolinium and fission neodymium isotopic analyses and determinations in irradiated nuclear fuels

    International Nuclear Information System (INIS)

    Lucas, M.; Chevalier, C.

    1975-01-01

    A separation method of rare earths on an ion exchange resin is described: it enables the gadolinium and fission neodymium contained in irradiated nuclear fuels to be separated and analyzed by isotopic dilution and mass spectrometry. The principle of the chemical separation and its efficiency and reproducibility are reported. This technique was applied to a series of spent fuels from a pressurized water reactor, with an initial gadolinium content of 2% and final fission neodymium 148 concentrations of a few hundred ppm. These results confirm the validity of the separation method studied, which can be easily adapted to the determination of other rare earths in spent fuels [fr

  5. A case report on a severe anaphylaxis reaction to Gadolinium-based MR contrast media

    Energy Technology Data Exchange (ETDEWEB)

    Park, Juil; Kim, Tae Hyung; Park, Chang Min; Yoon, Soon Ho; Lee, Whal; Kang, Hye Ryun; Choi, Young Hun [Seoul National University Hospital, Seoul (Korea, Republic of)

    2017-02-15

    Acute hypersensitivity reactions to gadolinium-based magnetic resonance (MR) contrast media have been shown to have a much lower incidence and they are generally milder in terms of severity than acute adverse reactions associated with the use of iodinated contrast media for computed tomography scans. However, even though it is rare, a severe hypersensitivity reaction to MR contrast media can occur. Here we present the case of a 66-year-old woman who experienced a severe hypersensitivity reaction after administration of gadolinium-based contrast media without a previous history of allergies.

  6. Spectral, Electrochemical, Fluorescence, Kinetic and Anti-microbial Studies of Acyclic Schiff-base Gadolinium(III) Complexes

    Energy Technology Data Exchange (ETDEWEB)

    Vijayaraj, A.; Prabu, R.; Suresh, R.; Narayanan, V.; Sangeetha Kumari, R.; Kaviyarasan, V. [Univ. of Madras, Madras (India)

    2012-11-15

    A new series of acyclic mononuclear gadolinium(III) complexes have been prepared by Schiff-base condensation derived from 5-methylsalicylaldehyde, diethylenetriamine, tris(2-aminoethyl) amine, triethylenetetramine, N,N-bis(3-aminopropyl)ethylene diamine, N,N-bis(aminopropyl) piperazine, and gadolinium nitrate. All the complexes were characterized by elemental and spectral analyses. Electronic spectra of the complexes show azomethine (CH=N) within the range of 410-420 nm. The fluorescence efficiency of Gd(III) ion in the cavity was completely quenched by the higher chain length ligands. Electrochemical studies of the complexes show irreversible one electron reduction process around -2.15 to -1.60 V. The reduction potential of gadolinium(III) complexes shifts towards anodic directions respectively upon increasing the chain length. The catalytic activity of the gadolinium(III) complexes on the hydrolysis of 4-nitrophenylphosphate was determined. All gadolinium(III) complexes were screened for antibacterial activity.

  7. Magnetocaloric properties of distilled gadolinium: effects of structural inhomogeneity and hydrogen impurity

    Czech Academy of Sciences Publication Activity Database

    Burkhanov, G.S.; Kolchugina, N.B.; Tereshina, Evgeniya; Tereshina, I. S.; Politova, G.A.; Chzhan, V.B.; Badurski, D.; Chistyakov, O.D.; Paukov, M.; Drulis, H.; Havela, L.

    2014-01-01

    Roč. 104, č. 24 (2014), "242402-1"-"242402-5" ISSN 0003-6951 R&D Projects: GA ČR GAP204/12/0150 Institutional support: RVO:68378271 Keywords : high-purity rare-earth metals * gadolinium * magnetocaloric effect * hydrogenation * structural studies Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 3.302, year: 2014

  8. Gadolinium chloride as a contrast agent for imaging wood composite components by magnetic resonance

    Science.gov (United States)

    Thomas L. Eberhardt; Chi-Leung So; Andrea Protti; Po-Wah So

    2009-01-01

    Although paramagnetic contrast agents have an established track record in medical uses of magnetic resonance imaging (MRI), only recently has a contrast agent been used for enhancing MRI images of solid wood specimens. Expanding on this concept, wood veneers were treated with a gadolinium-based contrast agent and used in a model system comprising three-ply plywood...

  9. 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...

  10. 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...

  11. International comparison calculations for a BWR lattice with adjacent gadolinium pins

    International Nuclear Information System (INIS)

    Maeder, C.; Wydler, P.

    1984-09-01

    The results of burnup calculations for a simplified BWR fuel element with two adjacent gadolinium rods are presented and discussed. Ten complete solutions were contributed by Denmark, France, Italy (3), Japan (3), Switzerland and the UK. Partial results obtained from Poland and the USA are included in an Appendix. (Auth.)

  12. Myocardial late gadolinium enhancement in specific cardiomyopathies by cardiovascular magnetic resonance: a preliminary experience.

    Science.gov (United States)

    Silva, Caterina; Moon, James C; Elkington, Andrew G; John, Anna S; Mohiaddin, Raad H; Pennell, Dudley J

    2007-12-01

    Late gadolinium enhancement cardiovascular magnetic resonance (CMR) can visualize myocardial interstitial abnormalities. The aim of this study was to assess whether regions of abnormal myocardium can also be visualized by late enhancement gadolinium CMR in the specific cardiomyopathies. A retrospective review of all referrals for gadolinium CMR with specific cardiomyopathy over 20 months. Nine patients with different specific cardiomyopathies were identified. Late enhancement was demonstrated in all patients, with a mean signal intensity of 390 +/- 220% compared with normal regions. The distribution pattern of late enhancement was unlike the subendocardial late enhancement related to coronary territories found in myocardial infarction. The affected areas included papillary muscles (sarcoid), the mid-myocardium (Anderson-Fabry disease, glycogen storage disease, myocarditis, Becker muscular dystrophy) and the global sub-endocardium (systemic sclerosis, Loeffler's endocarditis, amyloid, Churg-Strauss). Focal myocardial late gadolinium enhancement is found in the specific cardiomyopathies, and the pattern is distinct from that seen in infarction. Further systematic studies are warranted to assess whether the pattern and extent of late enhancement may aid diagnosis and prognostic assessment.

  13. Separation and purification of gadolinium and others rare earths, and yttrium

    International Nuclear Information System (INIS)

    Awwal, M.A.; Filgueiras, S.A.C.

    1988-01-01

    The experimental works in laboratories for developing a solvent extraction process with the purpose of gadolinium separation and purification, and secondarily samarium, europium, lanthanum and yttrium are described. Using as solvent di-2-ethylhexylphosphoric acid (DEHPA) a preliminary flow chart for separation for these elements are developed. (author)

  14. 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)

  15. Precipitation reactions in Magnesium-rare earth alloys containing Yttrium, Gadolinium or Dysprosium

    Energy Technology Data Exchange (ETDEWEB)

    Apps, P.J.; Karimzadeh, H.; King, J.F.; Lorimer, G.W

    2003-04-14

    Precipitation reactions have been evaluated in three magnesium-rare earth alloys, containing yttrium, gadolinium or dysprosium. Differences have been noted in precipitate morphology, volume fraction and formation kinetics. These features have been combined with phase composition data and related to mechanical properties.

  16. Phase compositions in magnesium-rare earth alloys containing yttrium, gadolinium or dysprosium

    Energy Technology Data Exchange (ETDEWEB)

    Apps, P.J.; Karimzadeh, H.; King, J.F.; Lorimer, G.W

    2003-03-03

    Phase compositions have been investigated, using thin foil energy dispersive X-ray spectroscopy, in three magnesium-rare earth alloys, containing yttrium, gadolinium or dysprosium. Compositions are suggested for the as-cast eutectic and {beta} precipitate phases and possible compositions for the {beta}{sub 1} precipitate phases are discussed.

  17. Fat saturation technique and gadolinium in MRI of lumbar spinal degenerative disease.

    Science.gov (United States)

    D'Aprile, P; Tarantino, A; Lorusso, V; Brindicci, D

    2006-11-30

    We evaluated the potential of MR sequences with Fat Saturation and gadolinium in patients with degenerative disease of the lumbar spine and low back pain, by studying both anterior and posterior elements of the lumbar spine. We examined 3323 patients (age range 15-78 years) presenting low back pain. We used T2-weighted sequences with Fat Saturation and in some selected cases (1063 patients, 32%) administered gadolinium using T1-weighted sequences with Fat Saturation. In particular we used gadolinium in the following cases: 1) presence of hyperintense areas on T2 weighted images with Fat Saturation in the osteo-articular and muscular-ligamentous structures of the lumbar spine; 2) Clinical-radiological discrepancy in patients without disc-root conflict and clinical suspicion of posterior vertebral compartment syndrome. We found degenerative-inflammatory changes in osteo-articular, ligamentous and muscular structures in 1063 patients: osteochondrosis, "aseptic discitis", facet joint effusion and synovitis, osteoarthritis, synovial cysts, spondylolysis, degenerative-inflammatory changes of the posterior ligaments (flava, interspinous and supraspinous ligaments) and posterior perispinal muscles. To improve diagnostic accuracy and allow correct therapeutic guidance, MR examination in patients with low back pain must evaluate both anterior and posterior elements of the lumbar spine. Our study indicates that T2 sequences with Fat Saturation and, in selected cases, gadolinium administration, better visualize or disclose degenerative-inflammatory changes in the lumbar spine, showing the active-inflammatory phase and extension of these processes which may not be depicted during a standard MR examination.

  18. Criticality experiments with low enriched UO2 fuel rods in water containing dissolved gadolinium

    International Nuclear Information System (INIS)

    Bierman, S.R.; Murphy, E.S.; Clayton, E.D.; Keay, R.T.

    1984-02-01

    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 UO 2 and PuO 2 -UO 2 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 UO 2 rods at two enrichments (2.35 wt % and 4.31 wt % 235 U) and on mixed fuel-water assemblies of UO 2 and PuO 2 -UO 2 rods containing 4.31 wt % 235 U and 2 wt % PuO 2 in natural UO 2 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 235 U 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

  19. Gadolinium retention after administration of contrast agents based on linear chelators and the recommendations of the European Medicines Agency.

    Science.gov (United States)

    Dekkers, Ilona A; Roos, Rick; van der Molen, Aart J

    2018-04-01

    The Pharmacovigilance Risk Assessment Committee (PRAC) of the European Medicines Agency (EMA) earlier this year recommended to suspend some marketing authorisations for Gadolinium Containing Contrast Agents (GCCAs) based on linear chelators due to the potential risk of gadolinium retention in the human body. These recommendations have recently been re-evaluated by EMA's Committee for Medicinal Products for Human Use (CHMP), and confirmed the final opinion of the European Medicines Agency. This editorial provides an overview of the available GCCAs and summarises the recent evidence of gadolinium retention. Moreover, a critical appraisal of the strengths and limitations of the scientific evidence currently available on gadolinium retention is given. • EMA recommended suspension of some EU marketing authorisations of four linear GCCAs. • Brain MRI findings indicating gadolinium retention have been confirmed by mass spectrometry. • Current scientific evidence for gadolinium retention has several methodological limitations. • No clear clinical evidence exists indicating that gadolinium retention causes neurotoxicity. • Long-term safety of GCCAs, however, remains unclear.

  20. Experimental and thermodynamic study of the erbium-oxygen-zirconium and gadolinium-oxygen-zirconium systems

    International Nuclear Information System (INIS)

    Jourdan, J.

    2009-11-01

    This work is a contribution to the development of innovative concepts for fuel cladding in pressurized water nuclear reactors. This concept implies the insertion of rare earth (erbium and gadolinium) in the zirconium fuel cladding. The determination of phase equilibria in the systems is essential prior to the implementation of such a promising solution. This study consisted in an experimental determination of the erbium-zirconium phase diagram. For this, we used many different techniques in order to obtain diagram data such as solubility limits, solidus, liquidus or invariant temperatures. These data allowed us to present a new diagram, very different from the previous one available in the literature. We also assessed the diagram using the CALPHAD approach. In the gadolinium-zirconium system, we determined experimentally the solubility limits. Those limits had never been determined before, and the values we obtained showed a very good agreement with the experimental and assessed versions of the diagram. Because these alloys are subjected to oxygen diffusion throughout their life, we focused our attention on the erbium-oxygen-zirconium and gadolinium-oxygen-zirconium systems. The first system has been investigated experimentally. The alloys fabrication has been performed using powder metallurgy. In order to obtain pure raw materials, we fabricated powder from erbium and zirconium bulk metals using hydrogen absorption/desorption. The characterisation of the ternary pellets allowed the determination of two ternary isothermal sections at 800 and 1100 C. For the gadolinium-oxygen-zirconium system, we calculated the phase equilibria at temperatures ranging from 800 to 1100 C, using a homemade database compiled from literature assessments of the oxygen-zirconium, gadolinium-zirconium and gadolinia-zirconia systems. Finally, we determined the mechanical properties, in connexion with the microstructure, of industrial quality alloys in order to identify the influence of

  1. 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.)

  2. 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

  3. Cerebrospinal fluid changes after intravenous injection of gadolinium chelate: assessment by FLAIR MR imaging

    International Nuclear Information System (INIS)

    Bozzao, Alessandro; Floris, Roberto; Fasoli, Fabrizio; Simonetti, Giovanni; Fantozzi, Luigi Maria; Colonnese, Claudio

    2003-01-01

    Fluid-attenuated inversion recovery (FLAIR) sequence is currently used in clinical practice. Some reports emphasize the possibility that, in pathologic conditions, intravenous injection of gadolinium chelates may lead to an increased signal inside the cerebrospinal fluid (CSF). The aim of this study was to evaluate the presence of CSF signal changes in pathologic conditions causing blood-brain barrier disruption or neovascularization when imaging is performed after intravenous injection of gadolinium. We obtained FLAIR sequences after gadolinium injection from 33 patients affected by different intracranial pathologies and 10 control subjects. Patients were affected by ischemic stroke in the subacute phase, from 2 to 7 days from onset of symptoms (12 patients), meningiomas (8 patients), high-grade gliomas (5 patients), previous surgical procedures for intra-axial neoplasms (5 patients), and multiple sclerosis with active plaques (3 patients). Magnetic resonance imaging was performed in patients and controls using a 1.5-T magnet, using T2- and T1-weighted FLAIR sequences. The FLAIR sequence was acquired before and 1-3 h after injection of a standard dose of gadolinium. In those patients affected by ischemic lesions, FLAIR sequences were repeated the next days and 3-4 days later. The CSF signal was visually evaluated by two readers and scored from 0 to 3 depending by the degree of enhancement. The location of CSF signal changes (close to the lesion, hemispheric, or diffuse) was also considered. The CSF signal was markedly increased after 3 h from intravenous injection of gadolinium in all the patients with stroke, in those with previous surgery, and in those with high-grade gliomas whose neoplasm's surface was in contact with the subarachnoid spaces (SAS) or ventricles; a strong enhancement was also evident inside the necrotic component of the tumor. The CSF changes were more evident close to the pathology and/or in the hemisphere involved by the pathology. Moderate

  4. The Role of Terbium and Gadolinium in Reversal of Cisplatin Resistance in Cultured Human Breast Cancer Cells

    National Research Council Canada - National Science Library

    Allworth, Ann

    2001-01-01

    ...+) or gadolinium ions (Gd3+) are added to cisplatin treatment of cisplatin resistant MDA-MB231 human breast cancer cells Preliminary data demonstrated that either trivalent lanthanide ion reverses the cellular phenotype...

  5. 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...

  6. Feasibility and accuracy of dual-layer spectral detector computed tomography for quantification of gadolinium: a phantom study

    Energy Technology Data Exchange (ETDEWEB)

    Hamersvelt, Robbert W. van; Willemink, Martin J.; Jong, Pim A. de; Schilham, Arnold M.R.; Leiner, Tim [University Medical Center Utrecht, Department of Radiology, P.O. Box 85500, Utrecht (Netherlands); Milles, Julien [CT Clinical Science, Philips HealthCare, Best (Netherlands); Vlassenbroek, Alain [CT Clinical Science, Philips HealthCare, Brussels (Belgium)

    2017-09-15

    The aim of this study was to evaluate the feasibility and accuracy of dual-layer spectral detector CT (SDCT) for the quantification of clinically encountered gadolinium concentrations. The cardiac chamber of an anthropomorphic thoracic phantom was equipped with 14 tubular inserts containing different gadolinium concentrations, ranging from 0 to 26.3 mg/mL (0.0, 0.1, 0.2, 0.4, 0.5, 1.0, 2.0, 3.0, 4.0, 5.1, 10.6, 15.7, 20.7 and 26.3 mg/mL). Images were acquired using a novel 64-detector row SDCT system at 120 and 140 kVp. Acquisitions were repeated five times to assess reproducibility. Regions of interest (ROIs) were drawn on three slices per insert. A spectral plot was extracted for every ROI and mean attenuation profiles were fitted to known attenuation profiles of water and pure gadolinium using in-house-developed software to calculate gadolinium concentrations. At both 120 and 140 kVp, excellent correlations between scan repetitions and true and measured gadolinium concentrations were found (R > 0.99, P < 0.001; ICCs > 0.99, CI 0.99-1.00). Relative mean measurement errors stayed below 10% down to 2.0 mg/mL true gadolinium concentration at 120 kVp and below 5% down to 1.0 mg/mL true gadolinium concentration at 140 kVp. SDCT allows for accurate quantification of gadolinium at both 120 and 140 kVp. Lowest measurement errors were found for 140 kVp acquisitions. (orig.)

  7. Atypical Distribution of Late Gadolinium Enhancement of the Left Ventricle on Cardiac Magnetic Resonance in Classical Anderson-Fabry Disease

    OpenAIRE

    Kasuya, Shusuke; Suzuki, Masayo; Inaoka, Tsutomu; Odashima, Masayuki; Nakatsuka, Tomoya; Ishikawa, Rumiko; Tokuyama, Wataru; Terada, Hitoshi

    2016-01-01

    Anderson-Fabry disease (AFD) is an X-linked lysosomal storage disorder caused by a deficiency of alpha-galactosidase A. Approximately 50% of patients with AFD may have cardiac involvement. Gadolinium-enhanced cardiac magnetic resonance (CMR) is useful for the diagnosis of cardiac involvement of AFD by recognizing typical late gadolinium enhancement (LGE) patterns. We report a 48-year-old man with cardiac involvement in classical AFD, showing atypical distribution of the LGE at the mid-lateral...

  8. An efficient one-pot multi component synthesis of polyhydroquinoline derivatives through Hantzsch reaction catalysed by Gadolinium triflate

    Directory of Open Access Journals (Sweden)

    S. Sheik Mansoor

    2017-02-01

    Full Text Available Gadolinium(III trifluoromethanesulfonate (Gadolinium triflate Gd(OTf3 catalysed efficient Hantzsch reaction via four-component coupling reactions of aldehydes, 5,5-dimethyl-1,3-cyclohexaedione (dimedone, ethyl acetoacetate and ammonium acetate at ambient temperature was described as the preparation of polyhydroquinoline derivatives. The process presented here is operationally simple, environmentally benign and has excellent yield. Furthermore, the catalyst can be recovered conveniently and reused efficiently.

  9. First measurements with new high-resolution gadolinium-GEM neutron detectors

    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

    2016-05-17

    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.

  10. Investigation of gadolinium (3)-, calcium (2)- and copper (2) complexes with riboflavin in acetonitrile

    International Nuclear Information System (INIS)

    Lugina, L.N.

    1984-01-01

    Electron and IR spectra of gadolinium-(3), calcium (2), and copper (2) complexes with riboflavin (RF) in acetopitrile against the background of LiClO 4 x3H 2 O are studied. The way of RF coordination by the atom of metal is shown to depend on the nature of metal. Gadolinium (3) coordinates RF through N and O atoms; copper - through O metal, calcium - through O atom and, evidently, through hydroxyl groups of ribitol. Directions of RF line shifts of π-π * electron transitions at RF complexing with metals are compared with the calculated results and directions of RF line shifts during the formation of hydrogen bonds with different donor atoms of the isoalloxazine ring

  11. Addendum to the procedure of KWU standard calculation for PWR fuel assembly with gadolinium

    International Nuclear Information System (INIS)

    Andrade, E.P. de

    1993-01-01

    The objective of this work is to solve a doubt appeared in the standard procedure of KWU/Siemens for fuel assembly (FA) with gadolinium. In this procedure, the σ's and form functions of such assembly are modified by his effective heterogeneity factor factor (f eff ), which is defined as the ratio between the heterogeneity factors (f het ) of FA's with and without poison. The doubt appeared at the time to calculated the f het of FA without poison: should one consider the pure FA or the FA with poison in which the concentration of gadolinium would be set to zero, but one should keep that of natural uranium? The best results were obtained considering the second hypothesis. (author)

  12. 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.

  13. Thermodynamic property evaluation and magnetic refrigeration cycle analysis for gadolinium gallium garnet

    Energy Technology Data Exchange (ETDEWEB)

    Murphy, R.W.

    1994-12-01

    Based on relevant material property data and previous model formulations, a magnetothermodynamic property map for gadolinium gallium garnet (Gd{sub 3}Ga{sub 5}O{sub 12}) was adapted for refrigeration cycle analysis in the temperature range 4-40 K and the magnetic field range 0-6 T. Employing methods similar to those previously developed for other materials and temperature ranges, assessments of limitations and relative performance were made for Carnot, ideal regenerative, and pseudo-constant field regenerative cycles. It was found that although Carnot cycle limitations on available temperature lift for gadolinium gallium garnet are not as severe as the limitations for materials previously examined, considerable improvement in cooling capacity and temperature lift combinations can be achieved by using regenerative cycles if serious loss mechanisms are avoided.

  14. 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.

  15. Magnetic refrigeration cycle analysis using selected thermodynamic property characterizations for gadolinium gallium garnet

    International Nuclear Information System (INIS)

    Murphy, R.W.

    1992-01-01

    Magneto-thermodynamic property characterizations were selected, adapted, and compared to material property data for gadolinium gallium garnet in the temperature range 4--40 K and magnetic field range 0--6 T. The most appropriate formulations were incorporated into a model in which methods similar to those previously developed for other materials and temperature ranges were used to make limitation and relative performance assessments of Carnot, ideal regenerative, and pseudo-constant field regenerative cycles. Analysis showed that although Carnot cycle limitations on available temperature lift for gadolinium gallium garnet are not as severe as those for materials previously examined, substantial improvements in cooling capacity/temperature lift combinations can be achieved using regenerative cycles within specified fields limits if significant loss mechanisms are mitigated

  16. Specific features of the WWER Uranium-Gadolinium fuel behavior at BOL

    International Nuclear Information System (INIS)

    Shcheglov, A.; Proselkov, V.; Volkov, B.

    2013-01-01

    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)

  17. 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.

  18. Phantom experiment of depth-dose distributions for gadolinium neutron capture therapy

    International Nuclear Information System (INIS)

    Matsumoto, T.; Kato, K.; Sakuma, Y.; Tsuruno, A.; Matsubayashi, M.

    1993-01-01

    Depth-dose distributions in a tumor simulated phantom were measured for thermal neutron flux, capture gamma-ray and internal conversion electron dose rates for gadolinium neutron capture therapy. The results show that (i) a significant dose enhancement can be achieved in the tumor by capture gamma-rays and internal conversion electrons but the dose is mainly due to capture gamma-rays from the Gd(n, γ) reactions, therefore, is not selective at the cellular level, (ii) the dose distribution was a function of strongly interrelated parameters such as gadolinium concentrations, tumor site and neutron beam size (collimator aperture size), and (iii) the Gd-NCT by thermal neutrons appears to be a potential for treatment of superficial tumor. (author)

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

    International Nuclear Information System (INIS)

    Bonnerot, V.; Sebag, G.; Montalembert, M. de; Wioland, M.; Glorion, C.; Girot, R.; Lallemand, D.

    1994-01-01

    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.)

  20. Low Temperature Synthesis and Properties of Gadolinium-Doped Cerium Oxide Nanoparticles

    DEFF Research Database (Denmark)

    Machado, M. F. S.; Moraes, L. P. R.; Monteiro, N. K.

    2017-01-01

    resistance to carbon deposition when hydrocarbons are used as fuels. However, an inconvenience of ceria-based oxides is the high sintering temperature needed to obtain a fully dense ceramic body. In this study, a green chemistry route for the synthesis of 10 mol% GDC nanoparticles is proposed. The aqueous......Gadolinium-doped cerium oxide (GDC) is an attractive ceramic material for solid oxide fuel cells (SOFCs) both as the electrolyte and in composite electrodes operating at low and intermediate temperatures. GDC exhibits high oxygen ion conductivity at a wide range of temperatures and displays a high...... precipitation method starts from the nitrates of both cerium and gadolinium and uses excess hexamethylenetetramine (HMT) to produce crystalline GDC at 80ºC. Such a low temperature synthesis provides control over particle size and sinterability of the material at low temperatures....

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

    International Nuclear Information System (INIS)

    Haddad, M.C.; Sharif, H.S.; Aabed, M.Y.; Al Shahed, M.S.; Sammak, B.M.; Clark, D.C.

    1993-01-01

    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.)

  2. 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.)

  3. Reduction of radiation dose by using digital luminescence radiography compared to conventional screen film system with grid cassette; Reduktion der Strahlendosis mittels Speicherfolienradiographie im Vergleich zum konventionellen Film-Folien-System mit Rasterkassette am Schaedelphantom

    Energy Technology Data Exchange (ETDEWEB)

    Heyne, J.P.; Merbold, H.; Neumann, R.; Freesmeyer, M.; Jonetz-Mentzel, L.; Kaiser, W.A. [Friedrich-Schiller-Univ. Jena, Inst. fuer Diagnostische und Interventionelle Radiologie (Germany); Sehner, J. [AGFA-Deutschland, Vertriebsgesellschaft (Germany)

    1999-07-01

    Purpose: How much can the radiation dose be reduced for skull radiography by using digital luminescence radiography (DLR) compared to a conventional screen film system with a grid cassette? Methods and Materials: A skull phantom (3M) was X-rayed in anterior-posterior orientation using both a conventional screen film system with grid cassette and DLR (ADC-70, Agfa). The tube current time product (mAs) was diminished gradually while keeping the voltage constant. The surface entrance dose was measured by a sensor of Dosimax (Wellhoefer). Five investigators evaluated the images by characteristic and critical features, spatial resolution and contrast. Results: The surface entrance dose at 73 kV/22 mAs was 0,432 mGy in conventional screen film system and 0,435 mGy in DLR. The images could be evaluated very well down to an average dose of 71% (0,308 mGy; SD 0,050); sufficient images were obtained down to an average dose of 31% (0,136 mGy; SD 0,065). The resolution of the line pairs were reduced down to a 2 levels depending on the investigator. Contrast was assessed as being very good to sufficient. The acceptance of the postprocessed images (MUSICA-software) was individually different and resultde in an improvement of the assessment of bone structures an contrast in higher dose ranges only. Conclusion: For the sufficient assessment of a possible fracture/of paranasal sinuses/of measurement the skull the dose can be reduced to at least 56% (31%; SD 14,9%)/40% (27%; SD 9,3%)/18% (14%; SD 4,4%). Digital radiography allows question-referred exposure parameters with clearly reduced dose, so e.g. for fracture exclusion 73 kV/12,5 mAs and to skull measurement 73 kV/4 mAs. (orig.) [Deutsch] Ziel: Wie weit kann unter Einsatz der rasterlosen Speicherfolienradiographie bei einer Schaedelaufnahme die Strahlendosis im Vergleich zum Film-Folien-System (FFS) mit Rasterkassette (RK) fragestellungsbezogen gesenkt werden? Material und Methode: Ein Schaedelphantom (3M) wurde konventionell

  4. One color multi-photon ionization of the Gadolinium atom in near UV region

    International Nuclear Information System (INIS)

    Kim, Jin Tae; Yi, Jong Hoon; Lhee, Yong Joo; Lee, Jong Min

    1999-01-01

    We have investigated the states of the gadolinium atom in near ultra-violet (UV) region (∼410 nm) using single photon excitation using resonance ionization mass spectrometry (RIMS). Around 70 transitions among observed 180 single color multi-photon ionization signals have been assigned. Most of the multi-photon processes of the assigned ion signals are through single photon resonant three photon ionization and through two photon resonant three photon ionization. (author)

  5. Gadolinium-Based GaN for Neutron Detection with Gamma Discrimination

    Science.gov (United States)

    2016-06-01

    towards our goal of a gamma discriminating device. Future studies should include determining the reason for double peaks appearing in the spectra of...Gadolinium-Based GaN for Neutron Detection with Gamma Discrimination Distribution Statement A. Approved for public release; distribution is...C kg –1 ) rad [absorbed dose] 1 × 10 –2 joule per kilogram (J kg –1 ) [gray (Gy)] rem [equivalent and effective dose] 1 × 10–2 joule per kilogram

  6. Some improvements in the microscopic depletion of assemblies with gadolinium rods

    International Nuclear Information System (INIS)

    Hoareau, F.; Couyras, D.; Girardi, E.

    2012-01-01

    EDF/R and D is developing a new calculation scheme based on the transport-Simplified Pn (SPn) approach. The lattice code used is the deterministic code APOLLO2, developed at CEA with the support of EDF and AREVA-NP. The core code is the code COCAGNE, developed at EDF R and D. The latter can take advantage of a microscopic depletion solver which improves the treatment of spectral history effects. However, comparisons with reference calculations show that the microscopic mode used in COCAGNE gives slightly less accurate results when used to simulate the depletion of assemblies with gadolinium rods. This study aims at determining whether specific models can be used to improve the results of the depletion of assemblies containing burnable poisons. Three possible models are considered in this paper. The first model consists in describing explicitly the gadolinium isotopic chain into the microscopic model implemented within COCAGNE. In the second model, one also uses an explicit description of the gadolinium chain. In addition, the LOCA concentration of gadolinium isotopes is used as interpolation parameter instead of the LOCA burnup, when evaluation microscopic cross sections. The last model consists in using the concentration of Pu239 as a spectral indicator: microscopic cross sections are then corrected according to the LOCA concentration of this nuclide. Comparisons with APOLLO2 depletion calculations were performed to validate these models in COCAGNE. These APOLLO2 calculations consisted in depleting the fuel from 0 GWd/t to 60 GWd/t while keeping perturbed thermal-hydracrylic conditions. CPCAGNE used as input the neutronic libraries generated via a depletion performed in nominal conditions and then a branch case corresponding to the perturbed thermal-hydracrylic conditions of the reference APOLLO2 calculations. These tests show that the microscopic model using Pu239 as a spectral indicator improves the treatment of spectral effects in COCAGNE

  7. About thermo-electric properties of bismuth telluride doped by gadolinium

    International Nuclear Information System (INIS)

    Akperov, M.M.; Ismailov, Sh.S.; Shukyurova, A.A.

    2004-01-01

    Results of study of the Gd impurities effect on the bismuth telluride thermo-electric properties are presented. The experiment was carried out within the temperature range T=300-700 K. It is determined, that at temperature increase the energy level is appreciably closing up to bismuth telluride forbidden zone which makes up 0.16-0.24 eV. Such anomalous energy properties of gadolinium in telluride affect on material thermoelectric properties

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

    Energy Technology Data Exchange (ETDEWEB)

    Dumazert, Jonathan; Coulon, Romain; Carrel, Frédérick; Corre, Gwenolé; Normand, Stéphane [CEA, LIST, Laboratoire Capteurs Architectures Electroniques, 91191 Gif-sur-Yvette (France); Méchin, Laurence [CNRS, UCBN, Groupe de Recherche en Informatique, Image, Automatique et Instrumentation de Caen, 14050 Caen (France); Hamel, Matthieu [CEA, LIST, Laboratoire Capteurs Architectures Electroniques, 91191 Gif-sur-Yvette (France)

    2016-08-21

    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.

  9. Hyperfine coupling in gadolinium-praseodymium alloys by specific heat measurements

    International Nuclear Information System (INIS)

    Michel, J.

    1969-01-01

    We have studied the hyperfine coupling in gadolinium-praseodymium alloys by specific heat measurements down to 0.3 K. In the first part we describe the apparatus used to perform our measurements. The second part is devoted to some theoretical considerations. We have studied in detail the case of praseodymium which is an exception in the rare earth series. The third part shows the results we have obtained. (author) [fr

  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. Subepicardial delayed gadolinium enhancement in asymptomatic athletes: let sleeping dogs lie?

    OpenAIRE

    Schnell, Frédéric; Claessen, Guido; La Gerche, André; Bogaert, Jan; Lentz, Pierre-Axel; Claus, Piet; Mabo, Philippe; Carré, Francois; Heidbuchel, Hein

    2016-01-01

    Background Subepicardial delayed gadolinium enhancement (DGE) patches without underlying cardiomyopathy is poorly understood. It is often reported as the result of prior silent myocarditis. Its prognostic relevance in asymptomatic athletes is unknown; therefore, medical clearance for competitive sports participation is debated. This case series aims to relate this pattern of DGE in athletes to outcome. Methods We report on seven young asymptomatic athletes with isolated subepicardial DGE dete...

  12. Magnetic Relaxation in Aluminosilicate Structures Containing Manganese(II) and Gadolinium(III) Complexes

    Science.gov (United States)

    Sur, S. K.; Heinsbergen, J. F.; Bryant, R. G.

    Electron-spin-resonance spectra and nuclear-magnetic-relaxation-dispersion measurements are reported for several aluminosilicate structures to which manganese (II) and gadolinium(III) ions have been added in several structurally distinct ways. EPR spectra demonstrate that diffusion of the hexaaquomanganese(II) ion or the aquogadolinium(III) ion into the zeolite structures is facile, apparently displacing sodium ion or protons. The addition of a complexing agent such as ethylenediaminetetraacetic acid or diethylenetriaminepentaacetic acid to the metal-loaded zeolite then yields a complex which in the gadolinium case forms inside the zeolite but in the manganese(II) case forms largely outside the zeolite under our preparation conditions. For the intrazeolite complexes, the gadolinium system is stable to both low pH and high sodium concentrations. The field dependence of the water-proton relaxation displays strong paramagnetic effects that increase with increasing temperature, consistent with exchange limitations on the access of the water-proton spin system to the paramagnetic centers. The shape of the relaxation-dispersion curves demonstrates the importance of anisotropy in the metal-ion EPR spectrum, which leads to a considerable distribution of electron-spin Larmor frequencies and a consequent weak dependence of the nuclear-spin-relaxation rate on the magnetic-field strength.

  13. Optical properties of pure and Ce3+ doped gadolinium gallium garnet crystals and epitaxial layers

    International Nuclear Information System (INIS)

    Syvorotka, I.I.; Sugak, D.; Wierzbicka, A.; Wittlin, A.; Przybylińska, H.; Barzowska, J.; Barcz, A.; Berkowski, M.; Domagała, J.; Mahlik, S.; Grinberg, M.; Ma, Chong-Geng

    2015-01-01

    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 Ce 3+ 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: • Ce 3+ 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 Ce 3+ by Pb ions from flux detected in GGG epitaxial layers. • X-ray diffraction allows measuring the amount of the rare-earth antisites in GGG

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

    Science.gov (United States)

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

    2014-10-06

    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. All iodinated and gadolinium contrast-enhanced radiologic examinations between August 2011 and February 2013 for which the premedication protocol was applied in our institution were assessed for BTRs. The protocol was applied to a total of 252 examinations (153 patients, ages 15-87 years; 63 males, 90 females). Of these, 152 were for prior acute adverse reactions to contrast media, 85 were for a history of bronchial asthma, and 15 were for other reasons. There were 198 contrast enhanced CTs and 54 contrast enhanced MRIs. There were nine BTR (4.5%) for iodinated contrast media, and only one BTR (1.9%) for gadolinium contrast media: eight were mild and one was moderate. No patient who had a mild index reaction (IR) had a severe BTR. Incidence of BTRs when following the premedication protocol was low. This study by no means proves the efficacy of premedication, but provides some support for following a premedication protocol to improve safety of contrast-enhanced examinations when prior adverse reactions are mild, or when there is a history of asthma.

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

    International Nuclear Information System (INIS)

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

    2014-01-01

    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. All iodinated and gadolinium contrast-enhanced radiologic examinations between August 2011 and February 2013 for which the premedication protocol was applied in our institution were assessed for BTRs. The protocol was applied to a total of 252 examinations (153 patients, ages 15–87 years; 63 males, 90 females). Of these, 152 were for prior acute adverse reactions to contrast media, 85 were for a history of bronchial asthma, and 15 were for other reasons. There were 198 contrast enhanced CTs and 54 contrast enhanced MRIs. There were nine BTR (4.5%) for iodinated contrast media, and only one BTR (1.9%) for gadolinium contrast media: eight were mild and one was moderate. No patient who had a mild index reaction (IR) had a severe BTR. Incidence of BTRs when following the premedication protocol was low. This study by no means proves the efficacy of premedication, but provides some support for following a premedication protocol to improve safety of contrast-enhanced examinations when prior adverse reactions are mild, or when there is a history of asthma

  16. Selective Filtration of Gadolinium Trichloride for Use in Neutron Detection in Large Water Cherenkov Detectors

    International Nuclear Information System (INIS)

    Vagins, Mark R.

    2013-01-01

    Super-??Kamiokande 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 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 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 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

  17. 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.

  18. 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.

  19. [Natural history of lumbar disc hernias: does gadolinium enhancement have any prognostic value?].

    Science.gov (United States)

    Ramos Amador, A; Alcaraz Mexía, M; González Preciado, J L; Fernández Zapardiel, S; Salgado, R; Páez, A

    2013-09-01

    To evaluate the percentage of disc hernias that have disappeared after one year of follow-up and the time to disappearance. To determine whether gadolinium enhancement is useful for predicting whether the hernia will disappear. To analyze whether the pattern of enhancement can help predict whether the fragment will disappear. This prospective study included 118 patients with acute symptoms of lumbosciatica and a herniated disc diagnosed by CT. In 72 patients, we performed gadolinium-enhanced MRI every 6 months for one year or until the herniation disappeared; we related the findings of protrusion, extrusion, and the enhancement pattern with the disappearance or persistence of herniated disc material. We analyzed the results with univariate and multivariate statistics. The 59% of the hernias disappeared within 1 year of follow-up and 66% disappeared within the first 8 months of follow-up. The 83% of the extruded hernias disappeared, and this was significant in the multivariate analysis (Phernia in the univariate analysis. The enhancement pattern was not useful for predicting whether the hernia would disappear. Five hernias disappeared within the first two months. A high percentage of disc hernias disappear. We found a significant association between extrusion and disappearance but no correlation between the pattern of gadolinium uptake and the disappearance of the hernia. Copyright © 2010 SERAM. Published by Elsevier Espana. All rights reserved.

  20. Radiation exposure in full-field digital mammography with a flat-panel X-ray detector based on amorphous silicon in comparison with conventional screen-film mammography

    International Nuclear Information System (INIS)

    Hermann, K.P.; Obenauer, S.; Grabbe, E.

    2000-01-01

    Comparison of radiation exposure between a digital amorphous silicon and a screen-film based mammography system. Evaluation of a possible potential of full-field digital mammography in order to decrease the radiation dose. Methods: The average glandular dose for phantom thicknesses from 30 to 60 mm was calculated from experimentally determined entrance surface air kerma for a digital and a conventional mammography system. The effect of reducing the detector dose and of changing the radiation quality on radiation exposure and on image quality were investigated. Results: By using the delivered settings of the automatic exposure control (AEC) devices, both mammographic systems needed nearly the same doses. Regulations and guidelines on radiation doses were complied. With the digital system, a reduction of radiation exposure of up to 40% by using a higher radiation quality and decreasing slightly the detector dose without loss of diagnostic image quality, might be possible. Conclusion: The potential of full-field digital mammography for radiation dose reduction, as shown in the present phantom study, needs however, a careful examination under clinical conditions. (orig.) [de

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

    Science.gov (United States)

    Mostafaei, F; McNeill, F E; Chettle, D R; Noseworthy, M D

    2015-01-01

    The feasibility of using a (109)Cd 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.

  2. Correlation between gadolinium-diethylenetriaminepentaacetic acid contrast enhancement and thallium-201 chloride uptake in pediatric brainstem glioma.

    Science.gov (United States)

    Maria, B L; Drane, W B; Quisling, R J; Hoang, K B

    1997-09-01

    We previously showed that thallium-201 (201Tl) chloride is accumulated in over 75% of brain tumors, including brainstem gliomas. The imaging of 201Tl with single photon emission computed tomography (SPECT) may require an abnormal increase in permeability of tumor vessels to allow penetration of the blood-brain barrier. To test this hypothesis, we evaluated the correlation between gadolinium enhancement and the degree of 201Tl uptake on SPECT and the contributions of either gadolinium enhancement or 201Tl uptake to the prognosis in children with brainstem gliomas. Forty-two sets of paired SPECT scans and magnetic resonance imaging (MRI) scans were obtained longitudinally in 13 cases. Altogether, 31 of 42 pairs (74%) of scans showed concordance between the presence of gadolinium enhancement and 201Tl uptake. There were no cases that demonstrated 201Tl uptake but lacked gadolinium enhancement. The results indicate that 201Tl SPECT is of value primarily when brainstem tumors have vessels that are demonstrably permeable to gadolinium, prior to or as a result of radiotherapy.

  3. 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.

  4. 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.

  5. Fat-saturated post gadolinium T1 imaging of the brain in multiple sclerosis

    Energy Technology Data Exchange (ETDEWEB)

    Al-Saeed, Osama; Sheikh, Mehraj (Dept. of Radiology, Kuwait Univ. (Kuwait)), email: osamas@hsc.edu.kw; Ismail, Mohammed (Ibn Sina Hospital (Kuwait)); Athyal, Reji (Amiri Hospital (Kuwait))

    2011-06-15

    Background Magnetic resonance imaging (MRI) is of vital importance in the diagnosis and follow-up of patients with multiple sclerosis (MS). Imaging sequences better demonstrating enhancing lesions can help in detecting active MS plaques. Purpose To evaluate the role of fat-saturated gadolinium-enhanced T1-weighted (T1W) images of the brain in MS and to assess the benefit of performing this additional sequence in the detection of enhancing lesions. Material and Methods In a prospective study over a six-month period, 70 consecutive patients with clinically diagnosed MS were enrolled. These constituted 14 male and 56 female patients between the ages of 21 and 44 years. All the patients underwent brain MRIs on a 1.5 Tesla Magnet. Gadolinium-enhanced T1 images with and without fat saturation were compared and results were recorded and analyzed using a conspicuity score and McNemar test. Results There were a total of 157 lesions detected in 70 patients on post-contrast T1W fat-saturated images compared with 139 lesions seen on the post-contrast T1W fast spin-echo (FSE) images. This was because 18 of the lesions (11.5%) were only seen on the fat-saturated images. In addition, 15 lesions were more conspicuous on the fat saturation sequence (9.5%). The total conspicuity score obtained, including all the lesions, was 2.24 +/-0.60 (SD). Using the two-tailed McNemar test for quantitative analysis, the P value obtained was <0.0001. Conclusion T1W fat-saturated gadolinium-enhanced images show better lesion enhancement than T1W images without fat saturation

  6. 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)

  7. Silica nanoparticles containing 159-Gadolinium as potential system for cancer treatment

    International Nuclear Information System (INIS)

    Oliveira, Andre Felipe de; Ferreira, Tiago Hilario; Sousa, Edesia Martins Barros de; Lacerda, Marco Aurelio

    2013-01-01

    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 159 Gd by neutron irradiation, wherein the isotope 158 Gd captures a neutron and becomes 159 Gd [ 15 '8Gd(n,c) 1 '5 9 Gd]. The 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 90 Y. In this work, the 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 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)

  8. Spontaneous magnetic contribution to a bulk modulus of ferromagnetic metals (with gadolinium taken as an example)

    International Nuclear Information System (INIS)

    Bodryakov, V.Yu.; Povzner, A.A.; Zelyukova, O.G.

    1999-01-01

    A thermodynamic approach to the description of magnetic contribution into ferromagnetic metals elastic modulus variations is developed on the basis of the Landau second type phase transitions theory. It is shown that the magnetostriction variation of not considered previously Landau's thermodynamic parameters α and β is an essential reason for all-round compression elastic modulus varying with magnetization. In addition, to detect the magnetic contribution into the elastic modulus from experimental data an expression is derived for its temperature dependence in a paramagnetic developed and experimental data is made for a ferromagnetic phase of gadolinium [ru

  9. Low Temperature Synthesis and Properties of Gadolinium-Doped Cerium Oxide Nanoparticles

    DEFF Research Database (Denmark)

    Machado, Marina F. S.; P. R. Moraes, Leticia; Monteiro, Natalia K.

    2017-01-01

    Gadolinium-doped cerium oxide (GDC) is an attractive ceramic material for solid oxide fuel cells (SOFCs) both as the electrolyte or in composite electrodes. The Ni/GDC cermet can be tuned as a catalytic layer, added to the conventional Ni/yttria-stabilized zirconia (YSZ), for the internal steam...... reforming of different fuels. Such an anode allows the SOFC to operate with hydrocarbon fuels by internal reforming. GDC exhibits high oxygen ion conductivity at a wide range of temperatures and displays a high resistance to carbon deposition. However, an inconvenience of ceria-based oxides is the high...

  10. Synthesis of samarium doped gadolinium oxide nanorods, its spectroscopic and physical properties

    Science.gov (United States)

    Boopathi, G.; Gokul Raj, S.; Ramesh Kumar, G.; Mohan, R.; Mohan, S.

    2017-12-01

    One-dimensional samarium doped gadolinium oxide [Sm:Gd2O3] nanorods have been synthesized successfully through co-precipitation technique in aqueous solution. The as-synthesized and calcined products were characterized by using powder X-ray diffraction pattern, Fourier transform Raman spectroscopy, thermogravimetric/differential thermal analysis, scanning electron microscopy with energy-dispersive X-ray analysis, transmission electron microscopy, Fourier transform infrared spectroscopy, Ultraviolet-Visible spectrometry, photoluminescence spectrophotometer and X-ray photoelectron spectroscopy techniques. The obtained results are discussed in detailed manner.

  11. Dielectric properties of gadolinium molybdate in low- and infralow frequency electric fields

    International Nuclear Information System (INIS)

    Galiyarova, N.M.; Gorin, S.V.; Dontsova, L.I.; Shil'nikov, A.V.; Shuvalov, L.A.; AN SSSR, Moscow

    1992-01-01

    Temperature dependences of complex dielectric permittivity of gadolinium molybdate (GMO) in low- (LF) and infralow-frequency (ILF) electric fields with 0.1 V·cm -1 amplitude within 0.25-10 4 Hz frequency range are studied. Substantial effect of the crystal prehistory on LF and ILF dielectric properties and domain structure state is revealed. An anomalous reduction of complex dielectric permittivity accompanied by the occurrence of the Debye LF-dispersion of permittivity is detected under the sample cooling from a nonpolar phase

  12. Peculiarities of gadolinium molybdate change-over using alternating electric field

    International Nuclear Information System (INIS)

    Alekseev, A.N.; Zlokazov, M.V.; Prokolov, A.L.; Tikhomirova, N.A.; Shuvalov, L.A.; AN SSSR, Moscow. Inst. Kristallografii)

    1984-01-01

    Experimental investigation into processes of total repolarization of a gadolinium molybdate monocrystal Gd(MoO 4 ) 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

  13. Differentiation of toxoplasmosis and lymphoma in HIV-positive patients with gadolinium-enhanced MR imaging

    International Nuclear Information System (INIS)

    Eisenberg, A.D.; Mani, J.R.; Norman, D.

    1990-01-01

    This paper determines whether gadolinium-enhanced MR imaging can be used to differentiate toxoplasmosis and lymphoma in patients with acquired immunodeficiency syndrome. One hundred fifty-nine lesions from 71 MR examinations of eight patients with lymphoma were evaluated for size, location, enhancement characteristics, lesion multiplicity. Multiple lesions occurred in 72% of toxoplasmosis and 75% of lymphoma cases. Toxoplasmosis lesions are smaller, with lesion most commonly between 1 and 2 cm, whereas lymphoma is most often between 2 and 3 cm. Except for a propensity for lymphoma to occur in the temporal lobes, no difference in lesion location was found. Both conditions usually markedly enhance, but the pattern of enhancement differs

  14. Controllable Fabrication and Optical Properties of Uniform Gadolinium Oxysulfate Hollow Spheres

    OpenAIRE

    Chen, Fashen; Chen, Gen; Liu, Tao; Zhang, Ning; Liu, Xiaohe; Luo, Hongmei; Li, Junhui; Chen, Limiao; Ma, Renzhi; Qiu, Guanzhou

    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...

  15. Deep learning enables reduced gadolinium dose for contrast-enhanced brain MRI.

    Science.gov (United States)

    Gong, Enhao; Pauly, John M; Wintermark, Max; Zaharchuk, Greg

    2018-02-13

    There are concerns over gadolinium deposition from gadolinium-based contrast agents (GBCA) administration. To reduce gadolinium dose in contrast-enhanced brain MRI using a deep learning method. Retrospective, crossover. Sixty patients receiving clinically indicated contrast-enhanced brain MRI. 3D T 1 -weighted inversion-recovery prepped fast-spoiled-gradient-echo (IR-FSPGR) imaging was acquired at both 1.5T and 3T. In 60 brain MRI exams, the IR-FSPGR sequence was obtained under three conditions: precontrast, postcontrast images with 10% low-dose (0.01mmol/kg) and 100% full-dose (0.1 mmol/kg) of gadobenate dimeglumine. We trained a deep learning model using the first 10 cases (with mixed indications) to approximate full-dose images from the precontrast and low-dose images. Synthesized full-dose images were created using the trained model in two test sets: 20 patients with mixed indications and 30 patients with glioma. For both test sets, low-dose, true full-dose, and the synthesized full-dose postcontrast image sets were compared quantitatively using peak-signal-to-noise-ratios (PSNR) and structural-similarity-index (SSIM). For the test set comprised of 20 patients with mixed indications, two neuroradiologists scored blindly and independently for the three postcontrast image sets, evaluating image quality, motion-artifact suppression, and contrast enhancement compared with precontrast images. Results were assessed using paired t-tests and noninferiority tests. The proposed deep learning method yielded significant (n = 50, P 5 dB PSNR gains and >11.0% SSIM). Ratings on image quality (n = 20, P = 0.003) and contrast enhancement (n = 20, P < 0.001) were significantly increased. Compared to true full-dose images, the synthesized full-dose images have a slight but not significant reduction in image quality (n = 20, P = 0.083) and contrast enhancement (n = 20, P = 0.068). Slightly better (n = 20, P = 0.039) motion

  16. MRT of experimental liver abscesses - comparison of a new blood pool contrast agent with gadolinium-DTPA

    International Nuclear Information System (INIS)

    Dick, A.; Adam, G.; Spuentrup, E.; Prescher, A.; Muehler, A.; Guenther, R.W.

    1996-01-01

    Purpose: In an experimental pyogenic liver abscess model, the signal intensities were compared intraindividually and interindividually after the application of a new blood pool contrast agent, 24-gadolinium-DTPA (diethylenetriamine-pentaacetic acid) cascade polymer, and after the application of gadopentetate dimeglumine. Methods: In 20 rabbits with experimentally induced liver abscesses, the relative signal intensities of the liver, abscess centre, abscess wall and portal vein were assessed before and between 30 seconds and 60 minutes after injection of a 25 μmol/kg dose of gadolinium polymer and of 100 μmol/kg of gadolinium-DTPA, respectively. Measurements were performed at 1.5 Tesla, using a head coil and a Flash-2-D sequence. Results: The interindividual comparison (unpaired T-test, p [de

  17. Prominent porto-systemic collateral pathways in patients with portal hypertension: demonstration by gadolinium-enhanced magnetic resonance angiography

    International Nuclear Information System (INIS)

    Caldana, Rogerio Pedreschi; Bezerra, Alexandre Araujo Sergio; Cecin, Alexnadre Oliveira; Souza, Luis Ronan Marques Ferreira de; Goldman, Susan Menasce; D'Ippolito, Giuseppe; Szejnfeld, Jacob

    2003-01-01

    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)

  18. Development of ICP-MS and ICP-OES methods for determination of gadolinium in samples related to hospital waste water treatment

    Czech Academy of Sciences Publication Activity Database

    Bendakovská, L.; Krejčovská, A.; Černohorský, T.; Zelenková, Jana

    2016-01-01

    Roč. 70, č. 9 (2016), s. 1155-1165 ISSN 0366-6352 Institutional support: RVO:67985874 Keywords : gadolinium * rare-earth elements * bioaccumulation * gadolinium anomaly * inductively coupled plasma mass spectrometry (ICP-MS) * inductively coupled plasma optical emission spectrometry (ICP-OES) Subject RIV: BK - Fluid Dynamics Impact factor: 1.258, year: 2016

  19. Separation of carrier-free gadolinium produced in an 80 MeV 12C6+ irradiated CeO2 target

    International Nuclear Information System (INIS)

    Nayak, Dalia; Lahiri, Susanta; Das, N.R.; Das, S.K.; Ramaswami, A.; Manohor, S.B.

    1999-01-01

    Charged particle activation of natural CeO 2 with 80 MeV 12 C +6 results in the formation of the carrier-free gadolinium isotopes, 147,149 Gd, in the matrix. The liquid cation exchanger, HDEHP, has been utilized effectively as an extractant in the quantitative separation of these gadolinium isotopes from the bulk target matrix of ceric oxide

  20. Development of ICP-MS and ICP-OES methods for determination of gadolinium in samples related to hospital waste water treatment

    Czech Academy of Sciences Publication Activity Database

    Bendakovská, L.; Krejčovská, A.; Černohorský, T.; Zelenková, Jana

    2016-01-01

    Roč. 70, č. 9 (2016), s. 1155-1165 ISSN 0366-6352 Institutional support: RVO:67985874 Keywords : gadolinium * rare-earth elements * bioaccumulation * gadolinium anomaly * inductively coupled plasma mass spectrometry ( ICP -MS) * inductively coupled plasma optical emission spectrometry ( ICP - OES ) Subject RIV: BK - Fluid Dynamics Impact factor: 1.258, year: 2016

  1. High Signal Intensity in the Dentate Nucleus and Globus Pallidus on Unenhanced T1-Weighted MR Images: Comparison between Gadobutrol and Linear Gadolinium-Based Contrast Agents.

    Science.gov (United States)

    Moser, F G; Watterson, C T; Weiss, S; Austin, M; Mirocha, J; Prasad, R; Wang, J

    2018-02-01

    In view of the recent observations that gadolinium deposits in brain tissue after intravenous injection, our aim of this study was to compare signal changes in the globus pallidus and dentate nucleus on unenhanced T1-weighted MR images in patients receiving serial doses of gadobutrol, a macrocyclic gadolinium-based contrast agent, with those seen in patients receiving linear gadolinium-based contrast agents. This was a retrospective analysis of on-site patients with brain tumors. Fifty-nine patients received only gadobutrol, and 60 patients received only linear gadolinium-based contrast agents. Linear gadolinium-based contrast agents included gadoversetamide, gadobenate dimeglumine, and gadodiamide. T1 signal intensity in the globus pallidus, dentate nucleus, and pons was measured on the precontrast portions of patients' first and seventh brain MRIs. Ratios of signal intensity comparing the globus pallidus with the pons (globus pallidus/pons) and dentate nucleus with the pons (dentate nucleus/pons) were calculated. Changes in the above signal intensity ratios were compared within the gadobutrol and linear agent groups, as well as between groups. The dentate nucleus/pons signal ratio increased in the linear gadolinium-based contrast agent group ( t = 4.215, P linear gadolinium-based contrast agent group ( t = 2.931, P linear gadolinium-based contrast agents. © 2018 by American Journal of Neuroradiology.

  2. Digital radiography of the skeleton using a large-area detector based on amorphous silicon technology: Image quality and potential for dose reduction in comparison with screen-film radiography

    International Nuclear Information System (INIS)

    Volk, M.; Strotzer, M.; Holzkneckt, N.; Manke, C.; Lenhart, M.; Gmeinwieser, J.; Link, J.; Reiser, M.; Feuerback, S.

    2000-01-01

    AIM: The purpose of this study was to evaluate a large-area, flat-panel X-ray detector (FD), based on caesium-iodide (CsI) and amorphous silicon (a-Si) with respect to skeletal radiography. Conventional images were compared with digital radiographs using identical and reduced radiation doses. MATERIALS AND METHODS: Thirty consecutive patients were studied prospectively using conventional screen-film radiography (SFR; detector dose 2.5 μGy). Digital images were taken from the same patients with detector doses of 2.5, 1.25 and 0.625 μGy, respectively. The active-matrix detector had a panel size of 43 x 43 cm, a matrix of 3 x 3K, and a pixel size of 143 μm. All hard copies were presented in a random order to eight independent observers, who rated image quality according to subjective quality criteria. Results were assessed for significance using the Student's t -test (confidence level 95%). RESULTS: A statistically significant preference for digital over conventional images was revealed for all quality criteria, except for over-exposure (detector dose 2.5 μGy). Digital images with a 50% dose showed a small, statistically not significant, inferiority compared with SFR. The FD-technique was significantly inferior to SFR at 75% dose reduction regarding bone cortex and trabecula, contrast and overall impression. No statistically significant differences were found with regard to over- and under-exposure and soft tissue presentation. CONCLUSION: Amorphous silicon-based digital radiography yields good image quality. The potential for dose reduction depends on the clinical query. Volk, M. (2000)

  3. In vivo dentate nucleus MRI relaxometry correlates with previous administration of Gadolinium-based contrast agents

    Energy Technology Data Exchange (ETDEWEB)

    Tedeschi, Enrico; Canna, Antonietta; Cocozza, Sirio; Russo, Carmela; Angelini, Valentina; Brunetti, Arturo [University ' ' Federico II' ' , Neuroradiology, Department of Advanced Biomedical Sciences, Naples (Italy); Palma, Giuseppe; Quarantelli, Mario [National Research Council, Institute of Biostructure and Bioimaging, Naples (Italy); Borrelli, Pasquale; Salvatore, Marco [IRCCS SDN, Naples (Italy); Lanzillo, Roberta; Postiglione, Emanuela; Morra, Vincenzo Brescia [University ' ' Federico II' ' , Department of Neurosciences, Reproductive and Odontostomatological Sciences, Naples (Italy)

    2016-12-15

    To evaluate changes in T1 and T2* relaxometry of dentate nuclei (DN) with respect to the number of previous administrations of Gadolinium-based contrast agents (GBCA). In 74 relapsing-remitting multiple sclerosis (RR-MS) patients with variable disease duration (9.8±6.8 years) and severity (Expanded Disability Status Scale scores:3.1±0.9), the DN R1 (1/T1) and R2* (1/T2*) relaxation rates were measured using two unenhanced 3D Dual-Echo spoiled Gradient-Echo sequences with different flip angles. Correlations of the number of previous GBCA administrations with DN R1 and R2* relaxation rates were tested, including gender and age effect, in a multivariate regression analysis. The DN R1 (normalized by brainstem) significantly correlated with the number of GBCA administrations (p<0.001), maintaining the same significance even when including MS-related factors. Instead, the DN R2* values correlated only with age (p=0.003), and not with GBCA administrations (p=0.67). In a subgroup of 35 patients for whom the administered GBCA subtype was known, the effect of GBCA on DN R1 appeared mainly related to linear GBCA. In RR-MS patients, the number of previous GBCA administrations correlates with R1 relaxation rates of DN, while R2* values remain unaffected, suggesting that T1-shortening in these patients is related to the amount of Gadolinium given. (orig.)

  4. Validation of the analytical methods in the LWR code BOXER for gadolinium-loaded fuel pins

    International Nuclear Information System (INIS)

    Paratte, J.M.; Arkuszewski, J.J.; Kamboj, B.K.; Kallfelz, J.M.; Abdel-Khalik, S.I.

    1990-01-01

    Due to the very high absorption occurring in gadolinium-loaded fuel pins, calculations of lattices with such pins present are a demanding test of the analysis methods in light water reactor (LWR) cell and assembly codes. Considerable effort has, therefore, been devoted to the validation of code methods for gadolinia fuel. The goal of the work reported in this paper is to check the analysis methods in the LWR cell/assembly code BOXER and its associated cross-section processing code ETOBOX, by comparison of BOXER results with those from a very accurate Monte Carlo calculation for a gadolinium benchmark problem. Initial results of such a comparison have been previously reported. However, the Monte Carlo calculations, done with the MCNP code, were performed at Los Alamos National Laboratory using ENDF/B-V data, while the BOXER calculations were performed at the Paul Scherrer Institute using JEF-1 nuclear data. This difference in the basic nuclear data used for the two calculations, caused by the restricted nature of these evaluated data files, led to associated uncertainties in a comparison of the results for methods validation. In the joint investigations at the Georgia Institute of Technology and PSI, such uncertainty in this comparison was eliminated by using ENDF/B-V data for BOXER calculations at Georgia Tech

  5. Qualification of calculation of light water moderated lattices and gadolinium burnable poisons

    International Nuclear Information System (INIS)

    Cerdan, C.

    1984-10-01

    The aim of this work is, on one hand, to qualify the calculation of fundamental parameters of Pressurized Water Reactors and basic nuclear data, and on the other, to qualify the gadolinium burnable poisons. Our calculations have shown an over-estimation of about 700 pcm, with the presently recommended nuclear data (1979), of the multiplication factor calculated by the assembly code APOLLO concerning cold cores (T=20 0 C). The decoupling shows that the over-estimation essentialy comes from the infinite multiplication factor; as a matter of fact, the migration area has been calculated at 3%. According to our results, we conclude that the calculation, by the APOLLO code, of the perturbation induced by the gadolinium absorbers, is not a problem of time zero, even in the case of interaction with a water hole. The comparison between the performances of the different APOLLO multicell calculation methods illustrates the superiority, with regards to the quality and price, of the EURYDICE modul in its ROTH x 4 option [fr

  6. High Relaxivity Gadolinium Hydroxypyridonate-Viral Capsid Conjugates: Nano-sized MRI Contrast Agents

    Energy Technology Data Exchange (ETDEWEB)

    Meux, Susan C.; Datta, Ankona; Hooker, Jacob M.; Botta, Mauro; Francis, Matthew B.; Aime, Silvio; Raymond, Kenneth N.

    2007-08-29

    High relaxivity macromolecular contrast agents based on the conjugation of gadolinium chelates to the interior and exterior surfaces of MS2 viral capsids are assessed. The proton nuclear magnetic relaxation dispersion (NMRD) profiles of the conjugates show up to a five-fold increase in relaxivity, leading to a peak relaxivity (per Gd{sup 3+} ion) of 41.6 mM{sup -1}s{sup -1} at 30 MHz for the internally modified capsids. Modification of the exterior was achieved through conjugation to flexible lysines, while internal modification was accomplished by conjugation to relatively rigid tyrosines. Higher relaxivities were obtained for the internally modified capsids, showing that (1) there is facile diffusion of water to the interior of capsids and (2) the rigidity of the linker attaching the complex to the macromolecule is important for obtaining high relaxivity enhancements. The viral capsid conjugated gadolinium hydroxypyridonate complexes appear to possess two inner-sphere water molecules (q = 2) and the NMRD fittings highlight the differences in the local motion for the internal ({tau}{sub RI} = 440 ps) and external ({tau}{sub RI} = 310 ps) conjugates. These results indicate that there are significant advantages of using the internal surface of the capsids for contrast agent attachment, leaving the exterior surface available for the installation of tissue targeting groups.

  7. MRI of acute cerebral infarcts: increased contrast enhancement with continuous infusion of gadolinium

    International Nuclear Information System (INIS)

    Merten, C.L.; Assheuer, J.; Bergmann-Kurz, B.; Bewermeyer, H.; Knitelius, H.O.; Hedde, J.P.

    1999-01-01

    We compared contrast enhancement on T1-weighted MRI of acute cerebral infarcts after conventional bolus administration and continuous infusion of gadolinium. We examined 12 patients with a history of acute stroke with contrast-enhanced MRI once a week for a 1 month. Only ischaemic lesions were investigated after cerebral haemorrhage had been excluded by CT. Each MRI study included T2- and proton density-weighted sequences for determination of the size and site of the infarct, immediate postinjection T1-weighted imaging after bolus administration of 0.1 mmol/kg gadolinium-DPTA and delayed T1-weighted imaging after additional continuous infusion of 0.1 mmol/kg over 2 h. A total of 42 MRI studies was performed. In the first week after the onset of stroke, most infarcts (8 of 10) did not enhance after bolus administration, whereas all showed distinct contrast enhancement after the infusion. In the following weeks all but two infarcts showed contrast enhancement after bolus administration; after continuous infusion contrast enhancement could be seen in all cases. While contrast enhancement after bolus administration showed the typical gyriform pattern, enhanced areas were more extensive after the infusion and usually covered the entire infarcted area shown on T2- and proton density-weighted images. We presume that the disturbed blood-brain barrier in ischaemic areas favours delivery of contrast medium to the infarcted tissue if it is offered continuously so that a steady state can develop. (orig.)

  8. Gadolinium-enhanced magnetic resonance angiography with ultra-short echo times. Initial experience

    International Nuclear Information System (INIS)

    Stehling, M.K.; Holzknecht, N.; Gauger, J.; Luboldt, W.; Smekal, A, von; Laub, G.

    1996-01-01

    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.) [de

  9. Hydrogen in-situ refining method for preparing high purity gadolinium

    International Nuclear Information System (INIS)

    Li, Guoling; Li, Li; Fu, Kai; Wang, Chongyun; Zheng, Jie; Xu, Li; Tian, Wenhuai; Li, Xingguo

    2015-01-01

    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

  10. 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.

  11. Preparation of new composite ceramics based on gadolinium-doped ceria and magnesia nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Yao, Jingying; Schelter, Matthias; Zosel, Jens; Oelssner, Wolfram [Kurt-Schwabe-Institut fuer Mess- und Sensortechnik e.V. Meinsberg, Waldheim (Germany); Mertig, Michael [Kurt-Schwabe-Institut fuer Mess- und Sensortechnik e.V. Meinsberg, Waldheim (Germany); Physikalische Chemie, Mess- und Sensortechnik, Technische Universitaet Dresden (Germany)

    2017-09-15

    To achieve solid electrolyte materials for electrochemical energy storage devices with very high oxygen ion conductivity, composites of gadolinium-doped ceria (GDC) and magnesia (MgO) are developed in this study. Three different preparation methods are used to prepare nanoparticles from these two components. According to the characterization results, the self-propagating high-temperature synthesis is best suited for the preparation of both nanometer-sized GDC powder as solid electrolyte and MgO powder as insulator. The structures of the prepared nanometer-sized powders have been characterized by X-ray diffraction and transmission electron microscopy. They show narrow size distributions in the lower nanometer range. Then, dense composite ceramics are prepared from a MgO-GDC mixture by sintering. The size of the crystallite domains in the sintered ceramic is in the upper nanometer range. TEM and TEM-EDX images of a new composite ceramic based on gadolinium-doped ceria and magnesia nanoparticles. (copyright 2017 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  12. 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.

  13. Silica-coated gadolinium-doped lanthanum strontium manganite nanoparticles for self-controlled hyperthermia applications

    Science.gov (United States)

    Ahmad, Ashfaq; Bae, Hongsub; Rhee, Ilsu

    2018-01-01

    Gadolinium-doped lanthanum strontium manganite (LSM) nanoparticles were synthesized by using a citrate-gel technique. The particles were then annealed at 850 oC to remove defects for a good crystallinity, followed by coating with silica for possible biomedical application to magnetic hyperthermia. The chemical composition was determined to be La0.54Sr0.27Gd0.19MnO3 using an inductively coupled plasma mass spectrometer. The nanoparticles were characterized by X-ray diffraction, transmission electron microscope, and Fourier transform infrared spectrometer to check the perovskite crystalline structure and to observe the particles size and coating status of silica on the surface of the particles. The Curie temperature of the particles was found to be about 280 K. The saturation temperature of the aqueous solution of the particles remained at the hyperthermia target temperature of 42 oC with increasing concentration of particles from 6 to 60 mg/mL in the dispersion. This saturation temperature for a highly concentrated 120-mg/mL-sample increased further, but less than the dangerous temperature of 47 oC for normal tissues. The saturation temperature of the powder sample reached only up to 53 oC. These results showed that the gadolinium-doped LSM nanoparticles can be used for the self-controlled hyperthermia in which the temperature does not exceed the target temperature of hyperthermia even at the tissue site of highly accumulated nanoparticles.

  14. Late Gadolinium Enhancement of the right ventricular myocardium: Is it really different from the left ?

    Directory of Open Access Journals (Sweden)

    Macgowan Christopher K

    2008-05-01

    Full Text Available Abstract It has been suggested that, in late gadolinium enhancement, the signal of right ventricular myocardium is nulled at a shorter inversion time than the left. While we initially made the same observation, we believe that the difference is not real, but results from artifacts. We present 7 cases as well as computer simulations to describe the nature of these artifacts and explain how they can create the impression of different inversion times for the right and left ventricle. At inversion times that are shorter than ideal for the myocardium a black rim can be seen at the border of the myocardium with blood on the inside and with fat on the outside. This is most likely a partial volume effect. The thin myocardium of the right ventricle is sandwiched between these black rims and, at a low spatial resolution, is no longer visible. In this case, the adjacent black rims may then be misinterpreted as myocardium. While black rims also occur on the left side, the myocardium is thicker and remains discernable as a separate layer. As a consequence, the optimal inversion time for the right ventricle only appears different from that for the left. In fact, in the presence of hypertrophy of the right ventricle or during systolic wall thickening we did not find a difference in inversion times between the left and right ventricle. We conclude that sufficient spatial resolution is important for adequate late gadolinium enhancement of the right ventricle.

  15. 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.)

  16. Gadolinium enhancement in acute and chronic-progressive experimental allergic encephalomyelitis in the guinea pig.

    Science.gov (United States)

    Karlik, S J; Grant, E A; Lee, D; Noseworthy, J H

    1993-09-01

    Magnetic resonance imaging detects blood-brain barrier disruption after gadolinium-DTPA enhancement of central nervous system lesions of multiple sclerosis. Experimental allergic encephalomyelitis has many clinical and pathological features in common with multiple sclerosis including alterations in the integrity of the blood-brain barrier. We have compared T2-weighted cranial MR images with Gd-DTPA dimeglumine-enhanced T1-weighted images of myelin basic protein-induced acute (Days 8-42 postimmunization) and central nervous system-induced chronic-progressive (Days 70-95 postimmunization) forms of experimental allergic encephalomyelitis in the guinea pig. Although animals from both groups had abnormal T2-weighted images, only the myelin basic protein-acute-EAE animals (Days 14-24 postimmunization) showed enhancement on postcontrast MR studies. The different responses of the acute and chronic diseases may result from different immunogens, severity of disease, or different permeability of the blood-brain barrier. Therefore, gadolinium-DTPA-enhanced, T1-weighted MR images distinguish acutely active and chronic inflammatory lesions in experimental allergic encephalomyelitis.

  17. 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.

  18. Luminescence properties of Ce3+ doped gadolinium-calcium-silicaborate glass scintillator

    International Nuclear Information System (INIS)

    Park, J.M.; Ha, D.H.; Kaewjeang, S.; Maghanemi, U.; Kothan, S.; Kaewkhao, J.; Kim, H.J.

    2016-01-01

    In this work, the Ce 3+ doped gadolinium-calcium-silicaborate glass scintillators of the composition ratio 25Gd 2 O 3 :10CaO:10SiO 2 :(55−x)B 2 O 3 :xCeF 3 , have been fabricated by using the melt-quenching technique. The doping concentration of the Ce 3+ was varied from 0.05 mol% to 2.5 mol%. The 4f-5d transition of the Ce 3+ allowed scintillation with a fast decay time. The absorption spectrum, X-ray induced emission spectrum, photo luminescence spectrum, laser luminescence spectrum and decay time of the scintillators were measured for studying the luminescence properties. From the X-ray induced emission spectrum result, we checked the trend between doping concentration and light yield. The laser induced luminescence spectrum was measured while changing the temperature from 300 K to 10 K. We also measured the decay time by using the laser excitation of the 0.15 mol% Ce 3+ doped glass scintillator. - Highlights: • Ce 3+ doped gadolinium-calcium-silicaborate glass scintillators were developed. • Glass is easily fabricated with large sizes and various doping materials. • The luminescence properties are studied by using various radiation sources. • The light yield and decay time were measured at low temperature. • One decay time component is found.

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

    International Nuclear Information System (INIS)

    Kalekar, Bhupesh B.; Raje, Naina; Reddy, A.V.R.

    2015-01-01

    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. Acute and chronic tears of anterior cruciate ligament : role of gadolinium-enhanced MR imaging

    International Nuclear Information System (INIS)

    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

    1998-01-01

    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

  1. Synthesis and characterization of gadolinium-doped nanotubular titania for enhanced photocatalysis

    International Nuclear Information System (INIS)

    Shi, Liang; Cao, Lixin; Gao, Rongjie; Zhao, Yanling; Zhang, Huibin; Xia, Chenghui

    2014-01-01

    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 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

  2. 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.

  3. Signal effects of various radiographic contrast media and their interaction with gadolinium DTPA during MRT

    International Nuclear Information System (INIS)

    Kopka, L.; Funke, M.; Fischer, U.; Vosshenrich, R.; Schroeder, M.; Grabbe, E.

    1994-01-01

    T 1 and T 2 weighted signals dereived from various radiological contrast media were studied during MRT spin-echo sequences. In addition, the interaction between radiological contrast media and Gadolinium-DTPA concerning T 1 signals was evaluated. Ionic (ioxitalaminic acid) and non-ionic radiological contrast media (Iopromid, Iotrolan) were used in diagnostic concentrations. Measurements were carried out with a superconductive magnet of 1.5 Tesla. Radiological contrast media produced significantly higher signals than a physiological sodium chloride solution in T 1 -weighted spin-echo sequences. Evn small amounts (15% of total volume) of radiological contrast media during T 1 -weighted spin-echo sequences led to a significant reduction (about 25%) of the signal intensity of a 2 mM Gadolinium-DTPA solution. This may lead to diagnostic problems, as was shown in a series of 25 MR arthrograms of the shoulder. It is recommended than an interval of at least 6 hours should elapse between the use of a radiological contrst medium and an MRT examination. (orig.) [de

  4. High-dose gadolinium-enhanced MRI for diagnosis of meningeal metastases

    International Nuclear Information System (INIS)

    Kallmes, D.F.; Gray, L.; Glass, J.P.

    1998-01-01

    We compared high-dose (0.3 mmol/kg) and standard-dose (0.1 mmol/kg) gadolinium-enhanced MRI for diagnosis of meningeal metastases in 12 patients with suspected meningeal metastases. They were imaged with both standard-dose and high-dose gadolinium. All patients with abnormal meningeal enhancement underwent at least one lumbar puncture for cerebrospinal fluid (CSF) cytology, while patients with normal meningeal enhancement were followed clinically. All patients with negative CSF cytology also were followed clinically. A single observer reviewed all the images, with specific attention to the enhancement pattern of the meninges. Abnormal leptomeningeal enhancement was present in three cases, and abnormal pachymeningeal enhancement in three other patients. All of these patients had abnormal CSF analyses. In two of the three cases of abnormal leptomeningeal enhancement the disease was more evident on high-dose than on standard-dose imaging; in one case the abnormal enhancement was visible only on high-dose imaging. In one of the three cases with abnormal pachymeningeal enhancement, the disease was evident prospectively only with high-dose imaging. (orig.)

  5. Injection of gadolinium contrast through pediatric central venous catheters: a safety study

    International Nuclear Information System (INIS)

    Moriarty, John M.; Ramos, Yanerys; Finn, J.P.; Kung, Geoffrey L.; Moghaddam, Abbas N.; Ennis, Daniel B.

    2012-01-01

    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. 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.)

  7. 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...

  8. The T2-Shortening Effect of Gadolinium and the Optimal Conditions for Maximizing the CNR for Evaluating the Biliary System: a Phantom Study

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Mi Jung; Kim, Myung Joon [Severance Children' s Hospital, Yensei University College of Medicine, Seoul (Korea, Republic of); Yoon, Choon Sik [Gangnam Severance Hospital, Yensei University College of Medicine, Seoul (Korea, Republic of); Song, Si Young [Severance Hospital, Yensei University College of Medicine, Seoul (Korea, Republic of); Park, Kyung Soo [Yensei University College of Medicine, Seoul (Korea, Republic of); Kim, Woo Sun [Seoul Nationa University College of Medicine, Seoul (Korea, Republic of)

    2011-06-15

    Clear depiction of the common bile duct is important when evaluating neonatal cholestasis in order to differentiate biliary atresia from other diseases. During MR cholangiopancreatography, the T2-shortening effect of gadolinium can increase the contrast-to-noise ratio (CNR) of the bile duct and enhance its depiction. The purpose of this study was to confirm, by performing a phantom study, the T2-shortening effect of gadolinium, to evaluate the effect of different gadolinium chelates with different gadolinium concentrations and different magnetic field strengths for investigating the optimal combination of these conditions, and for identifying the maximum CNR for the evaluation of the biliary system. MR imaging using a T2-weighted single-shot fast spin echo sequence and T2 relaxometry was performed with a sponge phantom in a syringe tube. Two kinds of contrast agents (Gd-DTPA and Gd-EOB-DTPA) with different gadolinium concentrations were evaluated with 1.5T and 3T scanners. The signal intensities, the CNRs and the T2 relaxation time were analyzed. The signal intensities significantly decreased as the gadolinium concentrations increased (p < 0.001) with both contrast agents. These signal intensities were higher on a 3T (p < 0.001) scanner. The CNRs were higher on a 1.5T (p < 0.001) scanner and they showed no significant change with different gadolinium concentrations. The T2 relaxation time also showed a negative correlation with the gadolinium concentrations (p < 0.001) and the CNRs showed decrease more with Gd-EOB-DTPA (versus Gd-DTPA; p < 0.001) on a 3T scanner (versus 1.5T; p < 0.001). A T2-shortening effect of gadolinium exhibits a negative correlation with the gadolinium concentration for both the signal intensities and the T2 relaxation time. A higher CNR can be obtained with Gd-DTPA on a 1.5T MRI scanner.

  9. Extreme ultra-violet emission spectroscopy of highly charged gadolinium ions with an electron beam ion trap

    International Nuclear Information System (INIS)

    Ohashi, Hayato; Nakamura, Nobuyuki; Sakaue, Hiroyuki A

    2013-01-01

    We present extreme ultra-violet emission spectra of highly charged gadolinium ions obtained with an electron beam ion trap at electron energies of 0.53–1.51 keV. The electron energy dependence of the spectra in the 5.7–11.3 nm range is compared with calculation with the flexible atomic code. (paper)

  10. Magnetic resonance tomography for focal lesions in the liver using the para-magnetic contrast medium gadolinium DTPA

    International Nuclear Information System (INIS)

    Hamm, B.; Roemer, T.; Felix, R.; Wolf, K.J.; Klinikum Charlottenburg, Berlin

    1986-01-01

    The use of the para-magnetic contrast medium gadolinium DTPA for magnetic resonance tomography of focal lesions in the liver was investigated in 31 patients. Two dosage schedules of the contrast medium (0.1 and 0.2 mmol/kg body weight) were used with field strengths of 0.35 and 0.5 Tesla. Using T 1 sequences, gadolinium DTPA showed increased signal intensity in the liver and in tumours, but this was significantly more marked in the tumour. On T 1 spin-echo sequences, previously iso-intense lesions became visible after administration of contrast. On the other hand, contrast-enhanced lesions were less well seen on inversion recovery sequences because of a reduction in the contrast between tumour and liver tissue. The contrast between tumour and liver tissue was not improved by gadolinium DTPA in comparison with precontrast inversion recovery sequences and T 2 spin-echo sequences. The perfusion of intra-hepatic tumours could be elucidated by magnetic resonance tomography after the administration of gadolinium DTPA. (orig.) [de

  11. Laser-enrichment of the odd isotopes of gadolinium for use as burnable poison in nuclear reactors

    International Nuclear Information System (INIS)

    Santala, M.I.K.; Lauranto, H.M.; Kajava, T.T.; Salomaa, R.R.E.

    1995-01-01

    Gadolinium (Gd) has two isotopes which are strong neutron absorbers. It would be desirable to enrich Gd in those isotopes for use in nuclear fuels. Isotope-selectivity based on spectral isotope shifts has been investigated. Our experimental results indicate that significant enrichment is achievable even with relatively broadband (∼3 GHz) lasers. copyright 1995 American Institute of Physics

  12. Laser-enrichment of the odd isotopes of gadolinium for use as burnable poison in nuclear reactors

    International Nuclear Information System (INIS)

    Santala, M. I. K.; Lauranto, H. M.; Kajava, T. T.; Salomaa, R. R. E.

    1995-01-01

    Gadolinium (Gd) has two isotopes which are strong neutron absorbers. It would be desirable to enrich Gd in those isotopes for use in nuclear fuels. Isotope-selectivity based on spectral isotope shifts has been investigated. Our experimental results indicate that significant enrichment is achievable even with relatively broadband (≅3 GHz) lasers

  13. 77 FR 42317 - Establish a Patient-Based Registry To Evaluate the Association of Gadolinium Based Contrast...

    Science.gov (United States)

    2012-07-18

    ... Quality Assurance (QA) registry of patients with renal failure who received GBCAs as the basis for a... of the development of a patient-based registry to evaluate the association of gadolinium based..., and a copy to Ira Krefting, Center for Drug Evaluation and Research, Division of Medical Imaging...

  14. Neutron detector with own power supply, with an emitter made of gadolinium foil and two concentric collectors

    International Nuclear Information System (INIS)

    Brixy, H.; Spillekothen, H.G.; Benninghofen, G.; Serafin, N.

    1985-01-01

    The emitter consists of a material with a high absorption crossection for thermal neutrons, particularly gadolinium, and is provided with an auxiliary emitter layer on the inside and/or the outside. This increases the electron yield with suitable dimensions and material. (orig./HP) [de

  15. Power release estimation inside of fuel pins neighbouring fuel pin with gadolinium in a WWER-1000 type core

    International Nuclear Information System (INIS)

    Mikus, J.

    2006-01-01

    The purpose of this work consists in investigation of the gadolinium fuel pin (fps) influence on space power distribution, especially from viewpoint of the values and gradient occurrence inside of neighbouring FPs that could result in static loads with some consequences, e.g., FP bowing. Since detailed power distributions cannot be obtained in the NPPs, needed information is provided by means of experiments on research reactors. As for the power release measurement inside of FPs, some special (e.g. track) detectors placed between fuel pellets are usually used. Since such works are relatively complicated and time consuming, an evaluation method based on mathematical modelling and numerical approximation was proposed by means of that, and using measured (integral) power release in selected FPs, relevant information about power release inside of needed (investigated) FP, can be obtained. For this purpose, an experiment on light water, zero-power research reactor LR-0 was realized in a WWER-1000 type core with 7 fuel assemblies at zero boron concentration and containing gadolinium FPs. Application of the above evaluation method is demonstrated on investigated FP neighbouring a FP with gadolinium by means of the 1) Azimuthal power distribution inside of investigated FP on their fuel pellet surface in horizontal plane and 2) Gradient of the power distribution inside of investigated FP in two opposite positions on pellets surface that are situated to- and outwards a FP with gadolinium. Similar information can be relevant from the viewpoint of the FP failures occurrence investigation (Authors)

  16. Design, synthesis, and evaluation of gadolinium cationic lipids as tools for biodistribution studies of gene delivery complexes.

    Science.gov (United States)

    Leclercq, Francoise; Cohen-Ohana, Mirit; Mignet, Nathalie; Sbarbati, Andrea; Herscovici, Jean; Scherman, Daniel; Byk, Gerardo

    2003-01-01

    Gadolinium-chelating cationic lipids have been synthesized to obtain lipoplexes with MRI contrast properties. These compounds were designed to follow the biodistribution of synthetic DNA for gene delivery by nuclear magnetic resonance imaging. The lipid MCO-I-68 was synthesized, and chelate complexes with gadolinium were formed and characterized in terms of physicochemical and DNA binding properties. The transfection activity of MCO-I-68-Gd/DNA complexes was assayed in vitro on NIH 3T3. Different formulations of the product were tested. When up to 5% of the gadolinium lipid complexes were co-formulated with the cationic lipid RPR120535 used as a reference, the transfection levels were maintained as compared to RPR120535 alone. To date, only a liposomal formulation of a gadolinium-cationic lipid chelate without DNA had been observed using magnetic resonance imaging. In vivo intratumoral administration of MCO-I-68-Gd/DNA lipoplexes to tumor model led to an important increase of the NMR signal. It was demonstrated that the new complexes also acted as transfection carriers when they were formulated from liposomes.

  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, Johannes J.

    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. Patterns of disease on MRI in 53 children with tuberculous spondylitis and the role of gadolinium

    International Nuclear Information System (INIS)

    Andronikou, Savvas; Jadwat, Saaleha; Douis, Hassan

    2002-01-01

    Tuberculosis (TB) of the spine is the most common site of osseous involvement and has a higher prevalence in developing nations with an increasing incidence in developed nations. There are few paediatric reports of TB spondylitis (TBS) that include MRI findings.Objective. To determine the MRI characteristics of TBS in children with special reference to gadolinium enhancement and findings on follow-up MRI.Materials and methods. A retrospective review of patient records and MRI scans by three readers using a consensus method of 53 patients below 13 years of age.Results. Seventy-nine percent presented with kyphosis. MRI showed thoracic involvement in 83%. Eighty-five percent showed contiguous involvement of two or more vertebral bodies. An intraspinal or paraspinal soft-tissue mass or abscess was present in 98%. Subligamentous extension was noted in 64% of patients. Gadolinium was administered in 26 patients. Ring enhancement of the soft-tissue mass was shown in 65% of these. Subligamentous enhancement was shown in 35% and bone enhancement was shown in 100% of patients. Follow-up MRI performed in 16 patients showed progressive bone destruction in 10 patients, progressive kyphosis in 2 patients and progression of soft-tissue disease in 4 patients.Conclusions. We have demonstrated an advanced pattern of TBS in this childhood population, which supports other reports that describe a more aggressive process in children. Kyphosis and cord compressions were the most common complications. The use of gadolinium is promising in detecting disease earlier, as it invariably results in bone enhancement and may assist in making the diagnosis when the rim-enhancing pattern of the soft-tissue mass is demonstrated. Follow-up imaging with MRI is a suitable way of assessing resolution of cord compression and decrease in size of the soft-tissue mass. Therefore, considering the pattern of involvement in children with TBS demonstrated by this study, MRI is considered an ideal modality for

  19. Reassessment of gadolinium odd isotopes neutron cross sections: scientific motivations and sensitivity-uncertainty analysis on LWR fuel assembly criticality calculations

    Directory of Open Access Journals (Sweden)

    Rocchi Federico

    2017-01-01

    Full Text Available Gadolinium odd isotopes cross sections are crucial in assessing the neutronic performance and safety features of a light water reactor (LWR core. Accurate evaluations of the neutron capture behavior of gadolinium burnable poisons are necessary for a precise estimation of the economic gain due to the extension of fuel life, the residual reactivity penalty at the end of life, and the reactivity peak for partially spent fuel for the criticality safety analysis of Spent Fuel Pools. Nevertheless, present gadolinium odd isotopes neutron cross sections are somehow dated and poorly investigated in the high sensitivity thermal energy region and are available with an uncertainty which is too high in comparison to the present day typical industrial standards and needs. This article shows how the most recent gadolinium cross sections evaluations appear inadequate to provide accurate criticality calculations for a system with gadolinium fuel pins. In this article, a sensitivity and uncertainty analysis (S/U has been performed to investigate the effect of gadolinium odd isotopes nuclear cross sections data on the multiplication factor of some LWR fuel assemblies. The results have shown the importance of gadolinium odd isotopes in the criticality evaluation, and they confirmed the need of a re-evaluation of the neutron capture cross sections by means of new experimental measurements to be carried out at the n_TOF facility at CERN.

  20. Nanosystem composed with MSNs, gadolinium, liposome and cytotoxic peptides for tumor theranostics.

    Science.gov (United States)

    Jin, Yaqing; Zhang, Nengpan; Li, Chunlin; Pu, Kefeng; Ding, Chen; Zhu, Yimin

    2017-03-01

    A dual-functional delivery system, based on mesoporous silica nanoparticles (MSNs) with the integration of Magnetic Resonance (MR) imaging and therapeutic peptide delivery, is reported in this paper. A lipid bilayer is attached onto the surface of the nanoparticles, following the doping of Gadolinium (Gd), a paramagnetic lanthanide ion. The liposome-coated GdMSNs exhibit improved colloidal stability, better biocompatibility and more efficient cellular uptake. The Gd renders the nano carrier a potential T1 contrast agent, confirmed by the MR imaging. A pro-apoptotic peptide, KLA (HGGKLAKLAKKLAKLAK), is encapsulated into the GdMSNs-LP and enters into the cells successfully to induce mitochondrial swelling and apoptosis, while it is nontoxic outside the cells. The synthesis procedure is convenient and free of toxic organic reagents. The nanosystem we construct may contribute to a promising theranostic platform for therapeutic peptide delivery in cancer treatment. Copyright © 2016 Elsevier B.V. All rights reserved.

  1. Excitation functions of radionuclides produced by proton induced reactions on gadolinium targets

    International Nuclear Information System (INIS)

    Challana, M.B.; Comsana, M.N.H.; Moawadb, G.S.; Abou-Zeid, M.A.

    2008-01-01

    Cross section study for proton induced reaction on natural Gadolinium targets were performed. Excitation functions for the reactions n atGd(p,x) 152m+g , 154m,154g Tb from threshold up to E p = 18 MeV have been measured employing the stacked foil activation technique, and using high resolution HPGe gamma spectrometry. Utilizing the simultaneous measurement of the excitation function of n atCu(p,x) 62 Zn, n atCu(p,x) 63 Zn, and n atCu(p,x) 65 Zn as monitor reactions. The theoretical analysis of the excitation functions has been done employing both ALICE-91 and EMPIRE-II codes. In general, theoretical calculations agree well with the experimental data. A significant contribution of pre-equilibrium component has been observed at these energies

  2. Radioluminescence and optical studies of gadolinium calcium phosphate oxyfluoride glasses doped with Sm3+

    Science.gov (United States)

    Meejitpaisan, P.; Insiripong, S.; Kedkaew, C.; Kim, H. J.; Kaewkhao, J.

    2017-08-01

    Sm3+-doped gadolinium calcium phosphate oxyfluoride glasses have been synthesized and investigated their optical, photo and radioluminescence properties. The glasses were prepared by melt quenching technique at 1400 °C. The characteristic absorption bands of Sm3+ ions originating from the 6H5/2 ground state and occurring absorbed photon in visible light (VIS) and near-infrared (NIR) region with clearly observed from absorption spectra. From the photoluminescence (PL), the glasses showed the emission at 561 (4G5/2→6H5/2), 598 (4G5/2→6H7/2), 644 (4G5/2→6H9/2) and 705 nm (4G5/2→6H11/2). The radioluminescence (RL), emission spectra were corresponding to those from PL measurements. From RL measurement, the integral scintillation efficiency of developed glass was determined at 43% when compared with BGO crystal.

  3. Gadolinium-, Calcium-, copper- and zirc complexes with riboflavin in acetone and acetonitrile

    International Nuclear Information System (INIS)

    Lugina, L.N.; Romanenko, V.I.; Davidenko, N.K.

    1983-01-01

    Using the methods of solubility and spectrophotometry, stability copstants Of complexes RFMSSUp(n+) (RF=riboflavin, Mnsup(n+)=Cdsup(3+), Ca 2+ , Cu 2+ and Zn 2+ ) in acetone and acetonitrile against the background of 1 mol/l LiClO 4 x3H 2 O have been determined. It was found that stability of copper and zinc complexes with riboflavin in acetone is higher than in acetonitrile, whereas the stability of gadolinium and calcium complexes, on the contrary, is higher in acetonitrile than in acetone. It is shown that the character of the absorption spectrum change of riboflavin in complexing with metal ions depends on the nature of coordinating cation

  4. Estimation of rare earth elements in gadolinium oxide by inductively coupled plasma mass spectrometry

    International Nuclear Information System (INIS)

    Kumar, Sanjukta A.; Venkataramani, B.; Kotekar, M.K.

    2007-01-01

    A method was developed for the direct determination of trace quantities of rare earth elements (REEs) in gadolinium oxide dissolved in nitric acid by inductively coupled plasma mass spectrometry. The matrix suppression effect of Gd on the ion peak signals of REEs impurities was effectively compensated with spiking In as an internal standard. The recoveries of spiked sample for REEs were found to be in the range of 91-109% by using the proposed method. The relative standard deviation varied between 1.5 to 6%. The methodology had been found to be suitable for the direct determination of trace REEs in Gd 2 O 3 and the results obtained from this method keep in good agreement with that acquired from inductively coupled plasma emission spectrometry. (author)

  5. Magnetic contribution to bulk modulus of elasticity of ferromagnetic metal (with gadolinium as an example)

    International Nuclear Information System (INIS)

    Bodryakov, V.Yu.; Povzner, A.A.

    2000-01-01

    Magnetic contribution into the bulk modulus of elasticity of ferromagnetic metal within the external magnetic fields depending on temperature was studied in terms of diamagnetic approach to the theory of phase transformations. The effect of magnetostriction on the Landau thermodynamic coefficients was determined to bring about that contribution. The value of the magnetic constituent of the bulk modulus of elasticity within B = 2.5 T magnetic field was calculated on the basis of data on ultrasonic measurements. The exact comparison with the experiment was conducted using data on the dependence of the bulk modulus of elasticity of gadolinium ferromagnetic phase on the external magnetic field as an example. Dissimilar nature of variation of the elastic modulus of bulk elasticity at transition of rare-earth magnetics and of 3d-metal ferromagnetic alloys to the ferromagnetic state was observed [ru

  6. Electrical properties of Hg3In2Te6 crystals doped with gadolinium

    International Nuclear Information System (INIS)

    Gorlej, P.M.; Grushka, O.G.; Frasunyak, V.M.

    2002-01-01

    The temperature dependences of electrical conductivity, the Hall coefficient, thermoelectric power, and the transversal Nernst-Ettingshausen effect of Hg 3 In 2 Te 6 crystals doped with gadolinium are investigated. It is shown that, under strong doping, the Fermi level descends and remains in the upper half of the energy gap in the impurity miscibility range, while the transparency of crystals is decreasing essentially. It causes the impurity self-compensation and preservation of bipolar conductivity typical of intrinsic semiconductors. In this case, the band gap, mobility ratio b=μ n /μp, and effective mass ratio m p /m n (n -electrons, p-holes) are reduced. Experimental results are explained by using the model of disordered semiconductor, in which the borders between forbidden and allowed energy bands are blurred and the transfer of electrons and holes occurs on the corresponding percolation levels because of the presence of the large density of localized states

  7. 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

    measurements. Six dispersants with different molecular weights and terminal groups were compared for their relative efficiency in dispersing the powders by viscosity measurements. A Rhodafac dispersant, a long chain polymer containing phosphoric acid terminal groups, was found to produce suspensions......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...... with the lowest viscosity at 1 wt.% dispersant and was chosen for subsequent suspension preparations. Increasing the surface area (from 7.0 to 35.5 m2/g) of the CGO powder lead to an increase in the viscosity of the suspension prepared with constant dispersant wt.%. The viscosity data obeyed the Herschel...

  8. Iron implantation in gadolinium gallium garnet studied by conversion-electron Moessbauer spectroscopy

    CERN Document Server

    Szucs, I; Fetzer, C; Langouche, G

    1998-01-01

    Gadolinium gallium garnet single crystals were implanted with doses of sup 5 sup 7 Fe ions in the range 8x10 sup 1 sup 5 - 6x10 sup 1 sup 6 atoms cm sup - sup 2. Depending on the dose, iron with Fe sup 2 sup + or Fe sup 3 sup + charge states was found to have formed after the implantation. After a subsequent annealing in air, the iron oxidized to Fe sup 3 sup +. The Moessbauer and channelling measurements showed lattice recrystallization taking place at 600 deg. C. After recrystallization, the iron was found to have substituted for gallium ions both at the octahedral and at the tetrahedral positions. The relative concentration of the two types of iron at the two sites shifted towards the equilibrium distribution upon high-temperature annealing. (author)

  9. General synthesis route to fabricate uniform upconversion luminescent gadolinium oxide hollow spheres.

    Science.gov (United States)

    Jia, Guang; Zhang, Cuimiao; Ding, Shiwen; Wang, Liyong

    2011-08-01

    Uniform upconversion luminescent gadolinium oxide hollow spheres were successfully synthesized via a homogeneous precipitation method with carbon spheres as template followed by a calcination process. During the annealing process, the carbon spheres template can be effectively removed and the amorphous precursor has converted to crystalline Gd2O3, which can be confirmed by the XRD and TG-DSC analysis. SEM and TEM images indicate that the Gd2O3 hollow spheres with diameters of 300-400 nm are uniform in size and distribution. The rare earth activator ions Ln3+-doped Gd2O3 hollow spheres exhibit intense upconversion luminescence with different colors under 980 nm light excitation, which may find potential applications in the fields such as drug delivery or biological labeling. Moreover, the upconversion luminescent mechanisms of the hollow spherical phosphors were investigated in detail.

  10. Synthesis of bulk-size transparent gadolinium oxide–polymer nanocomposites for gamma ray spectroscopy

    Science.gov (United States)

    Cai, Wen; Chen, Qi; Cherepy, Nerine; Dooraghi, Alex; Kishpaugh, David; Chatziioannou, Arion; Payne, Stephen; Xiang, Weidong

    2015-01-01

    Heavy element loaded polymer composites have long been proposed to detect high energy X- and γ-rays upon scintillation. The previously reported bulk composite scintillators have achieved limited success because of the diminished light output resulting from fluorescence quenching and opacity. We demonstrate the synthesis of a transparent nanocomposite comprising gadolinium oxide nanocrystals uniformly dispersed in bulk-size samples at a high loading content. The strategy to avoid luminescence quenching and opacity in the nanocomposite was successfully deployed, which led to the radioluminescence light yield of up to 27 000/MeV, about twice as much as standard commercial plastic scintillators. Nanocomposites monoliths (14 mm diameter by 3 mm thickness) with 31 wt% loading of nanocrystals generated a photoelectric peak for Cs-137 gamma (662 keV) with 11.4% energy resolution. PMID:26478816

  11. Modeling of gadolinium recovery from nitrate medium with 8-hydroxyquinoline by emulsion liquid membrane

    International Nuclear Information System (INIS)

    Hasan, M.A.; Aglan, R.F.; El-Reefy, S.A.

    2009-01-01

    The extraction equilibrium of Gd(III) from nitrate medium by 8-hydroxyquinoline (HOX) in toluene was studied. Liquid-liquid investigations were first carried out. Based on the equilibrium results, the extraction of Gd(III) from aqueous nitrate medium into an emulsion liquid membrane system (ELM) containing 8-hydroxyquinoline in toluene as extractant, HNO 3 as stripping solution, Span-80 as surfactant was studied. The stability of the prepared ELM was studied in terms of the degree of membrane breakage. The different parameters affecting the permeation of gadolinium (III) were also studied. A general permeation model for the recovery of Gd(III) by the selected membrane is presented. The internal mass transfer in the water in oil (W/O) emulsion drop, the external mass transfer around the drop, the rates of formation and decomposition of the complex at the external aqueous-organic interface were considered.

  12. Induction of skeletal abnormalities and autophagy in Paracentrotus lividus sea urchin embryos exposed to gadolinium.

    Science.gov (United States)

    Martino, Chiara; Chiarelli, Roberto; Bosco, Liana; Roccheri, Maria Carmela

    2017-09-01

    Gadolinium (Gd) concentration is constantly increasing in the aquatic environment, becoming an emergent environmental pollutant. We investigated the effects of Gd on Paracentrotus lividus sea urchin embryos, focusing on skeletogenesis and autophagy. We observed a delay of biomineral deposition at 24 hours post fertilization (hpf), and a strong impairment of skeleton growth at 48 hpf, frequently displayed by an asymmetrical pattern. Skeleton growth was found partially resumed in recovery experiments. The mesodermal cells designated to biomineralization were found correctly migrated at 24 hpf, but not at 48 hpf. Western blot analysis showed an increase of the LC3-II autophagic marker at 24 and 48 hpf. Confocal microscopy studies confirmed the increased number of autophagolysosomes and autophagosomes. Results show the hazard of Gd in the marine environment, indicating that Gd is able to affect different aspects of sea urchin development: morphogenesis, biomineralization, and stress response through autophagy. Copyright © 2017 Elsevier Ltd. All rights reserved.

  13. Gadolinium for neutron detection in current nuclear instrumentation research: A review

    Science.gov (United States)

    Dumazert, J.; Coulon, R.; Lecomte, Q.; Bertrand, G. H. V.; Hamel, M.

    2018-02-01

    Natural gadolinium displays a number of remarkable physical properties: it is a rare earth element, composed of seven stable or quasi-stable isotopes, with an exceptionally high magnetization and a Curie point near room temperature. Its use in the field of nuclear instrumentation historically relates to its efficiency as a neutron poison in power reactors. Gadolinium is indeed the naturally occurring element with the highest interaction probability with neutrons at thermal energy, shared between Gd-157 (15.65%, 254000 b cross section) and Gd-155 (14.8%, 60900 b) isotopes. Considering that neutron capture results in an isotopic change, followed by a radiative rearrangement of nuclear and atomic structures, Gd may be embodied not merely as a neutron poison but as a neutron converter into a prompt photon and an electron source term. Depending on the nature and energy of the reaction products (from a few-keV Auger electrons up to 8 MeV gamma rays) that the detector aims at isolating as an indirect neutron signature, a variety of sensor media and counting methods have been introduced during the last decades. This review first draws a theoretical description of the radiative cascade following Gd(n , γ) capture. The cascade may be subdivided into regions of interest, each corresponding to dedicated detection designs and optimizations whose current status is detailed. This inventory has allowed the authors to extract and benchmark key figures of merit for the definition of a detection scheme: neutron attenuation, neutron sensitivity (cps/nv), gamma rejection, neutron detection limit in a mixed field, intrinsic or extrinsic moderation, and transportability. On this basis, the authors have identified promising paths for Gd-based neutron detection in contemporary instrumentation.

  14. Critical phenomena and exchange interactions of an amorphous ferromagnet: gadolinium--gold

    International Nuclear Information System (INIS)

    Poon, S.J.; Durand, J.

    1976-07-01

    Magnetization was measured between 4 and 290 0 K in fields up to 70 kOe on liquid-quenched Gd 80 Au 20 amorphous alloys. The Curie temperature and critical exponents β, γ and delta are found to be 149.45 0 K, 0.439, 1.294 and 3.948 respectively. These values are compared with the Heisenberg and molecular field values. The data are fitted to an equation of state previously derived for second order phase transition in fluid systems. The results illustrate clearly a second order phase transition in the amorphous state. A discussion in terms of the Heisenberg model is presented. The effective magnetic moment in the paramagnetic state has a value of 9.37 μ/sub B/ per gadolinium atom. The saturation moment extrapolated to 0 0 K is 7.0 μ/sub B/ per gadolinium atom. The low temperature saturation magnetization observes the T/sup 3 / 2 / law from 0.13 T/sub c/ to 0.80 T/sub c/. The effective exchange integrals J/sub n/ determined from the Rushbrooke--Wood formula and spin-wave theory are found to be 2.28 and 1.34 0 K respectively. The differences in J/sub n/ and that between the effective moment and saturation moment are attributed to the nearest-neighbor antiferromagnetic couplings below T/sub c/. Possible effects of structural disorder on the magnetic properties of Gd in the amorphous state are discussed

  15. Gadolinium-enhanced dynamic MRI of the fractured carpal scaphoid: Preliminary results

    International Nuclear Information System (INIS)

    Munk, P.L.; Lee, M.J.; Janzen, D.; Connell, D.G.; Poon, P.Y.; Struk, D.; Munk, P.L.; Lee, M.; Janzen, D.L.; Connell, D.G.; Poon, P.Y.; Struk, D.; Munk, P.L.; Janzen, D.L.; Favero, K.J.; Poon, P.Y.; Vellet, A.D.; Logan, P.M.

    1998-01-01

    The aim of the present report was to evaluate the vascularity of fracture fragments of the fractured carpal scaphoid in the acute ( 3 months) phases using a gadolinium-enhanced dynamic MRI sequence. Eight patients with acute scaphoid fractures, six patients with chronic scaphoid fractures, and three control patients without fractures were evaluated using a T1-weighted fast spoiled gradient recalled acquisition (fSPGR) sequence with gadolinium-DTPA enhancement (0.1 mmol/kg bodyweight). Signal intensity over time plots were obtained using region of interest measurements from both fracture fragments. Enhancement factors (EF) were then calculated from the plots. No enhancement of the scaphoid was seen in control subjects (EF: distal scaphoid pole 1.04 + 0.01, proximal pole 1.07 + 0.08). In acute fracture patients, enhancement of the distal pole was greater than that of the proximal in all cases but one in which the two poles enhanced in a similar fashion (EF: distal 1.99 + 0.77, proximal 1.43 + 0.99). In chronic fracture patients the enhancement pattern was reversed, as the proximal pole enhanced to a greater degree than the distal with the exception of one case where both poles enhanced equally (EF: distal 1.74 + 0.52, proximal 2.64 + 0.50). Using a two-tailed non-parametric Mann-Whitney U-test, the difference in enhancement of the proximal poles between the acute and chronic groups was found to be highly significant (P < 0.003). Dynamic contrast- enhanced (fSPGR) MRI demonstrates significant differences in the enhancement patterns of the scaphoid when chronic and acute fractures are compared. Copyright (1998) Blackwell Science Pty Ltd

  16. 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.

  17. Gadolinium-enhanced excretory MR urography: comparison with MR urography using HASTE technique

    Energy Technology Data Exchange (ETDEWEB)

    Jin, Gong Yong; Lee, Jeong Min; Han, Young Min; Cheong, Gyung Ho; Oh, Hee Sul; Kim, Chong Soo; Park, Sung Kwang; Kim, Young Gon [Medical School, Chungbuk National University, Chongju (Korea, Republic of)

    2000-01-01

    To compare the feasibility of gadolinium-enhanced excretory MR urography (GEMRU) and conventional MR urography using the half-Fourier acquisition single-shot turbo spin-echo (HASTE) sequence in patients with hydronephrosis or non-visualized kidney. Fifteen patients with hydronephrosis or non-visualized kidney, as demonstrated by ultrasonography or intravenous urography, were enrolled in this study. Nine were men and six were women, and their age ranged from 18 to 77 (mean, 60.6) years. For all MR examinations, a 1.5T MR unit was employed. For breath-hold MR urography, the HASTE technique (MRU) was used, and reconstruction involved the use of a maximum intensity-projection (MIP) algorithm. For gadolinium-enhanced excretory MR urography, the fast low angle shot (FLASH) 3-D method was used and images were obtained at 5, 10, 20, and 30 minutes, and reconstruction again involved the use of MIP algorithm. In some cases, additional GEMRU was obtained 24 hour after contrast material injection, and an MIP algorithm was used for reconstruction. MRU and GEMRU were independently interpreted by two radiologists who for quantitative analysis compared SNR with CNR, and at each anatomic level qualitatively analyzed morphologic accuracy and diagnostic value of the lesions. In quantitative analysis, SNR and CNR differences between the two sequences at the renal pelvis and the level of the ureter were not significant (p greater than 0.05). In qualitative analysis, GEMRU was superior to MRU for the assessment of evaluated ureter at each level (p less than 0.05), anatomic anomaly and intrinsic tumor. Ureteral stones, however, were more easily diagnosed with MRU. For assessment of the ureter GEMRU is superior to MRU and has the advantage of evaluating renal function. We believe that for evaluation of the urinary tract, especially the distal ureter, GEMRU may be a valuable adjunct to routine MR urography. (author)

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

    Science.gov (United States)

    Gräfe, J L; McNeill, F E; Noseworthy, M D; Chettle, D R

    2014-09-01

    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.

  19. Gadolinium Retention, Brain T1 Hyperintensity, and Endogenous Metals: A Comparative Study of Macrocyclic Versus Linear Gadolinium Chelates in Renally Sensitized Rats.

    Science.gov (United States)

    Rasschaert, Marlène; Emerit, Andréa; Fretellier, Nathalie; Factor, Cécile; Robert, Philippe; Idée, Jean-Marc; Corot, Claire

    2018-01-12

    This preclinical study was designed to compare gadolinium (Gd) brain uptake after repeated injections of a macrocyclic Gd-based contrast agent (GBCA) (gadoterate meglumine) or 2 linear GBCAs (L-GBCAs) (gadobenate dimeglumine or gadodiamide) on a translational model of moderate renal impairment in rats. The study was carried out in subtotally nephrectomized rats. Animals received 4 intravenous injections per week of GBCA (gadoterate meglumine, gadobenate dimeglumine, or gadodiamide) for 5 weeks, resulting in a cumulative dose of 12 mmol/kg, followed by a 1-month injection-free period. T1 hyperintensity in the deep cerebellar nuclei (DCNs) was investigated, and brain structures were carefully dissected to determine elemental Gd, iron (Fe), copper (Cu), and zinc (Zn) distribution by mass spectrometry. Urinary excretion of endogenous metals was also investigated soon after GBCA administration and several days later in order to assess a potential transmetalation phenomenon. Unlike gadoterate, repeated injections of L-GBCAs gadobenate and gadodiamide both induced T1 hyperintensity in the DCNs. Fine dissection of cerebral and cerebellar structures demonstrated very low levels or absence of Gd after repeated injections of gadoterate, in contrast to the two L-GBCAs, for which the highest total Gd concentration was demonstrated in the DCNs (Gd concentration in DCNs after 4.5 weeks of injection-free period: 27.1 ± 6.5 nmol/g for gadodiamide [P download and share the work provided it is properly cited. The work cannot be changed in any way or used commercially without permission from the journal.

  20. 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)

    Runge, V.M.; Wells, J.W.; Williams, N.M.

    1995-01-01

    A new gadolinium (Gd) chelate with preferential hepatobiliary uptake, Gd Cy 2 DOTA, 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 Cy 2 DOTA. Two minutes after contrast, liver SI was 1.94 ± 0.05 with Gd Cy 2 DOTA 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 2 DOTA but not with Gd HP-DO3A. The maximum improvement in lesion conspicuity (rabbit) occurred 45 minutes after injection of Gd Cy 2 DOTA and 5 minutes after injection of Gd HP-DO3A. 22 refs., 12 figs

  1. 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

    threshold. Thereafter, the measured volumes remained practically unchanged. CONCLUSION: This study suggests that MR image acquisition in arthritic knee joints should be performed within the initial approximately 10 minutes after gadolinium contrast injection to achieve the most accurate distinction between...

  2. Prevention of isoflurane-induced preconditioning by 5-hydroxydecanoate and gadolinium: possible involvement of mitochondrial adenosine triphosphate-sensitive potassium and stretch-activated channels.

    Science.gov (United States)

    Piriou, V; Chiari, P; Knezynski, S; Bastien, O; Loufoua, J; Lehot, J J; Foëx, P; Annat, G; Ovize, M

    2000-09-01

    Both mitochondrial adenosine triphosphate-sensitive potassium (MKATP) channels (selectively blocked by 5-hydroxydecanoate) and stretch-activated channels (blocked by gadolinium) have been involved in the mechanism of ischemic preconditioning. Isoflurane can reproduce the protection afforded by ischemic preconditioning. We sought to determine whether isoflurane-induced preconditioning may involve MKATP and stretch-activated channels. Anesthetized open-chest rabbits underwent 30 min of coronary occlusion followed by 3 h of reperfusion. Before this, rabbits were randomized into one of six groups and underwent a treatment period consisting of either no intervention for 40 min (control group; n = 9) or 15 min of isoflurane inhalation (1.1% end tidal) followed by a 15-min washout period (isoflurane group; n = 9). The two groups received an intravenous bolus dose of either 5-hydroxydecanoate (5 mg/kg) or gadolinium (40 micromol/kg) before coronary occlusion and reperfusion (5-hydroxydecanoate, n = 9; gadolinium, n = 7). Two additional groups received 5-hydroxydecanoate or gadolinium before isoflurane exposure (isoflurane-5-hydroxydecanoate, n = 10; isoflurane-gadolinium, n = 8). Area at risk and infarct size were assessed by blue dye injection and tetrazolium chloride staining. Area at risk was comparable among the six groups (29 +/- 7, 30 +/- 5, 27 +/- 6, 35 +/- 7, 31 +/- 7, and 27 +/- 4% of the left ventricle in the control, isoflurane, isoflurane-5-hydroxydecanoate, 5-hydroxydecanoate, isoflurane-gadolinium, and gadolinium groups, respectively). Infarct size averaged 60 +/- 20% (SD) in untreated controls versus 54 +/- 27 and 65 +/- 15% of the risk zone in 5-hydroxydecanoate- and gadolinium-treated controls (P = nonsignificant). In contrast, infarct size in the isoflurane group was significantly reduced to 26 +/- 11% of the risk zone (P < 0.05 vs.control). Both 5-hydroxydecanoate and gadolinium prevented this attenuation: infarct size averaged 68 +/- 23 and 56 +/- 21

  3. Comparison between (99m)Tc-diphosphonate imaging and MRI with late gadolinium enhancement in evaluating cardiac involvement in patients with transthyretin familial amyloid polyneuropathy.

    Science.gov (United States)

    Minutoli, Fabio; Di Bella, Gianluca; Mazzeo, Anna; Donato, Rocco; Russo, Massimo; Scribano, Emanuele; Baldari, Sergio

    2013-03-01

    Cardiac involvement is not rare in systemic amyloidosis and is associated with poor prognosis. Both (99m)Tc-diphosphonate imaging and cardiac MRI with late gadolinium enhancement are considered valuable tools in revealing amyloid deposition in the myocardium; however, to our knowledge, no comparative study between the two techniques exists. We compared findings of these two techniques in patients with transthyretin-familial amyloid polyneuropathy (FAP). Eighteen patients with transthyretin-FAP underwent (99m)Tc-diphosphonate imaging and MRI with late gadolinium enhancement. Images were visually evaluated by independent readers to determine the presence of radiotracer accumulation or late gadolinium enhancement-positive areas at the level of cardiac chambers. Interobserver agreement ranged from moderate to very good for (99m)Tc-diphosphonate imaging findings and was very good for findings of MRI with late gadolinium enhancement. Left ventricle (LV) radiotracer uptake was found in 10 of 18 patients, whereas LV late gadolinium enhancement-positive areas were found in eight of 18 patients (χ(2) = 0.9; p = 0.343). One hundred fifty-nine LV segments showed (99m)Tc-diphosphonate accumulation, and 57 LV segments were late gadolinium enhancement positive (p < 0.0001). Radiotracer uptake was found in the right ventricle (RV) in eight patients and in both atria in five patients, whereas MRI showed that RV was involved in three patients and both atria in six patients; the differences were not statistically significant (RV, p = 0.07; atria, p = 1). Intermodality agreement between (99m)Tc-diphosphonate imaging and MRI ranged from fair to good. Our study shows that, although (99m)Tc-diphosphonate imaging and MRI with late gadolinium enhancement have similar capabilities to identify patients with myocardial amyloid deposition, cardiac amyloid infiltration burden can be significantly underestimated by visual analysis of MRI with late gadolinium enhancement compared with (99m

  4. Separation of carrier-free ytterbium and thulium produced in 80 MeV 12C6+ irradiated gadolinium foil target by liquid-liquid extraction with HDEHP

    International Nuclear Information System (INIS)

    Lahiri, Susanta; Nayak, Dalia; Ramaswami, A.; Manohor, S.B.

    2000-01-01

    Heavy ion activation of natural gadolinium foil with 80 MeV 12 C 6+ results in the formation of carrier-free ytterbium isotopes, 165,166,167 Yb and their corresponding decay products, 165,166,167 Tm, in the matrix. Carrier-free ytterbium and thulium isotopes have been separated quantitatively from the bulk target matrix gadolinium by employing di-(2-ethylhexyl)phosphoric acid (HDEHP) as a liquid cation exchanger

  5. Process-Structure-Property Relationships of Micron Thick Gadolinium Oxide Films Deposited by Reactive Electron Beam-Physical Vapor Deposition (EB-PVD)

    Science.gov (United States)

    2014-12-01

    group C2/m). The oxygen and gadolinium coordination for each phase is shown next to the unit cells . Red corresponds to oxygen atoms and gray...light). The light photon is subsequently converted to an electron ( photoelectric effect), which undergoes multiplication (photo- electrons) to...atoms per unit cell . The resulting coordination is six for gadolinium and four for oxygen. The monoclinic Gd2Ü3 structure shown in Figure 2.3b, space

  6. In vitro comparison of intracranial stent visibility using various concentrations of gadolinium contrast agent under 1.5 T and 3 T MR angiography.

    Science.gov (United States)

    Chiang, Chen-Hua; Tseng, Ying-Chi; Chen, Ai-Chi; Huang, Yen-Lin; Chen, David Yen-Ting; Chen, Chi-Jen; Lin, Yen-Kuang; Hsu, Hui-Ling

    2017-04-01

    MR angiography (MRA) is an increasingly used evaluation method following intracranial stenting. However, the various artifacts created by the stent limit this technique. The purpose of this study was to investigate the effects of various concentrations of gadolinium contrast agent on the visibility and signal characteristics of two stents using the a contrast enhanced MRA technique. Two intracranial stents (Enterprise and Helistent) were placed in polyvinyl chloride tubes as vascular phantoms. They were filled with six different doses of gadolinium contrast agent (1.0, 2.0, 4.0, 6.0, 8.0, and 10.0 mmol/L dimeglumine gadopentetate, respectively) and imaged using 3 T and 1.5 T MR systems. Relative in-stent signal (RIS) was calculated and artificial luminal narrowing (ALN) was obtained using pixel by pixel analysis. The Enterprise stent, performed in both 1.5 T and 3 T MR systems, showed mean RIS values much less than those for the Helistent for all different doses of gadolinium solution. Increased gadolinium concentration resulted in a gradual reduction in RIS values in the Enterprise group. Also, ALN in the Enterprise group showed no or little change with various gadolinium doses. The Enterprise stent demonstrated good luminal visibility regardless of gadolinium concentration. The relative in-stent signals were more predictable in the Enterprise stent with various doses of gadolinium. Therefore, the Enterprise stent has been shown to provide better in-stent visibility compared with the Helistent using various gadolinium doses. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

  7. Synthesis and characterization of nano structures of Silica SBA-16 containing Gadolinium-159 as potential nanoparticulated system for cancer therapy

    International Nuclear Information System (INIS)

    Oliveira, Andre Felipe de

    2013-01-01

    Cancer is a leading cause of death worldwide, and malignant neoplasms of the lung, stomach, liver, colon and breast in greater numbers. And recently observed in the literature a large number of reviews where new materials, especially nanoparticle, has been studied as drug carriers and radioisotopes applied to cancer treatment. How mesoporous materials based on silica, thanks to its huge surface area and biocompatibility, have been studied intensively providing broad applications in various areas, the use of nanostructured silica SBA-16 might be a carrier specific radioisotope accumulate in the cells malignant. Thus the aim of this study is to develop in vitro studies using SBA-16 can selectively concentrate in malignant cells therapeutic amounts of the radioisotope Gadolinium-159 escorting them to death. This work was performed orderly synthesis of mesoporous silica, SBA-16 and incorporating the complex Gd-DTPA-BMA, as well as chemical and structural characterization. The techniques used to analyze the occurrence of the incorporation of the gadolinium complex in the silica matrix were elemental analysis (CHN), atomic emission spectroscopy (ICP-AES), infrared spectroscopy (FTIR), nitrogen adsorption (BET), small-angle X-ray scattering (SAXS) and thermogravimetric analysis (TG). To analyze the morphology of pure silica used the scanning electron microscopy (SEM) and transmission electron microscopy (TEM). By photon correlation spectroscopy (PCS) it was possible to obtain a measure of mean particle size, the polydispersity index (PDI) of the silica SBA-16, and the zeta potential by laser Doppler anemometry (LDA). The results of incorporation analyzed by ICP-AES indicated that the material SBA-16 had a higher rate of incorporation of gadolinium (93%). The release kinetics in simulated body fluid, showed considerable stability and low release (1%). The mesoporous silica SBA-16 showed cell viability in direct contact with cell culture. Samples with gadolinium

  8. Quantifying Gamma/Neutron Discrimination in Gadolinium-Rich Real-Time Neutron Detection Materials and Devices

    Science.gov (United States)

    2016-05-01

    Quantifying Gamma/Neutron Discrimination in Gadolinium-Rich Real-time Neutron Detection Materials and Devices Distribution Statement A. Approved...rem [equivalent and effective dose] 1 × 10–2 joule per kilogram (J kg–1) [sievert (Sv)] * Specific details regarding the implementation of SI...crucial data were unsuccessful, as were attempts to clarify the analysis or pedigree of that data with the laboratories from which it came. It appeared as

  9. Distribution of late gadolinium enhancement in various types of cardiomyopathies: Significance in differential diagnosis, clinical features and prognosis

    OpenAIRE

    Satoh, Hiroshi; Sano, Makoto; Suwa, Kenichiro; Saitoh, Takeji; Nobuhara, Mamoru; Saotome, Masao; Urushida, Tsuyoshi; Katoh, Hideki; Hayashi, Hideharu

    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 suben...

  10. The histological basis of late gadolinium enhancement cardiovascular magnetic resonance in a patient with Anderson-Fabry disease

    OpenAIRE

    Moon, J. C.; Sheppard, M.; Reed, E.; Lee, P.; Elliott, P. M.; Pennell, D. J.

    2006-01-01

    Anderson-Fabry Disease (AFD) is a storage disease that mimics hypertrophic cardiomyopathy. Late gadolinium enhancement (LGE) by cardiovascular magnetic resonance occurs in approximately 50% of patients in the basal inferolateral LV wall, but how an intracellular storage disease causes focal LGE is unknown. We present a whole-heart histological validation that LGE is caused by focal myocardial collagen scarring. This scarring may be the substrate for electrical re-entry and sudden arrhythmic d...

  11. 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-enhance......-enhanced MR imaging combined with MR colonography could be used to differentiate a benign from a malignant obstructing colon tumor....

  12. 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.

  13. 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.

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

    Directory of Open Access Journals (Sweden)

    Scott D Swanson

    2008-06-01

    Full Text Available Scott D Swanson1, Jolanta F Kukowska-Latallo2, Anil K Patri5, Chunyan Chen6, Song Ge4, Zhengyi Cao3, Alina Kotlyar3, Andrea T East7, James R Baker31Department of Radiology, The University of Michigan Medical School, 2Department of Internal Medicine, The University of Michigan Medical School, 3Michigan Nanotechnology Institute for Medicine and Biological Sciences, The University of Michigan, 4Applied Physics, The University of Michigan, MD, USA; 5Present address: National Cancer Institute at Frederick (Contractor, MD, USA; 6Present address: Intel Corporation, Chandler, AZ, USA; 7Present address: Stritch School of Medicine, Chicago, ILL, USAAbstract: A target-specific MRI contrast agent for tumor cells expressing high affinity folate receptor was synthesized using generation five (G5 of polyamidoamine (PAMAM dendrimer. Surface modified dendrimer was functionalized for targeting with folic acid (FA and the remaining terminal primary amines of the dendrimer were conjugated with the bifunctional NCS-DOTA chelator that forms stable complexes with gadolinium (Gd III. Dendrimer-DOTA conjugates were then complexed with GdCl3, followed by ICP-OES as well as MRI measurement of their longitudinal relaxivity (T1 s−1 mM−1 of water. In xenograft tumors established in immunodeficient (SCID mice with KB human epithelial cancer cells expressing folate receptor (FAR, the 3D MRI results showed specific and statistically significant signal enhancement in tumors generated with targeted Gd(III-DOTA-G5-FA compared with signal generated by non-targeted Gd(III-DOTA-G5 contrast nanoparticle. The targeted dendrimer contrast nanoparticles infiltrated tumor and were retained in tumor cells up to 48 hours post-injection of targeted contrast nanoparticle. The presence of folic acid on the dendrimer resulted in specific delivery of the nanoparticle to tissues and xenograft tumor cells expressing folate receptor in vivo. We present the specificity of the dendrimer

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

    International Nuclear Information System (INIS)

    Zhang, Fan; Huang, Xinglu; Qian, Chunqi; Zhu, Lei; Hida, Naoki; Niu, Gang; Chen, Xiaoyuan

    2012-01-01

    Highlights: ► MR contrast agents exert influence on T 1 or T 2 relaxation time of the surrounding tissue. ► Combined use of iron oxide and Gd-DTPA can improve the sensitivity/specificity of lesion detection. ► Dual contrast MRI enhances the delineation of tumor borders and small lesions. ► The effect of DC-MRI can come from the high paramagnetic susceptibility of Gd 3+ . ► 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 1 ) or transverse (T 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 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 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 delineation of tumor borders and small lesions. Conclusions: DC-MRI will be helpful to improve diagnostic accuracy and decrease the threshold size for

  16. Optical properties of pure and Ce{sup 3+} doped gadolinium gallium garnet crystals and epitaxial layers

    Energy Technology Data Exchange (ETDEWEB)

    Syvorotka, I.I. [Scientific Research Company “Carat”, 202 Stryjska Street, Lviv 79031 (Ukraine); Sugak, D. [Scientific Research Company “Carat”, 202 Stryjska Street, Lviv 79031 (Ukraine); Lviv Polytechnic National University, 12, S. Bandera Street, Lviv, 79013 (Ukraine); Wierzbicka, A. [Institute of Physics, Polish Academy of Sciences, Al. Lotników 32/46, 02-668 Warsaw (Poland); Wittlin, A. [Institute of Physics, Polish Academy of Sciences, Al. Lotników 32/46, 02-668 Warsaw (Poland); Cardinal Stefan Wyszyński University in Warsaw, ul. Dewajtis 5, 01-815 Warsaw (Poland); Przybylińska, H. [Institute of Physics, Polish Academy of Sciences, Al. Lotników 32/46, 02-668 Warsaw (Poland); Barzowska, J. [Institute of Experimental Physics, Gdańsk University, ul. Wita Stwosza 57, Gdańsk (Poland); Barcz, A. [Institute of Physics, Polish Academy of Sciences, Al. Lotników 32/46, 02-668 Warsaw (Poland); Institute of Electron Technology, Al. Lotników 32/46, 02-668 Warsaw (Poland); Berkowski, M.; Domagała, J. [Institute of Physics, Polish Academy of Sciences, Al. Lotników 32/46, 02-668 Warsaw (Poland); Mahlik, S.; Grinberg, M. [Institute of Experimental Physics, Gdańsk University, ul. Wita Stwosza 57, Gdańsk (Poland); Ma, Chong-Geng [College of Mathematics and Physics, Chongqing University of Posts and Telecommunications, Chongqing 400065 (China); and others

    2015-08-15

    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 Ce{sup 3+} 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: • Ce{sup 3+} 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 Ce{sup 3+} by Pb ions from flux detected in GGG epitaxial layers. • X-ray diffraction allows measuring the amount of the rare-earth antisites in GGG.

  17. 3D gadolinium-enhanced MRI venography: Evaluation of central chest veins and impact on patient management

    International Nuclear Information System (INIS)

    Oxtoby, J.W.; Widjaja, E.; Gibson, K.M.; Uzoka, K.

    2001-01-01

    AIM: To assess the value of a simplified 3D gadolinium-enhanced magnetic resonance imaging (MRI) venography for central chest veins. MATERIALS AND METHODS: In this retrospective study of 24 patients, the MRI findings and medical records were reviewed to determine whether MRI results correlated with subsequent findings, and to determine the effect on clinical management. 3D steady state gradient-echo sequence, fast imaging with steady state precession (FISP), was used. We employed a simplified protocol not requiring bolus timing or subtraction to achieve rapid data acquisition and hence good compliance in this group of frail patients. Following intravenous administration of a bolus of gadolinium, two acquisitions were obtained in order to ensure adequate opacification of all veins. Individual partitions and maximum intensity projections were then analysed to determine whether the veins were patent, stenosed or occluded. RESULTS: The indications for MRI were to assess the patency of central veins for the purpose of cannulation or arteriovenous fistula formation in 17 patients. Out of the 12 patients who proceeded to an intervention, MRI venography successfully predicted an appropriate site in 10 patients. In the remaining seven patients, MRI venography was valuable in confirming or excluding the clinical suspicion of central venous thrombosis and directly influenced the management in five patients. CONCLUSION: 3D gadolinium-enhanced MRI venography is a valuable means of providing a global representation of the central venous system and guiding subsequent central venous cannulation. Oxtoby, J.W. et al. (2001)

  18. Gadolinium enhanced cardiovascular magnetic resonance in Anderson-Fabry disease. Evidence for a disease specific abnormality of the myocardial interstitium.

    Science.gov (United States)

    Moon, James C C; Sachdev, Bhavesh; Elkington, Andrew G; McKenna, William J; Mehta, Atul; Pennell, Dudley J; Leed, Philip J; Elliott, Perry M

    2003-12-01

    Anderson-Fabry Disease (AFD), an X-linked disorder of sphingolipid metabolism, is a cause of idiopathic left ventricular hypertrophy but the mechanism of hypertrophy is poorly understood. Gadolinium enhanced cardiovascular magnetic resonance can detect focal myocardial fibrosis. We hypothesised that hyperenhancement would be present in AFD. Eighteen males (mean 43+/-14 years) and eight female heterozygotes (mean 48+/-12 years) with AFD underwent cine and late gadolinium cardiovascular magnetic resonance. Nine male (50%) had myocardial hyperenhancement ranging from 3.4% to 20.6% (mean 7.7+/-5.7%) of total myocardium; in males, percentage hyperenhancement related to LV mass index (r=0.78, P=0.0002) but not to ejection fraction or left ventricular volumes. Lesser hyperenhancement was also found in four (50%) heterozygous females (mean 4.6%). In 12 (92%) patients with abnormal gadolinium uptake, hyperenhancement occurred in the basal infero-lateral wall where, unlike myocardial infarction, it was not sub-endocardial. In two male patients with severe LVH (left ventricular hypertrophy) and systolic impairment there was additional hyperenhancement in other myocardial segments. These observations suggests that myocardial fibrosis occurs in AFD and may contribute to the hypertrophy and the natural history of the disease.

  19. Gadolinium based contrast agents in current practice: Risks of accumulation and toxicity in patients with normal renal function

    Directory of Open Access Journals (Sweden)

    Anju Ranga

    2017-01-01

    Full Text Available Despite being decked as the most prized compounds in the nugget box of contrast agents for clinical radiologists, and carrying an indisputable tag of safety of the US Food and Drug Administration for close to three decades, all may not be seemingly well with the family of gadolinium compounds. If the first signs of violations of primum non nocere in relation to gadolinium-based contrast agents (GBCAs appeared in the millennium year with the first published report of skin fibrosis in patients with compromised renal function, the causal relationship between the development of nephrogenic systemic fibrosis (NSF and GBCAs, first proposed by two European groups in 2006, further precluded their use in renocompromised patients. The toxicity, pharmacokinetics, and pharmacodynamics of GBCAs, however, has come under hawk-eyed scrutiny with recent reports that gadolinium tends to deposit cumulatively in the brain of patients with normal hepatobiliary function and intact blood–brain barrier. While the jury on the long-term hazard significance of this critical scientific finding is still out, the use of GBCAs must be guided by due clinical diligence, avoidance of repeated doses, and preferring GBCAs with the best safety profiles.

  20. The use of gadolinium-carbon nanostructures to magnetically enhance stem cell retention for cellular cardiomyoplasty.

    Science.gov (United States)

    Tran, Lesa A; Hernández-Rivera, Mayra; Berlin, Ari N; Zheng, Yi; Sampaio, Luiz; Bové, Christina; Cabreira-Hansen, Maria da Graça; Willerson, James T; Perin, Emerson C; Wilson, Lon J

    2014-01-01

    In this work, the effectiveness of using Gadonanotubes (GNTs) with an external magnetic field to improve retention of transplanted adult mesenchymal stem cells (MSCs) during cellular cardiomyoplasty was evaluated. As a high-performance T1-weighted magnetic resonance imaging (MRI) cell tracking label, the GNTs are gadolinium-loaded carbon nanotube capsules that render MSCs magnetic when internalized. MSCs were internally labeled with either superparamagnetic GNTs or colloidal diamagnetic lutetium (Lu). In vitro cell rolling assays and ex vivo cardiac perfusion experiments qualitatively demonstrated increased magnetic-assisted retention of GNT-labeled MSCs. Subsequent in vivo epicardial cell injections were performed around a 1.3 T NdFeB ring magnet sutured onto the left ventricle of female juvenile pigs (n = 21). Cell dosage, magnet exposure time, and endpoints were varied to evaluate the safety and efficacy of the proposed therapy. Quantification of retained cells in collected tissues by elemental analysis (Gd or Lu) showed that the external magnet helped retain nearly three times more GNT-labeled MSCs than Lu-labeled cells. The sutured magnet was tolerated for up to 168 h; however, an inflammatory response to the magnet was noted after 48 h. These proof-of-concept studies support the feasibility and value of using GNTs as a magnetic nanoparticle facilitator to improve cell retention during cellular cardiomyoplasty. Copyright © 2013 Elsevier Ltd. All rights reserved.

  1. Usefulness of gadolinium in MRI evaluation of non surgically treated herniated disk.

    Science.gov (United States)

    Motta, E; Boniotti, V; Miserocchi, L; Caudana, R

    2005-01-01

    The rationale for the use of Gadolinium (Gd) in the MRI evaluation of non surgically treated herniated disk is based on the known presence of inflammatory granulation tissue and neoangiogenesis which plays an important role in both pain and the spontaneous resorption of the hernia. of this study was to determine the usefulness of Gd in MRI examination for detecting the inflammatory reaction around the discal hernia. Thirty-eight patients (mean age 45 years; range 20-70 years) with non surgically treated herniated disk were evaluated with MRI between January 2000 and July 2004. T2w-FAST-SE sagittal and T1w-SE transaxial and sagittal images were acquired before and after the administration of Gd. Twenty out of 22 patients with acute sciatic pain (symptoms =/discal hernia in the spinal canal. In the remaining 16 with chronic sciatic pain (symptoms > 6 months) the discal hernia did not show peri-hernial enhancement. In MRI evaluation of the herniated disk, peri-hernial enhancement is correlated with inflammatory reaction around the hernia which is associated with acute symptoms. The absence of peri-hernial enhancement in chronic herniated disk is due to the poorly vascular fibrotic tissue. Therefore, peri-hernial enhancement facilitates the differential diagnosis in uncertain cases and represents a reliable prognostic index of response to non-surgical therapy and of the possible spontaneous resorption of discal hernia.

  2. [Studies of three-dimensional cardiac late gadolinium enhancement MRI at 3.0 Tesla].

    Science.gov (United States)

    Ishimoto, Takeshi; Ishihara, Masaru; Ikeda, Takayuki; Kawakami, Momoe

    2008-12-20

    Cardiac late Gadolinium enhancement MR imaging has been shown to allow assessment of myocardial viability in patients with ischemic heart disease. The current standard approach is a 3D inversion recovery sequence at 1.5 Tesla. The aims of this study were to evaluate the technique feasibility and clinical utility of MR viability imaging at 3.0 Tesla in patients with myocardial infarction and cardiomyopathy. In phantom and volunteer studies, the inversion time required to suppress the signal of interests and tissues was prolonged at 3.0 Tesla. In the clinical study, the average inversion time to suppress the signal of myocardium at 3.0 Tesla with respect to MR viability imaging at 1.5 Tesla was at 15 min after the administration of contrast agent (304.0+/-29.2 at 3.0 Tesla vs. 283.9+/-20.9 at 1.5 Tesla). The contrast between infarction and viable myocardium was equal at both field strengths (4.06+/-1.30 at 3.0 Tesla vs. 4.42+/-1.85 at 1.5 Tesla). Even at this early stage, MR viability imaging at 3.0 Tesla provides high quality images in patients with myocardial infarction. The inversion time is significantly prolonged at 3.0 Tesla. The contrast between infarction and viable myocardium at 3.0 Tesla are equal to 1.5 Tesla. Further investigation is needed for this technical improvement, for clinical evaluation, and for limitations.

  3. Thermal shock behavior of toughened gadolinium zirconate/YSZ double-ceramic-layered thermal barrier coating

    International Nuclear Information System (INIS)

    Zhong, Xinghua; Zhao, Huayu; Zhou, Xiaming; Liu, Chenguang; Wang, Liang; Shao, Fang; Yang, Kai; Tao, Shunyan; Ding, Chuanxian

    2014-01-01

    Highlights: • Gd 2 Zr 2 O 7 /YSZ DCL thermal barrier coating was designed and fabricated. • The Gd 2 Zr 2 O 7 top ceramic layer was toughened by addition of nanostructured 3YSZ. • Remarkable improvement in thermal shock resistance of the DCL coating was achieved. - Abstract: Double-ceramic-layered (DCL) thermal barrier coating system comprising of toughened Gadolinium zirconate (Gd 2 Zr 2 O 7 , GZ) as the top ceramic layer and 4.5 mol% Y 2 O 3 partially-stabilized ZrO 2 (4.5YSZ) as the bottom ceramic layer was fabricated by plasma spraying and thermal shock behavior of the DCL coating was investigated. The GZ top ceramic layer was toughened by addition of nanostructured 3 mol% Y 2 O 3 partially-stabilized ZrO 2 (3YSZ) to improve fracture toughness of the matrix. The thermal shock resistance of the DCL coating was enhanced significantly compared to that of single-ceramic-layered (SCL) GZ-3YSZ composite coating, which is believed to be primarily attributed to the two factors: (i) the increase in fracture toughness of the top ceramic layer by incorporating nanostructured YSZ particles and (ii) the improvement in strain tolerance through the utilization of 4.5YSZ as the bottom ceramic layer. In addition, the failure mechanisms are mainly attributed to the still low fracture toughness of the top ceramic layer and oxidation of the bond-coat

  4. Gadolinium deposition in the brain: association with various GBCAs using a generalized additive model

    Energy Technology Data Exchange (ETDEWEB)

    Bae, Sohi; Lee, Ho-Joon; Han, Kyunghwa; Park, Yae-Won; Choi, Yoon Seong; Ahn, Sung Soo; Kim, Jinna; Lee, Seung-Koo [Yonsei University College of Medicine, Department of Radiology, Severance Hospital, Research Institute of Radiological Science, Seoul (Korea, Republic of)

    2017-08-15

    To determine the relationship between the number of administrations of various gadolinium-based contrast agents (GBCAs) and increased T1 signal intensity in the globus pallidus (GP) and dentate nucleus (DN). This retrospective study included 122 patients who underwent double-dose GBCA-enhanced magnetic resonance imaging. Two radiologists calculated GP-to-thalamus (TH) signal intensity ratio, DN-to-pons signal intensity ratio and relative change (R{sub change}) between the baseline and final examinations. Interobserver agreement was evaluated. The relationships between R{sub change} and several factors, including number of each GBCA administrations, were analysed using a generalized additive model. Six patients (4.9%) received linear GBCAs (mean 20.8 number of administration; range 15-30), 44 patients (36.1%) received macrocyclic GBCAs (mean 26.1; range 14-51) and 72 patients (59.0%) received both types of GBCAs (mean 31.5; range 12-65). Interobserver agreement was almost perfect (0.99; 95% CI: 0.99-0.99). R{sub change} (DN:pons) was associated with gadodiamide (p = 0.006) and gadopentetate dimeglumine (p < 0.001), but not with other GBCAs. R{sub change} (GP:TH) was not associated with GBCA administration. Previous administration of linear agents gadoiamide and gadopentetate dimeglumine is associated with increased T1 signal intensity in the DN, whereas macrocyclic GBCAs do not show an association. (orig.)

  5. Combustion of gadolinium and dysprosium chelates as a cellular integrity marker in MR imaging

    International Nuclear Information System (INIS)

    Ericsson, A.; Bach-Gansmo, T.; Niklasson, F.; Hemmingsson, A.

    1995-01-01

    A combination of gadolinium (Gd) and dysprosium (Dy) chelates was investigated as a potential marker of cell-membrane integrity by means of a double-contrast effect in MR imaging. Blood samples with varying hematocrit (Hct) levels containing intact or lysed cells were used as model systems. With intact cells, the agents were assumed to be distributed solely extracellularly and the highest Hct studied (69%) was assumed to mimic the ratio of extracellular to intracellular water in tissue. The combined effect on image intensity of Gd (in a concentration corresponding to 0.2 mmol/kg b.w. in humans) and Dy (0.6 mmol/kg b.w.) applied simultaneously was a marked difference in signal intensity between samples with intact and lysed cells in both the T1- and T2-weighted spin-echo images with a corresponding increase in the contrast-to-noise ratio. This was the result of a T1 reduction caused by Gd with a negligible Dy susceptibility effect in areas with lysed cells. On the other hand, the Dy susceptibility effect (i.e. reduced apparent T2) dominated in areas with intact cells. Thus, the combination of Gd and Dy may serve as a marker of cell-membrane integrity in MR examinations. (orig.)

  6. Automated left ventricle segmentation in late gadolinium-enhanced MRI for objective myocardial scar assessment.

    Science.gov (United States)

    Tao, Qian; Piers, Sebastiaan R D; Lamb, Hildo J; van der Geest, Rob J

    2015-08-01

    To develop and validate an objective and reproducible left ventricle (LV) segmentation method for late gadolinium enhanced (LGE) magnetic resonance imaging (MRI), which can facilitate accurate myocardial scar assessment. A cohort of 25 ischemic patients and 25 nonischemic patients were included. A four-step algorithm was proposed: first, the Cine-MRI and LGE-MRI volume were globally registered; second, the registered Cine-MRI contours were fitted to each LGE-MRI slice via the constructed contour image; third, the fitting was optimized in full LGE-MRI stack; finally, the contours were refined by taking into account patient-specific scar patterns. The automated LV segmentation results were compared with that of manual segmentation from two experienced observers. The accuracy of automated segmentation, expressed as the average contour distances to manual segmentation, was 0.82 ± 0.19 pixels, in the same order as interobserver difference between manual results (0.90 ± 0.26 pixels), but with lower variability (0.60 ± 0.37 pixels, P segmentation further demonstrated higher consistency than that of manual segmentation (Pearson correlation 0.97 vs. 0.84). An automated LV segmentation method for LGE-MRI was developed, providing high segmentation accuracy and lower interobserver variability compared to fully manual image analysis. The method facilitates objective assessment of myocardial scar. © 2014 Wiley Periodicals, Inc.

  7. Extent of Late Gadolinium Enhancement on Cardiac Magnetic Resonance Imaging in Japanese Hypertrophic Cardiomyopathy Patients.

    Science.gov (United States)

    Hen, Yasuki; Iguchi, Nobuo; Utanohara, Yuko; Takada, Kaori; Machida, Haruhiko; Takara, Ayako; Teraoka, Kunihiko; Sumiyoshi, Tetsuya; Takamisawa, Itaru; Takayama, Morimasa; Yoshikawa, Tsutomu

    2016-01-01

    In addition to the presence of late gadolinium enhancement (LGE) on cardiovascular magnetic resonance (CMR), the extent of LGE is considered clinically important in hypertrophic cardiomyopathy (HCM). We evaluated the extent of LGE on CMR in a large series of Japanese HCM patients. CMR was performed in 317 HCM patients (147 male). The extent of LGE was scored as the sum of LGE-positive segments in a left ventricle (LV) 17-segment model. LGE was present in 246 patients (77.6%). LGE was detected in 3.5±3.1 segments on average. When the patients were divided according to maximum wall thickness (mild, 65%), median LGE score increased as EF decreased (reduced, 7 vs. low-normal, 4 vs. normal, 2; P=0.000). On multivariate analysis, reduced EF (OR, 0.947, P=0.015), pressure gradient <30 mmHg (OR, 0.359, P=0.000) and increased maximum wall thickness (OR, 1.236, P=0.000) were independent factors associated with extensive LGE. Progression of LGE was related to increased wall thickness, decreased contractility, and reduced intraventricular pressure gradient.

  8. Acute myocarditis in a rat model: late gadolinium enhancement with histopathological correlation

    International Nuclear Information System (INIS)

    Korkusuz, Huedayi; Esters, Philip; Naguib, Nagy; Nour Eldin, N.E.; Lindemayr, Sebastian; Huebner, Frank; Koujan, Ahmed; Vogl, Thomas J.; Bug, Reinhold; Ackermann, Hanns

    2009-01-01

    The aim of the current study was to use an established animal model of autoimmune myocarditis and to judge the ability of cardiovascular MRI (CMR) in quantitatively measuring the extent of myocardial involvement compared with histopathological measurement of severity and extent. Experimental autoimmune myocarditis (EAM) was induced in 10 male Lewis rats. On day 21, all animals were investigated by CMR to measure the extent of late gadolinium enhancement (LGE). Subsequently, histopathological evaluation of the entire heart was performed. All animals of the experimental group fulfilled histopathological criteria of myocarditis, revealing necrosis in seven of eight cases. At reduced heart rate, area of LGE correlated highly with histologically proven area of myocarditis (r = 0.80-0.87, p < 0.05). LGE was mainly located in the anterior (range 50-62.5%) and lateral (range 62.5-75%) left ventricular wall and septum (range 25-50%) with a midwall to subepicardial accentuation. The LGE pattern found by CMR can be regarded as suggestive of EAM. With cellular necrosis being the main mechanism for LGE we were able to show high correlations between CMR examination results and histopathologically proven areas of myocarditis. Thus we think the current animal model can provide the opportunity for further fundamental research into myocarditis. (orig.)

  9. Gadolinium-doped ceria nanopowders synthesized by urea-based homogeneous co-precipitation (UBHP)

    Energy Technology Data Exchange (ETDEWEB)

    Accardo, G., E-mail: d16605@kist.re.kr [Fuel Cell Research Center, Korea Institute of Science and Technology, Hwarangno 14-gil, Seongbuk-gu, Seoul 136-791 (Korea, Republic of); Spiridigliozzi, L. [Department of Civil and Mechanical Engineering, INSTM Research Unit, University of Cassino and Southern Lazio, Via G. Di Biasio 43, 03043 Cassino, FR (Italy); Cioffi, R.; Ferone, C. [Department of Engineering, INSTM Research Unit, University Parthenope of Naples, Centro Direzionale, Is. C4, 80143 Napoli (Italy); Di Bartolomeo, E. [Department of Chemical Science and Technology, University of Rome “Tor Vergata”, Viale della Ricerca Scientifica, 00133 Rome (Italy); Yoon, Sung Pil [Fuel Cell Research Center, Korea Institute of Science and Technology, Hwarangno 14-gil, Seongbuk-gu, Seoul 136-791 (Korea, Republic of); Dell’Agli, G. [Department of Civil and Mechanical Engineering, INSTM Research Unit, University of Cassino and Southern Lazio, Via G. Di Biasio 43, 03043 Cassino, FR (Italy)

    2017-02-01

    Gadolinium (10%)-doped ceria was successfully synthesized by using an urea-based co-precipitation method (UBHP). A single fluorite phase was obtained after a low temperature (400 °C) calcination treatment. The resulting powders showed grains of nanometric size with some agglomerations and an overall good sinterability. Pellets were sintered at 1300 and 1500 °C for 3 h. The ionic conductivity was measured by electrochemical impedance spectroscopy measurements and a correlation between electrical properties and microstructure was revealed. The promising conductivity values showed that the synthesized powders are suitable for intermediate temperature solid oxide fuel cells (IT-SOFCs) applications. - Highlights: • Urea-based homogeneous co-precipitation is applied to synthesize nanocrystalline GDC. • Dense GDC samples at different sintering temperatures were characterized. • SEM and TEM revealed a well define microstructure and controlled composition. • Correlation between electrochemical properties by EIS and microstructure was discussed. • UBHP method can be used to prepare high performance GDC electrolytes.

  10. Influence of geochemical parameters on the sorption and desorption behaviour of europium and gadolinium onto kaolinite.

    Science.gov (United States)

    Kautenburger, Ralf; Beck, Horst P

    2010-06-01

    In this study we investigated the sorption and desorption behaviour of europium and gadolinium (homologues of the actinides americium and curium) onto the clay mineral kaolinite KGa-1b. In the model system metal/kaolinite, sorption isotherms and pH-edges were determined in different batch experiments. Calcium and magnesium as competing cations were used to simulate the influence of water hardness on the sorption and desorption processes. After centrifugation, the free metal ions in the supernatant solution were analysed by ICP-MS. With increasing lanthanide concentration, especially the relative desorption of these metals from kaolinite rises significantly before the cation exchange capacity (CEC) of 0.94 meq per 100 g is reached. This indicates that low lanthanide concentrations will result in a relatively lower metal migration due to sorption reactions at higher active sites in comparison with higher lanthanide concentrations. The K(d)-values and sorption isotherms of Eu(iii) and Gd(iii) were determined at pH 5.0 (+/-0.02) and analysed with Freundlich and Langmuir sorption models. The experimental data can best be fitted by Langmuir sorption isotherm. The pH-value has only a minor influence on the sorption onto kaolinite. Only at low pH-values (kaolinite to the aquifer.

  11. Asymmetric inhibition of spicule formation in sea urchin embryos with low concentrations of gadolinium ion.

    Science.gov (United States)

    Saitoh, Motoshi; Kuroda, Ritsu; Muranaka, Yoshinori; Uto, Norihiko; Murai, Junko; Kuroda, Hideyo

    2010-12-01

    As gastrulation proceeds during sea urchin embryogenesis, primary mesenchyme cells (PMCs) fuse to form syncytial cables, within which calcium is deposited as CaCO₃, and a pair of spicules is formed. Earlier studies suggested that calcium, previously sequestered by primary mesenchyme cells, is secreted and incorporated into growing spicules. We examined the effects of gadolinium ion (Gd(3+)), a Ca(2+) channel blocker, on spicule formation. Gd(3+) did not lead to a retardation of embryogenesis prior to the initiation of gastrulation and did not inhibit the ingression of PMCs from the blastula wall or their migration along the inner blastocoel surface. However, when embryos were raised in seawater containing submicromolar to a few micromolar Gd(3+), of which levels are considered to be insufficient to block Ca(2+) channels, a pair of triradiate spicules was formed asymmetrically. At 1-3 μmol/L Gd(3+), many embryos formed only one spicule on either the left or right side, or embryos formed a very small second spicule. Induction of the spicule abnormality required the presence of Gd(3+) specifically during late blastula stage prior to spicule formation. An accumulation or adsorption of Gd(3+) was not detected anywhere in the embryos by X-ray microanalysis, which suggests that Ca(2+) channels were not inhibited. These results suggest that Gd(3+) exerts an inhibitory effect on spicule formation through a mechanism that does not involve inhibition of Ca(2+) channels. © 2010 The Authors. Journal compilation © 2010 Japanese Society of Developmental Biologists.

  12. Random lasing in Nd{sup 3+} doped potassium gadolinium tungstate crystal powder

    Energy Technology Data Exchange (ETDEWEB)

    Moura, André L., E-mail: andre.moura@fis.ufal.br [Grupo de Física da Matéria Condensada, Núcleo de Ciências Exatas – NCEx, Campus Arapiraca, Universidade Federal de Alagoas, 57309-005, Arapiraca, AL (Brazil); Departamento de Física, Universidade Federal de Pernambuco, 50670-901 Recife, PE (Brazil); Fewo, Serge I. [Departamento de Física, Universidade Federal de Pernambuco, 50670-901 Recife, PE (Brazil); Laboratory of Mechanics, Department of Physics, University of Yaoundé I, Yaoundé (Cameroon); Carvalho, Mariana T.; Gomes, Anderson S. L.; Araújo, Cid B. de [Departamento de Física, Universidade Federal de Pernambuco, 50670-901 Recife, PE (Brazil); Kuzmin, Andrey N.; Prasad, Paras N. [Institute for Lasers, Photonics and Biophotonics, The State University of New York, Buffalo, New York 14260-3000 (United States)

    2015-02-28

    Random laser (RL) emission in Nd{sup 3+} doped potassium gadolinium tungstate—KGd(WO{sub 4}){sub 2}:Nd{sup 3+}—crystal powder is demonstrated. The powder was excited at 813 nm in resonance with the Nd{sup 3+} transition {sup 4}I{sub 9/2}→{sup 4}F{sub 5/2}. RL emission at 1067 nm due to the {sup 4}F{sub 3/2}→{sup 4}I{sub 11/2} transition was observed and characterized. An intensity threshold dependent on the laser spot area and bandwidth narrowing from ≈2.20 nm to ≈0.40 nm were observed and measured. For a beam spot area of 0.4 mm{sup 2}, a RL threshold of 6.5 mJ/mm{sup 2} (90 MW/cm{sup 2}) was determined. For excitation intensity smaller than the RL threshold, only spontaneous emission from level {sup 4}F{sub 3/2} with decay time in the tens microsecond range was observed, but for excitation above the RL threshold, significant shortening of excited level lifetime, characteristic of a stimulated process was found. The overall characteristics measured show that KGd(WO{sub 4}){sub 2}:Nd{sup 3+} is an efficient material for operation of solid state RLs in the near-infrared.

  13. Acute Respiratory Distress Syndrome after the Use of Gadolinium Contrast Media.

    Science.gov (United States)

    Park, Jihye; Byun, Il Hwan; Park, Kyung Hee; Lee, Jae-Hyun; Nam, Eun Ji; Park, Jung-Won

    2015-07-01

    Acute respiratory distress syndrome (ARDS) is a medical emergency that threatens life. To this day, ARDS is very rarely reported by iodine contrast media, and there is no reported case of ARDS induced by gadolinium contrast media. Here, we present a case with ARDS after the use of gadobutrol (Gadovist) as a magnetic resonance imaging (MRI) contrast medium. A 26 years old female without any medical history, including allergic diseases and without current use of drugs, visited the emergency room for abdominal pain. Her abdominopelvic computed tomography with iodine contrast media showed a right ovarian cyst and possible infective colitis. Eighty-three hours later, she underwent pelvis MRI after injection of 7.5 mL (0.1 mL/kg body weight) of gadobutrol (Gadovist) to evaluate the ovarian cyst. She soon presented respiratory difficulty, edema of the lips, nausea, and vomiting, and we could hear wheezing upon auscultation. She was treated with dexamethasone, epinephrine, and norepinephrine. Her chest X-ray showed bilateral central bat-wing consolidative appearance. Managed with mechanical ventilation, she was extubated 3 days later and discharged without complications.

  14. Influence of acquired obesity on coronary vessel wall late gadolinium enhancement in discordant monozygote twins

    Energy Technology Data Exchange (ETDEWEB)

    Makowski, Marcus R. [King' s College London, Division of Imaging Sciences and Biomedical Engineering, London (United Kingdom); Wellcome Trust and EPSRC Medical Engineering Centre, London (United Kingdom); King' s College London, BHF Centre of Excellence, London (United Kingdom); King' s College London, NIHR Biomedical Research Centre, London (United Kingdom); Charite-Universitaetsmedizin, Department of Radiology, Berlin (Germany); Jansen, Christian H.P. [King' s College London, Division of Imaging Sciences and Biomedical Engineering, London (United Kingdom); Ebersberger, Ullrich; Spector, Tim D. [Heart Center Munich-Bogenhausen, Department of Cardiology and Intensive Care Medicine, Munich (Germany); Schaeffter, Tobias; Razavi, Reza [King' s College London, Division of Imaging Sciences and Biomedical Engineering, London (United Kingdom); Wellcome Trust and EPSRC Medical Engineering Centre, London (United Kingdom); King' s College London, BHF Centre of Excellence, London (United Kingdom); King' s College London, NIHR Biomedical Research Centre, London (United Kingdom); Mangino, Massimo [King' s College London, Department of Twin Research and Genetic Epidemiology, London (United Kingdom); National Institute for Health Research (NIHR) Biomedical Research Centre at Guy' s and St. Thomas' Foundation Trust, London (United Kingdom); Botnar, Rene M. [King' s College London, Division of Imaging Sciences and Biomedical Engineering, London (United Kingdom); Wellcome Trust and EPSRC Medical Engineering Centre, London (United Kingdom); King' s College London, BHF Centre of Excellence, London (United Kingdom); King' s College London, NIHR Biomedical Research Centre, London (United Kingdom); Greil, Gerald F. [King' s College London, Division of Imaging Sciences and Biomedical Engineering, London (United Kingdom); Wellcome Trust and EPSRC Medical Engineering Centre, London (United Kingdom); King' s College London, BHF Centre of Excellence, London (United Kingdom); King' s College London, NIHR Biomedical Research Centre, London (United Kingdom)

    2017-11-15

    The aim of this study was to investigate the impact of BMI on late gadolinium enhancement (LGE) of the coronary artery wall in identical monozygous twins discordant for BMI. Coronary LGE represents a useful parameter for the detection and quantification of atherosclerotic coronary vessel wall disease. Thirteen monozygote female twin pairs (n = 26) with significantly different BMIs (>1.6 kg/m2) were recruited out of >10,000 twin pairs (TwinsUK Registry). A coronary 3D-T2prep-TFE MR angiogram and 3D-IR-TFE vessel wall scan were performed prior to and following the administration of 0.2 mmol/kg of Gd-DTPA on a 1.5 T MR scanner. The number of enhancing coronary segments and contrast to noise ratios (CNRs) of the coronary wall were quantified. An increase in BMI was associated with an increased number of enhancing coronary segments (5.3 ± 1.5 vs. 3.5 ± 1.6, p < 0.0001) and increased coronary wall enhancement (6.1 ± 1.1 vs. 4.8 ± 0.9, p = 0.0027) compared to matched twins with lower BMI. This study in monozygous twins indicates that acquired factors predisposing to obesity, including lifestyle and environmental factors, result in increased LGE of the coronary arteries, potentially reflecting an increase in coronary atherosclerosis in this female study population. (orig.)

  15. Computational assessment of improved cell-kill by gadolinium-supplemented boron neutron capture therapy

    Science.gov (United States)

    Culbertson, Christopher N.; Jevremovic, Tatjana

    2003-12-01

    Potential improvement in neutron capture therapy (NCT) by utilizing both 157Gd and 10B is assessed considering two parameters calculated in transport models in MCNP4B, the dose to quiescent cells and the therapeutic ratio. Improved sterilization of quiescent or more generally non-uptaking cells is demonstrated with the addition of 157Gd to conventional 10B loading. The improved dose delivery to non-uptaking cells from concurrent administration of 157Gd and 10B is weighed against a second index, degradation in the therapeutic ratio resulting from the longer interaction lengths of the 157Gd capture products. Optimal concentrations of 157Gd are determined considering varying assumptions for boron uptake levels and selectivity. By analysing the dosimetry results of varying 157Gd concentrations applied concurrently with BPA-delivered boron in NCT, this work seeks to determine a balance between the high tumour-specific dose provided by BPA and the high dose to quiescent cells provided by potential gadolinium agents. Depending upon the assumptions for drug specificity, tumour size and fraction of quiescent cells, NCT with low levels of 157Gd (125 µg g-1) supplementing 10B loadings was shown to be superior to treatments applying 10B alone.

  16. Quantitative and qualitative temporal evolution of gadolinium enhancement of spinal lesion

    International Nuclear Information System (INIS)

    Sze, G.; Krol, G.

    1988-01-01

    Seventy gadolinium-enhanced studies of spinal lesions were reviewed, and 34 were selected for analysis of the temporal quantitative and qualitative aspects of enhancement. Thirteen patients had intradural extramedullary lesions, eight had intramedullary lesions, and 13 had extradural lesions. Data analysis was conducted by measuring intensities of normal and pathologic tissues on short repetition-time (TR) scans. The evolution of enhancement of spinal tumors was found to differ, depending on which compartment the tumor was located. Intradural extramedullary nodules showed their most prominent enhancement on immediate postcontrast scans. Extradural lesions varied in behavior. Some demonstrated an increase in enhancement, while others showed a decrease. Intramedullary tumors usually showed an increase in enhancement on delayed scans. In most cases, however, the quantitative increase was minor. The exception occurred in a case of necrotic cord glioma. Immediate postcontrast short-TR scans will nearly always be sufficient for the evaluation of suspected spinal lesions. Only the very occasional case may benefit from delayed scans

  17. Gadolinium-enhanced dynamic magnetic resonance imaging with endorectal coil for local staging of rectal cancer

    International Nuclear Information System (INIS)

    Tamakawa, Mitsuharu; Kawaai, Yuriko; Shirase, Ryuji

    2010-01-01

    The aim of this study was to evaluate the accuracy of dynamic gadolinium (Gd)-enhanced magnetic resonance imaging (MRI) with endorectal coil for assessing tumor invasion based on simple classification criteria. A total of 58 patients with operable primary rectal cancer underwent preoperative MRI. An enhancement pattern in Gd-enhanced dynamic MRI with regard to tumor penetration was clarified. Retrospectively, two observers independently scored T2-weighted MRI and T2-weighted MRI combined with Gd-enhanced dynamic MRI for tumor penetration using the following criteria: With Gd-enhanced dynamic MRI, T1 tumors showed an early enhanced line around the tumor as rim enhancement; T2 tumors appeared as black lines or double layers, as the muscularis propria kept its integrity; T3 tumors showed partial discontinuity of the muscularis propria as a dotted line and a perforated area as an interrupted line. A confidence level scoring system was used, and receiver operating characteristic curves were generated. There were no significant differences at the T1 stage. There were significant differences for observer 1 (P=0.001 for observer 1) at the T2 stage. There were significant differences for both observers (P=0.001 for observer 1 and P=0.005 for observer 2) at the T3 stage. Our criteria for Gd-enhanced dynamic MRI were effective for T3 stage tumors. (author)

  18. Sequential gadolinium-DTPA enhanced MRI studies in neuro-Behcet's disease

    International Nuclear Information System (INIS)

    Kazui, S.; Naritomi, H.; Ogawa, M.; Sawada, T.; Imakita, S.; Yamada, N.

    1991-01-01

    Sequential gadolinium-DTPA (Gd-DTPA) enhanced MR images were obtained before and after steroid therapy in a case of neuro-Behcet's disease. Multiple scattered lesions, which could not be detected on pre- and post-contrast CT, were demonstrated mainly in the white matter of the pons and/or the cerebrum with both T1- and T2-weighted images. Some of these lesions, however, were not enhanced at all by infusion of Gd-DTPA. The Gd-DTPA infusion study demonstrated marked enhancement in the white matter of the pons and cerebrum. Some lesions not seen with T2-weighted images were also strongly enhanced by Gd-DTPA infusion at the acute stage. After steroid therapy, the symptoms and abnormal laboratory findings were resolved. The pontine and cerebral lesions on plain MR images remained unchanged even after resolution of the symptoms, suggesting that they were inactive old foci. On the other hand, the lesions detected in the enhancement study before steroid therapy disappeared with the repeat Gd-DTPA enhanced MR images which were performed after resolution of the symptoms. Some active inflammatory lesions in neuro-Behcet's disease may be demonstrated only on Gd-DTPA enhanced MR images. Gd-DTPA enhanced MR imaging appears to be potentially useful for detecting active inflammatory lesions in neuro-Behcet's disease and for evaluating the efficacy of treatment. (orig.)

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

    International Nuclear Information System (INIS)

    Hazarika, Samiran; Paul, Nibedita; Mohanta, Dambarudhar

    2014-01-01

    An inexpensive fabrication route and growth mechanism is being reported for obtaining quality gadolinium oxide ( Gd 2 O 3 ) 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 (∼7 nm) was much smaller than the rods prepared at pH = 10.8 (∼19 nm). 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 F g + A g modes of cubic phase of Gd 2 O 3 nanorods, apart from other independent modes. Furthermore, M ∼ H 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 Gd 2 O 3 nanorods have immense potential in the production of advanced contrast agents, smart drives and also in making novel ferrofluids of technological relevance. (author)

  20. Absence of magnetic ordering and field-induced phase diagram in the gadolinium aluminum garnet

    Science.gov (United States)

    Florea, O.; Lhotel, E.; Jacobsen, H.; Knee, C. S.; Deen, P. P.

    2017-12-01

    The robustness of spin liquids with respect to small perturbations, and the way magnetic frustration can be lifted by slight changes in the balance between competing magnetic interactions, remains a rich and open issue. We address this question through the study of the gadolinium aluminum garnet Gd3Al5O12 , a related compound to the extensively studied Gd3Ga5O12 . We report on its magnetic properties at very low temperatures. We show that despite a freezing at about 300 mK, no magnetic transition is observed, suggesting the presence of a spin-liquid state down to the lowest temperatures, similarly to Gd3Ga5O12 , in spite of a larger ratio between exchange and dipolar interactions. Finally, the phase diagram as a function of field and temperature is strongly reminiscent of the one reported in Gd3Ga5O12 . This study reveals the robust nature of the spin-liquid phase for Gd ions on the garnet lattice, in stark contrast to Gd ions on the pyrochlore lattice for which a slight perturbation drives the compound into a range of magnetically ordered states.

  1. Modelling of the Gadolinium Fuel Test IFA-681 using the BISON Code

    Energy Technology Data Exchange (ETDEWEB)

    Pastore, Giovanni [Idaho National Laboratory; Hales, Jason Dean [Idaho National Laboratory; Novascone, Stephen Rhead [Idaho National Laboratory; Spencer, Benjamin Whiting [Idaho National Laboratory; Williamson, Richard L [Idaho National Laboratory

    2016-05-01

    In this work, application of Idaho National Laboratory’s fuel performance code BISON to modelling of fuel rods from the Halden IFA-681 gadolinium fuel test is presented. First, an overview is given of BISON models, focusing on UO2/UO2-Gd2O3 fuel and Zircaloy cladding. Then, BISON analyses of selected fuel rods from the IFA-681 test are performed. For the first time in a BISON application to integral fuel rod simulations, the analysis is informed by detailed neutronics calculations in order to accurately capture the radial power profile throughout the fuel, which is strongly affected by the complex evolution of absorber Gd isotopes. In particular, radial power profiles calculated at IFE–Halden Reactor Project with the HELIOS code are used. The work has been carried out in the frame of the collaboration between Idaho National Laboratory and Halden Reactor Project. Some slide have been added as an Appendix to present the newly developed PolyPole-1 algorithm for modeling of intra-granular fission gas release.

  2. Gadolinium-DTPA enhancement of symptomatic nerve roots in MRI of the lumbar spine

    Energy Technology Data Exchange (ETDEWEB)

    Tyrrell, P.N.M.; Cassar-Pullicino, V.N.; McCall, I.W. [Department of Diagnostic Imaging, The Institute of Orthopaedics, The Robert Jones and Agnes Hunt Orthopaedic and District Hospital NHS Trust, Oswestry, Shropshire SY10 7AG (United Kingdom)

    1998-02-01

    Disc prolapse presenting with sciatica may be associated with enhancement of the symptomatic nerve root following magnetic resonance imaging (MRI) with intravenous gadolinium (Gd)-DTPA. Previous studies have shown, however, that this does not occur in all cases. The aim of this study was to assess the incidence of nerve root enhancement in patients with sciatica and disc prolapse and to try to identify any specific features that might be associated with the phenomenon. A total of 227 patients presenting with low back pain and/or sciatica underwent a MRI study of the lumbar spine with intravenous contrast enhancement. Nineteen of 81 (23.5 %) patients with disc prolapse demonstrated nerve root enhancement. Nerve root enhancement had a highly significant association with sequestrated disc lesions (13/19, 68 %; P < 0.0005), and was primarily seen in the symptomatic ipsilateral nerve root (16/19, 84 %). The sensitivity of nerve root enhancement associated with disc prolapse was 23.5 % with a specificity of 95.9 %, a positive predictive value of 76 % and a negative predictive value of 69.3 %. Nerve root enhancement may be indicative of the symptomatic level but its poor sensitivity negates the routine use of Gd-DTPA in MRI for sciatica. (orig.) With 4 figs., 1 tab., 37 refs.

  3. Influence of acquired obesity on coronary vessel wall late gadolinium enhancement in discordant monozygote twins

    International Nuclear Information System (INIS)

    Makowski, Marcus R.; Jansen, Christian H.P.; Ebersberger, Ullrich; Spector, Tim D.; Schaeffter, Tobias; Razavi, Reza; Mangino, Massimo; Botnar, Rene M.; Greil, Gerald F.

    2017-01-01

    The aim of this study was to investigate the impact of BMI on late gadolinium enhancement (LGE) of the coronary artery wall in identical monozygous twins discordant for BMI. Coronary LGE represents a useful parameter for the detection and quantification of atherosclerotic coronary vessel wall disease. Thirteen monozygote female twin pairs (n = 26) with significantly different BMIs (>1.6 kg/m2) were recruited out of >10,000 twin pairs (TwinsUK Registry). A coronary 3D-T2prep-TFE MR angiogram and 3D-IR-TFE vessel wall scan were performed prior to and following the administration of 0.2 mmol/kg of Gd-DTPA on a 1.5 T MR scanner. The number of enhancing coronary segments and contrast to noise ratios (CNRs) of the coronary wall were quantified. An increase in BMI was associated with an increased number of enhancing coronary segments (5.3 ± 1.5 vs. 3.5 ± 1.6, p < 0.0001) and increased coronary wall enhancement (6.1 ± 1.1 vs. 4.8 ± 0.9, p = 0.0027) compared to matched twins with lower BMI. This study in monozygous twins indicates that acquired factors predisposing to obesity, including lifestyle and environmental factors, result in increased LGE of the coronary arteries, potentially reflecting an increase in coronary atherosclerosis in this female study population. (orig.)

  4. 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.

  5. The influence of gadolinium and yttrium on biomass production and nutrient balance of maize plants

    International Nuclear Information System (INIS)

    Saatz, Jessica; Vetterlein, Doris; Mattusch, Jürgen; Otto, Matthias; Daus, Birgit

    2015-01-01

    Rare earth elements (REE) are expected to become pollutants by enriching in the environment due to their wide applications nowadays. The uptake and distribution of gadolinium and yttrium and its influence on biomass production and nutrient balance was investigated in hydroponic solution experiments with maize plants using increasing application doses of 0.1, 1 and 10 mg L −1 . It could be shown that concentrations of up to 1 mg L −1 of Gd and Y did not reduce or enhance the plant growth or alter the nutrient balance. 10 mg L −1  Gd or Y resulted in REE concentrations of up to 1.2 weight-% in the roots and severe phosphate deficiency symptoms. Transfer rates showed that there was only little transport of Gd and Y from roots to shoots. Significant correlations were found between the concentration of Gd and Y in the nutrient solution and the root tissue concentration of Ca, Mg and P. - Highlights: • Roots accumulate REE in very high concentrations. • Transfer factors from root to shoot tissue are very low, with HREE higher than MREE. • The nutrient balance of the plant is severely influenced by REE addition. • Phosphate deficiency appears at high concentrations of REE addition. - The addition of the rare-earth elements Gd and Y results in less Ca and Mg uptake and phosphate deficiency in maize plants grown in hydroponics

  6. Histology and Gadolinium Distribution in the Rodent Brain After the Administration of Cumulative High Doses of Linear and Macrocyclic Gadolinium-Based Contrast Agents

    Science.gov (United States)

    Lohrke, Jessica; Frisk, Anna-Lena; Frenzel, Thomas; Schöckel, Laura; Rosenbruch, Martin; Jost, Gregor; Lenhard, Diana Constanze; Sieber, Martin A.; Nischwitz, Volker; Küppers, Astrid; Pietsch, Hubertus

    2017-01-01

    Objectives Retrospective studies in patients with primary brain tumors or other central nervous system pathologies as well as postmortem studies have suggested that gadolinium (Gd) deposition occurs in the dentate nucleus (DN) and globus pallidus (GP) after multiple administrations of primarily linear Gd-based contrast agents (GBCAs). However, this deposition has not been associated with any adverse effects or histopathological alterations. The aim of this preclinical study was to systematically examine differences between linear and macrocyclic GBCAs in their potential to induce changes in brain and skin histology including Gd distribution in high spatial resolution. Materials and Methods Fifty male Wistar-Han rats were randomly allocated into control (saline, n = 10 rats) and 4 GBCA groups (linear GBCAs: gadodiamide and gadopentetate dimeglumine, macrocyclic GBCAs: gadobutrol and gadoteridol; n = 10 rats per group). The animals received 20 daily intravenous injections at a dose of 2.5 mmol Gd/kg body weight. Eight weeks after the last GBCA administration, the animals were killed, and the brain and skin samples were histopathologically assessed (hematoxylin and eosin; cresyl violet [Nissl]) and by immunohistochemistry. The Gd concentration in the skin, bone, brain, and skeletal muscle samples were analyzed using inductively coupled plasma mass spectroscopy (ICP-MS, n = 4). The spatial Gd distribution in the brain and skin samples was analyzed in cryosections using laser ablation coupled with ICP-MS (LA-ICP-MS, n = 3). For the ultra-high resolution of Gd distribution, brain sections of rats injected with gadodiamide or saline (n = 1) were assessed by scanning electron microscopy coupled to energy dispersive x-ray spectroscopy and transmission electron microscopy, respectively. Results No histological changes were observed in the brain. In contrast, 4 of 10 animals in the gadodiamide group but none of the animals in other groups showed macroscopic and histological

  7. Quantification and Assessment of the Chemical Form of Residual Gadolinium in the Brain After Repeated Administration of Gadolinium-Based Contrast Agents: Comparative Study in Rats.

    Science.gov (United States)

    Frenzel, Thomas; Apte, Chirag; Jost, Gregor; Schöckel, Laura; Lohrke, Jessica; Pietsch, Hubertus

    2017-07-01

    Multiple clinical and preclinical studies have reported a signal intensity increase and the presence of gadolinium (Gd) in the brain after repeated administration of Gd-based contrast agents (GBCAs). This bioanalytical study in rat brain tissue was initiated to investigate whether the residual Gd is present as intact GBCA or in other chemical forms by using tissue fractionation and chromatography. Rats were divided randomly in 6 groups of 10 animals each. They received 10 daily injections of 2.5 mmol/kg bodyweight of 1 of 5 different GBCAs: linear GBCAs such as gadodiamide (Omniscan; GE Healthcare), gadopentetate dimeglumine (Gd-DTPA, Magnevist; Bayer), or gadobenate dimeglumine (Multihance; Bracco) and macrocyclic GBCAs such as gadobutrol (Gadovist; Bayer) and gadoterate meglumine (Gd-DOTA, Dotarem; Guerbet) or saline. On days 3 and 24 after the last injection (p.i.), 5 randomly chosen animals of each group were killed by exsanguination, and their brains were excised and divided into cerebrum, pons, and cerebellum. The brain sections were homogenized by sonication in ice-cold buffer at pH 7.4. Soluble and insoluble fractions were separated by centrifugation, and the soluble fractions were further separated by gel permeation chromatography (GPC). The Gd concentration in all tissue fractions and in the GPC eluate was measured by inductively coupled plasma-mass spectrometry. In a recovery control experiment, all GBCAs were spiked to blank brain tissue and more than 94% recovery of Gd in the tissue fractions was demonstrated. Only traces of the administered Gd were found in the rat brain tissue on day 3 and day 24 p.i. In the animals treated with macrocyclic GBCAs, Gd was found only in the soluble brain fraction and was present solely as low molecular weight molecules, most likely the intact GBCA. In the animals treated with linear GBCAs Gd was found to a large extent in the insoluble tissue fraction. The Gd concentration in the soluble fraction was comparable to the

  8. Histology and Gadolinium Distribution in the Rodent Brain After the Administration of Cumulative High Doses of Linear and Macrocyclic Gadolinium-Based Contrast Agents.

    Science.gov (United States)

    Lohrke, Jessica; Frisk, Anna-Lena; Frenzel, Thomas; Schöckel, Laura; Rosenbruch, Martin; Jost, Gregor; Lenhard, Diana Constanze; Sieber, Martin A; Nischwitz, Volker; Küppers, Astrid; Pietsch, Hubertus

    2017-06-01

    Retrospective studies in patients with primary brain tumors or other central nervous system pathologies as well as postmortem studies have suggested that gadolinium (Gd) deposition occurs in the dentate nucleus (DN) and globus pallidus (GP) after multiple administrations of primarily linear Gd-based contrast agents (GBCAs). However, this deposition has not been associated with any adverse effects or histopathological alterations. The aim of this preclinical study was to systematically examine differences between linear and macrocyclic GBCAs in their potential to induce changes in brain and skin histology including Gd distribution in high spatial resolution. Fifty male Wistar-Han rats were randomly allocated into control (saline, n = 10 rats) and 4 GBCA groups (linear GBCAs: gadodiamide and gadopentetate dimeglumine, macrocyclic GBCAs: gadobutrol and gadoteridol; n = 10 rats per group). The animals received 20 daily intravenous injections at a dose of 2.5 mmol Gd/kg body weight. Eight weeks after the last GBCA administration, the animals were killed, and the brain and skin samples were histopathologically assessed (hematoxylin and eosin; cresyl violet [Nissl]) and by immunohistochemistry. The Gd concentration in the skin, bone, brain, and skeletal muscle samples were analyzed using inductively coupled plasma mass spectroscopy (ICP-MS, n = 4). The spatial Gd distribution in the brain and skin samples was analyzed in cryosections using laser ablation coupled with ICP-MS (LA-ICP-MS, n = 3). For the ultra-high resolution of Gd distribution, brain sections of rats injected with gadodiamide or saline (n = 1) were assessed by scanning electron microscopy coupled to energy dispersive x-ray spectroscopy and transmission electron microscopy, respectively. No histological changes were observed in the brain. In contrast, 4 of 10 animals in the gadodiamide group but none of the animals in other groups showed macroscopic and histological nephrogenic systemic fibrosis-like skin

  9. 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.

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

    Science.gov (United States)

    Aran, S; Shaqdan, K W; Abujudeh, H H

    2015-05-01

    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. 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. 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 reaction was higher in females (F: 146/113187, 0.13%/M: 58/81213, 0.07%; p reactions was higher in outpatient (180/158885, 0.11%), emergency (10/10413, 0.10%), and inpatients (14/25102, 0.05%), respectively (p reactions (0.17 versus 0.16 versus 0.15). The overall rate of adverse reaction to GBCAs was 0.1%. The rates of reactions were highest in gadofosveset trisodium with (0.80%), followed by gadoxetate disodium (0.31%), gadobenate dimeglumine (0.22%) and gadopentetate dimeglumine (0.09%). Copyright © 2015 The Royal College of Radiologists. Published by Elsevier Ltd. All rights reserved.

  11. Changes in gadolinium-DTPA enhanced magnetic resonance signal intensity ratio in hypertrophic cardiomyopathy

    Energy Technology Data Exchange (ETDEWEB)

    Tsukihashi, Hironori; Ishibashi, Yutaka; Shimada, Toshio; Hatano, Jun; Tanabe, Kazuaki; Ooyake, Nobuyuki; Morioka, Shigefumi; Moriyama, Katsutoshi (Shimane Medical Univ., Izumo (Japan))

    Serial gadolinium-diethylene-triamine-pentaacetic acid (Gd-DTPA) enhanced magnetic resonance (MR) signal intensity ratios were measured in 6 normal subjects and 20 hypertrophic cardiomyopathy (HCM) patients to try to differentiate normal from disorganized myocardial tissue. Images were obtained at 10-minute intervals 5-60 minutes after Gd-DTPA (0.1 mmol/kg) injection. The signal intensity ratio (myocardial signal intensity/skeletal muscle signal intensity) was measured at both hypertrophic and non-hypertrophic regions in each image at the apex and mid-ventricular levels. The signal intensity ratio was standardized to compare each case. Hypertrophic myocardium was classified into two types. Type I in 11 of 20 patients was visualized as a homogeneous image, while type II in the other 9 patients was revealed as a mixed isointensity and high intensity area. The peak value of the standardized signal intensity ratio at the apex level was 1.28[+-]0.09 in HCM patients and 1.23[+-]0.06 in normal subjects, and at the mid ventricular level was 1.26[+-]0.07 in hypertrophic regions, 1.17[+-]0.12 in non-hypertrophic regions, and 1.16[+-]0.07 in normal subjects. Thirty minutes after Gd injection, the standardized signal intensity ratio at the apex level was 1.21[+-]0.08 in HCM patients and 1.07[+-]0.08 in normal subjects, and those at the mid ventricular level was 1.20[+-]0.09 in hypertrophic regions, 1.11[+-]0.11 in non-hypertrophic regions, and 1.04[+-]0.06 in normal subjects. The delayed decay of the signal intensity ratio and high signal intensity ratio in Gd-DTPA enhanced MR images are useful in myocardial tissue characterization in hypertrophic cardiomyopathy. (author).

  12. Distribution of Hypertrophy and Late Gadolinium Enhancement in Children and Adolescents with Hypertrophic Cardiomyopathy.

    Science.gov (United States)

    Windram, Jonathan D; Benson, Lee N; Dragelescu, Andreea; Yoo, Shi-Joon; Mertens, Luc; Wong, Derek; Grosse-Wortmann, Lars

    2015-01-01

    While well characterized in adult patients, the pattern of hypertrophy and the extent of myocardial scarring in hypertrophic cardiomyopathy (HCM) are insufficiently known. The aim of this study was to assess the hypertrophy patterns and the prevalence and clinical significance of scars in the hearts of young patients with HCM. A retrospective analysis of the imaging findings of 38 children (aged 12.83 ± 2 years, 30 males) with HCM who underwent cardiac magnetic resonance imaging (CMR) was performed. In addition to left ventricular mass and volumes, the examinations were assessed for the pattern of hypertrophy and presence of late gadolinium enhancement (LGE). A myocardial signal intensity ≥6 standard deviations above the mean of normal myocardium defined positive LGE. Left ventricular mass index averaged 110 ± 34 g/m(2) . Nineteen children (50%) had diffuse septal, 13 (34%) diffuse concentric and 6 (16%) isolated basal hypertrophy. Seven children (18%) had LGE. Patients with LGE had a greater left ventricular mass index than those without (136 ± 34 g/m(2) vs. 104 ± 31 g/m(2) , P = .025). The only two patients who presented with an episode of aborted sudden cardiac death had LGE (P = .03). The most common hypertrophy pattern in children with HCM was diffuse septal hypertrophy. The incidence of LGE observed is lower than that reported in adults. The presence of LGE appears to confer a risk for adverse events. © 2015 Wiley Periodicals, Inc.

  13. MRI of spondylodiscities: contribution of gadolinium-DTPA and fat suppression sequence

    Energy Technology Data Exchange (ETDEWEB)

    Cova, M.A. [Dept. of Radiology, Univ. of Trieste, Cattinara Hospital (Italy); Dalla Palma, L. [Dept. of Radiology, Univ. of Trieste, Cattinara Hospital (Italy); Pozzi-Mucelli, R.S. [Dept. of Radiology, Univ. of Trieste, Cattinara Hospital (Italy); Ricci, C. [Dept. of Radiology, Univ. of Trieste, Cattinara Hospital (Italy)

    1993-12-01

    Twenty-six patients with a clinical diagnosis of spondylodiscitis were examined with non-contrast and contrast-enhanced MRI in order to define the contribution of gadolinium-DTPA (Gd-DTPA) and different pulse sequences, including a fat suppression sequence (SPIR). Spin echo (SE) T1-weighted images before and after Gd-DTPA injection and SE T2-weighted images were obtained in all patients. Twelve patients were also examined using the SPIR sequence following Gd-DTPA injection. Signal intensity and morphological features of the disc and vertebral lesions were then evaluated. The SE T1-weighted sequence with Gd-DTPA was very effective in showing the pathological changes at the level of the disc as an area of low signal intensity surrounded by a peripheral rim of enhancement in 24 of 26 cases (92%). This feature was not visible on non-enhanced images. As regards contiguous vertebral lesions this sequence was less informative, since in 8 of 26 cases (31%) the vertebral lesions became isointense and therefore not detectable. In 12 cases there was extension into the surrounding structures (spinal canal and/or paravertebral tissues). An enhanced SE T1-weighted sequence provided good anatomical definition of the extension of the infection in the spinal canal in all cases with this type of involvement (7 of 12). Regarding the 7 cases with paravertebral extension, no extension was visible in 1 case due to the reduced contrast with the surrounding fat following Gd-DTPA injection. The enhanced SPIR sequence was very effective, particularly in detecting the lesions in the vertebral bodies, avoiding the limitation of the enhanced SE T1-weighted sequence. The SPIR sequence was also effective in showing the extension within the spinal canal and the paravertebral fat. On the basis of our results the combination of a SE T1-weighted sequence without contrast and SPIR sequence with Gd-DTPA seems to be the best approach in cases of spondylodiscitis. (orig.)

  14. Microfabrication of a gadolinium-derived solid-state sensor for thermal neutrons.

    Science.gov (United States)

    Pfeifer, Kent B; Achyuthan, Komandoor E; Allen, Matthew; Denton, Michele L B; Siegal, Michael P; Manginell, Ronald P

    2017-07-01

    Neutron sensing is critical in civilian and military applications. Conventional neutron sensors are limited by size, weight, cost, portability and helium supply. Here the microfabrication of gadolinium (Gd) conversion material-based heterojunction diodes for detecting thermal neutrons using electrical signals produced by internal conversion electrons (ICEs) is described. Films with negligible stress were produced at the tensile-compressive crossover point, enabling Gd coatings of any desired thickness by controlling the radiofrequency sputtering power and using the zero-point near p(Ar) of 50 mTorr at 100 W. Post-deposition Gd oxidation-induced spallation was eliminated by growing a residual stress-free 50 nm neodymium-doped aluminum cap layer atop Gd. The resultant coatings were stable for at least 6 years, demonstrating excellent stability and product shelf-life. Depositing Gd directly on the diode surface eliminated the air gap, leading to a 200-fold increase in electron capture efficiency and facilitating monolithic microfabrication. The conversion electron spectrum was dominated by ICEs with energies of 72, 132 and 174 keV. Results are reported for neutron reflection and moderation by polyethylene for enhanced sensitivity, and γ- and X-ray elimination for improved specificity. The optimal Gd thickness was 10.4 μm for a 300 μm-thick partially depleted diode of 300 mm2 active surface area. Fast detection (within 10 min) at a neutron source-to-diode distance of 11.7 cm was achieved with this configuration. All ICE energies along with γ-ray and Kα,β X-rays were modeled to emphasize correlations between experiment and theory. Semi-conductor thermal neutron detectors offer advantages for field-sensing of radioactive neutron sources. © The Author 2017. Published by Oxford University Press on behalf of The Japan Radiation Research Society and Japanese Society for Radiation Oncology.

  15. Implications of post-gadolinium MRI results in 13 cases with posterior reversible encephalopathy syndrome

    International Nuclear Information System (INIS)

    Ugurel, Mehmet Sahin; Hayakawa, Minako

    2005-01-01

    Background: There is a relative lack of definitive information about the contrast-enhancement characteristics of lesions in posterior reversible encephalopathy syndrome (PRES). Objective: Evaluation of contrast-enhanced MRI findings in PRES with a special emphasis on pathophysiology of post-gadolinium behavior of these lesions. Materials and methods: Contrast-enhanced 1.5 T MRI findings and relevant clinical data of the patients were retrospectively reviewed on 13 cases (six males, seven females; age range: 22-78; mean age 47). Although fluid attenuated inversion recovery (FLAIR) and diffusion-weighted MR images were considered for identification of the entity, primarily post-contrast T1-weighted MR images were searched for traces of enhancement in the lesions. Results: No definitely enhancing lesion was identified in the MR images obtained in 6-48 h after onset of symptoms (mostly headaches, seizures and cortical visual field deficits) in this series. Severity of disease indicated by small hemorrhages, confluence of lesions or progression to cytotoxic edema did not seem to alter this result. Typical lesion characteristics were consistent with vasogenic edema on FLAIR and diffusion MR images. Acute elevation of blood pressure on chronic hypertensive background was responsible in four, eclampsia in three, uremia with blood pressure fluctuations in three, and cyclosporine-toxicity in three cases. Conclusion: Although occasional enhancing brain lesions have been reported in the literature on PRES, contrast-enhancement of lesions may be a factor of scan timing and underlying etiology. Prospective studies with larger series on PRES are required for better evaluation of contrast-enhancement in MRI with respect to scan timing, which in turn may help understand its pathophysiology better

  16. Functionalization of gadolinium metallofullerenes for detecting atherosclerotic plaque lesions by cardiovascular magnetic resonance

    Directory of Open Access Journals (Sweden)

    Dellinger Anthony

    2013-01-01

    Full Text Available Abstract Background The hallmark of atherosclerosis is the accumulation of plaque in vessel walls. This process is initiated when monocytic cells differentiate into macrophage foam cells under conditions with high levels of atherogenic lipoproteins. Vulnerable plaque can dislodge, enter the blood stream, and result in acute myocardial infarction and stroke. Imaging techniques such as cardiovascular magnetic resonance (CMR provides one strategy to identify patients with plaque accumulation. Methods We synthesized an atherosclerotic-targeting contrast agent (ATCA in which gadolinium (Gd-containing endohedrals were functionalized and formulated into liposomes with CD36 ligands intercalated into the lipid bilayer. In vitro assays were used to assess the specificity of the ATCA for foam cells. The ability of ATCA to detect atherosclerotic plaque lesions in vivo was assessed using CMR. Results The ATCA was able to detect scavenger receptor (CD36-expressing foam cells in vitro and were specifically internalized via the CD36 receptor as determined by focused ion beam/scanning electron microscopy (FIB-SEM and Western blotting analysis of CD36 receptor-specific signaling pathways. The ATCA exhibited time-dependent accumulation in atherosclerotic plaque lesions of ApoE −/− mice as determined using CMR. No ATCA accumulation was observed in vessels of wild type (C57/b6 controls. Non-targeted control compounds, without the plaque-targeting moieties, were not taken up by foam cells in vitro and did not bind plaque in vivo. Importantly, the ATCA injection was well tolerated, did not demonstrate toxicity in vitro or in vivo, and no accumulation was observed in the major organs. Conclusions The ATCA is specifically internalized by CD36 receptors on atherosclerotic plaque providing enhanced visualization of lesions under physiological conditions. These ATCA may provide new tools for physicians to non-invasively detect atherosclerotic disease.

  17. Nephrogenic systemic fibrosis associated with gadolinium based contrast agents: A summary of the medical literature reporting

    International Nuclear Information System (INIS)

    Broome, Dale R.

    2008-01-01

    Nephrogenic systemic fibrosis (NSF) is a systemic fibrosing disorder that principally affects the skin, but can involve virtually any tissue in the human body and result in significant disability and even death. Since 2006 numerous retrospective case reports and case series have reported a very strong association of this disease with exposure to gadolinium-based contrast agents (Gd-CA) for MR imaging in the setting of severe or end-stage renal disease. The purpose of this report is to summarize the medical literature reporting of biopsy-proven NSF cases in which the authors specifically investigated patient exposure to Gd-CA. A Pub Med MEDLINE search was performed using the key words-nephrogenic systemic fibrosis and nephrogenic fibrosing dermopathy. All case reports and case series of NSF were reviewed to determine if patients had a preceding exposure to Gd-CA and which specific Gd-CA was involved. If the original reports did not clarify the specific Gd-CA, I reviewed follow-up letters to the editors or contacted the authors to clarify which specific Gd-CA were linked to the NSF cases. If several reports originated from the same institution, clarification was also obtained to avoid redundant reporting. As of February 1, 2008 there have been 190 biopsy-proven cases of NSF published in the peer-reviewed literature with the following associations: 157 gadodiamide (Omniscan, GE Healthcare), 8 gadopentetate (Magnevist, Bayer Healthcare), 3 gadoversetamide (OptiMARK, Covidien), and 18 unspecified Gd-CA, and 4 confounded cases with more than one Gd-CA. Five cases of NSF were unassociated with Gd-CA

  18. Comparison of different quantification methods of late gadolinium enhancement in patients with hypertrophic cardiomyopathy

    Energy Technology Data Exchange (ETDEWEB)

    Spiewak, Mateusz, E-mail: mspiewak@ikard.p [First Department of Coronary Artery Disease, Magnetic Resonance Unit, Institute of Cardiology, ul. Alpejska 42, 04-628 Warsaw (Poland); Malek, Lukasz A., E-mail: lmalek@ikard.p [First Department of Coronary Artery Disease, Magnetic Resonance Unit, Institute of Cardiology, ul. Alpejska 42, 04-628 Warsaw (Poland); Misko, Jolanta, E-mail: jmisko@wp.p [Magnetic Resonance Unit, Institute of Cardiology, ul. Alpejska 42, 04-628 Warsaw (Poland); Chojnowska, Lidia, E-mail: lchojnowska@ikard.p [First Department of Coronary Artery Disease, Institute of Cardiology, ul. Alpejska 42, 04-628 Warsaw (Poland); Milosz, Barbara, E-mail: barbara-milosz@tlen.p [Magnetic Resonance Unit, Institute of Cardiology, ul. Alpejska 42, 04-628 Warsaw (Poland); Klopotowski, Mariusz, E-mail: mklopotowski@hotmail.co [First Department of Coronary Artery Disease, Institute of Cardiology, ul. Alpejska 42, 04-628 Warsaw (Poland); Petryka, Joanna, E-mail: joannapetryka@hotmail.co [First Department of Coronary Artery Disease, Magnetic Resonance Unit, Institute of Cardiology, ul. Alpejska 42, 04-628 Warsaw (Poland); Dabrowski, Maciej, E-mail: macidabro@yahoo.co [First Department of Coronary Artery Disease, Institute of Cardiology, ul. Alpejska 42, 04-628 Warsaw (Poland); Kepka, Cezary, E-mail: ckepka@ikard.p [First Department of Coronary Artery Disease, Magnetic Resonance Unit, Institute of Cardiology, ul. Alpejska 42, 04-628 Warsaw (Poland); Ruzyllo, Witold, E-mail: w.ruzyllo@ikard.p [First Department of Coronary Artery Disease, Institute of Cardiology, ul. Alpejska 42, 04-628 Warsaw (Poland)

    2010-06-15

    Aim: There is no consensus regarding the technique of quantification of late gadolinium enhancement (LGE). The aim of the study was to compare different methods of LGE quantification in patients with hypertrophic cardiomyopathy (HCM). Methods: Cardiac magnetic resonance was performed in 33 patients with HCM. First, LGE was quantified by visual assessment by the team of experienced readers and compared with different thresholding techniques: from 1SD to 6SD above mean signal intensity (SI) of remote myocardium, above 50% of maximal SI of the enhanced area (full-width at half maximum, FWHM) and above peak SI of remote myocardium. Results: LGE was present in 25 (78%) of patients. The median mass of LGE varied greatly depending on the quantification method used and was highest with the utilization of 1SD threshold [75.5 g, interquartile range (IQR): 63.3-112.3 g] and lowest for FWHM method (8.4 g, IQR: 4.3-13.3 g). There was no difference in mass of LGE as assessed with 6SD threshold and FWHM when compared to visual assessment (p = 0.19 and p = 0.1, respectively); all other thresholding techniques provided significant differences in the median LGE size when compared to visual analysis. Results for all thresholds, except FWHM were significantly correlated with visual assessment with the strongest correlation for 6SD (rho = 0.956, p < 0.0001). Conclusions: LGE quantification with the use of a threshold of 6SD above the mean SI of the remote myocardium provided the best agreement with visual assessment in patients with HCM.

  19. Reproducibility of Gadolinium Enhancement Patterns and Wall Thickness in Hypertrophic Cardiomyopathy

    Energy Technology Data Exchange (ETDEWEB)

    Rodriguez-Granillo, Gaston A., E-mail: grodriguezgranillo@gmail.com; Deviggiano, Alejandro; Capunay, Carlos; Zan, Macarena C. De; Carrascosa, Patricia [Department of Cardiovascular Imaging - Diagnóstico Maipú, Buenos Aires (Argentina)

    2016-07-15

    Reproducibility data of the extent and patterns of late gadolinium enhancement (LGE) in hypertrophic cardiomyopathy (HCM) is limited. To explore the reproducibility of regional wall thickness (WT), LGE extent, and LGE patterns in patients with HCM assessed with cardiac magnetic resonance (CMR). The extent of LGE was assessed by the number of segments with LGE, and by the total LV mass with LGE (% LGE); and the pattern of LGE-CMR was defined for each segment. A total of 42 patients (672 segments) with HCM constituted the study population. The mean WT measurements showed a mean difference between observers of -0.62 ± 1.0 mm (6.1%), with limits of agreement of 1.36 mm; -2.60 mm and intraclass correlation coefficient (ICC) of 0.95 (95% CI 0.93-0.96). Maximum WT measurements showed a mean difference between observers of -0.19 ± 0.8 mm (0.9%), with limits of agreement of 1.32 mm; -1.70 mm, and an ICC of 0.95 (95% CI 0.91-0.98). The % LGE showed a mean difference between observers of -1.17 ± 1.2 % (21%), with limits of agreement of 1.16%; -3.49%, and an ICC of 0.94 (95% CI 0.88-0.97). The mean difference between observers regarding the number of segments with LGE was -0.40 ± 0.45 segments (11%), with limits of agreement of 0.50 segments; -1.31 segments, and an ICC of 0.97 (95% CI 0.94-0.99). The number of segments with LGE might be more reproducible than the percent of the LV mass with LGE.

  20. Late gadolinium enhancement by magnetic resonance explains adverse cardiac events in individuals with ventricular arrhythmia

    International Nuclear Information System (INIS)

    Courtis, J.; Vasallo, J.; Arabia, L.; Dimitroff, M.; Gonzalez, A.; Tibaldi, M.

    2012-01-01

    Objective: To determine whether the presence of late gadolinium enhancement (LGE) by cardiovascular magnetic resonance (CMR) predict adverse cardiac events in patients with ventricular arrhythmia. Methods: We selected 74 consecutive patients with symptomatic ventricular arrhythmia (premature ventricular contractions and ventricular tachycardia) and left ventricular ejection fraction (LVEF) >55% sent to CMR for evaluation of structural heart disease previously undetected by other complementary methods. LGE, systolic function and volumes of both ventricles were analyzed. At follow-up was assessed a combined end point: hospitalization for ventricular arrhythmia, appropriate implantable cardioverter-defibrillator therapy and cardiac death. Results: During a median follow up of 575 days (interquartile range 24-1120 days) and by analyzing the population according to the presence (n=9, 12%) or not (n=65, 88%) LGE was observed that the group with positive Gd had lower LVEF (58% vs. 66% respectively, p=0.01) and larger volumes (EDV: 185 ml vs. 123 ml respectively, p=0.01 and ESV: 81 ml vs. 42 ml respectively, p=0.01) than the other group. Two (22%) patients in the LGE + group vs. one (4%) of those without LGE showed the combined endpoint (p=0.01) and when performing a logistic regression analysis it was found that the LGE is a predictor of adverse cardiac events analyzed (p=0.029). Conclusions: In this consecutive series of patients with ventricular arrhythmia we demonstrate a strong association between myocardial LGE and adverse cardiac events; this supports the hypothesis that myocardial fibrosis is an important arrhythmogenic substrate. In addition, almost all individuals without LGE were free of events during follow-up suggesting that it is possible to identify through the CMR low-risk individuals who can be treated conservatively. (authors) [es

  1. Characterization of chondroid matrix-forming sarcomas: gadolinium-enhanced and diffusion weighted MR imaging

    International Nuclear Information System (INIS)

    Cheng Kebin; Zhang Jing; Qu Hui; Zhang Wei; Liang Wei; Li Xiaosong; Cheng Xiaoguang; Gong Lihua

    2010-01-01

    Objective: To study the Gadolinium-enhanced MRI and diffusion weighted imaging (DWI) characteristics of the chondroid matrix-forming sarcomas. Methods: Contrast-enhanced MRI and DWI were performed in 14 cases of chondroid matrix-forming sarcomas (10 chondrosarcomas, 4 chondroblastic osteosarcomas) and 13 cases of other types of osteosarcomas. DWI was obtained with a single-shot echo-planar imaging (EPI) sequence using a 1.5 T MR imager with two different b values of 0 and 700 s/mm 2 . The apparent diffusion coefficient (ADC) values were obtained in GE Functiontool software. The contrast-enhancement pattern was evaluated and the ADC values of chondroid matrix-forming sarcomas was compared with that of other types of osteosareoma. Independent sample t-test was performed to evaluate the difference of ADC values between the group of chondroid matrix-forming sarcoma and the group of other types of osteosarcoma. In addition, nonparametric test was used to assess the difference of ADC values between the chondrosarcoma and the chondroblastic osteosarcoma. P value less than 0.05 was considered to represent a statistical significance. Results: For 14 cases of chondroid matrix-forming sarcomas, peripheral enhancement was found in all cases, septonodular enhancement was identified in 12 cases. While 13 cases of other types of osteosarcomas demonstrated heterogeneous enhancement. The mean ADC value of chondroid matrix-forming sarcomas [(2.56±0.35) x 10 -3 mm 2 /s] was significantly higher than that of other types of osteosarcoma [(1.16 ± 0.20) x 10 -3 mm 2 /s] (t=12.704, P<0.01). There was no significant difference in the ADC value between the chondrosarcoma and the chondroblastic osteosarcoma (Z=0.507, P=0.959). Conclusion: Contrast-enhanced MRI and DWI can improve differentiation between chondroid matrix-forming sarcomas and other types of osteosarcomas. (authors)

  2. Effects of motexafin gadolinium on tumor oxygenation and cellular oxygen consumption

    International Nuclear Information System (INIS)

    Donnelly, E.T.; Liu, Y.; Rockwell, S.; Magda, D.

    2003-01-01

    Full text: Recent work in our laboratory showed that motexafin gadolinium (MGd, Xcytrin), a drug currently in Phase III clinical trials as an adjuvant to radiation therapy, modulates the oxygen tensions in EMT6 tumors. The median pO 2 increased from the control value of 1.5±0.4 mmHg to 7.4 ± 3.8 mmHg six hours after treatment with 40 μmol/kg MGd and the percentage of severely hypoxic readings in the tumors ( 7 plateau phase EMT6 cells in 3 mL Dulbecco's Modified Eagle's Medium supplemented with 10% dialyzed fetal bovine serum, which contains no ascorbic acid. In the absence of ascorbic acid, 100 μM MGd did not alter the cellular oxygen consumption rate for EMT6 cells significantly. Marked inhibition of cellular oxygen consumption was observed when cells were incubated with 100 μM MGd in medium supplemented with equimolar ascorbic acid (a 31.5% decrease in consumption was observed after 6 hours of treatment). The 5% mannitol vehicle solution with equimolar ascorbic acid had no discernible effect on cellular oxygen consumption. Ascorbic acid may facilitate cellular uptake of MGd via the intermediate formation of a MGd-oxalate complex. These studies suggest that changes in cellular oxygen consumption could contribute to the changes in tumor oxygenation seen after administration of MGd. These experiments were supported by Pharmacyclics and training grant T32CA09085 from the NIH (E.T.D.). We thank Dr. Raymond Russell for allowing us to use his oxygen electrode apparatus

  3. Assessment of viability of acute myocardial infarction using MRI and gadolinium DTPA

    International Nuclear Information System (INIS)

    Toyama, Takuji; Nishimura, Tsunehiko; Yamada, Naoaki

    1993-01-01

    To evaluate the myocardial viability using gated MRI and gadolinium-DTPA enhancement, we compared with Tl-201 exercise myocardial scintigraphy (Ex-Tl) and two-dimensional echocardiography (UCG) in 22 patients with acute myocardial infarction (AMI). These patients were divided into three groups. In group A (8 patients), thallium redistribution (RD) was found at infarcted region. In group B (6 patients), RD was not found at infarcted region, but wall motion by UCG was normal or hypokinesis at infarcted region. In group C (8 patients), RD was not found at infarcted region, and wall motion by UCG was akinesis or dyskinesis at infarcted region. MRI was performed at one week, two weeks, one month and three months from the onset of AMI. We evaluated signal intensity (SI), extent of Gd-E and wall thinning at short axial image of T 1 weighted image. Ex-T l was performed at one month after AMI to evaluate presence of RD and extent of perfusion defect on delayed SPECT image. In addition, UCG was performed within one month after AMI to evaluate regional wall motion at infarcted region. In most cases of groups A and B Gd-E>PD was found. Decrease of Gd-E area was found in group A, but early disappearance of Gd-E within three months was not different among three groups. This study indicated that Gd-E>PD and decrease of Gd-E area reflected myocardial viability at infarcted region to some extent, but SI of Gd-E and early disappearance of Gd-E did not reflect myocardial viability. Gd-E was slightly useful for detecting the myocardial viability of acute myocardial infarction. (author)

  4. Investigation of europium(III) and gadolinium(III) complexes with naphthoyltrifluoroacetone and bidentate heterocyclic amines

    International Nuclear Information System (INIS)

    Fernandes, Jose A.; Sa Ferreira, Rute A.; Pillinger, Martyn; Carlos, Luis D.; Jepsen, Josua; Hazell, Alan; Ribeiro-Claro, Paulo; Goncalves, Isabel S.

    2005-01-01

    Lewis base adducts of the type Ln(NTA) 3 .phen and the binuclear complexes [Ln(NTA) 3 ] 2 .bpym [NTA=1-(2-naphthoyl)-3,3,3-trifluoroacetone, phen=1,10-phenanthroline, bpym=2,2'-bipyrimidine; Ln=Eu, Gd] have been prepared by replacement of the coordinated water molecules in the complexes Ln(NTA) 3 .2H 2 O. The compounds were characterised by elemental analysis, 1 H NMR, X-ray diffraction (XRD), thermogravimetric analysis, FTIR and FT Raman spectroscopy, and photoluminescence (PL) spectroscopy. For both, new bands were observed in the Raman spectra in the low-wavenumber region (100-600 cm -1 ), assigned to Ln-N stretching vibrations (in agreement with ab initio calculations). The crystal structures of the Eu III complexes were determined by single crystal XRD. In both complexes the coordination polyhedra can be regarded as square antiprisms, distorted towards a bicapped trigonal prism for the mononuclear complex and towards a dodecahedron for the binuclear complex. A Eu-Eu distance of 6.856 A was found for the latter. Powder XRD indicates that the corresponding gadolinium(III) compound has a similar structure. The room temperature PL spectra of the europium complexes in the solid state present a series of sharp lines assigned to 5 D 0 → 7 F 0-4 transitions. No emission from the organic part of the compounds is observed, indicating that energy transfer from the ligands to the Eu 3+ ion is quite efficient. A number of parameters were determined from the PL spectra, including estimates for the overall crystal field strengths, and 5 D 0 lifetimes and quantum efficiencies. The PL spectra for ethanol solutions of the Eu complexes confirm that the NTA and N-ligands remain attached. Slight changes in the PL data upon solubilisation are attributed to an interaction of solvent molecules with the metal centres

  5. Subepicardial delayed gadolinium enhancement in asymptomatic athletes: let sleeping dogs lie?

    Science.gov (United States)

    Schnell, Frédéric; Claessen, Guido; La Gerche, André; Bogaert, Jan; Lentz, Pierre-Axel; Claus, Piet; Mabo, Philippe; Carré, François; Heidbuchel, Hein

    2016-01-01

    Subepicardial delayed gadolinium enhancement (DGE) patches without underlying cardiomyopathy is poorly understood. It is often reported as the result of prior silent myocarditis. Its prognostic relevance in asymptomatic athletes is unknown; therefore, medical clearance for competitive sports participation is debated. This case series aims to relate this pattern of DGE in athletes to outcome. We report on seven young asymptomatic athletes with isolated subepicardial DGE detected during workup of abnormalities on their regular screening examination, that is, pathological T-wave inversions on ECG (n=4) or ventricular arrhythmias on exercise test (n=3). All underwent a comprehensive initial investigation in order to assess left ventricular (LV) function at rest and exercise (exercise cardiac MRI and/or exercise echocardiography) and occurrence of arrhythmias (exercise test, 24 h-ECG Holter, electrophysiological study). All underwent a careful follow-up with biannual evaluation. All athletes had extensive subepicardial DGE (12.0±4.8% of LV mass), predominantly in the lateral wall. Three athletes had non-sustained ventricular arrhythmias, whereas two of them had LV ejection fraction athletes, two had symptomatic ventricular tachycardia and one demonstrated progressive LV dysfunction. Hence, six of seven athletes had to be excluded from competitive sports participation. Isolated large areas of subepicardial DGE in an asymptomatic athlete are not benign and require a careful evaluation at exercise and a strict follow-up. These findings question whether extreme exercise during silent myocarditis may facilitate fibrosis generation and adverse remodelling. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

  6. First experiences with application of gadolinium-DTPA in infants and small children under two years of age. Erste Erfahrungen beim Einsatz von Gadolinium-DTPA bei Saeuglingen und Kleinkindern unter zwei Jahren

    Energy Technology Data Exchange (ETDEWEB)

    Maas, R.; Lausch, N.; Buecheler, E. (Hamburg Univ. (Germany). Radiologische Klinik); Grzyska, U. (Hamburg Univ. (Germany). Neurologische Klinik)

    1991-07-01

    The use of Gadolinium-DTPA as a paramagnetic contrast agent in MRI with adults and juveniles concerning brain and spinal cord pathology is well proven since years. In the FRG it is only introduced for children over two years of age. Therefore this report deales with the experience in four infants and small children under the age of two. They all were suffering from neurological tumors and got additional diagnostic information in three cases. Clinical side-effects like urticaria, vomiting or convulsions had not been observed nor had pathologic changes of the biochemical parameters been noticed. (orig./GDG).

  7. Comparison between a digital scanning system and a conventional screen film system in the full spine radiological procedure in pediatrics; Valoracion de un sistema de Scan digital frente a un sistema convencional cartulina pelicula en exploraciones de columna total en pediatria

    Energy Technology Data Exchange (ETDEWEB)

    Espana, M. L.; Gomez, G.; Romero, A.; Minambres, A.; Albi, G.; Floriano, A.; Rodirguez, A.; Lopez Franco, P.

    2004-07-01

    To compare from both dosimetry and image quality standpoints, a digital scanning system with a conventional screen film system, in the full spine radiological procedure. The standard patient is considered to be 12 years old, and a sample of forty patients referred for full spine radiological procedure has been studied. Gonad shielding has been used in all the patients, and its efficiency has been evaluated. Dosimetric study includes Kerma-area product, and thorax and gonad entrance surface dose. Kerma area product has been measured using a transmission camera, and for entrance surface dose estimation both thermoluminescent dosemeter LiF: Mg, Cu, P and LiF: Mg, Ti have been utilized. Three radiologists have evaluated the image quality according to the degree of fulfilment of the image quality criteria. (Author) 22 refs.

  8. Late gadolinium enhancement and adverse outcomes in a contemporary cohort of adult survivors of tetralogy of Fallot.

    Science.gov (United States)

    Dobson, Richard J; Mordi, Ify; Danton, Mark H; Walker, Niki L; Walker, Hamish A; Tzemos, Nikolaos

    2017-01-01

    Myocardial fibrosis has been associated with poorer outcomes in tetralogy of Fallot, however only a handful of studies have assessed its significance in the current era. Our aim was to quantify the amount of late gadolinium enhancement in both the LV and RV in a contemporary cohort of adults with surgically repaired tetralogy of Fallot, and assess the relationship with adverse clinical outcomes. Single centre cohort study SETTING: National tertiary referral center Patients: One hundred fourteen patients with surgically repaired tetralogy of Fallot with median age 29.5 years (range 17.5-64.2). Prospective follow-up for mean 2.4 years (SD 1.29). Cardiovascular magnetic resonance was performed, and late gadolinium enhancement mass was estimated for the LV using the 5-SD remote myocardium method, and for the RV using a segmental scoring system. Cohort characterization was determined through the use of a computerized database. Survival analysis from time of scan to first adverse event, defined as an episode of atrial arrhythmia, sustained ventricular arrhythmia, hospitalization with heart failure, or implantable cardioverter-defibrillator insertion. Eleven patients experienced an adverse outcome in the follow-up period, although there were no deaths. LV late gadolinium enhancement was associated with adverse outcomes in a univariate model (P = .027). However, when adjusted for age at scan the significant variables included NYHA class (P = .006), peak oxygen uptake (P = .028), number of prior sternotomies (P = .044), and higher indexed RV and LV end diastolic volumes (P = .002 and P tetralogy of Fallot survivors, however assessment particularly of the LV holds promise for the future. © 2016 Wiley Periodicals, Inc.

  9. Arterial double-contrast dual-energy MDCT: in-vivo rabbit atherosclerosis with iodinated nanoparticles and gadolinium agents

    Science.gov (United States)

    Carmi, Raz; Kafri, Galit; Altman, Ami; Goshen, Liran; Planer, David; Sosna, Jacob

    2010-03-01

    An in-vivo feasibility study of potentially improved atherosclerosis CT imaging is presented. By administration of two different contrast agents to rabbits with induced atherosclerotic plaques we aim at identifying both soft plaque and vessel lumen simultaneously. Initial injection of iodinated nanoparticle (INP) contrast agent (N1177 - Nanoscan Imaging), two to four hours before scan, leads to its later accumulation in macrophage-rich soft plaque, while a second gadolinium contrast agent (Magnevist) injected immediately prior to the scan blends with the aortic blood. The distinction between the two agents in a single scan is achieved with a double-layer dual-energy MDCT (Philips Healthcare) following material separation analysis using the reconstructed images of the different x-ray spectra. A single contrast agent injection scan, where only INP was injected two hours prior to the scan, was compared to a double-contrast scan taken four hours after INP injection and immediately after gadolinium injection. On the single contrast agent scan we observed along the aorta walls, localized iodine accumulation which can point on INP uptake by atherosclerotic plaque. In the double-contrast scan the gadolinium contributes a clearer depiction of the vessel lumen in addition to the lasting INP presence. The material separation shows a good correlation to the pathologies inferred from the conventional CT images of the two different scans while performing only a single scan prevents miss-registration problems and reduces radiation dose. These results suggest that a double-contrast dual-energy CT may be used for advanced clinical diagnostic applications.

  10. 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.)

  11. A novel cryogenic magnetic refrigerant metal-organic framework based on 1D gadolinium(III) chain

    Energy Technology Data Exchange (ETDEWEB)

    Tang, Qun; Li, Peng-Fei [Guangxi Key Laboratory of Electrochemical and Magneto-chemical Functional Materials, College of Chemistry and Bioengineering, Guilin University of Technology, Guilin, Guangxi 541004 (China); Zou, Zhi-Ming, E-mail: 2014005@glut.edu.cn [Guangxi Key Laboratory of Electrochemical and Magneto-chemical Functional Materials, College of Chemistry and Bioengineering, Guilin University of Technology, Guilin, Guangxi 541004 (China); Liu, Zheng [Guangxi Key Laboratory of Electrochemical and Magneto-chemical Functional Materials, College of Chemistry and Bioengineering, Guilin University of Technology, Guilin, Guangxi 541004 (China); Liu, Shu-Xia, E-mail: liusx@nenu.edu.cn [Key Laboratory of Polyoxometalate Science of Ministry of Education, College of Chemistry, Northeast Normal University, Changchun, Jilin 130024 (China)

    2017-02-15

    A metal-organic framework (MOF) based on gadolinium ion (Gd{sup 3+}) and tricarboxylate ligand, [Gd(BTPCA)(H{sub 2}O)]·2DMF·3H{sub 2}O (Gd-BTPCA) (H{sub 3}BTPCA =1,1′,1′-(benzene-1,3,5-triyl)tripiperidine-4-carboxylic acid; DMF=dimethylformamide), was synthesized and structurally characterized. The adjacent Gd{sup 3+} ions are intraconnected by the carboxylate groups of the BTPCA{sup 3-} ligands to form a 1D Gd{sup 3+} ion chain. The 1D Gd{sup 3+} ion chains are interconnected by the BTPCA{sup 3-} ligands, giving rise to a 3D framework with 1D open channel. The magnetic studies indicate that Gd-BTPCA exhibits weak ferromagnetic interactions, and acts as a cryogenic magnetic refrigerant having the magnetic entropy change (−ΔS{sub m}) of 20.40 J kg{sup −1} K{sup −1} for ΔH =7 T at 3 K. - Graphical abstract: A 1D gadolinium(III) chains-based metal-organic framework performed ferromagnetic coupling on the magnetic property. Magnetic investigation reveals that Gd-BTPCA exhibits the entropy change (−ΔS{sub m}) of 20.40 J kg{sup −1} K{sup −1} for ΔH =7 T at 3 K. - Highlights: • The MOF based on gadolinium ion and tricarboxylate ligand was synthesized. • This MOF is connected with 1D Gd{sup 3+} ions chain and the carboxylate groups of BTPCA{sup 3-} ligands. • The magnetic studies indicate that the MOF exhibits the weak ferromagnetic interactions. • Magnetic investigation reveals that the MOF exhibits the high entropy change.

  12. Nucleation front instability in two-dimensional (2D) nanosheet gadolinium-doped cerium oxide (CGO) formation

    DEFF Research Database (Denmark)

    Marani, Debora; Moraes, Leticia Poras Reis; Gualandris, Fabrizio

    2018-01-01

    Herein we report for the first time the synthesis of ceramic–organic three-dimensional (3D) layered gadolinium-doped cerium oxide (Ce1−XGdXO2−δ, CGO) and its exfoliation into two-dimensional (2D) nanosheets. We adopt a water-based synthetic route via a homogenous precipitation approach at low tem.......6 kJ mol−1. For the 3D-layered material, exfoliation experiments are conducted in water/ethanol solutions. Systems at volume fractions ranging from 0.15 to 0.35 are demonstrated to promote under ultrasonic treatment the delamination into 2D nanosheets....

  13. Association between delayed gadolinium-enhanced MRI of cartilage (dGEMRIC) and joint space narrowing and osteophytes

    DEFF Research Database (Denmark)

    Owman, H; Ericsson, Y B; Englund, M

    2014-01-01

    OBJECTIVE: To examine the association between the relaxation time (T1Gd) of delayed gadolinium-enhanced magnetic resonance imaging of cartilage (dGEMRIC) and grade of tibiofemoral joint space narrowing (JSN) and osteophytosis 11 years later, in a cohort of meniscectomized patients. DESIGN: Patients...... (n = 45) aged 35-50 who had undergone an arthroscopic partial medial meniscectomy 1-6 years earlier, due to degenerative meniscal tear, were examined using dGEMRIC. These patients had no cartilage changes defined as deep clefts or visible bone at the time of arthroscopy. Eleven years later (12...

  14. Gadolinium-doped water cerenkov-based neutron and high energy gamma-ray detector and radiation portal monitoring system

    Science.gov (United States)

    Dazeley, Steven A; Svoboda, Robert C; Bernstein, Adam; Bowden, Nathaniel

    2013-02-12

    A water Cerenkov-based neutron and high energy gamma ray detector and radiation portal monitoring system using water doped with a Gadolinium (Gd)-based compound as the Cerenkov radiator. An optically opaque enclosure is provided surrounding a detection chamber filled with the Cerenkov radiator, and photomultipliers are optically connected to the detect Cerenkov radiation generated by the Cerenkov radiator from incident high energy gamma rays or gamma rays induced by neutron capture on the Gd of incident neutrons from a fission source. The PMT signals are then used to determine time correlations indicative of neutron multiplicity events characteristic of a fission source.

  15. The histological basis of late gadolinium enhancement cardiovascular magnetic resonance in a patient with Anderson-Fabry disease.

    Science.gov (United States)

    Moon, James C; Sheppard, Mary; Reed, Emma; Lee, Phillip; Elliott, Perry M; Pennell, Dudley J

    2006-01-01

    Anderson-Fabry Disease (AFD) is a storage disease that mimics hypertrophic cardiomyopathy. Late gadolinium enhancement (LGE) by cardiovascular magnetic resonance occurs in approximately 50% of patients in the basal inferolateral LV wall, but how an intracellular storage disease causes focal LGE is unknown. We present a whole-heart histological validation that LGE is caused by focal myocardial collagen scarring. This scarring may be the substrate for electrical re-entry and sudden arrhythmic death. The reasons for this distribution of fibrosis are unclear, but may reflect inhomogeneous left ventricular wall stress.

  16. MRI with intrathecal MRI gadolinium contrast medium administration: a possible method to assess glymphatic function in human brain

    International Nuclear Information System (INIS)

    Eide, Per Kristian; Ringstad, Geir

    2015-01-01

    Recently, the “glymphatic system” of the brain has been discovered in rodents, which is a paravascular, transparenchymal route for clearance of excess brain metabolites and distribution of compounds in the cerebrospinal fluid. It has already been demonstrated that intrathecally administered gadolinium (Gd) contrast medium distributes along this route in rats, but so far not in humans. A 27-year-old woman underwent magnetic resonance imaging (MRI) with intrathecal administration of gadobutrol, which distributed throughout her entire brain after 1 and 4.5 h. MRI with intrathecal Gd may become a tool to study glymphatic function in the human brain

  17. 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

    The influence of hydroxyl content of binders on rheological properties of screen printing inks is investigated. The actual amount of hydroxyl groups is correlated to the level of hyper-entanglement that characterizes the binders in solution. Three of the most used binders (ethyl cellulose, and two...... 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...

  18. Characterization of composite metal-ceramic of nickel-oxide cerium doped gadolinium; Caracterizacao de compositos ceramica-metal de niquel e oxido de cerio dopado com gadolinio

    Energy Technology Data Exchange (ETDEWEB)

    Silva, M.L.A. da, E-mail: maria.andrade@pro.unifacs.br [Universidade Salvador (UNIFACS), BA (Brazil). Escola de Engenharia, Arquitetura e TI; Universidade Federal da Bahia (UFBA), BA (Brazil); Varela, M.C.R.S. [Universidade Federal da Bahia (UFBA), BA (Brazil)

    2016-07-01

    Composite nickel doped cerium oxide are used in SOFC anode materials. In this study we evaluated the effect of the presence of gadolinium on the properties of composite nickel and ceria and. The supports were synthesized by sol-gel method. The impregnation with nickel nitrate was taken sequentially, followed by calcination. The materials were characterized by X-ray diffraction, measurement of specific surface area, temperature programmed reduction, Raman spectroscopy. The presence of gadolinium retained the fluorite structure of ceria by forming a solid solution, also not influencing significantly on the specific surface area of the support. On the other hand, there was a decrease in the area catalysts, which can be attributed to sintering of nickel. Furthermore, addition of gadolinium favored the formation of intrinsic and extrinsic vacancies in cerium oxide, which leads to an increase in the ionic conductivity of the solid, desirable property for an SOFC anode catalyst. (author)

  19. Transient arterial phase respiratory motion-related artifact in MR imaging of the liver: an analysis of four different gadolinium-based contrast agents.

    Science.gov (United States)

    Shah, Mansi R; Flusberg, Milana; Paroder, Viktoriya; Rozenblit, Alla M; Chernyak, Victoria

    The purpose was to compare hepatic arterial phase (HAP) respiratory motion artifact (RMA) between gadoxetate, gadobutrol, gadopentetate, and gadobenate. Two hundred cases of each gadolinium agent were included. RMA was assigned using 5-point Likert scale (1=no motion, 5=extreme motion) on precontrast and HAP. RMA increase (increase ≥1 on HAP from precontrast) was the outcome in logistic regression. Odds of RMA increase for gadoxetate were 5.5 (P<.001), 3.6 (P=.034), and 9.5 (P<.001) times higher than gadobutrol, gadopentetate, and gadobenate, respectively. Gadolinium volume and dose were not independent predictors of RMA increase. Gadoxetate has increased odds of RMA compared with other gadolinium agents; tight contrast bolus is not a contributor. Copyright © 2016 Elsevier Inc. All rights reserved.

  20. Study for the determination of samarium, europium,terbium, dysprosium and yttrium in gadolinium oxide matrix by means of atomic absorption spectrophotometry using a graphite furnace

    International Nuclear Information System (INIS)

    Caires, A.C.F.

    1985-01-01

    A study for determination of samarium, europium, terbium, dysprosium and yttrium in a gadolinium oxide matrix by atomic absorption spectrophotometry using a graphite furnace is presented. The best charrring and atomization conditions were estabilished for each element, the most convenient ressonance lines being selected as well. The study was carried out for the mentioned lanthanides both when pure and when in binary mixtures with gadolinium, besides those where all for them were together with gadolinium. The determination limits for pure lanthanides were found to be between 1.3 and 9.6 ng assuming a 20% relative standard deviation as acceptable. The detection limits were in the range 0.51 and 7.5 ng, assuming as positive any answer higher than twofold the standard deviation. (author) [pt

  1. Gadolinium-based Contrast Agent Accumulates in the Brain Even in Subjects without Severe Renal Dysfunction: Evaluation of Autopsy Brain Specimens with Inductively Coupled Plasma Mass Spectroscopy.

    Science.gov (United States)

    Kanda, Tomonori; Fukusato, Toshio; Matsuda, Megumi; Toyoda, Keiko; Oba, Hiroshi; Kotoku, Jun'ichi; Haruyama, Takahiro; Kitajima, Kazuhiro; Furui, Shigeru

    2015-07-01

    To use inductively coupled plasma mass spectroscopy (ICP-MS) to evaluate gadolinium accumulation in brain tissues, including the dentate nucleus (DN) and globus pallidus (GP), in subjects who received a gadolinium-based contrast agent (GBCA). Institutional review board approval was obtained for this study. Written informed consent for postmortem investigation was obtained either from the subject prior to his or her death or afterward from the subject's relatives. Brain tissues obtained at autopsy in five subjects who received a linear GBCA (GBCA group) and five subjects with no history of GBCA administration (non-GBCA group) were examined with ICP-MS. Formalin-fixed DN tissue, the inner segment of the GP, cerebellar white matter, the frontal lobe cortex, and frontal lobe white matter were obtained, and their gadolinium concentrations were measured. None of the subjects had received a diagnosis of severely compromised renal function (estimated glomerular filtration rate brain regions. Gadolinium was detected in all specimens in the GBCA agent group (mean, 0.25 µg per gram of brain tissue ± 0.44 [standard deviation]), with significantly higher concentrations in each region (P = .004 vs the non-GBCA group for all regions). In the GBCA group, the DN and GP showed significantly higher gadolinium concentrations (mean, 0.44 µg/g ± 0.63) than other regions (0.12 µg/g ± 0.16) (P = .029). Even in subjects without severe renal dysfunction, GBCA administration causes gadolinium accumulation in the brain, especially in the DN and GP.

  2. Morphological imaging and T2 and T2* mapping of hip cartilage at 7 Tesla MRI under the influence of intravenous gadolinium

    Energy Technology Data Exchange (ETDEWEB)

    Lazik-Palm, Andrea; Geis, Christina; Goebel, Juliane; Theysohn, Jens M. [University Hospital Essen, Department of Diagnostic and Interventional Radiology and Neuroradiology, Essen (Germany); Kraff, Oliver; Johst, Soeren [University of Duisburg-Essen, Erwin L. Hahn Institute for Magnetic Resonance Imaging, Essen (Germany); Ladd, Mark E. [University Hospital Essen, Department of Diagnostic and Interventional Radiology and Neuroradiology, Essen (Germany); University of Duisburg-Essen, Erwin L. Hahn Institute for Magnetic Resonance Imaging, Essen (Germany); German Cancer Research Center (DKFZ), Division of Medical Physics in Radiology, Heidelberg (Germany); Quick, Harald H. [University of Duisburg-Essen, Erwin L. Hahn Institute for Magnetic Resonance Imaging, Essen (Germany); University Hospital Essen, High-Field and Hybrid MR Imaging, Essen (Germany)

    2016-11-15

    To investigate the influence of intravenous gadolinium on cartilage T2 and T2* relaxation times and on morphological image quality at 7-T hip MRI. Hips of 11 healthy volunteers were examined at 7 T. Multi-echo sequences for T2 and T2* mapping, 3D T1 volumetric interpolated breath-hold examination (VIBE) and double-echo steady-state (DESS) sequences were acquired before and after intravenous application of gadolinium according to a delayed gadolinium-enhanced MRI of cartilage (dGEMRIC) protocol. Cartilage relaxation times were measured in both scans. Morphological sequences were assessed quantitatively using contrast ratios and qualitatively using a 4-point Likert scale. Student's t-test, Pearson's correlation (ρ) and Wilcoxon sign-rank test were used for statistical comparisons. Pre- and post-contrast T2 and T2* values were highly correlated (T2: acetabular: ρ = 0.76, femoral: ρ = 0.77; T2*: acetabular: ρ = 0.80, femoral: ρ = 0.72). Gadolinium enhanced contrasts between cartilage and joint fluid in DESS and T1 VIBE according to the qualitative (p = 0.01) and quantitative (p < 0.001) analysis. The delineation of acetabular and femoral cartilage and the labrum predominantly improved with gadolinium. Gadolinium showed no relevant influence on T2 or T2* relaxation times and improved morphological image quality at 7 T. Therefore, morphological and quantitative sequences including dGEMRIC can be conducted in a one-stop-shop examination. (orig.)

  3. Selective modification of NMR relaxation time in human colorectal carcinoma by using gadolinium-diethylenetriaminepentaacetic acid conjugated with monoclonal antibody 19-9.

    OpenAIRE

    Curtet, C; Tellier, C; Bohy, J; Conti, M L; Saccavini, J C; Thedrez, P; Douillard, J Y; Chatal, J F; Koprowski, H

    1986-01-01

    Monoclonal antibody 19-9 (mAb 19-9) against human colon adenocarcinoma was conjugated with gadolinium X diethylenetriaminepentaacetic acid (Gd X DTPA) and used as a contrast agent in nuclear magnetic resonance (NMR) in an effort to improve tumor target selectivity in nude mice. The data indicate that Gd X DTPA-mAb 19-9 in solution decreased the T1 relaxation of water protons at 90 MHz in direct proportion to the gadolinium concentration, and this effect was greater than in Gd X DTPA solutions...

  4. Concentration of gadolinium-diethylene triamine pentaacetic acid in human kidney

    International Nuclear Information System (INIS)

    Takeda, Masayuki; Katayama, Yasushi; Tsutsui, Toshiki; Komeyama, Takeshi; Mizusawa, Takaki; Tanikawa, Toshiki; Sato, Shotaro

    1993-01-01

    Although gadolinium diethylene triamine pentaacetic acid (Gd-DTPA) has been used as a contrast material in magnetic resonance imaging, it is known that contrast enhancement effect disappears if the concentration of Gd-DTPA increases beyond some levels. In this study, to evaluate the proper pulse sequences for dynamic magnetic resonance imaging (MRI) in the human kidney, the concentration of Gd-DTPA was quantitatively measured by inductively coupled plasma (ICP) emission spectrometry in human biological samples after administration of Gd-DTPA, and the signal intensity of MRI is the solution of several concentrations of Gd-DTPA was measured. In using a low magnetic field apparatus, signal intensity linearly correlated with the concentration of Gd-DTPA between 0 and 2.0 μmol/g under saturation recovery sequences (flip angle was 60deg or 90deg). Using a high magnetic field apparatus, signal intensity linearly correlated with the concentration of Gd-DTPA between 0 and 2.0 or 3.0 μmol/g under spin echo or gradient-echo sequences. Gd-DTPA concentration of the renal cortex ranged from 0.132 to 0.152 μmol/g tissue at 5 min after intravenous injection of Gd-DTPA 0.05 mmol/kg body weight in 7 patients with adrenal tumor or renal cell cancer, and 1 patient with both urinary bladder cancer and prostatic cancer. Seven of them showed normal renal function and the other had renal insufficiency (GFR 25 ml/min/1.48 m 2 ). Gd-DTPA concentrations of renal medulla and renal cell cancer tissue were 0.123 and 0.108 μmol/g tissue, respectively, at 5 min after intravenous injection of Gd-DTPA 0.05 mmol/kg body weight. These results suggest that the signal intensity of renal cortex, renal medulla, and renal cell cancer tissue may linearly correlate with Gd-DTPA concentration of tissues at 5 min after intravenous injection of Gd-DTPA 0.5 mmol/kg body weight. (author)

  5. Low Temperature Constrained Sintering of Cerium Gadolinium OxideFilms for Solid Oxide Fuel Cell Applications

    Energy Technology Data Exchange (ETDEWEB)

    Nicholas, Jason Dale [Univ. of California, Berkeley, CA (United States)

    2007-01-01

    Cerium gadolinium oxide (CGO) has been identified as an acceptable solid oxide fuel cell (SOFC) electrolyte at temperatures (500-700 C) where cheap, rigid, stainless steel interconnect substrates can be used. Unfortunately, both the high sintering temperature of pure CGO, >1200 C, and the fact that constraint during sintering often results in cracked, low density ceramic films, have complicated development of metal supported CGO SOFCs. The aim of this work was to find new sintering aids for Ce0.9Gd0.1O1.95, and to evaluate whether they could be used to produce dense, constrained Ce0.9Gd0.1O1.95 films at temperatures below 1000 C. To find the optimal sintering aid, Ce0.9Gd0.1O1.95 was doped with a variety of elements, of which lithium was found to be the most effective. Dilatometric studies indicated that by doping CGO with 3mol% lithium nitrate, it was possible to sinter pellets to a relative density of 98.5% at 800 C--a full one hundred degrees below the previous low temperature sintering record for CGO. Further, it was also found that a sintering aid's effectiveness could be explained in terms of its size, charge and high temperature mobility. A closer examination of lithium doped Ce0.9Gd0.1O1.95 indicated that lithium affects sintering by producing a Li2O-Gd2O3-CeO2 liquid at the CGO grain boundaries. Due to this liquid phase sintering, it was possible to produce dense, crack-free constrained films of CGO at the record low temperature of 950 C using cheap, colloidal spray deposition processes. This is the first time dense constrained CGO films have been produced below 1000 C and could help commercialize metal supported ceria based solid oxide fuel cells.

  6. Clinical performance of high-resolution late gadolinium enhancement imaging with compressed sensing.

    Science.gov (United States)

    Basha, Tamer A; Akçakaya, Mehmet; Liew, Charlene; Tsao, Connie W; Delling, Francesca N; Addae, Gifty; Ngo, Long; Manning, Warren J; Nezafat, Reza

    2017-12-01

    To evaluate diagnostic image quality of 3D late gadolinium enhancement (LGE) with high isotropic spatial resolution (∼1.4 mm 3 ) images reconstructed from randomly undersampled k-space using LOw-dimensional-structure Self-learning and Thresholding (LOST). We prospectively enrolled 270 patients (181 men; 55 ± 14 years) referred for myocardial viability assessment. 3D LGE with isotropic spatial resolution of 1.4 ± 0.1 mm 3 was acquired at 1.5T using a LOST acceleration rate of 3 to 5. In a subset of 121 patients, 3D LGE or phase-sensitive LGE were acquired with parallel imaging with an acceleration rate of 2 for comparison. Two readers evaluated image quality using a scale of 1 (poor) to 4 (excellent) and assessed for scar presence. The McNemar test statistic was used to compare the proportion of detected scar between the two sequences. We assessed the association between image quality and characteristics (age, gender, torso dimension, weight, heart rate), using generalized linear models. Overall, LGE detection proportions for 3D LGE with LOST were similar between readers 1 and 2 (16.30% vs. 18.15%). For image quality, readers gave 85.9% and 80.0%, respectively, for images categorized as good or excellent. Overall proportion of scar presence was not statistically different from conventional 3D LGE (28% vs. 33% [P = 0.17] for reader 1 and 26% vs. 31% [P = 0.37] for reader 2). Increasing subject heart rate was associated with lower image quality (estimated slope = -0.009 (P = 0.001)). High-resolution 3D LGE with LOST yields good to excellent image quality in >80% of patients and identifies patients with LV scar at the same rate as conventional 3D LGE. 2 Technical Efficacy: Stage 2 J. Magn. Reson. Imaging 2017;46:1829-1838. © 2017 International Society for Magnetic Resonance in Medicine.

  7. Immediate Allergic Reactions to Gadolinium-based Contrast Agents: A Systematic Review and Meta-Analysis.

    Science.gov (United States)

    Behzadi, Ashkan Heshmatzadeh; Zhao, Yize; Farooq, Zerwa; Prince, Martin R

    2018-02-01

    Purpose To perform a systematic review and meta-analysis to determine if there are differences in rates of immediate allergic events between classes of gadolinium-based contrast agents (GBCAs). Materials and Methods PubMed and Google Scholar databases were searched for studies in which rates of immediate adverse events to GBCAs were reported. The American College of Radiology classification system was used to characterize allergic-like events as mild, moderate, or severe, and the total number of administrations of each GBCA was recorded. Where necessary, authors of studies were contacted to clarify data and eliminate physiologic reactions. Relative risks of GBCA types were estimated by using the Mantel-Haenszel type method. Results Nine studies in which immediate reactions to GBCA were recorded from a total of 716 978 administrations of GBCA met the criteria for inclusion and exclusion. The overall and severe rates of GBCA allergic-like adverse events were 9.2 and 0.52 per 10 000 administrations, respectively: 81% (539 of 662) were mild, 13% (86 of 662) were moderate, and 6% (37 of 662) were severe reactions. The nonionic linear chelate gadodiamide had the lowest rate of reactions, at 1.5 (95% confidence interval [CI]: 0.74, 2.4) per 10 000 administrations, which was significantly less than that of linear ionic GBCAs at 8.3 (95% CI: 7.5, 9.2) per 10 000 administrations (relative risk, 0.19 [95% CI: 0.099, 0.36]; P < .00001) and less than that for nonionic macrocyclic GBCAs at 16 (95% CI: 14, 19) per 10 000 administrations (relative risk, 0.12 [95% CI: 0.05, 0.31]; P < .001). GBCAs known to be associated with protein binding had a higher rate of reactions, at 17 (95% CI: 15, 20) per 10 000 administrations compared with the same chelate classification without protein binding, at 5.2 (95% CI: 4.5, 6.0) per 10 000 administrations (relative risk, 3.1 [95% CI: 2.4, 3.8]; P < .0001). Conclusion These data show the lowest rate of immediate allergic adverse events with use

  8. Novel high relaxivity colloidal particles based on the specific phase organisation of amphiphilic gadolinium chelates with cholesterol.

    Science.gov (United States)

    Gløgård, Christian; Stensrud, Gry; Klaveness, Jo

    2003-03-06

    To obtain high T(1)-relaxivity colloidal particles with a simultaneously high loading of amphiphilic Gd-chelates, a novel drug dosage form based on the phase organisation of amphiphilic gadolinium chelates with cholesterol was developed. In order to find a formulation, which exhibit both high T(1)-relaxivity and gives small particles a D-optimal mixture design (experimental design) was applied. Gadolinium 1,4,7-tris(carboxymethyl)-10-(2-hydroxyhexadecyl)-1,4,7,10-tetraazacyclododecane (Gd-HHD-DO3A) and cholesterol at approximately equimolar ratio proved to form thermodynamic stable disc-like colloidal particles as seen by cryo-electron micrographs. T(1)-relaxivity of these particles was typically around 20mM(-1)s(-1) and the size below 100 nm (photon correlation spectroscopy (PCS)). The particles do most probably not interact with blood components as no change in T(1)-relaxivity was observed when the particles were mixed with whole blood. The particles were stable at room temperature for at least 6 months.

  9. Magnetic resonance urography enhanced by gadolinium and diuretics: a comparison with conventional urography in diagnosing the cause of ureteric obstruction.

    Science.gov (United States)

    Jung, P; Brauers, A; Nolte-Ernsting, C A; Jakse, G; Günther, R W

    2000-12-01

    To compare the ability of magnetic resonance urography (MRU), enhanced using gadolinium and frusemide diuresis, and conventional intravenous urography (IVU) to diagnose the cause of ureteric obstruction. The study included 82 patients in whom IVU showed or suggested obstruction and who also underwent MRU. The images from both methods were interpreted by various investigators independently; two evaluated the IVU and two others the MRU, the latter being unaware of the diagnosis after IVU. If the diagnosis remained unclear, further investigations (e.g. computed tomography, retrograde pyelography or ureteroscopy) were conducted. The diagnoses were ureteric calculi in 72 patients, ureteric tumours in eight and extra-ureteric tumours in two. In those with urolithiasis, the diagnosis was correct with IVU in 49 patients and with MRU in 64. The diagnosis in this group was incorrect with MRU in only two patients. The main reason for the failure of IVU was absent contrast medium excretion. Three of eight patients with ureteric tumours were correctly diagnosed by IVU but in three patients the diagnosis was incorrect. MRU correctly diagnosed seven of the eight patients in this group, with no false diagnosis. IVU is currently likely to remain the standard procedure for imaging the upper urinary tract, but this study shows the potential of MRU when enhanced with gadolinium and frusemide. MRU may be helpful if there is a dilated system with no excretory function, in pregnant women, in children and in those with contrast medium allergy.

  10. 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.

  11. Safe use of iodinated and gadolinium-based contrast media in current practice in Japan: a questionnaire survey.

    Science.gov (United States)

    Tsushima, Yoshito; Ishiguchi, Tsuneo; Murakami, Takamichi; Hayashi, Hiromitsu; Hayakawa, Katsumi; Fukuda, Kunihiko; Korogi, Yukunori; Sugimoto, Hideharu; Takehara, Yasuo; Narumi, Yoshifumi; Arai, Yasuaki; Kuwatsuru, Ryohei; Yoshimitsu, Kengo; Awai, Kazuo; Kanematsu, Masayuki; Takagi, Ryo

    2016-02-01

    To help establish consensus on the safe use of contrast media in Japan. Questionnaires were sent to accredited teaching hospitals with radiology residency programs. The reply rate was 45.4% (329/724). For contrast-induced nephropathy (CIN), chronic and acute kidney diseases were considered a risk factor in 96.7 and 93.6%, respectively, and dehydration in 73.9%. As preventive actions, intravenous hydration (89.1%) and reduction of iodinated contrast media dose (86.9%) were commonly performed. For nephrogenic systemic fibrosis (NSF), chronic and acute kidney diseases were considered risk factors in 98.5 and 90.6%, respectively, but use of unstable gadolinium-based contrast media was considered a risk factor in only 55.6%. A renal function test was always (63.5% in iodinated; 65.7% in gadolinium) or almost always (23.1; 19.8%) performed, and estimated glomerular filtration rate (eGFR) was the parameter most frequently used (80.8; 82.6%). For the patients with risk factors for acute adverse reaction (AAR), steroid premedication or/and change of contrast medium were frequent preventive actions, but intravenous steroid administration immediately before contrast media use was still performed. Our questionnaire survey revealed that preventive actions against CIN were properly performed based on patients' eGFR. Preventive actions against NSF and AAR still lacked consensus.

  12. Diuretic-enhanced gadolinium excretory MR urography: comparison of conventional gradient-echo sequences and echo-planar imaging

    Energy Technology Data Exchange (ETDEWEB)

    Nolte-Ernsting, C.C.A.; Tacke, J.; Adam, G.B.; Haage, P.; Guenther, R.W. [Univ. of Technology, Aachen (Germany). Dept. of Diagnostic Radiology; Jung, P.; Jakse, G. [Univ. of Technology, Aachen (Germany). Dept. of Urology

    2001-01-01

    The aim of this study was to investigate the utility of different gadolinium-enhanced T1-weighted gradient-echo techniques in excretory MR urography. In 74 urologic patients, excretory MR urography was performed using various T1-weighted gradient-echo (GRE) sequences after injection of gadolinium-DTPA and low-dose furosemide. The examinations included conventional GRE sequences and echo-planar imaging (GRE EPI), both obtained with 3D data sets and 2D projection images. Breath-hold acquisition was used primarily. In 20 of 74 examinations, we compared breath-hold imaging with respiratory gating. Breath-hold imaging was significantly superior to respiratory gating for the visualization of pelvicaliceal systems, but not for the ureters. Complete MR urograms were obtained within 14-20 s using 3D GRE EPI sequences and in 20-30 s with conventional 3D GRE sequences. Ghost artefacts caused by ureteral peristalsis often occurred with conventional 3D GRE imaging and were almost completely suppressed in EPI sequences (p < 0.0001). Susceptibility effects were more pronounced on GRE EPI MR urograms and calculi measured 0.8-21.7% greater in diameter compared with conventional GRE sequences. Increased spatial resolution degraded the image quality only in GRE-EPI urograms. (orig.)

  13. Successful balloon pulmonary angioplasty with gadolinium contrast media for a patient with chronic thromboembolic pulmonary hypertension and iodine allergy

    Directory of Open Access Journals (Sweden)

    Tomohisa Nakamura

    2016-01-01

    Full Text Available A 28-year-old male was referred to our hospital with dyspnea. He was diagnosed as having chronic thromboembolic pulmonary hypertension, and a pulmonary endarterectomy (PEA was performed. However, exertional dyspnea remained because of residual pulmonary hypertension; therefore, the patient was re-admitted to our hospital 1 year after PEA. We performed computed tomography and pulmonary angiography and found web and band lesions in the distal pulmonary artery with a high pulmonary artery pressure. Although further management was complicated because the patient had an anaphylactic shock to iodine-based contrast media, we eventually completed five sessions of balloon pulmonary angioplasty (BPA using gadolinium contrast medium. His symptoms and hemodynamics dramatically improved after a series of BPA. After 15 months, mean pulmonary arterial pressure reduced from 67 mmHg to 20 mmHg, and subjective symptoms improved from stage Ⅳ to I as per the WHO classification system. BPA is a potential procedure for residual pulmonary hypertension after PEA and could be safely performed using gadolinium contrast medium for patients with iodine allergy.

  14. Effect of gadolinium on hepatic fat quantification using multi-echo reconstruction technique with T2* correction and estimation

    Energy Technology Data Exchange (ETDEWEB)

    Ge, Mingmei; Wu, Bing; Liu, Zhiqin; Song, Hai; Meng, Xiangfeng; Wu, Xinhuai [The Military General Hospital of Beijing PLA, Department of Radiology, Beijing (China); Zhang, Jing [The 309th Hospital of Chinese People' s Liberation Army, Department of Radiology, Beijing (China)

    2016-06-15

    To determine whether hepatic fat quantification is affected by administration of gadolinium using a multiecho reconstruction technique with T2* correction and estimation. Forty-eight patients underwent the investigational sequence for hepatic fat quantification at 3.0T MRI once before and twice after administration of gadopentetate dimeglumine (0.1 mmol/kg). A one-way repeated-measures analysis of variance with pairwise comparisons was conducted to evaluate the systematic bias of fat fraction (FF) and R2* measurements between three acquisitions. Bland-Altman plots were used to assess the agreements between pre- and post-contrast FF measurements in the liver. A P value <0.05 indicated statistically significant difference. FF measurements of liver, spleen and spine revealed no significant systematic bias between the three measurements (P > 0.05 for all). Good agreements (95 % confidence interval) of FF measurements were demonstrated between pre-contrast and post-contrast1 (-0.49 %, 0.52 %) and post-contrast2 (-0.83 %, 0.77 %). R2* increased in liver and spleen (P = 0.039, P = 0.01) after administration of gadolinium. Although under the impact of an increased R2* in liver and spleen post-contrast, the investigational sequence can still obtain stable fat quantification. Therefore, it could be applied post-contrast to substantially increase the efficiency of MR examination and also provide a backup for the occasional failure of FF measurements pre-contrast. (orig.)

  15. Heterogeneous intratumoral distribution of gadolinium nanoparticles within U87 human glioblastoma xenografts unveiled by micro-PIXE imaging.

    Science.gov (United States)

    Carmona, Asuncion; Roudeau, Stéphane; L'Homel, Baptiste; Pouzoulet, Frédéric; Bonnet-Boissinot, Sarah; Prezado, Yolanda; Ortega, Richard

    2017-04-15

    Metallic nanoparticles have great potential in cancer radiotherapy as theranostic drugs since, they serve simultaneously as contrast agents for medical imaging and as radio-therapy sensitizers. As with other anticancer drugs, intratumoral diffusion is one of the main limiting factors for therapeutic efficiency. To date, a few reports have investigated the intratumoral distribution of metallic nanoparticles. The aim of this study was to determine the quantitative distribution of gadolinium (Gd) nanoparticles after direct intratumoral injection within U87 human glioblastoma tumors grafted in mice, using micro-PIXE (Particle Induced X-ray Emission) imaging. AGuIX (Activation and Guiding of Irradiation by X-ray) 3 nm particles composed of a polysiloxane network surrounded by gadolinium chelates were used. PIXE results indicate that the direct injection of Gd nanoparticles in tumors results in their heterogeneous diffusion, probably related to variations in tumor density. All tumor regions contain Gd, but with markedly different concentrations, with a more than 250-fold difference. Also Gd can diffuse to the healthy adjacent tissue. This study highlights the usefulness of mapping the distribution of metallic nanoparticles at the intratumoral level, and proposes PIXE as an imaging modality to probe the quantitative distribution of metallic nanoparticles in tumors from experimental animal models with micrometer resolution. Copyright © 2017 Elsevier Inc. All rights reserved.

  16. Human Aortic Endothelial Cell Labeling with Positive Contrast Gadolinium Oxide Nanoparticles for Cellular Magnetic Resonance Imaging at 7 Tesla

    Directory of Open Access Journals (Sweden)

    Yasir Loai

    2012-03-01

    Full Text Available Positive T1 contrast using gadolinium (Gd contrast agents can potentially improve detection of labeled cells on magnetic resonance imaging (MRI. Recently, gadolinium oxide (Gd2O3 nanoparticles have shown promise as a sensitive T1 agent for cell labeling at clinical field strengths compared to conventional Gd chelates. The objective of this study was to investigate Gado CELLTrack, a commercially available Gd2O3 nanoparticle, for cell labeling and MRI at 7 T. Relaxivity measurements yielded r1 = 4.7 s−1 mM−1 and r2/r1 = 6.2. Human aortic endothelial cells were labeled with Gd2O3 at various concentrations and underwent MRI from 1 to 7 days postlabeling. The magnetic resonance relaxation times T1 and T2 of labeled cell pellets were measured. Cellular contrast agent uptake was quantified by inductively coupled plasma–atomic emission spectroscopy, which showed very high uptake compared to conventional Gd compounds. MRI demonstrated significant positive T1 contrast and stable labeling on cells. Enhancement was optimal at low Gd concentrations, attained in the 0.02 to 0.1 mM incubation concentration range (corresponding cell uptake was 7.26 to 34.1 pg Gd/cell. Cell viability and proliferation were unaffected at the concentrations tested and up to at least 3 days postlabeling. Gd2O3 is a promising sensitive and stable positive contrast agent for cellular MRI at 7 T.

  17. Magnetic and magnetothermal studies of pure and doped gadolinium silicide nanoparticles for self-controlled hyperthermia applications

    Science.gov (United States)

    Alnasir, M. Hisham; Awan, M. S.; Manzoor, Sadia

    2018-03-01

    We report on magnetic and magnetothermal properties of undoped and doped gadolinium silicide (Gd5Si4) nanoparticles with the objective of simultaneously attaining high specific absorption rate (SAR) and low Curie temperature (TC) suitable for self-controlled hyperthermia applications for which TC ∼ 315-320 K. Pellets of doped gadolinium silicide Gd5(Si1-xGex)4 and (Gd1-xRx)5Si4 with R = Ho, Nd and Er and 0 ≤ x ≤ 0.35 were made by arc melting and reduced to nanoparticulate form by surfactant assisted ball milling. Structural and morphological studies were done using X-ray diffraction and scanning electron microscopy respectively. All samples show soft magnetic properties. At low fields there is a ferromagnetic to paramagnetic transition that reduces remanance and coercivity to zero making these materials very attractive for biomedical applications. Zero-field-cooled thermal demagnetization measurements showed that TC of these nanoparticles can be lowered to lie within the limits required for self-controlled hyperthermia by varying the dopant concentration. Specific absorption rates (SAR's) were obtained from magnetothermia measurements made in an ac magnetic field of amplitude 10 Oe and frequency 300 kHz. We have identified samples that have SAR values larger or comparable to those of magnetite and several ferrite nanoparticles, while having Curie temperatures that are low enough for self controlled hyperthermia applications.

  18. Critical Questions Regarding Gadolinium Deposition in the Brain and Body After Injections of the Gadolinium-Based Contrast Agents, Safety, and Clinical Recommendations in Consideration of the EMA's Pharmacovigilance and Risk Assessment Committee Recommendation for Suspension of the Marketing Authorizations for 4 Linear Agents.

    Science.gov (United States)

    Runge, Val M

    2017-06-01

    For magnetic resonance, the established class of intravenous contrast media is the gadolinium-based contrast agents. In the 3 decades since initial approval, these have proven in general to be very safe for human administration. However, in 2006, a devastating late adverse reaction to administration of the less stable gadolinium-based contrast agents was identified, nephrogenic systemic fibrosis. The result of actions taken by the European Medicines Agency and the US Food and Drug Administration, stratifying the agents by risk and contraindicating specific agents in severe renal dysfunction, has led to no new cases being identified in North America or Europe. Subsequently, in 2014, long-term deposition in the brain of gadolinium was first shown, after administration of 2 nonionic linear chelates, gadodiamide, and gadopentetate dimeglumine. This has led to an intense focus on the question of in vivo distribution, possible dechelation, and subsequent deposition of gadolinium, together with substantial clarification of the phenomenon as well as stratification of the agents on this basis. This review focuses on 8 critical questions regarding gadolinium deposition in the brain and body, with the answers and discussion therein important for future regulatory decisions and clinical practice. It is now clear that dechelation of gadolinium occurs in vivo with the linear agents and is responsible for this phenomenon, with key experts in the field recommending, except where there is no suitable alternative, a shift in clinical practice from the linear to macrocyclic agents. In addition, on March 10, 2017, the Pharmacovigilance and Risk Assessment Committee of the European Medicines Agency recommended suspension of the marketing authorization for 4 linear gadolinium contrast agents-specifically Omniscan, Optimark, Magnevist, and MultiHance (gadodiamide, gadoversetamide, gadopentetate dimeglumine, and gadobenate dimeglumine)-for intravenous injection. Cited in the report was

  19. Gadolinium- and manganite-based contrast agents with fluorescent probes for both magnetic resonance and fluorescence imaging of pancreatic islets: a comparative study

    Czech Academy of Sciences Publication Activity Database

    Berková, Z.; Jirák, D.; Zacharovová, K.; Lukeš, I.; Kotková, Z.; Kotek, J.; Kačenka, M.; Kaman, Ondřej; Řehoř, I.; Hájek, M.; Saudek, F.

    2013-01-01

    Roč. 8, č. 4 (2013), s. 614-621 ISSN 1860-7179 Institutional support: RVO:68378271 Keywords : contrast agents * gadolinium * magnetic resonance imaging * manganite * pancreatic islets Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 3.046, year: 2013

  20. Left Ventricular Function Evaluation on a 3T MR Scanner with Parallel RF Transmission Technique: Prospective Comparison of Cine Sequences Acquired before and after Gadolinium Injection.

    Science.gov (United States)

    Caspar, Thibault; Schultz, Anthony; Schaeffer, Mickaël; Labani, Aïssam; Jeung, Mi-Young; Jurgens, Paul Thomas; El Ghannudi, Soraya; Roy, Catherine; Ohana, Mickaël

    To compare cine MR b-TFE sequences acquired before and after gadolinium injection, on a 3T scanner with a parallel RF transmission technique in order to potentially improve scanning time efficiency when evaluating LV function. 25 consecutive patients scheduled for a cardiac MRI were prospectively included and had their b-TFE cine sequences acquired before and right after gadobutrol injection. Images were assessed qualitatively (overall image quality, LV edge sharpness, artifacts and LV wall motion) and quantitatively with measurement of LVEF, LV mass, and telediastolic volume and contrast-to-noise ratio (CNR) between the myocardium and the cardiac chamber. Statistical analysis was conducted using a Bayesian paradigm. No difference was found before or after injection for the LVEF, LV mass and telediastolic volume evaluations. Overall image quality and CNR were significantly lower after injection (estimated coefficient cine after > cine before gadolinium: -1.75 CI = [-3.78;-0.0305], prob(coef>0) = 0% and -0.23 CI = [-0.49;0.04], prob(coef>0) = 4%) respectively), but this decrease did not affect the visual assessment of LV wall motion (cine after > cine before gadolinium: -1.46 CI = [-4.72;1.13], prob(coef>0) = 15%). In 3T cardiac MRI acquired with parallel RF transmission technique, qualitative and quantitative assessment of LV function can reliably be performed with cine sequences acquired after gadolinium injection, despite a significant decrease in the CNR and the overall image quality.

  1. Four Gadolinium(III) Complexes Appended to a Porphyrin: A Water-Soluble Molecular Theranostic Agent with Remarkable Relaxivity Suited for MRI Tracking of the Photosensitizer.

    Science.gov (United States)

    Sour, Angélique; Jenni, Sébastien; Ortí-Suárez, Ana; Schmitt, Julie; Heitz, Valérie; Bolze, Frédéric; Loureiro de Sousa, Paulo; Po, Chrystelle; Bonnet, Célia S; Pallier, Agnès; Tóth, Éva; Ventura, Barbara

    2016-05-02

    A molecular theranostic agent for magnetic resonance imaging (MRI) and photodynamic therapy (PDT) consisting of four [GdDTTA](-) complexes (DTTA(4-) = diethylenetriamine-N,N,N″,N″-tetraacetate) linked to a meso-tetraphenylporphyrin core, as well as its yttrium(III) analogue, was synthesized. A variety of physicochemical methods were used to characterize the gadolinium(III) conjugate 1 both as an MRI contrast agent and as a photosensitizer. The proton relaxivity measured in H2O at 20 MHz and 25 °C, r1 = 43.7 mmol(-1) s(-1) per gadolinium center, is the highest reported for a bishydrated gadolinium(III)-based contrast agent of medium size and can be related to the rigidity of the molecule. The complex displays also a remarkable singlet oxygen quantum yield of ϕΔ = 0.45 in H2O, similar to that of a meso-tetrasulfonated porphyrin. We also evidenced the ability of the gadolinium(III) conjugate to penetrate in cancer cells with low cytotoxicity. Its phototoxicity on Hela cells was evaluated following incubation at low micromolar concentration and moderate light irradiation (21 J cm(-2)) induced 50% of cell death. Altogether, these results demonstrate the high potential of this conjugate as a theranostic agent for MRI and PDT.

  2. Highly-crystalline ultrathin gadolinium doped and carbon-coated Li4Ti5O12 nanosheets for enhanced lithium storage

    Science.gov (United States)

    Xu, G. B.; Yang, L. W.; Wei, X. L.; Ding, J. W.; Zhong, J. X.; Chu, P. K.

    2015-11-01

    Highly-crystalline gadolinium doped and carbon-coated ultrathin Li4Ti5O12 (LTO) nanosheets (denoted as LTO-Gd-C) as an anode material for Li-ion batteries (LIBs) are synthesized on large scale by controlling the amount of carbon precursor in the topotactic transformation of layered ultrathin Li1.81H0.19Ti2O5·xH2O (H-LTO) nanosheets at 700 °C. The characterizations of structure and morphology reveal that the gadolinium doped and carbon-coated ultrathin LTO nanosheets have high crystallinity with a thickness of about 10 nm. Gadolinium doping allows the spinel LTO products to be stabilized, thereby preserving the precursor's sheet morphology and single crystal structure. Carbon encapsulation serves dual functions by restraining crystal growth of the LTO primary nanoparticles in the LTO-Gd-C nanosheets and decreasing the external electron transport resistance. Owing to the synergistic effects rendered by ultrathin nanosheets with high crystallinity, gadolinium doping and carbon coating, the developed ultrathin LTO nanosheets possess excellent specific capacity, cycling performance, and rate capability compared with reference materials, when evaluated as an anode material for lithium ion batteries (LIBs). The simple and effective strategy encompassing nanoscale morphological engineering, surface modification, and doping improves the performance of LTO-based anode materials for high energy density and high power LIBs applied in large scale energy storage.

  3. Comparative in vivo dissociation of gadolinium chelates in renally impaired rats: a relaxometry study.

    Science.gov (United States)

    Fretellier, Nathalie; Idée, Jean-Marc; Dencausse, Anne; Karroum, Oussama; Guerret, Sylviane; Poveda, Nicolas; Jestin, Gaëlle; Factor, Cécile; Raynal, Isabelle; Zamia, Philippe; Port, Marc; Corot, Claire

    2011-05-01

    Investigation of dissociated versus chelated gadolinium (Gd) in plasma, skin, and bone of rats with impaired renal function after administration of ionic macrocyclic (gadoterate or Dotarem) or nonionic linear (gadodiamide or Omniscan) Gd chelates. Subtotally nephrectomized Wistar rats were subjected to receive daily injections of 2.5 mmol/kg of Omniscan, gadodiamide without excess ligand caldiamide, Dotarem, or saline (n = 7-10 rats/group) for 5 consecutive days. The Gd concentration was measured by inductively coupled plasma mass spectrometer in skin, femur epiphysis, and plasma on completion of the study (day 11), and dissociated Gd(3+) was measured in the plasma at day 11 (liquid chromatography inductively coupled plasma mass spectrometry). The r(1) relaxivity constant was measured in skin (at day 4 and day 11) and bone (day 11) to investigate the dissociated or chelated form of Gd found in tissue samples. Clinical and skin histopathologic studies were performed. Subtotal nephrectomy decreased creatinine clearance by 60%. No macroscopic skin lesions were observed in the Dotarem and Omniscan groups in contrast with the gadodiamide group (2 rats survived the study period and 4 of 10 rats showed skin ulcerations and scabs). Skin histopathologic lesions were in the range gadodiamide > Omniscan > Dotarem (similar to control rats). At day 11, the skin Gd concentration was lower in the Dotarem group (161.0 ± 85.5 nmol/g) as compared with the Omniscan (490.5 ± 223.2 nmol/g) and gadodiamide groups (mean value, 776.1 nmol/g; n = 2 survivors). The total Gd concentration in the femur was significantly higher in the Omniscan group than in the Dotarem group. At day 11, the dissociated Gd(3+) concentration in plasma was below the limit of detection in the Dotarem group and was 1.5 ± 0.7 μmol/L in the Omniscan group corresponding to 62% ± 15% of the total Gd concentration. The dissociated Gd(3+) concentration was 1.1 μmol/L in gadodiamide rats (n = 2 survivors). In the

  4. 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

  5. Free-breathing motion-corrected late-gadolinium-enhancement imaging improves image quality in children

    International Nuclear Information System (INIS)

    Olivieri, Laura; O'Brien, Kendall J.; Cross, Russell; Xue, Hui; Kellman, Peter; Hansen, Michael S.

    2016-01-01

    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

  6. Performance of Large Neutron Detectors Containing Lithium-Gadolinium-Borate Scintillator

    Energy Technology Data Exchange (ETDEWEB)

    Slaughter, David M.; Stuart, Cory R.; Klaass, R. Fred; Merrill, David B. [MSI/Photogenics Division, Orem, Utah (United States)

    2015-07-01

    This paper describes the development and testing of a neutron counter, spectrometer, and dosimeter that is compact, efficient, and accurate. A self-contained neutron detection instrument has wide applications in health physics, scientific research, and programs to detect, monitor, and control strategic nuclear materials (SNM). The 1.3 liter detector head for this instrument is a composite detector with an organic scintillator containing uniformly distributed {sup 6}Li{sub 6}{sup nat}Gd{sup 10}B{sub 3}O{sub 9}:Ce (LGB:Ce) microcrystals. The plastic scintillator acts to slow impinging neutrons and emits light proportional to the energy lost by the neutrons as they moderate in the detector body. Moderating neutrons that have slowed sufficiently capture in one of the Lithium-6, Boron-10, or Gadolinium-157 atoms in the LGB:Ce scintillator, which then releases the capture energy in a characteristic cerium emission pulse. The measured captured pulses indicate the presence of neutrons. When a scintillating fluor is present in the plastic, the light pulse resulting from the neutron moderating in the plastic is paired with the LGB:Ce capture pulse to identify the energy of the neutron. About 2% of the impinging neutrons lose all of their energy in a single collision with the detector. There is a linear relationship between the pulse areas of this group of neutrons and energy. The other 98% of neutrons have a wide range of collision histories within the detector body. When these neutrons are 'binned' into energy groups, each group contains a distribution of pulse areas. This data was used to assist in the unfolding of the neutron spectra. The unfolded spectra were then validated with known spectra, at both neutron emitting isotopes and fission/accelerator facilities. Having validated spectra, the dose equivalent and dose rate are determined by applying standard, regulatory damage coefficients to the measured neutron counts for each energy bin of the spectra. Testing

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

    International Nuclear Information System (INIS)

    Aran, S.; Shaqdan, K.W.; Abujudeh, H.H.

    2015-01-01

    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. Intensity of MRI Gadolinium Enhancement in Cerebral Adrenoleukodystrophy: A Biomarker for Inflammation and Predictor of Outcome following Transplantation in Higher Risk Patients.

    Science.gov (United States)

    Miller, W P; Mantovani, L F; Muzic, J; Rykken, J B; Gawande, R S; Lund, T C; Shanley, R M; Raymond, G V; Orchard, P J; Nascene, D R

    2016-02-01

    Outcomes following hematopoietic stem cell transplantation for higher risk childhood-onset cerebral adrenoleukodystrophy are variable. We explored whether a brain MR imaging gadolinium intensity scoring system improves prediction of neurologic outcome. We developed a 4-point scale of gadolinium intensity relative to the choroid plexus: 0 = no enhancement; 1 = hypointense; 2 = isointense; 3 = hyperintense. The interobserver concordance of the scale was assessed on 30 randomly chosen studies. Scores were generated for 64 evaluable patients and compared with CSF chitotriosidase levels, a known inflammatory marker correlating with outcomes following transplantation. For 25 evaluable higher risk patients (Loes ≥10), the gadolinium intensity score was compared with longer term posttransplantation clinical change. The gadolinium intensity scoring system showed good interobserver reproducibility (κ = 0.72). Of 64 evaluable boys, the score positively correlated with average concomitant CSF chitotriosidase activity in nanograms/milliliter/hour: 0: 2717, n = 5; 1: 3218, n = 13; 2: 6497, n = 23; and 3: 12,030, n = 23 (P adrenoleukodystrophy neurologic function scale following transplantation: 0/1: adrenoleukodystrophy neurologic function scale score difference = 4.3, n = 7; 2/3: adrenoleukodystrophy neurologic function scale score difference = 10.4, n = 18 (P = .05). Gadolinium enhancement intensity on brain MR imaging can be scored simply and reproducibly for cerebral adrenoleukodystrophy. The enhancement score significantly correlates with chitotriosidase. In boys with higher risk cerebral disease (Loes ≥10), the enhancement score itself predicts neurologic outcome following treatment. Such data may help guide treatment decisions for clinicians and families. © 2016 by American Journal of Neuroradiology.

  9. Intensity of MRI gadolinium enhancement in cerebral adrenoleukodystrophy: a biomarker for inflammation and predictor of outcome following transplant in higher-risk patients

    Science.gov (United States)

    Miller, Weston P.; Mantovani, Luiz F.; Muzic, John; Rykken, Jeffrey B.; Gawande, Rakhee S.; Lund, Troy C.; Shanley, Ryan M.; Raymond, Gerald V.; Orchard, Paul J.; Nascene, David R.

    2016-01-01

    BACKGROUND AND PURPOSE Outcomes following hematopoietic stem cell transplantation for higher-risk childhood-onset cerebral adrenoleukodystrophy are variable. We explored whether a brain MRI gadolinium intensity scoring system improves prediction of neurologic outcome. METHODS A four-point scale of gadolinium intensity relative to the choroid plexus was developed: 0 = no enhancement; 1 = hypo-intense; 2 = iso-intense; 3 = hyper-intense. The scale’s inter-observer concordance was assessed on 30 randomly chosen studies. Scores were generated for 64 evaluable patients and compared with cerebrospinal fluid chitotriosidase levels, a known inflammatory marker correlating with outcomes following transplant. For 25 evaluable higher-risk patients (Loes ≥ 10), the gadolinium intensity score was compared with longer-term post-transplant clinical change. RESULTS The gadolinium intensity scoring system showed good inter-observer reproducibility (kappa = 0.72). Of 64 evaluable boys, the score positively correlated with average concomitant cerebrospinal fluid chitotriosidase activity in ng/mL/hr: (0), 2,717, n=5; (1), 3,218, n=13; (2), 6,497, n=23; and (3), 12,030, n=23 (p adrenoleukodystrophy neurologic function scale following transplant: (0/1), ΔNFS = 4.3, n = 7; (2/3), ΔNFS = 10.4, n = 18 (p = 0.05). CONCLUSION Gadolinium enhancement intensity on brain MRI can be scored simply and reproducibly for cerebral adrenoleukodystrophy. Enhancement score significantly correlates with chitotriosidase. In boys with higher-risk cerebral disease (Loes ≥ 10), enhancement score itself predicts neurologic outcome following treatment. Such data may help to guide treatment decisions for clinicians and families. PMID:26427835

  10. 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.

  11. Chelator-Free and Biocompatible Melanin Nanoplatform with Facile-Loading Gadolinium and Copper-64 for Bioimaging.

    Science.gov (United States)

    Hong, Su Hyun; Sun, Yao; Tang, Chu; Cheng, Kai; Zhang, Ruiping; Fan, Quli; Xu, Liying; Huang, Daijuan; Zhao, Anthony; Cheng, Zhen

    2017-07-19

    Development of a chelator-free and biocompatible platform for the facile construction of gadolinium 3+ (Gd 3+ )-loaded nanoparticle based probes for in vivo magentic resonance imaging (MRI) is still challenging. Herein, biocompatible Gd 3+ -loading melanin dots (Gd-M-dots) have been easily prepared and have exhibited good loading efficiency for Gd 3+ , high stability, and higher T 1 relaxivity compared to the commercial Gd-1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA) agent. Furthermore, Gd-M-dots showed unique photoacoustic (PA) properties, and a high PA imaging signal could be observed in vivo 1 h after injection. Compared to the traditional Gd 3+ -loaded nanoparticles for single-modal MRI, Gd-M-dots can also be radiolabeled with 64 Cu 2+ for positron emission tomography. Overall, these attractive properties of Gd-M-dots render them a promising imaging agent for various biomedical applications.

  12. Effectiveness of late gadolinium enhancement to improve outcomes prediction in patients referred for cardiovascular magnetic resonance after echocardiography

    Science.gov (United States)

    2013-01-01

    Background Echocardiography (echo) is a first line test to assess cardiac structure and function. It is not known if cardiovascular magnetic resonance (CMR) with late gadolinium enhancement (LGE) ordered during routine clinical practice in selected patients can add additional prognostic information after routine echo. We assessed whether CMR improves outcomes prediction after contemporaneous echo, which may have implications for efforts to optimize processes of care, assess effectiveness, and allocate limited health care resources. Methods and results We prospectively enrolled 1044 consecutive patients referred for CMR. There were 38 deaths and 3 cardiac transplants over a median follow-up of 1.0 years (IQR 0.4-1.5). We first reproduced previous survival curve strata (presence of LGE and ejection fraction (EF) echocardiography, CMR with LGE further improves risk stratification of individuals at risk for death or death/cardiac transplant. PMID:23324403

  13. Constructing experimental devices for half-ton synthesis of gadolinium-loaded liquid scintillator and its performance

    Science.gov (United States)

    Park, Young Seo; Jang, Yeong Min; Joo, Kyung Kwang

    2018-04-01

    This paper describes in brief features of various experimental devices constructed for half-ton synthesis of gadolinium(Gd)-loaded liquid scintillator (GdLS) and also includes the performances and detailed chemical and physical results of a 0.5% high-concentration GdLS. Various feasibility studies on useful apparatus used for loading Gd into solvents have been carried out. The transmittance, Gd concentration, density, light yield, and moisture content were measured for quality control. We show that with the help of adequate automated experimental devices and tools, it is possible to perform ton scale synthesis of GdLS at moderate laboratory scale without difficulty. The synthesized GdLS was satisfactory to meet chemical, optical, and physical properties and various safety requirements. These synthesizing devices can be expanded into massive scale next-generation neutrino experiments of several hundred tons.

  14. Recent progress in advanced optical materials based on gadolinium aluminate garnet (Gd3Al5O12)

    Science.gov (United States)

    Li, Ji-Guang; Sakka, Yoshio

    2015-02-01

    This review article summarizes the recent achievements in stabilization of the metastable lattice of gadolinium aluminate garnet (Gd3Al5O12, GAG) and the related developments of advanced optical materials, including down-conversion phosphors, up-conversion phosphors, transparent ceramics, and single crystals. Whenever possible, the materials are compared with their better known YAG and LuAG counterparts to demonstrate the merits of the GAG host. It is shown that novel emission features and significantly improved luminescence can be attained for a number of phosphor systems with the more covalent GAG lattice and the efficient energy transfer from Gd3+ to the activator. Ce3+ doped GAG-based single crystals and transparent ceramics are also shown to simultaneously possess the advantages of high theoretical density, fast scintillation decay, and high light yields, and hold great potential as scintillators for a wide range of applications. The unresolved issues are also pointed out.

  15. Ultra high molecular weight polyethylene (UHMWPE) fiber epoxy composite hybridized with Gadolinium and Boron nanoparticles for radiation shielding

    Science.gov (United States)

    Mani, Venkat; Prasad, Narasimha S.; Kelkar, Ajit

    2016-09-01

    Deep space radiations pose a major threat to the astronauts and their spacecraft during long duration space exploration missions. The two sources of radiation that are of concern are the galactic cosmic radiation (GCR) and the short lived secondary neutron radiations that are generated as a result of fragmentation that occurs when GCR strikes target nuclei in a spacecraft. Energy loss, during the interaction of GCR and the shielding material, increases with the charge to mass ratio of the shielding material. Hydrogen with no neutron in its nucleus has the highest charge to mass ratio and is the element which is the most effective shield against GCR. Some of the polymers because of their higher hydrogen content also serve as radiation shield materials. Ultra High Molecular Weight Polyethylene (UHMWPE) fibers, apart from possessing radiation shielding properties by the virtue of the high hydrogen content, are known for extraordinary properties. An effective radiation shielding material is the one that will offer protection from GCR and impede the secondary neutron radiations resulting from the fragmentation process. Neutrons, which result from fragmentation, do not respond to the Coulombic interaction that shield against GCR. To prevent the deleterious effects of secondary neutrons, targets such as Gadolinium are required. In this paper, the radiation shielding studies that were carried out on the fabricated sandwich panels by vacuum-assisted resin transfer molding (VARTM) process are presented. VARTM is a manufacturing process used for making large composite structures by infusing resin into base materials formed with woven fabric or fiber using vacuum pressure. Using the VARTM process, the hybridization of Epoxy/UHMWPE composites with Gadolinium nanoparticles, Boron, and Boron carbide nanoparticles in the form of sandwich panels were successfully carried out. The preliminary results from neutron radiation tests show that greater than 99% shielding performance was

  16. Differentiation between benign and malignant colon tumors using fast dynamic gadolinium-enhanced MR colonography; a feasibility study

    Energy Technology Data Exchange (ETDEWEB)

    Achiam, M.P., E-mail: achiam1@dadlnet.d [Department of Diagnostic Radiology, Copenhagen University Hospital Herlev, Herlev Ringvej, DK-2730 Herlev (Denmark); Department of Surgical Gastroenterology D, Copenhagen University Hospital Herlev, Herlev Ringvej, DK-2730 Herlev (Denmark); Department of Diagnostic Sciences, Faculty of Health Sciences, University of Copenhagen, Blegdamsvej 3C, DK-2200 Copenhagen (Denmark); Andersen, L.P.H.; Klein, M. [Department of Surgical Gastroenterology D, Copenhagen University Hospital Herlev, Herlev Ringvej, DK-2730 Herlev (Denmark); Department of Diagnostic Sciences, Faculty of Health Sciences, University of Copenhagen, Blegdamsvej 3C, DK-2200 Copenhagen (Denmark); Logager, V.; Chabanova, E.; Thomsen, H.S. [Department of Diagnostic Radiology, Copenhagen University Hospital Herlev, Herlev Ringvej, DK-2730 Herlev (Denmark); Department of Diagnostic Sciences, Faculty of Health Sciences, University of Copenhagen, Blegdamsvej 3C, DK-2200 Copenhagen (Denmark); Rosenberg, J. [Department of Surgical Gastroenterology D, Copenhagen University Hospital Herlev, Herlev Ringvej, DK-2730 Herlev (Denmark); Department of Diagnostic Sciences, Faculty of Health Sciences, University of Copenhagen, Blegdamsvej 3C, DK-2200 Copenhagen (Denmark)

    2010-06-15

    Background: 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-enhanced MR imaging combined with MR colonography could be used to differentiate a benign from a malignant obstructing colon tumor. Methods: Patients with benign colon tumor stenosis, based on diverticulitis, were asked to participate in the study. The same number of patients with verified colorectal cancer was included. Both groups had to be scheduled for surgery to be included. Two blinded observers analyzed the tumors on MR by placing a region of interest in the tumor and a series of parameters were evaluated, e.g. wash-in, wash-out and time-to-peak. Results: 14 patients were included. The wash-in and wash-out rates were significantly different between the benign and malignant tumors, and a clear distinction between benign and malignant disease was therefore possible by looking only at the MR data. Furthermore, MR colography evaluating the rest of the colon past the stenosis was possible with all patients. Conclusion: The results showed the feasibility of using fast dynamic gadolinium-enhanced MR imaging to differentiate between benign and malignant colonic tumors. With a high intra-class correlation and significant differences found on independent segments of the tumor, the method appears to be reproducible. Furthermore, the potential is big in performing a full preoperative colon evaluation even in patients with obstructing cancer. Trial number: (NCT00114829).

  17. Assessment of renal artery stenosis: Comparison of captopril renography and gadolinium-enhanced breath-hold MR angiography

    Energy Technology Data Exchange (ETDEWEB)

    Bongers, V.; Bakker, J.; Beutler, J.J.; Beek, F.J.A.; De Klerk, J.M.H

    2000-05-01

    AIM: To determine the accuracy of captopril renography (CR) and gadolinium-enhanced breath-hold magnetic resonance (MR) angiography in the diagnosis of 50-99% renal artery stenosis (RAS). MATERIALS AND METHODS: Forty-three patients with possible RAS, of whom 53% had renal function impairment (creatinine >130 {mu}mol/l), were included.{sup 99m}Tc-mercaptoacetyl triglycine (MAG{sub 3}) renography was performed after an oral dose of 25 mg captopril. Gadolinium-enhanced MR angiography was performed on a standard 1.5 Tesla system: TR 13.5, TE 3.5, flip angle 60 deg. , matrix 195 x 512. Intra-arterial digital subtraction angiography (DSA) was the standard of reference. RESULTS: Captropril renography accurately categorized 22 of 26 patients who had either uni- or bilateral RAS of 50-99%. The sensitivity and specificity of CR for the detection of 50-99% stenosis were 85 and 71%, respectively. With MR angiography one occluded artery was incorrectly diagnosed as a stenosis. Sensitivity and specificity were 100 and 94%, respectively. The difference between the accuracies of MR angiography and CR was statistically significant (P = 0.02). The accuracy of CR was lower in patients with renal impairment (70%) than in those with normal renal function (90%). CONCLUSION: MR angiography showed a high accuracy in diagnosing RAS of between 50 and 99%. CR was less accurate than MR angiography, especially in patients with renal function impairment. In patients with normal renal function, however, CR remains a useful diagnostic test. Bongers, V. (2000)

  18. Gadolinium chloride elicits apoptosis in human osteosarcoma U-2 OS cells through extrinsic signaling, intrinsic pathway and endoplasmic reticulum stress.

    Science.gov (United States)

    Tsai, Yuh-Feng; Huang, Ching-Wen; Chiang, Jo-Hua; Tsai, Fuu-Jen; Hsu, Yuan-Man; Lu, Chi-Cheng; Hsiao, Chen-Yu; Yang, Jai-Sing

    2016-12-01

    Gadolinium (Gd) compounds are important as magnetic resonance imaging (MRI) contrast agents, and are potential anticancer agents. However, no report has shown the effect of gadolinium chloride (GdCl3) on osteosarcoma in vitro. The present study investigated the apoptotic mechanism of GdCl3 on human osteosarcoma U-2 OS cells. Our results indicated that GdCl3 significantly reduced cell viability of U-2 OS cells in a concentration-dependent manner. GdCl3 led to apoptotic cell shrinkage and DNA fragmentation in U-2 OS cells as revealed by morphologic changes and TUNEL staining. Colorimetric assay analyses also showed that activities of caspase-3, caspase-8, caspase-9 and caspase-4 occurred in GdCl3-treated U-2 OS cells. Pretreatment of cells with pan-caspase inhibitor (Z-VAD-FMK) and specific inhibitors of caspase-3/-8/-9 significantly reduced cell death caused by GdCl3. The increase of cytoplasmic Ca2+ level, ROS production and the decrease of mitochondria membrane potential (ΔΨm) were observed by flow cytometric analysis in U-2 OS cells after GdCl3 exposure. Western blot analyses demonstrated that the levels of Fas, FasL, cytochrome c, Apaf-1, GADD153 and GRP78 were upregulated in GdCl3-treated U-2 OS cells. In conclusion, death receptor, mitochondria-dependent and endoplasmic reticulum (ER) stress pathways contribute to GdCl3-induced apoptosis in U-2 OS cells. GdCl3 might have potential to be used in treatment of osteosarcoma patients.

  19. Differentiation between benign and malignant colon tumors using fast dynamic gadolinium-enhanced MR colonography; a feasibility study

    International Nuclear Information System (INIS)

    Achiam, M.P.; Andersen, L.P.H.; Klein, M.; Logager, V.; Chabanova, E.; Thomsen, H.S.; Rosenberg, J.

    2010-01-01

    Background: 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-enhanced MR imaging combined with MR colonography could be used to differentiate a benign from a malignant obstructing colon tumor. Methods: Patients with benign colon tumor stenosis, based on diverticulitis, were asked to participate in the study. The same number of patients with verified colorectal cancer was included. Both groups had to be scheduled for surgery to be included. Two blinded observers analyzed the tumors on MR by placing a region of interest in the tumor and a series of parameters were evaluated, e.g. wash-in, wash-out and time-to-peak. Results: 14 patients were included. The wash-in and wash-out rates were significantly different between the benign and malignant tumors, and a clear distinction between benign and malignant disease was therefore possible by looking only at the MR data. Furthermore, MR colography evaluating the rest of the colon past the stenosis was possible with all patients. Conclusion: The results showed the feasibility of using fast dynamic gadolinium-enhanced MR imaging to differentiate between benign and malignant colonic tumors. With a high intra-class correlation and significant differences found on independent segments of the tumor, the method appears to be reproducible. Furthermore, the potential is big in performing a full preoperative colon evaluation even in patients with obstructing cancer. Trial number: (NCT00114829).

  20. Role of MRI T2-DRIVE in the Assessment of Pituitary Stalk Abnormalities without Gadolinium in Pituitary Diseases.

    Science.gov (United States)

    Godano, Elisabetta; Morana, Giovanni; Di Iorgi, Natascia; Pistorio, Angela; Allegri, Anna Elsa Maria; Napoli, Flavia; Gastaldi, Roberto; Calcagno, Annalisa; Patti, Giuseppa; Gallizia, Annalisa; Notarnicola, Sara; Giaccardi, Marta; Noli, Serena; Severino, Mariasavina; Tortora, Domenico; Rossi, Andrea; Maghnie, Mohamad

    2018-04-12

    To investigate the role of T2-DRIVE MRI sequence in the accurate measurement of pituitary stalk (PS) size and the identification of PS abnormalities in patients with hypothalamic-pituitary disorders without the use of gadolinium. This was a retrospective study conducted on 242 patients who underwent MRI due to pituitary dysfunction between 2006 - 2015. Among 135 eligible patients, 102 showed eutopic posterior pituitary (PP) gland and 33 showed "ectopic" PP (EPP). Two readers independently measured the size of PS in patients with eutopic PP at the proximal, midpoint and distal levels on pre- and post-contrast T1-weighted as well as T2-DRIVE images; PS visibility was assessed on pre-contrast T1 and T2-DRIVE sequences in those with EPP. The length, height, width and volume of the anterior pituitary (AP), PP height and length, and PP area were analyzed. Significant agreement between the two readers was obtained for T2-DRIVE PS measurements in patients with "eutopic" PP; a significant difference was demonstrated between the Intraclass correlation coefficient calculated on the T2-DRIVE and the T1-pre- and post-contrast sequences. The percentage of PS identified by T2-DRIVE in EPP patients was 72.7% compared to 30.3% of T1 pre-contrast sequences. A significant association was found between the visibility of PS on T2-DRIVE and the height of AP. T2-DRIVE sequence is extremely precise and reliable for the evaluation of PS size and the recognition of PS abnormalities; the use of gadolinium-based contrast media does not add significant information and may thus be avoided.

  1. Combined magnetic resonance coronary artery imaging, myocardial perfusion and late gadolinium enhancement in patients with suspected coronary artery disease

    Directory of Open Access Journals (Sweden)

    Dreysse Stephan

    2008-10-01

    Full Text Available Abstract Background Cardiovascular Magnetic Resonance (CMR imaging offers methods for the detection of ischemia and myocardial infarction as well as visualization of the coronary arteries (MRCA. However, a direct comparison of adenosine perfusion (PERF, late gadolinium enhancement (LGE and MRCA or the results of their combination has not been performed. Aim of the study was to evaluate the feasibility/diagnostic performance of rest/stress perfusion, late gadolinium enhancement and MRCA and their combination in patients with suspected coronary artery disease (CAD in comparison to invasive angiography. Methods Fifty-four patients (60 ± 10 years, 35 men, CAD 48% underwent CMR including MRCA (steady state free precession, navigator whole heart approach, spatial resolution 0.7 × 0.7 × .0.9 mm, trigger delay and temporal resolution adjusted individually, stress PERF (adenosine 140 μg/min/kg, rest PERF (SSFP, 3 short axis, 1 saturation prepulse per slice and LGE (3D inversion recovery technique using Gd-BOPTA. Images were analyzed visually. Stenosis >50% in invasive angiography was considered significant. Results Mean study time was 68 ± 11 minutes. Sensitivity for PERF, LGE, MRCA and the combination of PERF/LGE and PERF/LGE/MRCA was 87%, 50%, 91%, 88% and 92%, respectively and specificity 88%, 96%, 46%, 88% and 56%, respectively. If image quality of MRCA was excellent (n = 18 the combination of MRCA/PERF/LGE yield a sensitivity of 86% and specificity of 91%. However, no test or combination improved diagnostic performance significantly compared to PERF alone. Conclusion In patients with CAD, the combination of stress PERF, LGE and MRCA is feasible. When compared to invasive angiography, adenosine stress perfusion outperforms CMR coronary angiography in direct comparison and yields the best results with non-significant improvement in combination with LGE and significant deterioration in combination with MRCA. MRCA may be of additional value only in

  2. 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.

  3. Biodegradable gadolinium-chelated cationic poly(urethane amide) copolymers for gene transfection and magnetic resonance imaging

    International Nuclear Information System (INIS)

    Gao, Xiaolong; Wang, Gangmin; Shi, Ting; Shao, Zhihong; Zhao, Peng; Shi, Donglu; Ren, Jie; Lin, Chao; Wang, Peijun

    2016-01-01

    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 T 1 -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 25 kDa 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 T 1 -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. - Highlights: • Novel cationic gadolinium-chelated poly(urethane amide)s (GdCPUAs) are prepared. • GdCPUAs can induce a high transfection efficacy in different cancer cells. • GdCPUAs reveal good cyto-compatibility against cancer cells. • GdCPUAs may be applied as T 1 -contrast agents for magnetic resonance imaging. • GdCPUAs hold high potential for cancer theranostics.

  4. Effects of motexafin gadolinium on DNA damage and X-ray-induced DNA damage repair, as assessed by the Comet assay

    International Nuclear Information System (INIS)

    Donnelly, Erling T.; Liu Yanfeng; Paul, Tracy K.; Rockwell, Sara

    2005-01-01

    Purpose: To investigate the effects of motexafin gadolinium (MGd) on the levels of reactive oxygen species (ROS), glutathione (GSH), and DNA damage in EMT6 mouse mammary carcinoma cells. The ability of MGd to alter radiosensitivity and to inhibit DNA damage repair after X-ray irradiation was also evaluated. Methods and Materials: Reactive oxygen species and GSH levels were assessed by 2,7-dichlorofluorescein fluorescence flow cytometry and the Tietze method, respectively. Cellular radiosensitivity was assessed by clonogenic assays. Deoxyribonucleic acid damage and DNA damage repair were assessed in plateau-phase EMT6 cells by the Comet assay and clonogenic assays. Results: Cells treated with 100 μmol/L MGd plus equimolar ascorbic acid (AA) had significantly increased levels of ROS and a 58.9% ± 3.4% decrease in GSH levels, relative to controls. Motexafin gadolinium plus AA treatment increased the hypoxic, but not the aerobic, radiosensitivity of EMT6 cells. There were increased levels of single-strand breaks in cells treated with 100 μmol/L MGd plus equimolar AA, as evidenced by changes in the alkaline tail moment (MGd + AA, 6 h: 14.7 ± 1.8; control: 2.8 ± 0.9). The level of single-strand breaks was dependent on the length of treatment. Motexafin gadolinium plus AA did not increase double-strand breaks. The repair of single-strand breaks at 2 h, but not at 4 h and 6 h, after irradiation was altered significantly in cells treated with MGd plus AA (MGd + AA, 2 h: 15.8 ± 3.4; control: 5.8 ± 0.6). Motexafin gadolinium did not alter the repair of double-strand breaks at any time after irradiation with 10 Gy. Conclusions: Motexafin gadolinium plus AA generated ROS, which in turn altered GSH homeostasis and induced DNA strand breaks. The MGd plus AA-mediated alteration of GSH levels increased the hypoxic, but not aerobic, radiosensitivity of EMT6 cells. Motexafin gadolinium altered the kinetics of single-strand break repair soon after irradiation but did not

  5. MRI evaluation of myometrial invasion by endometrial carcinoma. Comparison between fast-spin-echo T2W and coronal FMPSPGR Gadolinium-Dota-Enhanced Sequences

    International Nuclear Information System (INIS)

    Nasi, Francesca; Fiocchi, Federica; Pecchi, Annarita; Torricelli, Pietro; Rivasi, Francesco

    2005-01-01

    Purpose. The depth of myometrial invasion by endometrial carcinoma strongly affects the incidence of metastasis to regional nodes and influences the surgical strategies. The aim of this paper is to compare the results of FSE T2-w and Gadolinium-enhanced FMPSGR MR sequences in assessing the depth of myometrial invasion by endometrial cancer. Materials and methods. Forty-five women with histopathologically-proven endometrial carcinoma underwent preoperative MRI. Axial SE TI w, axial, sagittal and para-coronal FSE T2w and para-coronal Gadolinium enhanced FMPSGR sequences were performed using a high field strength magnet (1.5T). Within one month of MR all patients underwent hysterectomy, and anatomical evaluation of the surgical specimen was done sectioning the uterus along the short axis. Based upon the results of the histological evaluation the results of the FSE T2w and Gadolinium-enhanced sequences were compared and the statistical difference between the results obtained was statistically evaluated. Results. The histological evaluation showed intra mucosal neoplasm in 11 patients, myometrial infiltration less than 50% in 31 patients, myometrial infiltration more than 50% in 12 patients and transmural cancer 1 patient. Statistical evaluation showed that the FSE T2w sequence had a global sensitivity and specificity of 80.6% and 87.6%, respectively, with a mean Negative Predictive Value of 92.6% and a mean Positive Predictive Value of 86%. Gadolinium-enhanced FMPSPGR sequence had a global sensitivity and specificity of 90.6% and 93.3%, respectively, with a mean Negative Predictive Value of 96,3% and a mean Positive Predictive Value of 88%. The staging accuracy (χ 2 test) on FMPSPGR images (95%) was higher than that on FSE T2w images (78%). Conclusions. In our experience Gadolinium-enhanced dynamic sequences increase the accuracy of MR imaging in diagnosing the depth of myometrial invasion. In particular they improve the visualisation of the inner myometrium, the so

  6. 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.

  7. Severe thrombocytopenia induced by iodinated contrast after coronary angiography: The use of gadolinium contrast and intravascular ultrasound as an alternative to guide percutaneous coronary intervention.

    Science.gov (United States)

    Cubero-Gómez, José María; Guerrero Márquez, Francisco J; Diaz-de la-Llera, Luis; Fernández-Quero, Mónica; Guisado-Rasco, Agustín; Villa-Gil-Ortega, Manuel

    2017-01-01

    Acute contrast-induced thrombocytopenia is a rare event with the use of modern low osmolarity iodinated contrast media. The pathophysiological mechanism that causes platelet counts to drop has not been identified, but an immunological mechanism is suspected due to cytotoxicity after previous exposure to contrast. We report the case of a 47-year-old male patient with acute severe thrombocytopenia due to iodinated contrast media exposure. His platelet count after the procedure with the highest amount of contrast was zero, which is the lowest reported platelet count to date. Percutaneous coronary revascularization under both intravascular ultrasound and gadolinium contrast guidance was performed without complications. The most feared complication after the use of gadolinium is nephrogenic systemic fibrosis, especially in patients on hemodialysis. Copyright © 2016 Sociedade Portuguesa de Cardiologia. Publicado por Elsevier España, S.L.U. All rights reserved.

  8. Investigation of the variations in the crystallization front shape during growth of gadolinium gallium and terbium gallium crystals by the Czochralski method

    International Nuclear Information System (INIS)

    Budenkova, O. N.; Vasiliev, M. G.; Yuferev, V. S.; Ivanov, I. A.; Bul'kanov, A. M.; Kalaev, V. V.

    2008-01-01

    Numerical investigation of the variations in the crystallization front shape during growth of gadolinium gallium and terbium gallium garnet crystals in the same thermal zone and comparison of the obtained results with the experimental data have been performed. It is shown that the difference in the behavior of the crystallization front during growth of the crystals is related to their different transparency in the IR region. In gadolinium gallium garnet crystals, which are transparent to thermal radiation, a crystallization front, strongly convex toward the melt, is formed in the growth stage, which extremely rapidly melts under forced convection. Numerical analysis of this process has been performed within the quasistationary and nonstationary models. At the same time, in terbium gallium garnet crystals, which are characterized by strong absorption of thermal radiation, the phase boundary shape changes fairly smoothly and with a small amplitude. In this case, as the crystal is pulled, the crystallization front tends to become convex toward the crystal bulk.

  9. Assessment of Degree of Applicability of Benchmarks for Gadolinium Using KENO V.a and the 238-Group SCALE Cross-Section Library

    Energy Technology Data Exchange (ETDEWEB)

    Goluoglu, S.

    2003-12-01

    A review of the degree of applicability of benchmarks containing gadolinium using the computer code KENO V.a and the gadolinium cross sections from the 238-group SCALE cross-section library has been performed for a system that contains {sup 239}Pu, H{sub 2}O, and Gd{sub 2}O{sub 3}. The system (practical problem) is a water-reflected spherical mixture that represents a dry-out condition on the bottom of a sludge receipt and adjustment tank around steam coils. Due to variability of the mixture volume and the H/{sup 239}Pu ratio, approximations to the practical problem, referred to as applications, have been made to envelop possible ranges of mixture volumes and H/{sup 239}Pu ratios. A newly developed methodology has been applied to determine the degree of applicability of benchmarks as well as the penalty that should be added to the safety margin due to insufficient benchmarks.

  10. MAGNETIC RESONANCE IMAGING OF INTRACRANIAL INFLAMMATORY CONDITIONS IN DOGS: SENSITIVITY OF SUBTRACTION IMAGES VERSUS PRE- AND POST-GADOLINIUM T1-WEIGHTED IMAGE PAIRS.

    Science.gov (United States)

    Dirrig, Helen; Lamb, Christopher R

    2016-07-01

    Ante mortem diagnosis of canine meningoencephalitis is usually based on the results of neurologic examination, cerebrospinal fluid analysis and magnetic resonance (MR) imaging. It has been hypothesized that subtraction MR imaging may increase the sensitivity of MR for intracranial inflammatory lesions compared to conventional post-gadolinium T1-weighted imaging. Sensitivity of pre- and post-gadolinium (C-/C+) image pairs and dynamic subtraction (DS) images was compared in a retrospective diagnostic accuracy study of 52 dogs with inflammatory cerebrospinal fluid and 67 dogs with idiopathic epilepsy. Series of transverse C-/C+ and DS images were reviewed independently for signs of abnormal enhancement affecting the pachymeninges, leptomeninges or intra-axial structures. Sensitivity of C-/C+ image pairs and DS images was 48% (95% CI: 35-61%) and 65% (95% CI: 52-77%), respectively (P = 0.01). Intra-axial lesions were observed more frequently than meningeal lesions in both C-/C+ (43% vs. 31%) and DS images (61% vs. 22%). The difference in sensitivities of C-/C+ and DS series was entirely due to increased sensitivity of DS images for intra-axial lesions. Eight (12%) dogs with epilepsy had evidence of intra-axial gadolinium accumulation affecting the cerebral cortex in DS images. This finding may represent a false-positive result or a true sign of pathology, possibly associated with a leaky blood-brain barrier in areas of the brain affected by neovascularization secondary to repeated seizures. Results suggest that DS imaging has higher sensitivity than comparison of pre- and post-gadolinium image pairs for inflammatory intra-axial lesions. © 2016 American College of Veterinary Radiology.

  11. Signal Increase on Unenhanced T1-Weighted Images in the Rat Brain After Repeated, Extended Doses of Gadolinium-Based Contrast Agents

    OpenAIRE

    Jost, Gregor; Lenhard, Diana Constanze; Sieber, Martin Andrew; Lohrke, Jessica; Frenzel, Thomas; Pietsch, Hubertus

    2016-01-01

    Objectives In this prospective preclinical study, we evaluated T1-weighted signal intensity in the deep cerebellar nuclei (CN) and globus pallidus (GP) up to 24 days after repeated administration of linear and macrocyclic gadolinium-based contrast agents (GBCAs) using homologous imaging and evaluation methods as in the recently published retrospective clinical studies. In a second part of the study, cerebrospinal fluid (CSF) spaces were evaluated for contrast enhancement by fluid-attenuated m...

  12. Clinically useful dilution factors for iodine and gadolinium contrast material: an animal model of pediatric digital subtraction angiography using state-of-the-art flat-panel detectors.

    Science.gov (United States)

    Racadio, John M; Kashinkunti, Soumya R; Nachabe, Rami A; Racadio, Judy M; Johnson, Neil D; Kukreja, Kamlesh U; Patel, Manish N; Privitera, Mary Beth; Hales, Jasmine E; Abruzzo, Todd A

    2013-11-01

    Iodinated and gadolinium contrast agents pose some risk for certain pediatric patients, including allergic-like reactions, contrast-induced nephropathy (CIN) and nephrogenic systemic fibrosis (NSF). Digital flat-panel detectors enhance image quality during angiography and might allow use of more dilute contrast material to decrease risk of complications that might be dose-dependent, such as CIN and NSF. To assess the maximum dilution factors for iodine- and gadolinium-based contrast agents suitable for vascular imaging with fluoroscopy and digital subtraction angiography (DSA) on digital flat-panel detectors in an animal model. We performed selective catheterization of the abdominal aorta, renal artery and common carotid artery on a rabbit. In each vessel we performed fluoroscopy and DSA during contrast material injection using iodinated and gadolinium contrast material at 100%, 80%, 50%, 33% and 20% dilutions. An image quality score (0 to 3) was assigned by each of eight evaluators. Intracorrelation coefficient, paired t-test, one-way repeated analysis of variance, Spearman correlation and receiver operating characteristic curve analysis were applied to the data. Overall the image quality scores correlated linearly with dilution levels. For iodinated contrast material, the optimum cut-off level for DSA when a score of at least 2 is acceptable is above 33%; it is above 50% when a score of 3 is necessary. For gadolinium contrast material, the optimum cut-off for DSA images is above 50% when a score of at least 2 is acceptable and above 80% when a score of 3 is necessary. Knowledge of the relationship between image quality and contrast material dilution might allow a decrease in overall contrast load while maintaining appropriate image quality when using digital flat-panel detectors.

  13. Grueneisen-approach for the experimental determination of transient spin and phonon energies from ultrafast x-ray diffraction data: gadolinium.

    Science.gov (United States)

    Koc, A; Reinhardt, M; von Reppert, A; Rössle, M; Leitenberger, W; Gleich, M; Weinelt, M; Zamponi, F; Bargheer, M

    2017-07-05

    We study gadolinium thin films as a model system for ferromagnets with negative thermal expansion. Ultrashort laser pulses heat up the electronic subsystem and we follow the transient strain via ultrafast x-ray diffraction. In terms of a simple Grueneisen approach, the strain is decomposed into two contributions proportional to the thermal energy of spin and phonon subsystems. Our analysis reveals that upon femtosecond laser excitation, phonons and spins can be driven out of thermal equilibrium for several nanoseconds.

  14. Biodegradable gadolinium-chelated cationic poly(urethane amide) copolymers for gene transfection and magnetic resonance imaging

    Energy Technology Data Exchange (ETDEWEB)

    Gao, Xiaolong [Department of Radiology, Tongji Hospital, Tongji University School of Medicine, Shanghai 200065 (China); Wang, Gangmin [Department of Urology, Huashan Hospital, Fudan University, Shanghai 200040 (China); Shi, Ting [The Institute for Translational Nanomedicine, Shanghai East Hospital, Institute for Biomedical Engineering and Nanoscience, Tongji University School of Medicine, Shanghai 200092 (China); Shao, Zhihong [Department of Radiology, Tongji Hospital, Tongji University School of Medicine, Shanghai 200065 (China); Zhao, Peng; Shi, Donglu [The Institute for Translational Nanomedicine, Shanghai East Hospital, Institute for Biomedical Engineering and Nanoscience, Tongji University School of Medicine, Shanghai 200092 (China); Ren, Jie [Institute of Nano and Biopolymeric Materials, School of Materials Science and Engineering, Tongji University, 4800 Caoan Road, Shanghai 201804 (China); Lin, Chao, E-mail: chaolin@tongji.edu.cn [The Institute for Translational Nanomedicine, Shanghai East Hospital, Institute for Biomedical Engineering and Nanoscience, Tongji University School of Medicine, Shanghai 200092 (China); Wang, Peijun, E-mail: tjpjwang@sina.com [Department of Radiology, Tongji Hospital, Tongji University School of Medicine, Shanghai 200065 (China)

    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 T{sub 1}-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 25 kDa 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 T{sub 1}-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. - Highlights: • Novel cationic gadolinium-chelated poly(urethane amide)s (GdCPUAs) are prepared. • GdCPUAs can induce a high transfection efficacy in different cancer cells. • GdCPUAs reveal good cyto-compatibility against cancer cells. • GdCPUAs may be applied as T{sub 1}-contrast agents for magnetic resonance imaging. • GdCPUAs hold high potential for cancer theranostics.

  15. Physico-chemical characterization of terbium-161-chloride (161TbCl3) radioisotope from irradiated natural gadolinium oxide target

    International Nuclear Information System (INIS)

    Azmairit Aziz; Nana Suherman

    2015-01-01

    Currently cancer patients are increasing every year in Indonesia and become the third leading cause of death after heart disease and high blood pressure. Terbium-161 ( 161 Tb) is a low β- emitter (E β - = 0.155 MeV, T 1/2 = 6.9 d) and very similar to 177 Lu in terms of half-life, E β - energy and chemical properties.However, 161 Tb also ejects internal conversion electrons and Auger electrons which can provide a greater therapeutic effect than 177 Lu. Radioisotope of 161 Tb can be produced as a carrier-free for use in labeling of biomolecules as a targeted radiopharmaceutical for cancer therapy. 161 Tb was obtained through 160 Gd(n,γ) 161 Tb nuclear reaction by thermal neutron bombardment on 100 mg of natural gadolinium oxide target in RSG-G.A. Siwabessy at a thermal neutron flux of ~10 14 n.cm -2 .s -1 and followed by radiochemical separation of 161 Tb from Gd isotopes using extraction chromatography method. The physico-chemical characterization of 161 TbCl 3 solution was studied by determination of its radionuclide purity by means of a γ-rays spectrometry with HP-Ge detector coupled to a multichannel analyzer (MCA). Radiochemical purity was determined using paper chromatography and paper electrophoresis methods. The results showed that 161 TbCl 3 radioisotope has a pH of 2, radiochemical purity of 99.64 ± 0.34%, radionuclide purity of 99.69 ± 0.20%, specific activity and radioactive concentration at the end of irradiation (EOI) of 2.26 – 5.31 Ci/mg and 3.84 – 9.03 mCi/mL, respectively. 161 TbCl 3 solution stable for 3 weeks at room temperature with a radiochemical purity of 98.41 ± 0.42%. 161 TbCl 3 solution from irradiated natural gadolinium oxide target has the physico-chemical characteristic that meets the requirements for use as a precursor in preparation of radiopharmaceuticals. (author)

  16. Investigation of suspected Guillain-Barre syndrome in childhood: what is the role for gadolinium enhanced magnetic resonance imaging of the spine?

    Science.gov (United States)

    Smith, Nicholas; Pereira, John; Grattan-Smith, Padraic

    2014-10-01

    To review the role of gadolinium-enhanced magnetic resonance imaging of the spine in the diagnosis of paediatric Guillain-Barre syndrome and compare it with nerve conduction studies and cerebrospinal fluid analysis. A retrospective review of investigations undertaken in children admitted to our institution with acute Guillain-Barre syndrome over a 10-year period was performed. Seven of eight children (88%) displayed post-gadolinium nerve root enhancement consistent with Guillain-Barre syndrome. This compared with supportive nerve conduction studies in 21/24 children (88%) and cerebrospinal fluid protein analysis consistent with the diagnosis in 16/20 children (80%). Nerve conduction studies are the recognised 'gold standard' technique for confirming a clinical diagnosis of Guillain-Barre syndrome. In this study, a high positive rate was demonstrated. While more experience is necessary, this study and the literature support gadolinium enhanced magnetic resonance imaging of the spine as a valuable, although not necessarily superior, investigation in the diagnosis of Guillain-Barre syndrome. It may be of particular benefit when specialist neurophysiology expertise is unavailable. © 2010 The Authors. Journal compilation © 2010 Paediatrics and Child Health Division (Royal Australasian College of Physicians).

  17. Comparision between biphasic helical CT and dynamic gadolinium-enhanced MR in the detection and characterization of focal hepatic lesions in cirrhotic patients

    International Nuclear Information System (INIS)

    Puig, J.; Martin, J.; Donoso, L.; Falco, J.; Rue, M.

    1997-01-01

    To assess the agreement between biphasic helical computerized tomography (BHCT) and dynamic gadolinium-enhanced magnetic resonance (MR) in the detection and characterization of focal hepatic lesions in a group of cirrhotic patients. A prospective study was done in 50 cirrhotic patients suspected of having hepatocarcinoma (HC) on the basis of ultrasonographic images evaluated by means of BHCT and dynamic gadolinium-enhanced MR using fast low-angle shot (FLASH) sequences (110-135/4/90 degree centigree). The images were assessed jointly by four radiologists. Between the two techniques, a total of 83 lesions were detected. MR disclosed more lesions (n=79) than BHCT (n=67) (p<0.005). Moreover, 25 of the lesions that were visible by both techniques were more clearly evident in MR images (p<0.01). MR correctly classified 6 of 7 benign lesions (85%) and 49 of 66 malignant ones (74%). BHCT correctly classifed 2 of 7 benign lesions (28%) and 32 of 66 malignant ones (48%). The sensitivities of MR and BHCT for the characterization of these lesions were 74% and 48%, respectively (p=0.0009), while the respective specificities were 86% and 29% (P<0.001). Dynamic gadolinium-enhanced MR with FLASH sequences is more efficient than BHCT in the detection and characterization of focal lesions in cirrhotic patients. (Author) 37 refs

  18. BSA-Bioinspired Gadolinium Hybrid-Functionalized Hollow Gold Nanoshells for NIRF/PA/CT/MR Quadmodal Diagnostic Imaging-Guided Photothermal/Photodynamic Cancer Therapy.

    Science.gov (United States)

    You, Qing; Sun, Qi; Yu, Meng; Wang, Jinping; Wang, Siyu; Liu, Li; Cheng, Yu; Wang, Yidan; Song, Yilin; Tan, Fengping; Li, Nan

    2017-11-22

    Multimodal imaging-guided synergistic therapy promises a more accurate diagnosis and higher therapeutic efficiency than single imaging modality or their simple "mechanical" combination. In this research, we have constructed an innovative multifunctional drug delivery platform by gadolinium (Gd)-based bovine serum albumin (BSA) hybrid-coated hollow gold nanoshells (Au@BSA-Gd). The obtained nanoparticles exhibited excellent photothermal effect and computed tomography (CT)/photoacoustic (PA) activity. Besides, the BSA-bioinspired gadolinium complex endowed the nanoparticles with an excellent T 1 contrast agent for magnetic resonance imaging (MRI). In addition, the near-infrared (NIR) absorbing phototherapeutic agent [indocyanine green (ICG)] was loaded into the Au@BSA-Gd nanoparticles because of their unique, hollow, and porous structures, thus possessing photodynamic/photothermal property and near-infrared fluorescence (NIRF)/PA imaging capability. As a result, a combined cancer therapy containing the photothermal therapy of Au@BSA-Gd and the synchronous photodynamic/photothermal therapy of ICG was constructed. Furthermore, the well-designed nanocomposites with multiple integrated modalities enabled them to be an ideal nanotheranostic agent for NIRF/PA/CT/MR quadmodal imaging. Therefore, the ICG-loaded albumin-bioinspired gadolinium hybrid-functionalized hollow gold nanoshells (ICG-Au@BSA-Gd) hold great promise as a theranostic platform for simultaneous therapeutic monitoring and precise cancer therapy.

  19. Penetration and distribution of gadolinium-based contrast agents into the cerebrospinal fluid in healthy rats: a potential pathway of entry into the brain tissue

    Energy Technology Data Exchange (ETDEWEB)

    Jost, Gregor; Frenzel, Thomas; Lohrke, Jessica; Pietsch, Hubertus [MR and CT Contrast Media Research, Bayer Pharma AG, Berlin (Germany); Lenhard, Diana Constanze [Charite, Institute of Vegetative Physiology, Berlin (Germany); Naganawa, Shinji [Nagoya University Graduate School of Medicine, Department of Radiology, Nagoya (Japan)

    2017-07-15

    Signal hyperintensity on unenhanced MRI in certain brain regions has been reported after multiple administrations of some, but not all, gadolinium-based contrast agents (GBCAs). One potential initial pathway of GBCA entry into the brain, infiltration from blood into the cerebrospinal fluid (CSF), was systematically evaluated in this preclinical study. GBCA infiltration and distribution in the CSF were investigated in healthy rats using repeated fluid-attenuated MRI up to 4 h after high-dose (1.8 mmol/kg) administration of six marketed and one experimental GBCA. Additionally, gadolinium measurements in CSF, blood and brain tissue samples (after 24 h) were performed using inductively coupled plasma mass spectrometry. Enhanced MRI signals in the CSF spaces with similar distribution kinetics were observed for all GBCAs. No substantial differences in the gadolinium concentrations among the marketed GBCAs were found in the CSF, blood or brain tissue. After 4.5 h, the concentration in the CSF was clearly higher than in blood but was almost completely cleared and lower than the brain tissue concentration after 24 h. In contrast to the brain signal hyperintensities, no differences in penetration and distribution into the CSF of healthy rats exist among the marketed GBCAs. (orig.)

  20. Evaluation of Novel 64Cu-Labeled Theranostic Gadolinium-Based Nanoprobes in HepG2 Tumor-Bearing Nude Mice

    Science.gov (United States)

    Hu, Pengcheng; Cheng, Dengfeng; Huang, Tao; Banizs, Anna B.; Xiao, Jie; Liu, Guobing; Chen, Quan; Wang, Yuenan; He, Jiang; Shi, Hongcheng

    2017-09-01

    Radiation therapy of liver cancer is limited by low tolerance of the liver to radiation. Radiosensitizers can effectively reduce the required radiation dose. AGuIX nanoparticles are small, multifunctional gadolinium-based nanoparticles that can carry radioisotopes or fluorescent markers for single-photon emission computed tomography (SPECT), positron emission tomography (PET), fluorescence imaging, and even multimodality imaging. In addition, due to the high atomic number of gadolinium, it can also serve as a tumor radiation sensitizer. It is critical to define the biodistribution and pharmacokinetics of these gadolinium-based nanoparticles to quantitate the magnitude and duration of their retention within the tumor microenvironment during radiotherapy. Therefore, in this study, we successfully labeled AGuIX with 64Cu through the convenient built-in chelator. The biodistribution studies indicated that the radiotracer 64Cu-AGuIX accumulates to high levels in the HepG2 xenograft of nude mice, suggesting that it would be a potential theranostic nanoprobe for image-guided radiotherapy in HCC. We also used a transmission electron microscope to confirm AGuIX uptake in the HepG2 cells. In radiation therapy studies, a decrease in 18F-FDG uptake was observed in the xenografts of the nude mice irradiated with AGuIX, which was injected 1 h before. These results provide proof-of-concept that AGuIX can be used as a theranostic radiosensitizer for PET imaging to guide radiotherapy for liver cancer.

  1. Gadolinium-enhanced MR imaging of the wrist in rheumatoid arthritis: value of fat suppression pulse sequences

    International Nuclear Information System (INIS)

    Nakahara, N.; Uetani, M.; Hayashi, K.; Kawahara, Y.; Matsumoto, T.; Oda, J.

    1996-01-01

    Objective. To determine the usefulness of fat-suppressed gadolinium (Gd)-enhanced MR imaging of the wrist in patients with rheumatoid arthritis (RA). Design and patients. Fat-suppressed Gd-enhanced T1-weighted spin-echo (SE) images were obtained and compared with other standard techniques in 38 wrists of 27 patients (22-77 years) with RA. Scoring based on the degree of synovial enhancement of each joint was developed and the total scores (J-score) were correlated with radiographic stage, C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), and symptomatic change in the follow-up study. Results. Synovial proliferations showed marked enhancement in all the wrists. In addition, contrast enhancement in the bone marrow and tenosynovium was seen in 36 and eight wrists respectively. Fat-suppressed Gd-enhanced T1-weighted images demonstrated these abnormalities better than other techniques. The J-scores correlated well with values of CRP (P=0.0034), but not with radiographic stages and ESR. Conclusion. Fat-suppressed Gd-enhanced T1-weighted SE images can clearly demonstrate most of the essential lesions in RA including the proliferative synovium, bone erosion, bone marrow inflammatory change, and tenosynovitis. Scoring based on the extent of Gd-enhancement of synovium can be useful in the assessment of the inflammatory status. (orig.). With 8 figs

  2. Gadolinium-enhanced MR imaging of the wrist in rheumatoid arthritis: value of fat suppression pulse sequences

    Energy Technology Data Exchange (ETDEWEB)

    Nakahara, N. [Department of Radiology, Nagasaki University School of Medicine, Sakamoto 1-7-1, Nagasaki 852 (Japan); Uetani, M. [Department of Radiology, Nagasaki University School of Medicine, Sakamoto 1-7-1, Nagasaki 852 (Japan); Hayashi, K. [Department of Radiology, Nagasaki University School of Medicine, Sakamoto 1-7-1, Nagasaki 852 (Japan); Kawahara, Y. [Department of Radiology, Nagasaki University School of Medicine, Sakamoto 1-7-1, Nagasaki 852 (Japan); Matsumoto, T. [Department of Orthopedics, Nagasaki University School of Medicine, Nagasaki (Japan); Oda, J. [Department of Orthopedics, Nagasaki University School of Medicine, Nagasaki (Japan)

    1996-10-01

    Objective. To determine the usefulness of fat-suppressed gadolinium (Gd)-enhanced MR imaging of the wrist in patients with rheumatoid arthritis (RA). Design and patients. Fat-suppressed Gd-enhanced T1-weighted spin-echo (SE) images were obtained and compared with other standard techniques in 38 wrists of 27 patients (22-77 years) with RA. Scoring based on the degree of synovial enhancement of each joint was developed and the total scores (J-score) were correlated with radiographic stage, C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), and symptomatic change in the follow-up study. Results. Synovial proliferations showed marked enhancement in all the wrists. In addition, contrast enhancement in the bone marrow and tenosynovium was seen in 36 and eight wrists respectively. Fat-suppressed Gd-enhanced T1-weighted images demonstrated these abnormalities better than other techniques. The J-scores correlated well with values of CRP (P=0.0034), but not with radiographic stages and ESR. Conclusion. Fat-suppressed Gd-enhanced T1-weighted SE images can clearly demonstrate most of the essential lesions in RA including the proliferative synovium, bone erosion, bone marrow inflammatory change, and tenosynovitis. Scoring based on the extent of Gd-enhancement of synovium can be useful in the assessment of the inflammatory status. (orig.). With 8 figs.

  3. Effect of geometrical shape of the working substance Gadolinium on the performance of a regenerative magnetic Brayton refrigeration cycle

    International Nuclear Information System (INIS)

    Diguet, Gildas; Lin, Guoxing; Chen, Jincan

    2013-01-01

    Based on Mean Field Theory (MFT), the entropy of magnetic material Gadolinium (Gd), which is a function of the local magnetic field and temperature, is calculated and analyzed. This local magnetic field is the sum of the applied field H 0 plus the exchange field H W =λM and the demagnetizing field H d =−NM, where the demagnetizing factor N depends on the shape of magnetic materials. Hereby, the impacts of the demagnetizing factor N on the magnetic entropy, magnetic entropy change and main thermodynamics performance of a regenerative magnetic Brayton refrigeration cycle using Gd as the working substance are investigated and evaluated in detail. The results obtained underline the importance of the shape of the working substance used in magnetic refrigerators for room-temperature application; elongated materials provide better thermodynamics performance such as higher COP and net heat absorption. It is pointed out that for low external fields, the magnetic refrigerator ceased to be functional if flat materials were used. - Highlights: ► Gd entropy is calculated as a function of temperature and internal magnetic field. ► Magnetic Brayton cycle properties generally depend on the demagnetizing factor. ► Redundant heat transfer is highly sensitive to the demagnetizing factor. ► The net cooling quantity is highly sensitive to the demagnetizing factor. ► Coefficient of performance is dependant to the magnetic material shape.

  4. Photothermally modulated magnetic resonance applied to the study of the magnetic phase transition in gadolinium thin films

    Energy Technology Data Exchange (ETDEWEB)

    Soffner, M.E.; Tedesco, J.C.G. [Instituto de Fisica Gleb Wataghin, Universidade Estadual de Campinas (UNICAMP), 13083-859, Campinas, SP (Brazil); Pedrochi, F. [Centro de Ciencias Sociais, Saude e Tecnologia, Universidade Federal do Maranhao, Rua Urbano Santos, s/n, Centro, 65900-000, Imperatriz, MA (Brazil); Gadioli, G.Z.; Moraes, M.A.B. de [Instituto de Fisica Gleb Wataghin, Universidade Estadual de Campinas (UNICAMP), 13083-859, Campinas, SP (Brazil); Guimaraes, A.O.; Silva, E.C. da [Laboratorio de Ciencias Fisicas, Universidade Estadual do Norte Fluminense Darcy Ribeiro, UENF, 28013-602 Campos dos Goytacazes, RJ (Brazil); Mansanares, A.M., E-mail: manoel@ifi.unicamp.br [Instituto de Fisica Gleb Wataghin, Universidade Estadual de Campinas (UNICAMP), 13083-859, Campinas, SP (Brazil)

    2012-02-29

    We explore the photothermally modulated magnetic resonance technique to investigate gadolinium thin films deposited on fused quartz substrate, as a function of thickness and thermal treatment, around the magnetic phase transition temperature. It has been observed that the maximum amplitude of the photothermally modulated magnetic resonance (PM-MR) signal takes place near the phase transition temperature, similarly to the magnetocaloric effect, for which Gd has been the prototype material. The reason is that both depend on the temperature derivative of the magnetization, which maximizes at the phase transition. Besides, there is a narrowing of transition with thermal treatment, confirming that thermal treatment stabilizes the film structure. For frequency scan measurements, the heat diffusion in a two-layer system was considered, and a depth profile study was carried out in order to investigate heterogeneities along the film thickness. From the PM-MR response as a function of the modulation frequency it was possible to estimate the thermal properties of the Gd film. Magnetization, X-ray and electron spin resonance measurements were used to complement the analysis and support the conclusions. - Highlights: Black-Right-Pointing-Pointer TC values increase with thermal treatment and film thickness. Black-Right-Pointing-Pointer PM-MR signal amplitude of the main peak is maximum at temperatures close to TC. Black-Right-Pointing-Pointer Frequency scan showed uniform film profile. Black-Right-Pointing-Pointer Gd film thermal diffusivity was found to be smaller than the bulk one.

  5. Influence of gadolinium content on the tetragonal to cubic phase transition in zirconia-silica binary oxides

    Energy Technology Data Exchange (ETDEWEB)

    Behera, Pallavi Suhasinee; Vasanthavel, S.; Ponnilavan, V.; Kannan, S., E-mail: para_kanna@yahoo.com

    2015-05-15

    The present study reports the effect of gadolinium (Gd{sup 3+}) in zirconia-silica (ZrO{sub 2}-SiO{sub 2}) binary oxides. The pure ZrO{sub 2}-SiO{sub 2} synthesized at 1100 °C was tetragonal. The addition of Gd{sup 3+} in the concentration range of 5%–10% resulted in the formation of t-ZrO{sub 2}, whereas higher contents of Gd{sup 3+} led to the formation of cubic ZrO{sub 2} (c-ZrO{sub 2}). The presence of Gd{sup 3+} also affected the lattice parameters of both t-ZrO{sub 2} and c-ZrO{sub 2}. Magnetic studies confirmed a steady increase in the paramagnetic behaviour with increasing content of Gd{sup 3+}. - Graphical abstract: t-ZrO{sub 2} to c-ZrO{sub 2} phase transition influenced by Gd{sup 3+} content. - Highlights: • Sol-gel synthesis of Gd{sup 3+} added SiO{sub 2}-ZrO{sub 2} binary oxides. • Significant role of Gd{sup 3+} content in the tetragonal and cubic stabilization of ZrO{sub 2}. • Phase stability of either tetragonal or cubic stabilization till 1100 °C. • Gd{sup 3+} additions ensured additional paramagnetic behaviour in SiO{sub 2}-ZrO{sub 2} binary oxide.

  6. Gadolinium-based magnetic resonance contrast agents at 7 Tesla: in vitro T1 relaxivities in human blood plasma.

    Science.gov (United States)

    Noebauer-Huhmann, Iris M; Szomolanyi, Pavol; Juras, Vladimír; Kraff, Oliver; Ladd, Mark E; Trattnig, Siegfried

    2010-09-01

    PURPOSE/INTRODUCTION: The aim of this study was to determine the T1 relaxivities (r1) of 8 gadolinium (Gd)-based MR contrast agents in human blood plasma at 7 Tesla, compared with 3 Tesla. Eight commercially available Gd-based MR contrast agents were diluted in human blood plasma to concentrations of 0, 0.25, 0.5, 1, and 2 mmol/L. In vitro measurements were performed at 37 degrees C, on a 7 Tesla and on a 3 Tesla whole-body magnetic resonance imaging scanner. For the determination of T1 relaxation times, Inversion Recovery Sequences with inversion times from 0 to 3500 ms were used. The relaxivities were calculated. The r1 relaxivities of all agents, diluted in human blood plasma at body temperature, were lower at 7 Tesla than at 3 Tesla. The values at 3 Tesla were comparable to those published earlier. Notably, in some agents, a minor negative correlation of r1 with a concentration of up to 2 mmol/L could be observed. This was most pronounced in the agents with the highest protein-binding capacity. At 7 Tesla, the in vitro r1 relaxivities of Gd-based contrast agents in human blood plasma are lower than those at 3 Tesla. This work may serve as a basis for the application of Gd-based MR contrast agents at 7 Tesla. Further studies are required to optimize the contrast agent dose in vivo.

  7. Immediate Adverse Reactions to Gadolinium-Based MR Contrast Media: A Retrospective Analysis on 10,608 Examinations.

    Science.gov (United States)

    Granata, Vincenza; Cascella, Marco; Fusco, Roberta; dell'Aprovitola, Nicoletta; Catalano, Orlando; Filice, Salvatore; Schiavone, Vincenzo; Izzo, Francesco; Cuomo, Arturo; Petrillo, Antonella

    2016-01-01

    Background and Purpose. Contrast media (CM) for magnetic resonance imaging (MRI) may determine the development of acute adverse reactions. Objective was to retrospectively assess the frequency and severity of adverse reactions associated with gadolinium-based contrast agents (GBCAs) injection in patients who underwent MRI. Material and Methods. At our center 10608 MRI examinations with CM were performed using five different GBCAs: Gd-BOPTA (MultiHance), Gd-DTPA (Magnevist), Gd-EOBDTPA (Primovist), Gd-DOTA (Dotarem), and Gd-BTDO3A (Gadovist). Results. 32 acute adverse reactions occurred, accounting for 0.3% of all administration. Twelve reactions were associated with Gd-DOTA injection (0.11%), 9 with Gd-BOPTA injection (0.08%), 6 with Gd-BTDO3A (0.056%), 3 with Gd-EOB-DTPA (0.028%), and 2 with Gd-DTPA (0.018%). Twenty-four reactions (75.0%) were mild, four (12.5%) moderate, and four (12.5%) severe. The most severe reactions were seen associated with use of Gd-BOPTA, with 3 severe reactions in 32 total reactions. Conclusion. Acute adverse reactions are generally rare with the overall adverse reaction rate of 0.3%. The most common adverse reactions were not severe, consisting in skin rash and hives.

  8. A Rare Case of Hypertrophic Cardiomyopathy with Subendocardial Late Gadolinium Enhancement in an Apical Aneurysm with Thrombus

    Directory of Open Access Journals (Sweden)

    Yusuke Morita

    2014-01-01

    Full Text Available The mechanisms responsible for the development of apical aneurysms in cases of hypertrophic cardiomyopathy (HCM are currently unclear but likely involve multiple factors. Here, we present a case of HCM with marked subendocardial fibrosis involving the apical and proximal portions of the left ventricle. A 71-year-old man with left ventricular hypertrophy presented with signs and symptoms of heart failure. The presence of asymmetrical left ventricular hypertrophy and bilateral, thickened ventricular walls with an apical aneurysm on transthoracic echocardiography suggested a diagnosis of HCM with ventricular dysfunction. No intraventricular pressure gradients with obstruction were identified. Late gadolinium enhancement (LGE with cardiac magnetic resonance imaging and endomyocardial biopsies showed subendocardial fibrosis involving the apical aneurysm and proximal portion. Whereas LGE in a transmural pattern is commonly observed in HCM apical aneurysms, subendocardial LGE, as noted in the present case, is a relatively rare occurrence. Thus, the present case may provide unique insights into the adverse remodeling process and formation of apical aneurysms in cases of HCM.

  9. 3D Late Gadolinium Enhancement in a Single Prolonged Breath-hold using Supplemental Oxygenation and Hyperventilation

    Science.gov (United States)

    Roujol, Sébastien; Basha, Tamer A.; Akçakaya, Mehmet; Foppa, Murilo; Chan, Raymond H.; Kissinger, Kraig V.; Goddu, Beth; Berg, Sophie; Manning, Warren J.; Nezafat, Reza

    2013-01-01

    Purpose: To evaluate the feasibility of 3D single breath-hold late gadolinium enhancement (LGE) of the left ventricle (LV) using supplemental oxygen and hyperventilation and compressed-sensing acceleration. Methods: Breath-hold metrics (breath-hold duration, diaphragmatic/LV position drift, and maximum variation of RR interval) without and with supplemental oxygen and hyperventilation were assessed in healthy adult subjects using a real time single shot acquisition. Ten healthy subjects and 13 patients then underwent assessment of the proposed 3D breath-hold LGE acquisition (FOV=320×320×100 mm3, resolution=1.6×1.6×5.0 mm3, acceleration rate of 4) and a free breathing acquisition with right hemidiaphragm navigator (NAV) respiratory gating. Semi-quantitative grading of overall image quality, motion artifact, myocardial nulling, and diagnostic value was performed by consensus of two blinded observers. Results: Supplemental oxygenation and hyperventilation increased the breath-hold duration (35±11 s to 58±21 s, p0.01). LGE images were of similar quality when compared to free breathing acquisitions but with reduced total scan time (85±22 s to 35±6 s, pbreath-holding and enable single breath-hold 3D accelerated LGE with similar image quality as free breathing with NAV. PMID:24186772

  10. 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.

  11. Innovative Perspective: Gadolinium-Free Magnetic Resonance Imaging in Long-Term Follow-Up after Kidney Transplantation

    Directory of Open Access Journals (Sweden)

    Mick J. M. van Eijs

    2017-05-01

    Full Text Available Since the mid-1980s magnetic resonance imaging (MRI has been investigated as a non- or minimally invasive tool to probe kidney allograft function. Despite this long-standing interest, MRI still plays a subordinate role in daily practice of transplantation nephrology. With the introduction of new functional MRI techniques, administration of exogenous gadolinium-based contrast agents has often become unnecessary and true non-invasive assessment of allograft function has become possible. This raises the question why application of MRI in the follow-up of kidney transplantation remains restricted, despite promising results. Current literature on kidney allograft MRI is mainly focused on assessment of (sub acute kidney injury after transplantation. The aim of this review is to survey whether MRI can provide valuable diagnostic information beyond 1 year after kidney transplantation from a mechanistic point of view. The driving force behind chronic allograft nephropathy is believed to be chronic hypoxia. Based on this, techniques that visualize kidney perfusion and oxygenation, scarring, and parenchymal inflammation deserve special interest. We propose that functional MRI mechanistically provides tools for diagnostic work-up in long-term follow-up of kidney allografts.

  12. The informative value of MR tomography using gadolinium-DTPA in the diagnosis of the lumbar post-discotomy syndrome

    International Nuclear Information System (INIS)

    Beyer, H.K.; Hoetzinger, H.; Toedt, C.; Oppel, U.

    1989-01-01

    Our results have shown that MR tomography - especially if gadolinium-DTPA is used as a contrast medium - is an excellent method to differentiate between the various possible causes of the post-discotomy syndrome. In particular, it is definitely possible to differentiate between a relapsed hernia of an intervertebral dis and a postoperative development of cicatricial tissue which is practically inevitable. This differentiation is of vital importance to the clinician, because a second operation should be performed only in case of a relapse, whereas cicatricial tissue is best left alone, because no matter how carefully the operation is performed with preparation of the neural structures, even more extensive cicatricial plates are bound to develop. Instability of the vertebral column in the operated disc segment, or other causes of complaints, can be identified via MR equally well if not better than by other means. Hence, the method should be the method of choice in postdiscotomy syndrome, since it facilitates the difficult choice between conservative therapy and reoperation. (orig.) [de

  13. Informative value of MR tomography using gadolinium-DTPA in the diagnosis of the lumbar post-discotomy syndrome

    Energy Technology Data Exchange (ETDEWEB)

    Beyer, H.K.; Hoetzinger, H.; Toedt, C.; Oppel, U.

    1989-03-01

    Our results have shown that MR tomography - especially if gadolinium-DTPA is used as a contrast medium - is an excellent method to differentiate between the various possible causes of the post-discotomy syndrome. In particular, it is definitely possible to differentiate between a relapsed hernia of an intervertebral dis and a postoperative development of cicatricial tissue which is practically inevitable. This differentiation is of vital importance to the clinician, because a second operation should be performed only in case of a relapse, whereas cicatricial tissue is best left alone, because no matter how carefully the operation is performed with preparation of the neural structures, even more extensive cicatricial plates are bound to develop. Instability of the vertebral column in the operated disc segment, or other causes of complaints, can be identified via MR equally well if not better than by other means. Hence, the method should be the method of choice in postdiscotomy syndrome, since it facilitates the difficult choice between conservative therapy and reoperation.

  14. Distribution of late gadolinium enhancement in various types of cardiomyopathies: Significance in differential diagnosis, clinical features and prognosis.

    Science.gov (United States)

    Satoh, Hiroshi; Sano, Makoto; Suwa, Kenichiro; Saitoh, Takeji; Nobuhara, Mamoru; Saotome, Masao; Urushida, Tsuyoshi; Katoh, Hideki; Hayashi, Hideharu

    2014-07-26

    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. Gadolinium perturbs expression of skeletogenic genes, calcium uptake and larval development in phylogenetically distant sea urchin species.

    Science.gov (United States)

    Martino, Chiara; Costa, Caterina; Roccheri, Maria Carmela; Koop, Demian; Scudiero, Rosaria; Byrne, Maria

    2018-01-01

    Chelates of Gadolinium (Gd), a lanthanide metal, are employed as contrast agents for magnetic resonance imaging and are released into the aquatic environment where they are an emerging contaminant. We studied the effects of environmentally relevant Gd concentrations on the development of two phylogenetically and geographically distant sea urchin species: the Mediterranean Paracentrotus lividus and the Australian Heliocidaris tuberculata. We found a general delay of embryo development at 24h post-fertilization, and a strong inhibition of skeleton growth at 48h. Total Gd and Ca content in the larvae showed a time- and concentration-dependent increase in Gd, in parallel with a reduction in Ca. To investigate the impact of Gd on the expression of genes involved in the regulation of skeletogenesis, we performed comparative RT-PCR analysis and found a misregulation of several genes involved in the skeletogenic and left-right axis specification gene regulatory networks. Species-specific differences in the biomineralization response were evident, likely due to differences in the skeletal framework of the larvae and the amount of biomineral produced. Our results highlight the hazard of Gd for marine organisms. Copyright © 2017 Elsevier B.V. All rights reserved.

  16. Response of gadolinium doped liquid scintillator to charged particles: measurement based on intrinsic U/Th contamination

    Science.gov (United States)

    Du, Q.; Lin, S. T.; He, H. T.; Liu, S. K.; Tang, C. J.; Wang, L.; Wong, H. T.; Xing, H. Y.; Yue, Q.; Zhu, J. J.

    2018-04-01

    A measurement is reported for the response to charged particles of a liquid scintillator named EJ-335 doped with 0.5% gadolinium by weight. This liquid scintillator was used as the detection medium in a neutron detector. The measurement is based on the in-situ α-particles from the intrinsic Uranium and Thorium contamination in the scintillator. The β–α and the α–α cascade decays from the U/Th decay chains were used to select α-particles. The contamination levels of U/Th were consequently measured to be (5.54±0.15)× 10‑11 g/g, (1.45±0.01)× 10‑10 g/g and (1.07±0.01)× 10‑11 g/g for 232Th, 238U and 235U, respectively, assuming secular equilibrium. The stopping power of α-particles in the liquid scintillator was simulated by the TRIM software. Then the Birks constant, kB, of the scintillator for α-particles was determined to be (7.28±0.23) mg/(cm2ṡMeV) by Birks' formulation. The response for protons is also presented assuming the kB constant is the same as for α-particles.

  17. Pinhole X-ray fluorescence imaging of gadolinium and gold nanoparticles using polychromatic X-rays: a Monte Carlo study.

    Science.gov (United States)

    Jung, Seongmoon; Sung, Wonmo; Ye, Sung-Joon

    2017-01-01

    This work aims to develop a Monte Carlo (MC) model for pinhole K-shell X-ray fluorescence (XRF) imaging of metal nanoparticles using polychromatic X-rays. The MC model consisted of two-dimensional (2D) position-sensitive detectors and fan-beam X-rays used to stimulate the emission of XRF photons from gadolinium (Gd) or gold (Au) nanoparticles. Four cylindrical columns containing different concentrations of nanoparticles ranging from 0.01% to 0.09% by weight (wt%) were placed in a 5 cm diameter cylindrical water phantom. The images of the columns had detectable contrast-to-noise ratios (CNRs) of 5.7 and 4.3 for 0.01 wt% Gd and for 0.03 wt% Au, respectively. Higher concentrations of nanoparticles yielded higher CNR. For 1×10 11 incident particles, the radiation dose to the phantom was 19.9 mGy for 110 kVp X-rays (Gd imaging) and 26.1 mGy for 140 kVp X-rays (Au imaging). The MC model of a pinhole XRF can acquire direct 2D slice images of the object without image reconstruction. The MC model demonstrated that the pinhole XRF imaging system could be a potential bioimaging modality for nanomedicine.

  18. Development and in vitro testing of liposomal gadolinium-formulations for neutron capture therapy of glioblastoma multiforme

    International Nuclear Information System (INIS)

    Peters, Tanja

    2013-01-01

    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.

  19. Luminescence properties of barium--gadolinium-titanate ceramics doped with rare-earth ions (Eu3+ and Tb3+).

    Science.gov (United States)

    Hemasundara Raju, S; Muni Sudhakar, B; Sudhakar Reddy, B; Dhoble, S J; Thyagarajan, K; Nageswara Raju, C

    2014-11-01

    Barium-gadolinium-titanate (BaGd2 Ti4 O12) powder ceramics doped with rare-earth ions (Eu(3+) and Tb(3+)) were synthesized by a solid-state reaction method. From the X-ray diffraction spectrum, it was observed that Eu(3+) and Tb(3+):BaGd2 Ti4 O12 powder ceramics are crystallized in the form of an orthorhombic structure. Scanning electron microscopy image shows that the particles are agglomerated and the particle size is about 200 nm. Eu(3+) - and Tb(3+) -doped BaGd2 Ti4 O12 powder ceramics were examined by energy dispersive X-ray analysis, Fourier transform infrared spectroscopy, photoluminescence and thermoluminescence (TL) spectra. Emission spectra of Eu(3+)-doped BaGd2 Ti4 O12 powder ceramics showed bright red emission at 613 nm ((5)D0 →(7)F2) with an excitation wavelength λ(exci)  = 408 nm ((7)F0 → (5)D3) and Tb(3+):BaGd2 Ti4 O12 ceramic powder has shown green emission at 534 nm ((5)D4 → (7)F5) with an excitation wavelength λ(exci)  = 331 nm (((7)F6 → (5)D1). TL spectra show that Eu(3+) and Tb(3+) ions affect TL sensitivity. Copyright © 2014 John Wiley & Sons, Ltd.

  20. Immediate Adverse Reactions to Gadolinium-Based MR Contrast Media: A Retrospective Analysis on 10,608 Examinations

    Directory of Open Access Journals (Sweden)

    Vincenza Granata

    2016-01-01

    Full Text Available Background and Purpose. Contrast media (CM for magnetic resonance imaging (MRI may determine the development of acute adverse reactions. Objective was to retrospectively assess the frequency and severity of adverse reactions associated with gadolinium-based contrast agents (GBCAs injection in patients who underwent MRI. Material and Methods. At our center 10608 MRI examinations with CM were performed using five different GBCAs: Gd-BOPTA (MultiHance, Gd-DTPA (Magnevist, Gd-EOBDTPA (Primovist, Gd-DOTA (Dotarem, and Gd-BTDO3A (Gadovist. Results. 32 acute adverse reactions occurred, accounting for 0.3% of all administration. Twelve reactions were associated with Gd-DOTA injection (0.11%, 9 with Gd-BOPTA injection (0.08%, 6 with Gd-BTDO3A (0.056%, 3 with Gd-EOB-DTPA (0.028%, and 2 with Gd-DTPA (0.018%. Twenty-four reactions (75.0% were mild, four (12.5% moderate, and four (12.5% severe. The most severe reactions were seen associated with use of Gd-BOPTA, with 3 severe reactions in 32 total reactions. Conclusion. Acute adverse reactions are generally rare with the overall adverse reaction rate of 0.3%. The most common adverse reactions were not severe, consisting in skin rash and hives.

  1. Comparison between gadolinium-enhanced 2D T1-weighted gradient-echo and spin-echo sequences in the detection of active multiple sclerosis lesions on 3.0T MRI

    Energy Technology Data Exchange (ETDEWEB)

    Aymerich, F.X. [Hospital Universitari Vall d' Hebron, Universitat Autonoma de Barcelona, MR Unit. Department of Radiology (IDI), Barcelona (Spain); Universitat Politecnica de Catalunya - Barcelona Tech (UPC), Department of Automatic Control (ESAII), Barcelona (Spain); Auger, C.; Alcaide-Leon, P.; Pareto, D.; Huerga, E.; Corral, J.F.; Mitjana, R.; Rovira, A. [Hospital Universitari Vall d' Hebron, Universitat Autonoma de Barcelona, MR Unit. Department of Radiology (IDI), Barcelona (Spain); Sastre-Garriga, J.; Montalban, X. [Hospital Universitari Vall d' Hebron, Universitat Autonoma de Barcelona, Centre d' Esclerosi Multiple de Catalunya (Cemcat), Department of Neurology/Neuroimmunology, Barcelona (Spain)

    2017-04-15

    To compare the sensitivity of enhancing multiple sclerosis (MS) lesions in gadolinium-enhanced 2D T1-weighted gradient-echo (GRE) and spin-echo (SE) sequences, and to assess the influence of visual conspicuity and laterality on detection of these lesions. One hundred MS patients underwent 3.0T brain MRI including gadolinium-enhanced 2D T1-weighted GRE and SE sequences. The two sets of contrast-enhanced scans were evaluated in random fashion by three experienced readers. Lesion conspicuity was assessed by the image contrast ratio (CR) and contrast-to-noise ratio (CNR). The intracranial region was divided into four quadrants and the impact of lesion location on detection was assessed in each slice. Six hundred and seven gadolinium-enhancing MS lesions were identified. GRE images were more sensitive for lesion detection (0.828) than SE images (0.767). Lesions showed a higher CR in SE than in GRE images, whereas the CNR was higher in GRE than SE. Most misclassifications occurred in the right posterior quadrant. The gadolinium-enhanced 2D T1-weighted GRE sequence at 3.0T MRI enables detection of enhancing MS lesions with higher sensitivity and better lesion conspicuity than 2D T1-weighted SE. Hence, we propose the use of gadolinium-enhanced GRE sequences rather than SE sequences for routine scanning of MS patients at 3.0T. (orig.)

  2. Filter materials for dose reduction in screen-film radiography

    NARCIS (Netherlands)

    Koedooder, K.; Venema, H. W.

    1986-01-01

    A computer program was developed to calculate both integral absorbed dose in a water phantom and entrance exposure, for the imaging of iodine contrast with x-ray intensifying screens. The effect of filtration of the x-ray beam on integral absorbed dose and entrance exposure was studied for 27

  3. Evaluation of mammographic screen-film combinations in the clinic

    International Nuclear Information System (INIS)

    Shepard, J.

    1987-01-01

    Six commercially available mammographic film-screen combinations were evaluated in the authors department. Film speed and contrast was measured by obtaining H and D curves. Sensitivity to processing conditions was determined by analyzing changes in the H and D cures as a function of development time and temperature and by examining artifacts in a uniformly exposed film. Radiographs of a 0.5 0 star pattern show relative screen unsharpness. The speed of the film-screen combination is indicated by calculating patient dose necessary to produce optical densities of 1.5 through phantom thicknesses of 3.5 cm of acrylic. Images of a modified RMI detail phantom obtained with each film-screen combination were evaluated by 22 radiologist. Results indicate the physicians' overall preference

  4. Results of the Phase I Dose-Escalating Study of Motexafin Gadolinium With Standard Radiotherapy in Patients With Glioblastoma Multiforme

    International Nuclear Information System (INIS)

    Ford, Judith M.; Seiferheld, Wendy; Alger, Jeffrey R.; Wu, Genevieve; Endicott, Thyra J.; Mehta, Minesh; Curran, Walter; Phan, See-Chun

    2007-01-01

    Purpose: Motexafin gadolinium (MGd) is a putative radiation enhancer initially evaluated in patients with brain metastases. This Phase I trial studied the safety and tolerability of a 2-6-week course (10-22 doses) of MGd with radiotherapy for glioblastoma multiforme. Methods and Materials: A total of 33 glioblastoma multiforme patients received one of seven MGd regimens starting at 10 doses of 4 mg/kg/d MGd and escalating to 22 doses of 5.3 mg/kg/d MGd (5 or 10 daily doses then three times per week). The National Cancer Institute Cancer Therapy Evaluation Program toxicity and stopping rules were applied. Results: The maximal tolerated dose was 5.0 mg/kg/d MGd (5 d/wk for 2 weeks, then three times per week) for 22 doses. The dose-limiting toxicity was reversible transaminase elevation. Adverse reactions included rash/pruritus (45%), chills/fever (30%), and self-limiting vesiculobullous rash of the thumb and fingers (42%). The median survival of 17.6 months prompted a case-matched analysis. In the case-matched analysis, the MGd patients had a median survival of 16.1 months (n = 31) compared with the matched Radiation Therapy Oncology Group database patients with a median survival of 11.8 months (hazard ratio, 0.43; 95% confidence interval, 0.20-0.94). Conclusion: The maximal tolerated dose of MGd with radiotherapy for glioblastoma multiforme in this study was 5 mg/kg/d for 22 doses (daily for 2 weeks, then three times weekly). The baseline survival calculations suggest progression to Phase II trials is appropriate, with the addition of MGd to radiotherapy with concurrent and adjuvant temozolomide

  5. Clinical value of 4-hour delayed gadolinium-Enhanced 3D FLAIR MR Images in Acute Vestibular Neuritis.

    Science.gov (United States)

    Byun, Hayoung; Chung, Jae Ho; Lee, Seung Hwan; Park, Chul Won; Park, Dong Woo; Kim, Tae Yoon

    2018-01-13

    To investigate the clinical significance of 4-hour delayed-enhanced 3.0 Tesla three-dimensional (3D) fluid-attenuated inversion recovery (FLAIR) magnetic resonance (MR) imaging in acute vestibular neuritis. A prospective observational study. Twenty-nine vestibular neuritis patients were enrolled between January 2017 and June 2017. Vestibular function tests, comprising the caloric and video head impulse tests and vestibular-evoked myogenic potential measurements, were performed. Precontrast, 10-minute, and 4-hour delayed-enhanced 3D-FLAIR MR images using double-dose IV gadolinium were obtained. After laterality and extent of inner ear enhancement were defined, the patients were divided into groups based on the patterns of enhancement, and clinical parameters were analyzed according to the groups. Twenty patients (20 of 29, 69.0%) had obviously asymmetric enhancement of the affected inner ear structures on 4-hour delayed images, whereas only three patients (10.3%) had marked enhancement on 10-minute delayed images. The duration of spontaneous nystagmus (DurSN) was significantly longer in the patients with enhancement, especially with enhancement of the whole inner ear, including the vestibule and semicircular canals (P vestibular function tests did not reveal any significant associations with MR enhancement. Contrast enhancement of the vestibular nerve and inner ear structures can be identified on 4-hour delayed-enhanced 3T 3D-FLAIR MR images in acute vestibular neuritis. The extent of inner ear enhancement may be associated with the DurSN. IV. Laryngoscope, 2017. © 2018 The American Laryngological, Rhinological and Otological Society, Inc.

  6. Late gadolinium uptake demonstrated with magnetic resonance in patients where automated PERFIT analysis of myocardial SPECT suggests irreversible perfusion defect

    International Nuclear Information System (INIS)

    Rosendahl, Lene; Blomstrand, Peter; Ohlsson, Jan L; Björklund, Per-Gunnar; Ahlander, Britt-Marie; Starck, Sven-Åke; Engvall, Jan E

    2008-01-01

    Myocardial perfusion single photon emission computed tomography (MPS) is frequently used as the reference method for the determination of myocardial infarct size. PERFIT ® is a software utilizing a three-dimensional gender specific, averaged heart model for the automatic evaluation of myocardial perfusion. The purpose of this study was to compare the perfusion defect size on MPS, assessed with PERFIT, with the hyperenhanced volume assessed by late gadolinium enhancement magnetic resonance imaging (LGE) and to relate their effect on the wall motion score index (WMSI) assessed with cine magnetic resonance imaging (cine-MRI) and echocardiography (echo). LGE was performed in 40 patients where clinical MPS showed an irreversible uptake reduction suggesting a myocardial scar. Infarct volume, extent and major coronary supply were compared between MPS and LGE as well as the relationship between infarct size from both methods and WMSI. MPS showed a slightly larger infarct volume than LGE (MPS 29.6 ± 23.2 ml, LGE 22.1 ± 16.9 ml, p = 0.01), while no significant difference was found in infarct extent (MPS 11.7 ± 9.4%, LGE 13.0 ± 9.6%). The correlation coefficients between methods in respect to infarct size and infarct extent were 0.71 and 0.63 respectively. WMSI determined with cine-MRI correlated moderately with infarct volume and infarct extent (cine-MRI vs MPS volume r = 0.71, extent r = 0.71, cine-MRI vs LGE volume r = 0.62, extent r = 0.60). Similar results were achieved when wall motion was determined with echo. Both MPS and LGE showed the same major coronary supply to the infarct area in a majority of patients, Kappa = 0.84. MPS and LGE agree moderately in the determination of infarct size in both absolute and relative terms, although infarct volume is slightly larger with MPS. The correlation between WMSI and infarct size is moderate

  7. Fabrication and in vitro characterization of gadolinium-based nanoclusters for simultaneous drug delivery and radiation enhancement

    Science.gov (United States)

    Yoo, Shannon S.; Guo, Linghong; Sun, Xuejun; Shaw, Andrew R.; Yuan, Zhipeng; Löbenberg, Raimar; Roa, Wilson H.

    2016-09-01

    We report the synthesis of a gadolinium hydroxide (Gd(OH)3) nanorod based doxorubicin (Dox) delivery system that can enhance both magnetic resonance imaging contrast and radiation sensitivity. A simple and cost effective wet-chemical method was utilized in the presence of manganese (Mn) ions and Dox to produce the Gd(OH)3:Mn·Dox nanocluster structure. The Gd(OH)3:Mn·Dox nanocluster was composed of Mn-doped Gd(OH)3 nanorods arranged in parallel with Dox as a linker molecule between the adjacent nanorods. No other studies have utilized Dox as both the linker and therapeutic molecule in a nanostructure to date. The Gd(OH)3 nanorod is reported to have no significant cellular or in vivo toxicity, which makes it an ideal base material for this biomedical application. The Gd(OH)3:Mn·Dox nanocluster exhibited paramagnetic behavior and was stable in a colloidal solution. The nanocluster also enabled high Dox loading capacity and specifically released Dox in a sustained and pH-dependent manner. The positively charged Gd(OH)3:Mn·Dox nanoclusters were readily internalized into MDA-MB-231 breast cancer cells via endocytosis, which resulted in intracellular release of Dox. The released Dox in cells was effective in conferring cytotoxicity and inhibiting proliferation of cancer cells. Furthermore, a synergistic anticancer effect could be observed with radiation treatment. Overall, the Gd(OH)3:Mn·Dox nanocluster drug delivery system described herein may have potential utility in clinics as a multifunctional theranostic nanoparticle with combined benefits in both diagnosis and therapy in the management of cancer.

  8. Protective effect of gadolinium chloride on early warm ischemia/reperfusion injury in rat bile duct during liver transplantation.

    Directory of Open Access Journals (Sweden)

    Biao Wang

    Full Text Available BACKGROUND: Activation of Kupffer cell (KC is acknowledged as a key event in the initiation and perpetuation of bile duct warm ischemia/reperfusion injury. The inhibitory effect of gadolinium chloride (GdCl(3 on KC activation shows potential as a protective intervention in liver injury, but there is less research with regard to bile duct injury. METHODS: Sixty-five male Sprague-Dawley rats (200-250 g were randomly divided into three experimental groups: a sham group (n = 15, a control group (n = 25, and a GdCl(3 group (n = 25. Specimen was collected at 0.5, 2, 6, 12 and 24 h after operation. Alanine aminotransferase (ALT, alkaline phosphatase (ALP and total bilirubin (TBIL of serum were measured. Tumor necrosis factor-α (TNF-α, Capase-3 activity and soluble Fas (sFas were detected. The pathologic changes of bile duct were observed. Immunochemistry for bile duct Fas was performed. Apoptosis of bile duct cells was evaluated by the terminal UDP nick end labeling assay. RESULTS: GdCl(3 significantly decreased the levels of ALT, ALP and TBIL at 2, 6, 12, and 24 h, and increased serum sFas at 2, 6 and 12 h (P<0.05. TNF-α was lower in the GdCl(3 group than in the control group at 2, 6, 12 and 24 h (P<0.05. Preadministration of GdCl(3 significantly reduced the Caspase-3 activity and bile duct cell apoptosis at 2, 6, 12 and 24 h. After operation for 2, 6 and 12 h, the expression of Fas protein was lower in the GdCl(3 group than in the control group (P<0.05. CONCLUSIONS: GdCl(3 plays an important role in suppressing bile duct cell apoptosis, including decreasing ALT, ALP, TBIL and TNF-α; suppressing Fas-FasL-Caspase signal transduction during transplantation.

  9. Protective effect of gadolinium chloride on early warm ischemia/reperfusion injury in rat bile duct during liver transplantation.

    Science.gov (United States)

    Wang, Biao; Zhang, Qi; Zhu, Bili; Cui, Zhonglin; Zhou, Jie

    2013-01-01

    Activation of Kupffer cell (KC) is acknowledged as a key event in the initiation and perpetuation of bile duct warm ischemia/reperfusion injury. The inhibitory effect of gadolinium chloride (GdCl(3)) on KC activation shows potential as a protective intervention in liver injury, but there is less research with regard to bile duct injury. Sixty-five male Sprague-Dawley rats (200-250 g) were randomly divided into three experimental groups: a sham group (n = 15), a control group (n = 25), and a GdCl(3) group (n = 25). Specimen was collected at 0.5, 2, 6, 12 and 24 h after operation. Alanine aminotransferase (ALT), alkaline phosphatase (ALP) and total bilirubin (TBIL) of serum were measured. Tumor necrosis factor-α (TNF-α), Capase-3 activity and soluble Fas (sFas) were detected. The pathologic changes of bile duct were observed. Immunochemistry for bile duct Fas was performed. Apoptosis of bile duct cells was evaluated by the terminal UDP nick end labeling assay. GdCl(3) significantly decreased the levels of ALT, ALP and TBIL at 2, 6, 12, and 24 h, and increased serum sFas at 2, 6 and 12 h (Pbile duct cell apoptosis at 2, 6, 12 and 24 h. After operation for 2, 6 and 12 h, the expression of Fas protein was lower in the GdCl(3) group than in the control group (Pbile duct cell apoptosis, including decreasing ALT, ALP, TBIL and TNF-α; suppressing Fas-FasL-Caspase signal transduction during transplantation.

  10. Intracranial arterial wall enhancement using gadolinium-enhanced 3D black-blood T1-weighted imaging

    Energy Technology Data Exchange (ETDEWEB)

    Takano, Koichi, E-mail: k-takano@fukuoka-u.ac.jp; Hida, Kosuke; Kuwabara, Yasuo; Yoshimitsu, Kengo

    2017-01-15

    Purpose: We investigated the enhancement of the intracranial arterial walls with gadolinium-enhanced, black-blood three-dimensional T1-weighted imaging (Gd-3DBB) by using an improved motion-sensitized driven-equilibrium (iMSDE)—prepared volumetric isotropic turbo spin-echo acquisition (VISTA). Methods: A total of 115 patients underwent FLAIR, 3D-TOF-MRA and Gd-3DBB with a 1.5-T scanner. The degree and distribution of the arterial wall enhancement on Gd-3DBB was assessed. The association of the degree of wall enhancement with brain infarction/ischemic lesions on FLAIR, luminal changes on 3D-TOF-MRA, and cardiovascular risk factors (CVRFs) was investigated by univariate and multiple logistic regression analyses. Results: Strong enhancement of the arterial walls was observed in 77 vertebral arteries (33.5%), 4 basilar arteries (3.5%), 31 supraclinoid internal carotid arteries (ICAs) (13.5%) and 8 middle cerebral arteries (3.5%). In addition, 221 intrapetrous ICAs (96.1%) showed strong enhancement. After adjusting for confounding factors, multivariate analyses showed that the patient age was independently associated with the strong wall enhancement of the arteries for both the posterior (OR, 1.088; 95% CI, 1.034–1.146) and the anterior circulation (OR, 1.098, 95% CI 1.029–1.172). In addition, the presence of the supratentorial brain infarctions was independently associated with the strong wall enhancement in the anterior circulation excluding the intrapetrous ICAs (OR, 4.097; 95% CI, 1.483–11.319). Conclusions: Although the arterial wall enhancement on the Gd-3DBB probably reflects normal aging, the enhancement in the anterior circulation might be related to brain infarctions. On the other hand, the intrapetrous ICA enhancement is considered a nonspecific finding and should not be mistaken for arterial pathologies such as atherosclerosis or arteritis.

  11. Graphene Oxide as a Nanocarrier for a Theranostics Delivery System of Protocatechuic Acid and Gadolinium/Gold Nanoparticles

    Directory of Open Access Journals (Sweden)

    Muhammad Sani Usman

    2018-02-01

    Full Text Available We have synthesized a graphene oxide (GO-based theranostic nanodelivery system (GOTS for magnetic resonance imaging (MRI using naturally occurring protocatechuic acid (PA as an anticancer agent and gadolinium (III nitrate hexahydrate (Gd as the starting material for a contrast agent,. Gold nanoparticles (AuNPs were subsequently used as second diagnostic agent. The GO nanosheets were first prepared from graphite via the improved Hummer’s protocol. The conjugation of the GO and the PA was done via hydrogen bonding and π–π stacking interactions, followed by surface adsorption of the AuNPs through electrostatic interactions. GAGPA is the name given to the nanocomposite obtained from Gd and PA conjugation. However, after coating with AuNPs, the name was modified to GAGPAu. The physicochemical properties of the GAGPA and GAGPAu nanohybrids were studied using various characterization techniques. The results from the analyses confirmed the formation of the GOTS. The powder X-ray diffraction (PXRD results showed the diffractive patterns for pure GO nanolayers, which changed after subsequent conjugation of the Gd and PA. The AuNPs patterns were also recorded after surface adsorption. Cytotoxicity and magnetic resonance imaging (MRI contrast tests were also carried out on the developed GOTS. The GAGPAu was significantly cytotoxic to the human liver hepatocellular carcinoma cell line (HepG2 but nontoxic to the standard fibroblast cell line (3T3. The GAGPAu also appeared to possess higher T1 contrast compared to the pure Gd and water reference. The GOTS has good prospects of serving as future theranostic platform for cancer chemotherapy and diagnosis.

  12. Optimization of single injection liver arterial phase gadolinium enhanced MRI using bolus track real-time imaging.

    Science.gov (United States)

    Sharma, Puneet; Kalb, Bobby; Kitajima, Hiroumi D; Salman, Khalil N; Burrow, Bobbie; Ray, Gaye L; Martin, Diego R

    2011-01-01

    To measure contrast agent enhancement kinetics in the liver and to further evaluate and develop an optimized gadolinium enhanced MRI using a single injection real-time bolus-tracking method for reproducible imaging of the transient arterial-phase. A total of 18 subjects with hypervascular liver lesions were imaged with four dimensional (4D) perfusion scans to measure time-to-peak (TTP) delays of arterial (aorta-celiac axis), liver parenchyma, liver lesion, portal, and hepatic veins. Time delays were calculated from the TTP-aorta signal, and then related to the gradient echo (GRE) k-space acquisition design, to determine optimized timing for real-time bolus-track triggering methodology. As another measure of significance, 200 clinical patients were imaged with 3D-GRE using either a fixed time-interval or by individualized arterial bolus real-time triggering. Bolus TTP-aorta was calculated and arterial-phase acquisitions were compared for accuracy and reproducibility using specific vascular enhancement indicators. The mean bolus transit-time to peak-lesion contrast was 8.1 ± 2.7 seconds following arterial detection, compared to 32.1 ± 5.4 seconds from contrast injection, representing a 62.1% reduction in the time-variability among subjects (N = 18). The real-time bolus-triggered technique more consistently captured the targeted arterial phase (94%), compared to the fixed timing technique (73%), representing an expected improvement of timing accuracy in 28% of patients (P = 0.0001389). Our results show detailed timing window analysis required for optimized arterial real-time bolus-triggering acquisition of transient arterial phase features of liver lesions, with optimized arterial triggering expected to improve reproducibility in a significant number of patients. Copyright © 2010 Wiley-Liss, Inc.

  13. Retrospective analysis of patients for development of nephrogenic systemic fibrosis following conventional angiography using gadolinium-based contrast agents

    Energy Technology Data Exchange (ETDEWEB)

    Hoppe, Hanno; Spagnuolo, Sara; Froehlich, Johannes M.; Thoeny, Harriet C. [University Hospital Bern, Institute of Diagnostic, Interventional, and Pediatric Radiology, Inselspital, Bern (Switzerland); Nievergelt, Helga [University Hospital Bern, Clinic of Dermatology, Bern (Switzerland); Dinkel, Hans-Peter [Hospital Landshut, Institute of Diagnostic and Interventional Radiology, Landshut (Germany); Gretener, Silvia [University Hospital of Bern, Division of Vascular Medicine, Swiss Cardiovascular Center, Bern (Switzerland)

    2010-03-15

    The purpose was to retrospectively review the data of 27 patients with renal insufficiency who underwent conventional angiography with gadolinium-based contrast agents (GDBCA) as alternative contrast agents and assess the occurrence of nephrogenic systemic fibrosis (NSF) together with associated potential risk factors. This HIPAA-compliant study had institutional review board approval, and informed consent was waived. Statistical analysis was performed for all available laboratory and clinical data, including dermatology reports. Type and amount of the GDBCA used were recorded for angiography and additional MRI studies, if applicable. Serum creatinine levels (SCr) pre- and post-angiography were recorded, and estimated glomerular filtration rates (eGFR) were calculated. Ten female and 17 male patients who underwent angiography with GDBCA were included. The mean amount of GDBCA administered was 44 {+-} 15.5 ml (range 15-60 ml) or 0.24 + 0.12 mmol/kg (range 0.1-0.53 mmol/kg). At the time of angiography all patients had renal insufficiency (eGFR <60 ml/min/1.73 m{sup 2}). Mean eGFR pre-angiography was 26 ml/min/1.73 m{sup 2} and 33 ml/min/1.73 m{sup 2} post-angiography. The mean follow-up period covers 28 months, range 1-84 months. Additional MRI studies with GDBCA administration were performed in 15 patients. One patient with typical skin lesions had developed biopsy-confirmed NSF. Conventional arterial angiography with GDBCA may play a role in the development of NSF in patients with renal insufficiency. Alternative contrast agents, such as CO{sub 2} angiography or rather the use of low doses of iodinated contrast agents, should be considered in these patients. (orig.)

  14. Whole-heart 3D late gadolinium-enhanced MR imaging. Investigation of optimal scan parameters and clinical usefulness

    International Nuclear Information System (INIS)

    Yorimitsu, Misako; Yokoyama, Kenichi; Nitatori, Toshiaki; Yoshino, Hideaki; Isono, Sachiko; Kuhara, Shigehide

    2012-01-01

    Whole-heart 3-dimensional (3D) late-gadolinium-enhanced magnetic resonance (MR) imaging (WH-LGE) uses respiratory gating combined with acquisition of 3D data for the entire heart in a single scan, which permits reconstruction of any plane with high resolution. We investigated the optimal scan parameters and compared WH-LGE with the conventional scanning method. We employed inversion recovery 3D fast field echo using a 1.5-tesla system and scan parameters: repetition time (TR), 6.6 ms; echo time (TE), 2.5 ms; number of segments, 2; parallel imaging factor, 1.8; matrix size, 128 x 256; field of view (FOV), 320 x 320 mm; and acquisition slice thickness, 3 mm (reconstruction slice thickness, 1.5 mm). Five healthy volunteers underwent scanning during free breathing with real-time motion correction, from which we determined optimal scan parameters. We then used those parameters to scan 25 patients with myocardial infarction to compare scan time and image quality between the WH-LGE and conventional 3D breath-holding methods (slice thickness, 10 mm; matrix size, 128 x 256). Results in volunteers showed optimal scan parameters of 12deg flip angle, fat suppression turned off in combination, and interleaved ordering. In clinical cases, scan times did not differ significantly. Sharpness of the margins of normal myocardium at the apex of the heart and contrast between enhanced and nonenhanced myocardium improved significantly with WH-LGE. WH-LGE yields high resolution images during free breathing and is considered useful for accurately estimating the area and transmural extent of myocardial infarction. (author)

  15. Intracranial arterial wall enhancement using gadolinium-enhanced 3D black-blood T1-weighted imaging

    International Nuclear Information System (INIS)

    Takano, Koichi; Hida, Kosuke; Kuwabara, Yasuo; Yoshimitsu, Kengo

    2017-01-01

    Purpose: We investigated the enhancement of the intracranial arterial walls with gadolinium-enhanced, black-blood three-dimensional T1-weighted imaging (Gd-3DBB) by using an improved motion-sensitized driven-equilibrium (iMSDE)—prepared volumetric isotropic turbo spin-echo acquisition (VISTA). Methods: A total of 115 patients underwent FLAIR, 3D-TOF-MRA and Gd-3DBB with a 1.5-T scanner. The degree and distribution of the arterial wall enhancement on Gd-3DBB was assessed. The association of the degree of wall enhancement with brain infarction/ischemic lesions on FLAIR, luminal changes on 3D-TOF-MRA, and cardiovascular risk factors (CVRFs) was investigated by univariate and multiple logistic regression analyses. Results: Strong enhancement of the arterial walls was observed in 77 vertebral arteries (33.5%), 4 basilar arteries (3.5%), 31 supraclinoid internal carotid arteries (ICAs) (13.5%) and 8 middle cerebral arteries (3.5%). In addition, 221 intrapetrous ICAs (96.1%) showed strong enhancement. After adjusting for confounding factors, multivariate analyses showed that the patient age was independently associated with the strong wall enhancement of the arteries for both the posterior (OR, 1.088; 95% CI, 1.034–1.146) and the anterior circulation (OR, 1.098, 95% CI 1.029–1.172). In addition, the presence of the supratentorial brain infarctions was independently associated with the strong wall enhancement in the anterior circulation excluding the intrapetrous ICAs (OR, 4.097; 95% CI, 1.483–11.319). Conclusions: Although the arterial wall enhancement on the Gd-3DBB probably reflects normal aging, the enhancement in the anterior circulation might be related to brain infarctions. On the other hand, the intrapetrous ICA enhancement is considered a nonspecific finding and should not be mistaken for arterial pathologies such as atherosclerosis or arteritis.

  16. Extent of late gadolinium enhancement at right ventricular insertion points in patients with hypertrophic cardiomyopathy: relation with diastolic dysfunction

    Energy Technology Data Exchange (ETDEWEB)

    Zhu, Yinsu [Seoul National University Hospital, Department of Radiology, Seoul (Korea, Republic of); The First Affiliated Hospital of Nanjing Medical University, Department of Radiology, Nanjing, Jiangsu (China); Park, Eun-Ah; Lee, Whal; Chu, Ajung; Chung, Jin Wook; Park, Jae Hyung [Seoul National University Hospital, Department of Radiology, Seoul (Korea, Republic of); Kim, Hyung-Kwan [Seoul National University Hospital, Division of Cardiology, Department of Internal Medicine, Seoul (Korea, Republic of)

    2015-04-01

    Our aim was to examine the association between the extent of late gadolinium enhancement (LGE) at right ventricular insertion points (RVIP) and left ventricular (LV) functional parameters in patients with hypertrophic cardiomyopathy (HCM). Sixty-one HCM patients underwent echocardiography and cardiovascular magnetic resonance (CMR) within one week. Mitral annular velocities (E/E') were obtained from echocardiography; LV ejection fraction (EF), LV mass index, LV wall maximal thickness, and left atrial volume index (LAVI) were obtained from MR. LGE extent was quantified (proportion of total LV myocardial mass) according to location: % RVIP-LGE and % non-RVIP-LGE. Although LGE was commonly present in both apical (74 %) and non-apical HCMs (88 %) (p = 0.163), RVIP-LGE was more frequent (86 % vs. 47 %, p = 0.002) in non-apical HCMs in which E/E' was significantly higher (19.23 ± 8.40 vs. 13.13 ± 5.06, p = 0.009). In addition, RVIP-LGE extent was associated with LV diastolic dysfunction (r = 0.45, p < 0.001 for E/E'; r = 0.53, p < 0.001 for LAVI) and lower LVEF (r = -0.42, p = 0.001). There was no correlation between non-RVIP-LGE extent and other parameters. Multiple linear regression analysis revealed RVIP-LGE extent as an independent predictor of E/E' (β = 0.45, p < 0.001) and LAVI in HCM patients (β = 0.53, p < 0.001). The extent of LGE at RVIPs in HCM patients is associated with increased estimated LV filling pressure and chronic diastolic burden. (orig.)

  17. Temporal change of enhancement after gadolinium injection on contrast-enhanced CMR in reperfused acute myocardial infarction.

    Science.gov (United States)

    Matsumoto, Hidenari; Matsuda, Tetsuya; Miyamoto, Kenichi; Shimada, Toshihiko; Ushimaru, Shunpei; Mikuri, Mikiko; Yamazaki, Taketoshi

    2015-01-01

    A recent report demonstrated that early enhancement on contrast-enhanced cardiac magnetic resonance (CE-CMR) correlated with myocardial edema detected by T2-weighted CMR in reperfused acute myocardial infarction (AMI). However, the time at which the enhancement in salvaged myocardium disappears is yet to be determined. We aimed to examine the time course of the enhancement with the use of different quantification techniques and to compare the extent of enhancement with the myocardial edema. CE-CMR was performed at 2-20 min after gadolinium administration in 32 AMI patients. The extent of enhancement (% myocardium) was quantified by manual delineation and the threshold methods of 2-5 SDs above remote myocardium. In subendocardial infarct, the enhancement was greatest at 2 min regardless of the quantification techniques and decreased with time, particularly in the first 6 min. In transmural infarct, the change in the size of enhancement was modest although the time course of enhancement varied according to the quantification techniques. The sizes of enhancement were not significantly different between 15 and 20 min regardless of the techniques and infarct transmurality. The best agreement with myocardial edema was found at 2 min with average differences of 0.5% and -1.2% and limits of agreement of ±20.2% and ±21.2% for the manual and 2-SD techniques, respectively. The optimal timing for delineation of salvaged myocardium on CE-CMR is at 2min when the manual or 2-SD technique was employed. Imaging needs to be completed in a short time (ideally within a minute) because of rapid reduction of enhancement in salvaged myocardium. Copyright © 2014 Japanese College of Cardiology. Published by Elsevier Ltd. All rights reserved.

  18. Effect of inversion time on the precision of myocardial late gadolinium enhancement quantification evaluated with synthetic inversion recovery MR imaging

    Energy Technology Data Exchange (ETDEWEB)

    Varga-Szemes, Akos; Schoepf, U.J.; De Cecco, Carlo N.; Fuller, Stephen R.; Suranyi, Pal [Medical University of South Carolina, Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Charleston, SC (United States); Geest, Rob J. van der [Leiden University Medical Center, Department of Radiology, Leiden (Netherlands); Spottiswoode, Bruce S. [Siemens Medical Solutions, Chicago, IL (United States); Muscogiuri, Giuseppe [Medical University of South Carolina, Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Charleston, SC (United States); Bambino Gesu Children' s Hospital IRCCS, Department of Imaging, Rome (Italy); Wichmann, Julian L. [Medical University of South Carolina, Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Charleston, SC (United States); University Hospital Frankfurt, Department of Diagnostic and Interventional Radiology, Frankfurt (Germany); Mangold, Stefanie [Medical University of South Carolina, Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Charleston, SC (United States); Eberhard-Karls University Tuebingen, Department of Diagnostic and Interventional Radiology, Tuebingen (Germany); Maurovich-Horvat, Pal; Merkely, Bela [Semmelweis University, MTA-SE Cardiovascular Imaging Research Group, Heart and Vascular Center, Budapest (Hungary); Litwin, Sheldon E. [Medical University of South Carolina, Division of Cardiology, Department of Medicine, Charleston, SC (United States); Vliegenthart, Rozemarijn [Medical University of South Carolina, Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Charleston, SC (United States); University of Groningen, University Medical Center Groningen, Center for Medical Imaging-North East Netherlands, Department of Radiology, Groningen (Netherlands)

    2017-08-15

    To evaluate the influence of inversion time (TI) on the precision of myocardial late gadolinium enhancement (LGE) quantification using synthetic inversion recovery (IR) imaging in patients with myocardial infarction (MI). Fifty-three patients with suspected prior MI underwent 1.5-T cardiac MRI with conventional magnitude (MagIR) and phase-sensitive IR (PSIR) LGE imaging and T1 mapping at 15 min post-contrast. T1-based synthetic MagIR and PSIR images were calculated with a TI ranging from -100 to +150 ms at 5-ms intervals relative to the optimal TI (TI{sub 0}). LGE was quantified using a five standard deviation (5SD) and full width at half-maximum (FWHM) thresholds. Measurements were compared using one-way analysis of variance. The MagIR{sub sy} technique provided precise assessment of LGE area at TIs ≥ TI{sub 0}, while precision was decreased below TI{sub 0}. The LGE area showed significant differences at ≤ -25 ms compared to TI{sub 0} using 5SD (P < 0.001) and at ≤ -65 ms using the FWHM approach (P < 0.001). LGE measurements did not show significant difference over the analysed TI range in the PSIR{sub sy} images using either of the quantification methods. T1 map-based PSIR{sub sy} images provide precise quantification of MI independent of TI at the investigated time point post-contrast. MagIR{sub sy}-based MI quantification is precise at TI{sub 0} and at longer TIs while showing decreased precision at TI values below TI{sub 0}. (orig.)

  19. Delayed gadolinium-enhanced magnetic resonance imaging of cartilage (dGEMRIC), after slipped capital femoral epiphysis

    International Nuclear Information System (INIS)

    Zilkens, Christoph; Miese, Falk; Bittersohl, Bernd; Jaeger, Marcus; Schultz, Johannes; Holstein, Arne; Kim, Young-jo; Millis, Michael B.; Mamisch, Tallal C.; Krauspe, Ruediger

    2011-01-01

    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 50 o -60 o ), and group 3 = subjects with severe offset decrease (alpha-angle >60 o ). Results: There was statistically significant difference noted for the T1 Gd values, lateral and central, between group 1 and group 3 (p-values = 0.038 and 0.041). The T1 Gd values measured within the lateral portion were slightly lower compared with the T1 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.

  20. Combined magnetic resonance and optical imaging of head and neck tumor xenografts using Gadolinium-labelled phosphorescent polymeric nanomicelles

    Science.gov (United States)

    2010-01-01

    Background The overall objective of this study was to develop a nanoparticle formulation for dual modality imaging of head and neck cancer. Here, we report the synthesis and characterization of polymeric phospholipid-based nanomicelles encapsulating near-infrared (NIR) phosphorescent molecules of Pt(II)-tetraphenyltetranaphthoporphyrin [Pt(TPNP)] and surface functionalized with gadolinium [Pt(TPNP)-Gd] for combined magnetic resonance imaging (MRI) and NIR optical imaging applications. Methods Dynamic light scattering, electron microscopy, optical spectroscopy and MR relaxometric measurements were performed to characterize the optical and magnetic properties of nanoparticles in vitro. Subsequently, in vivo imaging experiments were carried out using nude mice bearing primary patient tumor-derived human head and neck squamous cell carcinoma xenografts. Results The nanomicelles were ~100 nm in size and stable in aqueous suspension. T1-weighted MRI and relaxation rate (R1 = 1/T1) measurements carried out at 4.7 T revealed enhancement in the tumor immediately post injection with nanomicelles, particularly in the tumor periphery which persisted up to 24 hours post administration. Maximum intensity projections (MIPs) generated from 3D T1-weighted images also demonstrated visible enhancement in contrast within the tumor, liver and blood vessels. NIR optical imaging performed (in vivo and ex vivo) following completion of MRI at the 24 h time point confirmed tumor localization of the nanoparticles. The large spectral separation between the Pt(TPNP) absorption (~700 nm) and phosphorescence emission (~900 nm) provided a dramatic decrease in the level of background, resulting in high contrast optical (NIR phosphorescence) imaging. Conclusions In conclusion, Pt(TPNP)-Gd nanomicelles exhibit a high degree of tumor-avidity and favorable imaging properties that allow for combined MR and optical imaging of head and neck tumors. Further investigation into the potential of Pt

  1. Subendocardial enhancement in gadolinium-diethylene-triamine-pentaacetic acid-enhanced magnetic resonance imaging in aortic stenosis.

    Science.gov (United States)

    Ochiai, K; Ishibashi, Y; Shimada, T; Murakami, Y; Inoue, S; Sano, K

    1999-05-15

    We investigated the usefulness of magnetic resonance imaging (MRI) with gadolinium-diethylene-triamine-pentaacetic acid (Gd-DTPA) in assessing myocardial damage from valvular aortic stenosis (AS). Cardiac catheterization and echocardiography were performed in 17 patients with AS. T1-weighted spin-echo sequence was used to obtain magnetic resonance images of short-axis planes of the left ventricle before and after intravenous Gd-DTPA injection in all patients using a 1.5 Tesla imager. Patients were divided into 2 groups according to the presence or absence of regional myocardial enhancement in the images. The Gd-DTPA-enhanced magnetic resonance images of 7 patients showed circumferential subendocardial enhancement. All patients with enhancement had a history of heart failure and were in New York Heart Association functional class III or IV, whereas patients without enhancement were in New York Heart Association functional class I or II. Patients with enhancement had a smaller aortic valve area (0.28 +/- 0.09 vs 0.38 +/- 0.07 cm2/m2, p <0.05), a higher transvalvular pressure gradient (109 +/- 40 vs 68 +/- 18 mm Hg, p <0.05), greater elevation of left ventricular end-diastolic pressure (22 +/- 11 vs 12 +/- 2 mm Hg, p <0.05), and greater reduction in left ventricular ejection fraction (40 +/- 9 vs 59 +/- 10%, p <0.05). Subendocardial enhancement by Gd-DTPA-enhanced MRI was thus shown to be closely related to the severity of AS. In conclusion, Gd-DTPA-enhanced MRI is a new noninvasive tool that can provide useful information about myocardial damage in AS.

  2. Nano-laminate vs. direct deposition of high permittivity gadolinium scandate on silicon by high pressure sputtering

    Energy Technology Data Exchange (ETDEWEB)

    Feijoo, P.C., E-mail: pedronska@fis.ucm.es [Dpto. Física Aplicada III (Electricidad y Electrónica), Universidad Complutense de Madrid, Fac. de CC. Físicas. Av/Complutense S/N, E-28040 Madrid (Spain); Pampillón, M.A.; San Andrés, E. [Dpto. Física Aplicada III (Electricidad y Electrónica), Universidad Complutense de Madrid, Fac. de CC. Físicas. Av/Complutense S/N, E-28040 Madrid (Spain); Fierro, J.L.G. [Instituto de Catálisis y Petroleoquímica, Consejo Superior de Investigaciones Científicas, C/Marie Curie 2, E-28049 Cantoblanco (Spain)

    2015-10-30

    In this work we use the high pressure sputtering technique to deposit the high permittivity dielectric gadolinium scandate on silicon substrates. This nonconventional deposition technique prevents substrate damage and allows for growth of ternary compounds with controlled composition. Two different approaches were assessed: the first one consists of depositing the material directly from a stoichiometric GdScO{sub 3} target; in the second one, we anneal a nano-laminate of < 0.5 nm thick Gd{sub 2}O{sub 3} and Sc{sub 2}O{sub 3} films in order to control the composition of the scandate. Metal–insulator–semiconductor capacitors were fabricated with platinum gates for electrical characterization. Accordingly, we grew a Gd-rich Gd{sub 2−x}Sc{sub x}O{sub 3} film that, in spite of higher leakage currents, presents a better effective relative permittivity of 21 and lower density of defects. - Highlights: • GdScO is deposited on Si as a high permittivity dielectric by two procedures. • Films sputtered from GdScO{sub 3} target are Sc-rich and present thick interface SiO{sub x}. • Gd-rich GdScO is obtained from a nano-laminate sputtered from Sc{sub 2}O{sub 3} and Gd{sub 2}O{sub 3}. • Gd{sub 1.8}Sc{sub 0.2}O{sub 3} shows good effective permittivity and electrical properties.

  3. 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.

  4. 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

  5. Survey of gadolinium-based contrast agent utilization among the members of the Society for Pediatric Radiology: a Quality and Safety Committee report

    International Nuclear Information System (INIS)

    Blumfield, Einat; Moore, Michael M.; Drake, Mary K.; Goodman, Thomas R.; Lewis, Kristopher N.; Meyer, Laura T.; Ngo, Thang D.; Sammet, Christina; Stanescu, Arta Luana; Iyer, Ramesh S.; Swenson, David W.; Slovis, Thomas L.

    2017-01-01

    Gadolinium-based contrast agents (GBCAs) have been used for magnetic resonance (MR) imaging over the last three decades. Recent reports demonstrated gadolinium retention in patients' brains following intravenous administration. Since gadolinium is a highly toxic heavy metal, there is a potential for adverse effects from prolonged retention or deposition, particularly in children. For this reason, the Society (SPR) for Pediatric Radiology Quality and Safety committee conducted a survey to evaluate the current status of GBCAs usage among pediatric radiologists. To assess the usage of GBCAs among SPR members. An online 15-question survey was distributed to SPR members. Survey questions pertained to the type of GBCAs used, protocoling workflow, requirement of renal function or pregnancy tests, and various clinical indications for contrast-enhanced MRI examinations. A total of 163 survey responses were compiled (11.1% of survey invitations), the majority of these from academic institutions in the United States. Ninety-four percent reported that MR studies are always or usually protocoled by pediatric radiologists. The most common GBCA utilized by survey respondents were Eovist (60.7%), Ablavar (45.4%), Gadovist (38.7%), Magnevist (34.4%) and Dotarem (32.5%). For several clinical indications, survey responses regarding GBCA administration were concordant with American College of Radiology (ACR) Appropriateness Criteria, including seizures, headache and osteomyelitis. For other indications, including growth hormone deficiency and suspected vascular ring, survey responses revealed potential overutilization of GBCAs when compared to ACR recommendations. Survey results demonstrate that GBCAs are administered judiciously in children, yet there is an opportunity to improve their utilization with the goal of reducing potential future adverse effects. (orig.)

  6. Survey of gadolinium-based contrast agent utilization among the members of the Society for Pediatric Radiology: a Quality and Safety Committee report

    Energy Technology Data Exchange (ETDEWEB)

    Blumfield, Einat [Jacobi Medical Center, Department of Radiology, Albert Einstein College of Medicine, South Bronx, NY (United States); Moore, Michael M. [The Pennsylvania State University College of Medicine, Department of Radiology, Penn State Hershey Children' s Hospital, Hershey, PA (United States); Drake, Mary K. [University of Nebraska Medical Center, Department of Radiology, Children' s Hospital and Medical Center, Omaha, NE (United States); Goodman, Thomas R. [Yale School of Medicine, Department of Radiology and Biomedical Imaging, New Haven, CT (United States); Lewis, Kristopher N. [Augusta University, Department of Radiology, Children' s Hospital of Georgia, Augusta, GA (United States); Meyer, Laura T. [Wake Radiology, Raleigh, NC (United States); Ngo, Thang D. [Nemours Children' s Hospital, Department of Medical Imaging, Orlando, FL (United States); Sammet, Christina [Ann and Robert H. Lurie Children' s Hospital of Chicago, Department of Radiology, Chicago, IL (United States); Stanescu, Arta Luana; Iyer, Ramesh S. [Seattle Children' s Hospital, University of Washington School of Medicine, Department of Radiology, Seattle, WA (United States); Swenson, David W. [Warren Alpert Medical School of Brown University, Department of Diagnostic Imaging, Providence, RI (United States); Slovis, Thomas L. [Children' s Hospital of Michigan, Wayne State University School of Medicine, Department of Radiology, Detroit, MI (United States)

    2017-05-15

    Gadolinium-based contrast agents (GBCAs) have been used for magnetic resonance (MR) imaging over the last three decades. Recent reports demonstrated gadolinium retention in patients' brains following intravenous administration. Since gadolinium is a highly toxic heavy metal, there is a potential for adverse effects from prolonged retention or deposition, particularly in children. For this reason, the Society (SPR) for Pediatric Radiology Quality and Safety committee conducted a survey to evaluate the current status of GBCAs usage among pediatric radiologists. To assess the usage of GBCAs among SPR members. An online 15-question survey was distributed to SPR members. Survey questions pertained to the type of GBCAs used, protocoling workflow, requirement of renal function or pregnancy tests, and various clinical indications for contrast-enhanced MRI examinations. A total of 163 survey responses were compiled (11.1% of survey invitations), the majority of these from academic institutions in the United States. Ninety-four percent reported that MR studies are always or usually protocoled by pediatric radiologists. The most common GBCA utilized by survey respondents were Eovist (60.7%), Ablavar (45.4%), Gadovist (38.7%), Magnevist (34.4%) and Dotarem (32.5%). For several clinical indications, survey responses regarding GBCA administration were concordant with American College of Radiology (ACR) Appropriateness Criteria, including seizures, headache and osteomyelitis. For other indications, including growth hormone deficiency and suspected vascular ring, survey responses revealed potential overutilization of GBCAs when compared to ACR recommendations. Survey results demonstrate that GBCAs are administered judiciously in children, yet there is an opportunity to improve their utilization with the goal of reducing potential future adverse effects. (orig.)

  7. Intravenous Calcium-/Zinc-Diethylene Triamine Penta-Acetic Acid in Patients With Presumed Gadolinium Deposition Disease: A Preliminary Report on 25 Patients.

    Science.gov (United States)

    Semelka, Richard C; Ramalho, Miguel; Jay, Michael; Hickey, Lisa; Hickey, Joseph

    2018-02-06

    The aim of this study was to report the use of intravenous calcium (Ca)-/zinc (Zn)-diethylene triamine penta-acetic acid (DTPA) for the treatment of 25 symptomatic patients diagnosed with gadolinium deposition disease (GDD). Written informed consent was obtained. Twenty-five patients (18 women; mean age, 46.8 ± 15.3 years) with a diagnosis of GDD were included. All patients had received at least 1 administration of a gadolinium (Gd)-based contrast agent. Patients received 3 treatment sessions with Ca-/Zn-DTPA, 15 with treatments spaced 1 month apart, and 10 with treatments spaced 1 week apart. In all cases, every treatment consisted of an application of Ca-DTPA and Zn-DTPA separated by 24 hours. Measurements of 24-hour urine Gd content before dosing and on the first and second days of therapy were performed. Symptomatic improvement of patients was determined by use of a 10-point scale of patient symptoms. Serum electrolytes were quantified. Gadolinium content increased in the urine, with an overall mean of 30.3-fold increase in the monthly regimen (P < 0.001) and 12.9-fold in the weekly regimen (P < 0.001). Eleven patients experienced transient worsening of at least some of their symptoms, termed a "flare-up" phenomenon, in most of whom symptoms improved or receded. Overall, symptoms improved in 13 patients, unchanged in 10, and worse in 2. Significant clinical improvement was present for headache, brain fog, and bone pain for the monthly regimen and arm pain and leg pain for the weekly regimen. There were no significant changes in major serum electrolytes. Three courses of intravenous Ca-/Zn-DTPA therapy results in significantly increased urine content of Gd after treatment and moderate symptomatic improvement.

  8. All that glitters is not gold: Increased Signal in the Subarachnoid Space on Fluid-Attenuated Inversion Recovery Imaging after gadolinium injection

    Directory of Open Access Journals (Sweden)

    Juliana Avila Duarte

    2016-08-01

    Full Text Available A 61-year-old woman arrived at the emergency department of the Hospital Nossa Senhora das Graças, Canoas, southern Brazil, with suspected ischemic stroke. After clinical and laboratory examination, the clinical diagnosis of ischemic stroke was made, without fulfilling criteria for thrombolysis. The patient had no history of renal failure. Three days later, she performed a magnetic resonance imaging (MRI examination that confirmed the suspected diagnosis. This examination was performed without sedation or supplemental oxygen. Brain MRI was performed after gadolinium injection, using fluid-attenuated inversion recovery (FLAIR imaging, T1-weighted image, diffusion-weighted imaging, and T2-weighted image sequences that revealed signs of subacute watershed stroke in the lef