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Sample records for gadolinium chelates contrast

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

    International Nuclear Information System (INIS)

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

    2018-01-01

    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. (orig.)

  2. Use of gadolinium chelate to confirm epidural needle placement in patients with an iodinated contrast reaction

    International Nuclear Information System (INIS)

    Shetty, Sanjay K.; Nelson, Erik N.; Lawrimore, Tara M.; Palmer, William E.

    2007-01-01

    When performing epidural steroid injections for the management of chronic back pain, imaging guidance and a limited epidurogram improve accuracy of needle placement and ensure appropriate delivery of the injectate into the epidural space. We describe our experience using a gadolinium chelate as an alternative contrast agent for limited epidurography in patients with a history of an iodinated contrast reaction. Thirty-eight of 2,067 (1.8%) epidural steroid injections performed in our department over a 25-month period (December 2003-January 2006) employed gadolinium. All injections were performed in the lumbar spine employing a paramedian interlaminar approach. Procedural notes and patient charts were reviewed to evaluate for immediate or delayed complications related to incorrect intrathecal or intravascular needle placement. A retrospective analysis of selected fluoroscopic spot images was performed to evaluate confidence of epidural needle placement; this analysis compared these spot images against those obtained from age- and gender-matched control patients in whom iodinated contrast was used to confirm needle placement. Real-time fluoroscopic guidance permitted confident visualization of an epidurogram at the time of procedure in all 38 cases as documented in the procedural report, and no procedure resulted in a complication due to incorrect needle placement. Retrospective review of fluoroscopic spot images revealed at least moderate confidence of epidural needle placement by both readers in 29/38 cases (76.3%). Fluoroscopic spot images obtained using gadolinium yielded significantly less confidence than images obtained in control patients whose procedures were performed using iodinated contrast (P < 0.01). However, operators were sufficiently confident in needle placement based on real-time fluoroscopic images (not available in our subsequent review) to inject anesthestic in all 38 cases, despite the immediate consequences that could result from intrathecal

  3. Use of gadolinium chelate to confirm epidural needle placement in patients with an iodinated contrast reaction

    Energy Technology Data Exchange (ETDEWEB)

    Shetty, Sanjay K. [Massachusetts General Hospital, Harvard Medical School, Division of Musculoskeletal Radiology, Department of Radiology, Boston, MA (United States); Beth Israel Deaconess Medical Center, Harvard Medical School, Department of Radiology, Boston, MA (United States); Nelson, Erik N.; Lawrimore, Tara M.; Palmer, William E. [Massachusetts General Hospital, Harvard Medical School, Division of Musculoskeletal Radiology, Department of Radiology, Boston, MA (United States)

    2007-04-15

    When performing epidural steroid injections for the management of chronic back pain, imaging guidance and a limited epidurogram improve accuracy of needle placement and ensure appropriate delivery of the injectate into the epidural space. We describe our experience using a gadolinium chelate as an alternative contrast agent for limited epidurography in patients with a history of an iodinated contrast reaction. Thirty-eight of 2,067 (1.8%) epidural steroid injections performed in our department over a 25-month period (December 2003-January 2006) employed gadolinium. All injections were performed in the lumbar spine employing a paramedian interlaminar approach. Procedural notes and patient charts were reviewed to evaluate for immediate or delayed complications related to incorrect intrathecal or intravascular needle placement. A retrospective analysis of selected fluoroscopic spot images was performed to evaluate confidence of epidural needle placement; this analysis compared these spot images against those obtained from age- and gender-matched control patients in whom iodinated contrast was used to confirm needle placement. Real-time fluoroscopic guidance permitted confident visualization of an epidurogram at the time of procedure in all 38 cases as documented in the procedural report, and no procedure resulted in a complication due to incorrect needle placement. Retrospective review of fluoroscopic spot images revealed at least moderate confidence of epidural needle placement by both readers in 29/38 cases (76.3%). Fluoroscopic spot images obtained using gadolinium yielded significantly less confidence than images obtained in control patients whose procedures were performed using iodinated contrast (P < 0.01). However, operators were sufficiently confident in needle placement based on real-time fluoroscopic images (not available in our subsequent review) to inject anesthestic in all 38 cases, despite the immediate consequences that could result from intrathecal

  4. Low-Molecular-Weight Iron Chelates May Be an Alternative to Gadolinium-based Contrast Agents for T1-weighted Contrast-enhanced MR Imaging.

    Science.gov (United States)

    Boehm-Sturm, Philipp; Haeckel, Akvile; Hauptmann, Ralf; Mueller, Susanne; Kuhl, Christiane K; Schellenberger, Eyk A

    2018-02-01

    Purpose To synthesize two low-molecular-weight iron chelates and compare their T1 contrast effects with those of a commercial gadolinium-based contrast agent for their applicability in dynamic contrast material-enhanced (DCE) magnetic resonance (MR) imaging. Materials and Methods The animal experiments were approved by the local ethics committee. Two previously described iron (Fe) chelates of pentetic acid (Fe-DTPA) and of trans-cyclohexane diamine tetraacetic acid (Fe-tCDTA) were synthesized with stability constants several orders of magnitude higher than those of gadolinium-based contrast agents. The T1 contrast effects of the two chelates were compared with those of gadopentetate dimeglumine in blood serum phantoms at 1.5 T, 3 T, and 7 T. For in vivo studies, a human breast cancer cell line (MDA-231) was implanted in five mice per group. The dynamic contrast effects of the chelates were compared by performing DCE MR imaging with intravenous application of Fe-DTPA or Fe-tCDTA on day 1 and DCE MR imaging in the same tumors with gadopentetate dimeglumine on day 2. Quantitative DCE maps were generated with software and were compared by means of a one-tailed Pearson correlation test. Results Relaxivities in serum (0.94 T at room temperature) of Fe-tCDTA (r1 = 2.2 mmol -1 · sec -1 , r2 = 2.5 mmol -1 · sec -1 ) and Fe-DTPA (r1 = 0.9 mmol -1 · sec -1 , r2 = 0.9 mmol -1 · sec -1 ) were approximately twofold and fivefold lower, respectively, compared with those of gadopentetate dimeglumine (r1 = 4.1 mmol -1 · sec -1 , r2 = 4.8 mmol -1 · sec -1 ). Used at moderately higher concentrations, however, iron chelates generated similar contrast effects at T1-weighted MR imaging in vitro in serum, in vivo in blood, and for DCE MR imaging of breast cancer xenografts. The volume transfer constant values for Fe-DTPA and Fe-tCDTA in the same tumors correlated well with those observed for gadopentetate dimeglumine (Fe-tCDTA Pearson R, 0.99; P = .0003; Fe-DTPA Pearson R, 0.97; P

  5. Highly stabilized gadolinium chelates functionalized on metal nanoparticles as magnetic resonance imaging contrast agent

    Science.gov (United States)

    Siddiqui, Talha S.

    Magnetic resonance imaging (MRI) is a non-invasive method for imaging and diagnosing tissue damage, organ function and the vascular system. Magnevist(TM) a complex of diethylenetriaminepentaacetic acid (DTPA) and Gd3+ is a clinically approved contrast agent for MRI. A derivative of DTPA was formed by the addition of two cysteine groups (DTPA-L-Cys) through amide linkage. The Gd complex of this ligand bonds with the silver surfaces through the cysteine thiols. GdDTPA-L-Cys was bound to ˜10nm diameter Ag nanoparticles for use as a multifunctional MRI contrast agent. The ligand and complex were characterized by 1H and 13C NMR, ESI-MS and IR spectroscopy. The silver construct was characterized by TEM, TGA and UV-Vis absorption spectra. The per metal complex r1 relaxivity of GdDTPA-L-Cys{Ag} greater than that of Magnavist(TM) with the same molarity for both compounds. The synthesis of a DTPA derivative is described that allows it to bind to silver or gold nanoparticles through a single thiol linkage (DTPASH). The resulting Gd complex, GdDTPASH, was bound to Ag nanoparticles to create a single monolayer on the surface. The construct was further stabilized in buffered solution with the addition of a thiolated PEG chain. The highly stabilized nanoparticle construct delivers a high payload of Gd compelex and is an effective T1 brightening agent. The production of this type of construct opens the way for engineered multimodal MRI contrast agents.

  6. Preparation and Evaluation of Multiple Nanoemulsions Containing Gadolinium (III) Chelate as a Potential Magnetic Resonance Imaging (MRI) Contrast Agent.

    Science.gov (United States)

    Sigward, Estelle; Corvis, Yohann; Doan, Bich-Thuy; Kindsiko, Kadri; Seguin, Johanne; Scherman, Daniel; Brossard, Denis; Mignet, Nathalie; Espeau, Philippe; Crauste-Manciet, Sylvie

    2015-09-01

    The objective was to develop, characterize and assess the potentiality of W1/O/W2 self-emulsifying multiple nanoemulsions to enhance signal/noise ratio for Magnetic Resonance Imaging (MRI). For this purpose, a new formulation, was designed for encapsulation efficiency and stability. Various methods were used to characterize encapsulation efficiency ,in particular calorimetric methods (Differential Scanning Calorimetry (DSC), thermogravimetry analysis) and ultrafiltration. MRI in vitro relaxivities were assessed on loaded DTPA-Gd multiple nanoemulsions. Characterization of the formulation, in particular of encapsulation efficiency was a challenge due to interactions found with ultrafiltration method. Thanks to the specifically developed DSC protocol, we were able to confirm the formation of multiple nanoemulsions, differentiate loaded from unloaded nanoemulsions and measure the encapsulation efficiency which was found to be quite high with a 68% of drug loaded. Relaxivity studies showed that the self-emulsifying W/O/W nanoemulsions were positive contrast agents, exhibiting higher relaxivities than those of the DTPA-Gd solution taken as a reference. New self-emulsifying multiple nanoemulsions that were able to load satisfactory amounts of contrasting agent were successfully developed as potential MRI contrasting agents. A specific DSC protocol was needed to be developed to characterize these complex systems as it would be useful to develop these self-formation formulations.

  7. Extracellular gadolinium contrast agents: Differences in stability

    International Nuclear Information System (INIS)

    Morcos, S.K.

    2008-01-01

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

  8. Reaction of gadolinium chelates with ozone and hydroxyl radicals.

    Science.gov (United States)

    Cyris, Maike; Knolle, Wolfgang; Richard, Jessica; Dopp, Elke; von Sonntag, Clemens; Schmidt, Torsten C

    2013-09-03

    Gadolinium chelates are used in increasing amounts as contrast agents in magnetic resonance imaging, and their fate in wastewater treatment has recently become the focus of research. Oxidative processes, in particular the application of ozone, are currently discussed or even implemented for advanced wastewater treatment. However, reactions of the gadolinium chelates with ozone are not yet characterized. In this study, therefore, rate constants with ozone were determined for the three commonly used chelates Gd-DTPA, Gd-DTPA-BMA, and Gd-BT-DO3A, which were found to be 4.8 ± 0.88, 46 ± 2.5, and 24 ± 1.5 M(-1) s(-1), respectively. These low rate constants indicate that a direct reaction with ozone in wastewater is negligible. However, application of ozone in wastewater leads to substantial yields of (•)OH. Different methods have been applied and compared for determination of k((•)OH+Gd chelate). From rate constants determined by pulse radiolysis experiments (k((•)OH+Gd-DTPA) = 2.6 ± 0.2 × 10(9) M(-1) s(-1), k((•)OH+Gd-DTPA-BMA) = 1.9 ± 0.7 × 10(9) M(-1) s(-1), k((•)OH+Gd-BT-DO3A) = 4.3 ± 0.2 × 10(9) M(-1) s(-1)), it is concluded that a reaction in wastewater via (•)OH radicals is feasible. Toxicity has been tested for educt and product mixtures of both reactions. Cytotoxicity (MTT test) and genotoxicity (micronuclei assay) were not detectable.

  9. Contrast-enhanced magnetic resonance angiography: first-pass arterial enhancement as a function of gadolinium-chelate concentration, and the saline chaser volume and injection rate.

    Science.gov (United States)

    Husarik, Daniela B; Bashir, Mustafa R; Weber, Paul W; Nichols, Eli B; Howle, Laurens E; Merkle, Elmar M; Nelson, Rendon C

    2012-02-01

    To evaluate the effect of the contrast medium (CM) concentration and the saline chaser volume and injection rate on first-pass aortic enhancement characteristics in contrast-enhanced magnetic resonance angiography using a physiologic flow phantom. Imaging was performed on a 3.0-T magnetic resonance system (MAGNETOM Trio, Siemens Healthcare Solutions, Inc, Erlangen, Germany) using a 2-dimensional fast low angle shot T1-weighted sequence (repetition time, 500 milliseconds; echo time, 1.23 milliseconds; flip angle, 8 degrees; 1 frame/s × 60 seconds). The following CM concentrations injected at 2 mL/s were used with 3 different contrast agents (gadolinium [Gd]-BOPTA, Gd-HP-DO3A, Gd-DTPA): 20 mL of undiluted CM (100%) and 80%, 40%, 20%, 10%, 5%, and 2.5% of the full amount, all diluted in saline to a volume of 20 mL to ensure equal bolus volume. The CM was followed by saline chasers of 20 to 60 mL injected at 2 mL/s and 6 mL/s. Aortic signal intensity (SI) was measured, and normalized SI versus time (SI/Tn) curves were generated. The maximal SI (SI(max)), bolus length, and areas under the SI/Tn curve were calculated. Decreasing the CM concentration from 100% to 40% resulted in a decrease of SI(max) to 86.1% (mean). Further decreasing the CM concentration to 2.5% decreased SI(max) to 5.1% (mean). Altering the saline chaser volume had no significant effect on SI(max). Increasing the saline chaser injection rate had little effect (mean increase, 2.2%) on SI(max) when using ≥40% of CM. There was a larger effect (mean increase, 19.6%) when ≤20% of CM were used. Bolus time length was significantly shorter (P < 0.001), and area under the SI/T(n) curve was significantly smaller (P < 0.01) for the CM protocols followed by a saline chaser injected at 6 mL/s compared with a saline chaser injected at 2 mL/s. With 40% of CM and a fast saline chaser, SImax close to that with undiluted CM can be achieved. An increased saline chaser injection rate has a more pronounced effect on

  10. 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.)

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

    International Nuclear Information System (INIS)

    Strunk, Holger M.; Schild, H.

    2004-01-01

    For many years, alternatives to iodinated X-ray contrast media have been sought. Of the contrast media investigated to date, only CO 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.)

  12. Manganese(II) chelate contrast media

    International Nuclear Information System (INIS)

    Rocklage, S.M.; Quay, S.C.

    1994-01-01

    New chelate forming compounds for use as contrast media in NMR imaging are described. Especially mentioned are manganese(II) ion chelates of N,N' dipyridoxaldiamine, N,N' diacetic acid, and salts and esters thereof. 1 fig

  13. Advantages of gadolinium based ultrasmall nanoparticles vs molecular gadolinium chelates for radiotherapy guided by MRI for glioma treatment

    OpenAIRE

    Le Duc, G.; Roux, S.; Paruta-Tuarez, A.; Dufort, S.; Bräuer, E.; Marais, A.; Truillet, C.; Sancey, L.; Perriat, P.; Lux, F.; Tillement, O.

    2014-01-01

    AGuIX nanoparticles are formed of a polysiloxane network surrounded by gadolinium chelates. They present several characteristics. They are easy to produce, they present very small hydrodynamic diameters (

  14. Modeling systemic and renal gadolinium chelate transport with MRI

    Energy Technology Data Exchange (ETDEWEB)

    Votaw, John R.; Martin, Diego [Emory University Hospital, Department of Radiology, Atlanta, GA (United States)

    2008-01-15

    The advent of modern MRI scanners and computer equipment permits the rapid sequential collection of images of gadolinium chelate (Gd) transit through the kidney. The excellent spatial and temporal (0.9 s) resolution permits analyzing the shape of the recovered curves with a sophisticated model that includes both space and time. The purpose of this manuscript is to present such a mathematical model. By building into the model significant physical processes that contribute to the shape of the measured curve, quantitative values can be assigned to important parameters. In this work, quantitative values are determined for blood dispersion through the cardio-pulmonary system, systemic clearance rate of Gd, blood flow into each kidney, blood transit time in each kidney, the extraction rate of Gd across the capillary membrane, interstitial distribution volume, and the GFR for each kidney. (orig.)

  15. Contrast effects of a gadolinium filter

    International Nuclear Information System (INIS)

    Burgess, A.E.

    1981-01-01

    Several authors have suggested using heavy metal filters with K edges in the diagnostic energy range to reduce the width of the x-ray spectrum and hence reduce patient radiation exposure. This spectral narrowing also increases subject contrast and permits an increase in tube potential. Results of contrast measurements are presented for a 250 mu gadolinium filter. It was found that aluminum filter contrast could be matched by using 8 to 10 kVp higher potential with the gadolinium filter. Similar results were found for calcium tungstate and rare-earth screens. Measurements were also done to determine skin exposure and mAs ratios for both constant contrast and constant kVp technique conversion methods. A simple theory with one adjustable parameter gives a reasonable fit to the experimental results

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

    International Nuclear Information System (INIS)

    Idee, Jean-Marc; Port, Marc; Medina, Christelle; Lancelot, Eric; Fayoux, Emmanuelle; Ballet, Sebastien; Corot, Claire

    2008-01-01

    Nephrogenic systemic fibrosis (NSF) is a recently described, highly debilitating scleroderma-like disease occurring in patients with severe or end-stage renal failure. NSF is characterized by cutaneous papules and coalescing plaques ('peau d'orange' appearance) and a wooden consistency. It may ultimately cause disabling contractures of several joints, thus making many patients wheelchair-dependent. NSF has been associated to prior administration of gadolinium chelates (GC) used as contrast agents for magnetic resonance imaging. The best available treatment option at the present time is renal transplantation. The mechanism of NSF has not been fully elucidated. Several hypotheses have been proposed so far and are critically discussed in the present review article. Gadolinium has been found in skin biopsy samples of patients. The most widely accepted hypothesis is related to dechelation of less stable GC, progressively releasing free Gd 3+ which may subsequently lead to the attraction of CD34+, CD45+, pro-collagen+ circulating fibrocytes via the release of chemokines, thereby inducing systemic fibrosing disorders. Pre-existing renal failure may facilitate the process by delaying the excretion of GC. A complex interplay between gadolinium and co-factors (pro-inflammatory status, vascular injury, high dose of erythropoietin, high levels of calcium, phosphorus, etc.) may occur in patients with impaired renal function. This and other hypotheses remain to be investigated, as well as the role and independence of co-factors

  17. Gadolinium-based contrast agent toxicity: a review of known and proposed mechanisms.

    Science.gov (United States)

    Rogosnitzky, Moshe; Branch, Stacy

    2016-06-01

    Gadolinium chelates are widely used as contrast media for magnetic resonance imaging. The approved gadolinium-based contrast agents (GBCAs) have historically been considered safe and well tolerated when used at recommended dosing levels. However, for nearly a decade, an association between GBCA administration and the development of nephrogenic systemic fibrosis (NSF) has been recognized in patients with severe renal impairment. This has led to modifications in clinical practices aimed at reducing the potential and incidence of NSF development. Newer reports have emerged regarding the accumulation of gadolinium in various tissues of patients who do not have renal impairment, including bone, brain, and kidneys. Despite the observations of gadolinium accumulation in tissues regardless of renal function, very limited clinical data regarding the potential for and mechanisms of toxicity is available. This significant gap in knowledge warrants retrospective cohort study efforts, as well as prospective studies that involve gadolinium ion (Gd(3+)) testing in patients exposed to GBCA. This review examines the potential biochemical and molecular basis of gadolinium toxicity, possible clinical significance of gadolinium tissue retention and accumulation, and methods that can limit gadolinium body burden.

  18. Characteristics of gadolinium-DTPA complex: a potential NMR contrast agent

    International Nuclear Information System (INIS)

    Weinmann, H.J.; Brasch, R.C.; Press, W.R.; Wesbey, G.E.

    1984-01-01

    Chelation of the rare-earth element gadolinium (Gd) with diethylenetriaminepentaacetic acid (DTPA) results in a strongly paramagnetic, stable complex that is well tolerated in animals. The strongly paramagnetic gadolinium complex reduces hydrogen-proton relaxation times even in low concentrations (less than 0.01 mmol/L). The pharmacokinetic behavior of intravenously delivered Gd-DTPA is similar to the well known iodinated contrast agents used in urography and angiography; excretion is predominately through the kidneys with greater than 90% recovery in 24 hr. The intravenous LD 50 of the meglumine salt of Gd-DTPA is 10 mmol/kg for the rat; in vivo there is no evidence of dissociation of the gadolinium ion from the DTPA ligand. The combination of strong proton relaxation, in-vivo stability, rapid urinary excretion, and high tolerance favors the further development and the potential clinical application of gadolinium-DTPA as a contrast enhancer in magnetic resonance imaging

  19. 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 neph...... guidelines regarding gadolinium contrast agents minimises the risk of NSF • Potential long-term harm from gadolinium accumulation in the body is discussed.......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...

  20. Are gadolinium contrast agents suitable for gadolinium neutron capture therapy?

    Science.gov (United States)

    De Stasio, Gelsomina; Rajesh, Deepika; Casalbore, Patrizia; Daniels, Matthew J; Erhardt, Robert J; Frazer, Bradley H; Wiese, Lisa M; Richter, Katherine L; Sonderegger, Brandon R; Gilbert, Benjamin; Schaub, Sebastien; Cannara, Rachel J; Crawford, John F; Gilles, Mary K; Tyliszczak, Tolek; Fowler, John F; Larocca, Luigi M; Howard, Steven P; Mercanti, Delio; Mehta, Minesh P; Pallini, Roberto

    2005-06-01

    Gadolinium neutron capture therapy (GdNCT) is a potential treatment for malignant tumors based on two steps: (1) injection of a tumor-specific (157)Gd compound; (2) tumor irradiation with thermal neutrons. The GdNC reaction can induce cell death provided that Gd is proximate to DNA. Here, we studied the nuclear uptake of Gd by glioblastoma (GBM) tumor cells after treatment with two Gd compounds commonly used for magnetic resonance imaging, to evaluate their potential as GdNCT agents. Using synchrotron X-ray spectromicroscopy, we analyzed the Gd distribution at the subcellular level in: (1) human cultured GBM cells exposed to Gd-DTPA or Gd-DOTA for 0-72 hours; (2) intracerebrally implanted C6 glioma tumors in rats injected with one or two doses of Gd-DOTA, and (3) tumor samples from GBM patients injected with Gd-DTPA. In cell cultures, Gd-DTPA and Gd-DOTA were found in 84% and 56% of the cell nuclei, respectively. In rat tumors, Gd penetrated the nuclei of 47% and 85% of the tumor cells, after single and double injection of Gd-DOTA, respectively. In contrast, in human GBM tumors 6.1% of the cell nuclei contained Gd-DTPA. Efficacy of Gd-DTPA and Gd-DOTA as GdNCT agents is predicted to be low, due to the insufficient number of tumor cell nuclei incorporating Gd. Although multiple administration schedules in vivo might induce Gd penetration into more tumor cell nuclei, a search for new Gd compounds with higher nuclear affinity is warranted before planning GdNCT in animal models or clinical trials.

  1. Hybrid Calcium Phosphate-Polymeric Micelles Incorporating Gadolinium Chelates for Imaging-Guided Gadolinium Neutron Capture Tumor Therapy.

    Science.gov (United States)

    Mi, Peng; Dewi, Novriana; Yanagie, Hironobu; Kokuryo, Daisuke; Suzuki, Minoru; Sakurai, Yoshinori; Li, Yanmin; Aoki, Ichio; Ono, Koji; Takahashi, Hiroyuki; Cabral, Horacio; Nishiyama, Nobuhiro; Kataoka, Kazunori

    2015-06-23

    Gadolinium (Gd) chelates-loaded nanocarriers have high potential for achieving magnetic resonance imaging (MRI)-guided Gd neutron capture therapy (GdNCT) of tumors. Herein, we developed calcium phosphate micelles hybridized with PEG-polyanion block copolymers, and incorporated with the clinical MRI contrast agent Gd-diethylenetriaminepentaacetic acid (Gd-DTPA/CaP). The Gd-DTPA/CaP were nontoxic to cancer cells at the concentration of 100 μM based on Gd-DTPA, while over 50% of the cancer cells were killed by thermal neutron irradiation at this concentration. Moreover, the Gd-DTPA/CaP showed a dramatically increased accumulation of Gd-DTPA in tumors, leading to the selective contrast enhancement of tumor tissues for precise tumor location by MRI. The enhanced tumor-to-blood distribution ratio of Gd-DTPA/CaP resulted in the effective suppression of tumor growth without loss of body weight, indicating the potential of Gd-DTPA/CaP for safe cancer treatment.

  2. 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

  3. Fundamental study of DSA images using gadolinium contrast agent

    International Nuclear Information System (INIS)

    Nagashima, Hiroyuki; Shiraishi, Akihisa; Igarashi, Hitoshi; Sakamoto, Hajime; Sano, Yoshitomo

    2002-01-01

    Most contrast agents used in digital subtraction angiography (DSA) are non-ionic iodinated contrast agents, which can cause severe side effects in patients with contraindications for iodine or allergic reactions to iodine. Therefore, DSA examinations using carbon dioxide gas or examinations done by magnetic resonance imaging (MRI) and ultrasound (US) were carried out in these patients. However, none of these examinations provided mages as clear as those of DSA with an iodinated contrast agent. We experienced DSA examination using a gadolinium contrast agent in a patient contraindicated for iodine. The patient had undergone MRI examination with a gadolinium contrast agent previously without side effects. The characteristics of gadolinium and the iodinated contrast agent were compared, and the DSA images obtained clinically using these media were also evaluated. The signal-to-noise (SN) ratio of the gadolinium contrast agent was the highest at tube voltages of 70 to 80 kilovolts and improved slightly when the image intensifier (I.I.) entrance dose was greater than 300 μR (77.4 nC/kg). The dilution ratios of five iodinated contrast agents showed the same S/N value as the undiluted gadolinium contrast agent. Clinically, the images obtained showed a slight decrease in contrast but provided the data necessary to make a diagnosis and made it possible to obtain interventional radiology (IVR) without any side effects. DSA examinations using a gadolinium contrast agent have some benefit with low risk and are thought to be useful for patients contraindicated for iodine. (author)

  4. 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.

  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. 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.)

  7. Enhancement of the normal pancreas: comparison of manganese-DPDP and gadolinium chelate

    International Nuclear Information System (INIS)

    Kettritz, U.; Warshauer, D.M.; Brown, E.D.; Schlund, J.F.; Eisenberg, L.B.; Semelka, R.C.

    1996-01-01

    The purpose of this paper was to compare manganese-DPDP (Mn-DPDP) and gadolinium chelate (Gd-DTPA) contrast agents for enhancement of the normal pancreas. A total of 14 patients with focal liver disease underwent Mn-DPDP-and Gd-DTPA-enhanced 1.5 T MR examinations using spoiled gradient-echo (FLASH) technique at two separate times. Contrast agents were injected according to the currently recommended practices; Gd-DTPA was injected as a rapid bolus injection in a dosage of 0.1 mmol/kg, and Mn-DPDP was injected as a slow IV injection in a dosage of 5 μmol/kg. Quantitative region of interest measurements were made in 11 patients, and percent contrast enhancement of the pancreas and pancreas-fat signal-to-noise ratios (SNR) were determined for each agent. Images were also evaluated qualitativley by consensus reading of two investigators and overall scan quality was rated on a scale from 1 (poor) to 4 (very good). Enhancement of the pancreas immediately post Gd-DTPA was significantly higher than 15 min post Mn-DPDP (73.3 vs 36.3%; p=0.003). On postcontrast images the pancreas-fat SNR measruements were 7.7 (i.e., pancreas higher in signal than fat) and -6.1 for Gd-DTPA and Mn-DPDP, respectively, which was significantly different (p<0.001). Image quality was rated as 3.1 and 2.5 for Gd-DTPA- and Mn-DPDP-enhanced images, respectively. The normal pan creas enhances significantly more with Gd-DTPA than with Mn-DPDP administered under the conditions of this study. Overall image quality is also greater on the Gd-DTPA-enhanced images. (orig.)

  8. 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.

  9. 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.

  10. Simple method for quantification of gadolinium magnetic resonance imaging contrast agents using ESR spectroscopy.

    Science.gov (United States)

    Takeshita, Keizo; Kinoshita, Shota; Okazaki, Shoko

    2012-01-01

    To develop an estimation method of gadolinium magnetic resonance imaging (MRI) contrast agents, the effect of concentration of Gd compounds on the ESR spectrum of nitroxyl radical was examined. A solution of either 4-oxo-2,2,6,6-tetramethylpiperidine-N-oxyl (TEMPONE) or 4-hydroxy-2,2,6,6-tetramethylpiperidine-N-oxyl (TEMPOL) was mixed with a solution of Gd compound and the ESR spectrum was recorded. Increased concentration of gadolinium-diethylenetriamine pentaacetic acid chelate (Gd-DTPA), an MRI contrast agent, increased the peak-to-peak line widths of ESR spectra of the nitroxyl radicals, in accordance with a decrease of their signal heights. A linear relationship was observed between concentration of Gd-DTPA and line width of ESR signal, up to approximately 50 mmol/L Gd-DTPA, with a high correlation coefficient. Response of TEMPONE was 1.4-times higher than that of TEMPOL as evaluated from the slopes of the lines. The response was slightly different among Gd compounds; the slopes of calibration curves for acua[N,N-bis[2-[(carboxymethyl)[(methylcarbamoyl)methyl]amino]ethyl]glycinato(3-)]gadolinium hydrate (Gd-DTPA-BMA) (6.22 μT·L/mmol) and gadolinium-1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid chelate (Gd-DOTA) (6.62 μT·L/mmol) were steeper than the slope for Gd-DTPA (5.45 μT·L/mmol), whereas the slope for gadolinium chloride (4.94 μT·L/mmol) was less steep than that for Gd-DTPA. This method is simple to apply. The results indicate that this method is useful for rough estimation of the concentration of Gd contrast agents if calibration is carried out with each standard compound. It was also found that the plot of the reciprocal square root of signal height against concentrations of contrast agents could be useful for the estimation if a constant volume of sample solution is taken and measured at the same position in the ESR cavity every time.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2016-05-15

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

  12. Value of 1.0-M gadolinium chelates: review of preclinical and clinical data on gadobutrol

    International Nuclear Information System (INIS)

    Tombach, Bernd; Heindel, Walter

    2002-01-01

    Several preclinical and clinical studies with the first commercially available highly concentrated Gd-chelate gadobutrol (1 mol/l) are reviewed. Physicochemical, pharmacological, and pharmacokinetic properties, safety analysis, as well as experimental and clinical efficacy studies are highlighted in comparison with 0.5-M Gd-chelates. The 1-mol gadobutrol has been proven to be safe in an examined dose range from 0.04 up to 0.5 mmol/kg body weight (b.w.). Even in patients with chronic renal impairment, including hemodialysis, gadobutrol can safely be applied at doses up to 0.3 mmol/kg b.w. For contrast-enhanced MRI in the equilibrium phase, efficacy data analysis shows comparable results to other commercially available extracellular Gd-chelates with lower Gd-concentrations (0.5 M). Studies focused on the potential benefit of a tighter bolus, such as brain perfusion imaging using T2*-effects, document the superiority of a highly concentrated Gd contrast agent. For contrast-enhanced MRA, clinical studies are still ongoing; therefore, the ultimate potential of a more compact bolus, using 1-M Gd-chelates, for contrast-enhanced MRI, has still to be analyzed, especially for time-resolved magnetic resonance angiography. (orig.)

  13. Extracellular gadolinium-based contrast media: An overview

    International Nuclear Information System (INIS)

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

    2008-01-01

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

  14. Extracellular gadolinium-based contrast media: An overview

    Energy Technology Data Exchange (ETDEWEB)

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

    2008-05-15

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

  15. Incidence of immediate adverse effects of gadolinium contrast media

    International Nuclear Information System (INIS)

    Ujita, Kouishi; Matsui, Satomi; Oikawa, Satoko; Habano, Youji; Ozaki, Daisuke; Ootake, Hidenori; Amanuma, Makoto; Endo, Keigo

    2010-01-01

    We investigated the adverse effects of intravenous injection of one of 4 types of gadolinium contrast media in 6550 patients: gadopentate dimeglumine (Gd-DTPA), 4299 patients; gadodiamide (Gd-DTPA-BMA), 1612; gadoteridol (Gd (HP-DO3A)), 565; and gadoterate meglumin (Gd-DOTA), 74. Thirty-two (0.49%) patients experienced adverse effects, which included rash (18.8%), nausea (40.6%), vomiting (34.4%), and an unpleasant sensation in the throat (6.3%). No patient required hospitalization. We compared the incidence of adverse effects from the 4 types of contrast media and found no difference in sex, age, body region examined, or method of contrast administration. Incidence was significantly higher for Gd (HP-DO3A) than Gd-DTPA and Gd-DTPA-BMA (P<0.000001). (author)

  16. 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.

  17. Synthesis and evaluation of gadolinium complexes based on PAMAM as MRI contrast agents.

    Science.gov (United States)

    Yan, Guo-Ping; Hu, Bin; Liu, Mai-Li; Li, Li-Yun

    2005-03-01

    Diethylenetriaminepentaacetic acid (DTPA) and pyridoxamine (PM) were incorporated into the amine groups on the surface of ammonia-core poly(amidoamine) dendrimers (PAMAM, Generation 2.0-5.0) to obtain dendritic ligands. These dendritic ligands were reacted with gadolinium chloride to yield the corresponding dendritic gadolinium (Gd) complexes. The dendritic ligands and their gadolinium complexes were characterized by(1)HNMR, IR, UV and elemental analysis. Relaxivity studies showed that the dendritic gadolinium complexes possessed higher relaxation effectiveness compared with the clinically used Gd-DTPA. After administration of the dendritic gadolinium complexes (0.09 mmol kg(-1) ) to rats, magnetic resonance imaging of the liver indicated that the dendritic gadolinium complexes containing pyridoxamine groups enhanced the contrast of the MR images of the liver, provided prolonged intravascular duration and produced highly contrasted visualization of blood vessels.

  18. Gadolinium-conjugated PLA-PEG nanoparticles as liver targeted molecular MRI contrast agent.

    Science.gov (United States)

    Chen, Zhijin; Yu, Dexin; Liu, Chunxi; Yang, Xiaoyan; Zhang, Na; Ma, Chunhong; Song, Jibin; Lu, Zaijun

    2011-09-01

    A nanoparticle magnetic resonance imaging (MRI) contrast agent targeted to liver was developed by conjugation of gadolinium (Gd) chelate groups onto the biocompatible poly(l-lactide)-block-poly (ethylene glycol) (PLA-PEG) nanoparticles. PLA-PEG conjugated with diethylenetriaminopentaacetic acid (DTPA) was used to formulate PLA-PEG-DTPA nanoparticles by solvent diffusion method, and then Gd was loaded onto the nanoparticles by chelated with the unfolding DTPA on the surface of the PLA-PEG-DTPA nanoparticles. The mean size of the nanoparticles was 265.9 ± 6.7 nm. The relaxivity of the Gd-labeled nanoparticles was measured, and the distribution in vivo was evaluated in rats. Compared with conventional contrast agent (Magnevist), the Gd-labeled PLA-PEG nanoparticles showed significant enhancement both on liver targeting ability and imaging signal intensity. The T(1) and T(2) relaxivities per [Gd] of the Gd-labeled nanoparticles was 18.865 mM(-1) s(-1) and 24.863 mM(-1) s(-1) at 3 T, respectively. In addition, the signal intensity in vivo was stronger comparing with the Gd-DTPA and the T(1) weight time was lasting for 4.5 h. The liver targeting efficiency of the Gd-labeled PLA-PEG nanoparticles in rats was 14.57 comparing with Magnevist injection. Therefore, the Gd-labeled nanoparticles showed the potential as targeting molecular MRI contrast agent for further clinical utilization.

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

    Science.gov (United States)

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

    2016-03-01

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

  20. 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

  1. Studies on polyaspartamide gadolinium complexes as potential magnetic resonance imaging contrast agents

    International Nuclear Information System (INIS)

    Yan Guoping; Liu Maili; Li Liyun

    2005-01-01

    Purpose: A series of polyaspartamide gadolinium complexes containing pyridoxamine groups were studied as the potential magnetic resonance imaging (MRI) contrast agents for liver enhancement. Methods: These polyaspartamide gadolinium complexes were prepared and evaluated by relaxivity, acute toxicity studies and magnetic resonance imaging of the liver in rats. Results: These polyaspartamide gadolinium complexes have higher relaxation effectiveness than that of the clinically used gadolinium diethylenetriaminepentaacetic acid and possess the low intravenous acute toxicities to Institute for Cancer Research (ICR) mice. Magnetic resonance imaging of the liver in rats indicated that they greatly enhance the contrast of magnetic resonance images and provide prolonged intravascular duration in the liver. Conclusion: These results indicated that the polyaspartamide gadolinium complexes containing pyridoxamine groups could be considered as the appropriate MRI contrast agents for liver enhancement

  2. Extracellular gadolinium-based contrast media: Differences in diagnostic efficacy

    Energy Technology Data Exchange (ETDEWEB)

    Molen, Aart J. van der [Department of Radiology C-2S, Leiden University Medical Centre, Albinusdreef 2, NL-2333 ZA Leiden (Netherlands)], E-mail: molen@lumc.nl; Bellin, Marie-France [Universite Paris-Sud XI, AP-HP, Service de Radiologie, Hopital Paul Brousse, 12-14 Avenue Paul Vaillant Couturier, F-94804 Villejuif Cedex (France)

    2008-05-15

    Since the introduction of the first gadolinium-based contrast agent (Gd-CA) in 1988 it has become clear that these agents significantly improve the diagnostic efficacy of MRI. Studies on single agents have shown that, in comparison to unenhanced sequences, all agents help to improve the detection and delineation of lesions which can alter diagnosis in up to 40% of patients. Doubling or tripling the standard dose of 0.1 mmol/kg body weight may be beneficial for selected indications (e.g. brain perfusion, equivocal single dose study in MRI for brain metastasis, small vessel MR angiography). A more limited number of studies have compared the various agents. These studies do not show clinically significant differences in diagnostic efficacy between the various extracellular Gd-CA. Agents with higher concentration or protein binding may be relatively better suitable for selected applications (e.g. perfusion MRI). The higher relaxivity agents may be used in somewhat lower doses than the extracellular agents.

  3. Extracellular gadolinium-based contrast media: Differences in diagnostic efficacy

    International Nuclear Information System (INIS)

    Molen, Aart J. van der; Bellin, Marie-France

    2008-01-01

    Since the introduction of the first gadolinium-based contrast agent (Gd-CA) in 1988 it has become clear that these agents significantly improve the diagnostic efficacy of MRI. Studies on single agents have shown that, in comparison to unenhanced sequences, all agents help to improve the detection and delineation of lesions which can alter diagnosis in up to 40% of patients. Doubling or tripling the standard dose of 0.1 mmol/kg body weight may be beneficial for selected indications (e.g. brain perfusion, equivocal single dose study in MRI for brain metastasis, small vessel MR angiography). A more limited number of studies have compared the various agents. These studies do not show clinically significant differences in diagnostic efficacy between the various extracellular Gd-CA. Agents with higher concentration or protein binding may be relatively better suitable for selected applications (e.g. perfusion MRI). The higher relaxivity agents may be used in somewhat lower doses than the extracellular agents

  4. 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.)

  5. Can aquatic macrophytes be biofilters for gadolinium based contrasting agents?

    Science.gov (United States)

    Braun, Mihály; Zavanyi, Györgyi; Laczovics, Attila; Berényi, Ervin; Szabó, Sándor

    2018-05-15

    The use of gadolinium-based contrasting agents (GBCA) is increasing because of the intensive usage of these agents in magnetic resonance imaging (MRI). Waste-water treatment does not reduce anthropogenic Gd-concentration significantly. Anomalous Gd-concentration in surface waters have been reported worldwide. However, removal of GBCA-s by aquatic macrophytes has still hardly been investigated. Four aquatic plant species (Lemna gibba, Ceratophyllum demersum, Elodea nuttallii, E. canadensis) were investigated as potential biological filters for removal of commonly used but structurally different GBCA-s (Omniscan, Dotarem) from water. These plant species are known to accumulate heavy metals and are used for removing pollutants in constructed wetlands. The Gd uptake and release of the plants was examined under laboratory conditions. Concentration-dependent infiltration of Gd into the body of the macrophytes was measured, however significant bioaccumulation was not observed. The tissue concentration of Gd reached its maximum value between day one and four in L. gibba and C. demersum, respectively, and its volume was significantly higher in C. demersum than in L. gibba. In C. demersum, the open-chain ligand Omniscan causes two-times higher tissue Gd concentration than the macrocyclic ligand Dotarem. Gadolinium was released from Gd-treated duckweeds into the water as they were grown further in Gd-free nutrient solution. Tissue Gd concentration dropped by 50% in duckweed treated by Omniscan and by Dotarem within 1.9 and 2.9 days respectively. None of the macrophytes had a significant impact on the Gd concentration of water in low and medium concentration levels (1-256 μg L -1 ). Biofiltration of GBCA-s by common macrophytes could not be detected in our experiments. Therefore it seems that in constructed wetlands, aquatic plants are not able to reduce the concentration of GBCA-s in the water. Furthermore there is a low risk that these plants cause the

  6. Magnetic Resonance Imaging of Therapy-Induced Necrosis Using Gadolinium-Chelated Polyglutamic Acids

    International Nuclear Information System (INIS)

    Jackson, Edward F.; Esparza-Coss, Emilio; Wen Xiaoxia; Ng, Chaan S.; Daniel, Sherita L.; Price, Roger E.; Rivera, Belinda; Charnsangavej, Chusilp; Gelovani, Juri G.; Li Chun

    2007-01-01

    Purpose: Necrosis is the most common morphologic alteration found in tumors and surrounding normal tissues after radiation therapy or chemotherapy. Accurate measurement of necrosis may provide an early indication of treatment efficacy or associated toxicity. The purpose of this report is to evaluate the selective accumulation of polymeric paramagnetic magnetic resonance (MR) contrast agents-gadolinium p-aminobenzyl-diethylenetriaminepentaacetic acid-poly(glutamic acid) (L-PG-DTPA-Gd and D-PG-DTPA-Gd)-in necrotic tissue. Methods and Materials: Two different solid tumor models, human Colo-205 xenograft and syngeneic murine OCA-1 ovarian tumors, were used in this study. Necrotic response was induced by treatment with poly(L-glutamic acid)-paclitaxel conjugate (PG-TXL). T 1 -weighted spin-echo images were obtained immediately and up to 4 days after contrast injection and compared with corresponding histologic specimens. Two low-molecular-weight contrast agents, DTPA-Gd and oligomeric(L-glutamic acid)-DTPA-Gd, were used as nonspecific controls. Results: Initially, there was minimal tumor enhancement after injection of either L-PG-DTPA-Gd or D-PG-DTPA-Gd, but rapid enhancement after injection of low-molecular-weight agents. However, polymeric contrast agents, but not low-molecular-weight contrast agents, caused sustained enhancement in regions of tumor necrosis in both tumors treated with PG-TXL and untreated tumors. These data indicate that high molecular weight, rather than in vivo biodegradation, is necessary for the specific localization of polymeric MR contrast agents to necrotic tissue. Moreover, biotinylated L-PG-DTPA-Gd colocalized with macrophages in the tumor necrotic areas, suggesting that selective accumulation of L- and D-PG-DTPA-Gd in necrotic tissue was mediated through residing macrophages. Conclusions: Our data suggest that MR imaging with PG-DTPA-Gd may be a useful technique for noninvasive characterization of treatment-induced necrosis

  7. 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.

  8. Gadolinium-based Contrast Media, Cerebrospinal Fluid and the Glymphatic System: Possible Mechanisms for the Deposition of Gadolinium in the Brain.

    Science.gov (United States)

    Taoka, Toshiaki; Naganawa, Shinji

    2018-04-10

    After Kanda's first report in 2014 on gadolinium (Gd) deposition in brain tissue, a considerable number of studies have investigated the explanation for the observation. Gd deposition in brain tissue after repeated administration of gadolinium-based contrast medium (GBCM) has been histologically proven, and chelate stability has been shown to affect the deposition. However, the mechanism for this deposition has not been fully elucidated. Recently, a hypothesis was introduced that involves the 'glymphatic system', which is a coined word that combines 'gl' for glia cell and 'lymphatic' system. According to this hypothesis, the perivascular space functions as a conduit for cerebrospinal fluid to flow into the brain parenchyma. The perivascular space around the arteries allows cerebrospinal fluid to enter the interstitial space of the brain tissue through water channels controlled by aquaporin 4. The cerebrospinal fluid entering the interstitial space clears waste proteins from the tissue. It then flows into the perivascular space around the vein and is discharged outside the brain. In addition to the hypothesis regarding the glymphatic system, some reports have described that after GBCM administration, some of the GBCM distributes through systemic blood circulation and remains in other compartments including the cerebrospinal fluid. It is thought that the GBCM distributed into the cerebrospinal fluid cavity via the glymphatic system may remain in brain tissue for a longer duration compared to the GBCM in systemic circulation. Glymphatic system may of course act as a clearance system for GBCM from brain tissue. Based on these findings, the mechanism for Gd deposition in the brain will be discussed in this review. The authors speculate that the glymphatic system may be the major contributory factor to the deposition and clearance of gadolinium in brain tissue.

  9. 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

  10. Vessel diameter measurements in gadolinium contrast-enhanced three-dimensional MRA of peripheral arteries

    NARCIS (Netherlands)

    Westenberg, J.J.M.; Geest, van der R.J.; Wasser, M.N.J.M.; Linden, van der E.L.; Walsum, van T.; Assen, van H.C.; Roos, de A.; Vanderschoot, J.; Reiber, J.H.C.

    2000-01-01

    In this study, the possibilities for quantification of vessel diameters of peripheral arteries in gadolinium contrast-enhanced magnetic resonance angiography (Gd CE MRA) were evaluated. Absolute vessel diameter measurements were assessed objectively and semi-automatically in maximum intensity

  11. 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.)

  12. 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.)

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

    International Nuclear Information System (INIS)

    Rinck, P.A.; Muller, R.N.

    1999-01-01

    The relaxivities r 1 and r 2 of magnetic resonance contrast agents and the T 1 relaxation time values of tissues are strongly field dependent. We present quantitative data and simulations of different gadolinium-based extracellular fluid contrast agents and the modulation of their contrast enhancement by the magnetic field to be able to answer the following questions: How are the dose and field dependences of their contrast enhancement? Is there an interrelationship between dose and field dependence? Should one increase or decrease doses at specific fields? Nuclear magnetic relaxation dispersion data were acquired for the following contrast agents: gadopentetate dimeglumine, gadoterate meglumine, gadodiamide injection, and gadoteridol injection, as well as for several normal and pathological human tissue samples. The magnetic field range stretched from 0.0002 to 4.7 T, including the entire clinical imaging range. The data acquired were then fitted with the appropriate theoretical models. The combination of the diamagnetic relaxation rates (R 1 = 1/T 1 and R 2 = 1/T 2 ) of tissues with the respective paramagnetic contributions of the contrast agents allowed the prediction of image contrast at any magnetic field. The results revealed a nearly identical field and dose-dependent increase of contrast enhancement induced by these contrast agents within a certain dose range. The target tissue concentration (TTC) was an important though nonlinear factor for enhancement. The currently recommended dose of 0.1 mmol/kg body weight seems to be a compromise close to the lower limits of diagnostically sufficient contrast enhancement for clinical imaging at all field strengths. At low field contrast enhancement might be insufficient. Adjustment of dose or concentration, or a new class of contrast agents with optimized relaxivity, would be a valuable contribution to a better diagnostic yield of contrast enhancement at all fields. (orig.)

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

    International Nuclear Information System (INIS)

    Mithal, Leena B.; Patel, Payal S.; Mithal, Divakar; Palac, Hannah L.; Rozenfeld, Michael N.

    2017-01-01

    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

  15. 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

  16. 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...

  17. 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.

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

    International Nuclear Information System (INIS)

    Safriel, Yair; Ang, Roberto; Ali, Muhammed

    2008-01-01

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

  19. N-acetylcysteine protects rats with chronic renal failure from gadolinium-chelate nephrotoxicity.

    Directory of Open Access Journals (Sweden)

    Leonardo Victor Barbosa Pereira

    Full Text Available The aim of this study was to evaluate the effect of Gd-chelate on renal function, iron parameters and oxidative stress in rats with CRF and a possible protective effect of the antioxidant N-Acetylcysteine (NAC. Male Wistar rats were submitted to 5/6 nephrectomy (Nx to induced CRF. An ionic-cyclic Gd (Gadoterate Meglumine was administrated (1.5 mM/KgBW, intravenously 21 days after Nx. Clearance studies were performed in 4 groups of anesthetized animals 48 hours following Gd- chelate administration: 1--Nx (n = 7; 2--Nx+NAC (n = 6; 3--Nx+Gd (n = 7; 4--Nx+NAC+Gd (4.8 g/L in drinking water, initiated 2 days before Gd-chelate administration and maintained during 4 days (n = 6. This group was compared with a control. We measured glomerular filtration rate, GFR (inulin clearance, ml/min/kg BW, proteinuria (mg/24 hs, serum iron (µg/dL; serum ferritin (ng/mL; transferrin saturation (%, TIBC (µg/dL and TBARS (nmles/ml. Normal rats treated with the same dose of Gd-chelate presented similar GFR and proteinuria when compared with normal controls, indicating that at this dose Gd-chelate is not nephrotoxic to normal rats. Gd-chelate administration to Nx-rats results in a decrease of GFR and increased proteinuria associated with a decrease in TIBC, elevation of ferritin serum levels, transferrin oversaturation and plasmatic TBARS compared with Nx-rats. The prophylactic treatment with NAC reversed the decrease in GFR and the increase in proteinuria and all alterations in iron parameters and TBARS induced by Gd-chelate. NAC administration to Nx rat did not modify the inulin clearance and iron kinetics, indicating that the ameliorating effect of NAC was specific to Gd-chelate. These results suggest that NAC can prevent Gd-chelate nephrotoxicity in patients with chronic renal failure.

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

    Energy Technology Data Exchange (ETDEWEB)

    Neubert, Claudia

    2008-07-08

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

  1. Investigation of a potential macromolecular MRI contrast agent prepared from PPI (G = 2, polypropyleneimine, generation 2) dendrimer bifunctional chelates

    Science.gov (United States)

    Wang, Jianxin Steven

    The long-term objective is to develop magnetic resonance (MR) contrast agents that actively and passively target tumors for diagnosis and therapy. Many diagnostic imaging techniques for cancer lack specificity. A dendrimer based magnetic resonance imaging contrast agent has been developed with large proton relaxation enhancements and high molecular relaxivities. A new type of linear dendrimer based MRI contrast agent that is built from the polypropyleneimine and polyamidoamine dendrimers in which free amines have been conjugated to the chelate DTPA, which further formed the complex with Gadolinium (Gd) was studied. The specific research goals were to test the hypothesis that a linear chelate with macromolecular agents can be used in vitro and in vivo. This work successfully examined the adequacy and viability of the application for this agent in vitro and in vivo. A small animal whole body counter was designed and constructed to allow us to monitor biodistribution and kinetic mechanisms using a radioisotope labeled complex. The procedures of metal labeling, separation and purification have been established from this work. A biodistribution study has been performed using radioisotope induced organ/tissue counting and gamma camera imaging. The ratio of percentage of injected dose per gram organ/tissue for kidney and liver is 3.71 from whole body counter and 3.77 from the gamma camera. The results suggested that retention of Gd (III) is too high and a more kinetically stable chelate should be developed. The pharmacokinetic was evaluated in the whole animal model with the whole body clearance, and a kinetics model was developed. The pharmacokinetic results showed a bi-exponential decay in the animal model with two component excretion constants 1.43e(-5) and 0.0038511, which give half-lives of 3 hours and 33.6 days, respectively. Magnetic resonance imaging of this complex resulted in a 52% contrast enhancement in the rat kidney following the agents' administration in

  2. Magnetic resonance tomography of the orbit: First experiences with the paramagnetic contrast medium gadolinium-DTPA

    International Nuclear Information System (INIS)

    Markl, A.; Vogl, T.; Scheidhauer, K.; Riedel, K.G.; Oeckler, R.

    1986-01-01

    In 21 patients with orbital mass lesions MRI was performed before and after administration of paramagnetic contrast medium, gadolinium-DPTA. In comparison to the plain scan the differentiation of the tumorous tissue against the surrounding structures was improved after application of contrast medium despite a partially moderate increase in signal intensity. Especially highly vascular tumors and vessel diseases show a significant contrast enhancement. With increasing experience in larger number of patients a tissue differentiation seems to be possible. (orig.) [de

  3. 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.

  4. 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

  5. Gadolinium released by the linear gadolinium-based contrast-agent Gd-DTPA decreases the activity of human epithelial Na+ channels (ENaCs).

    Science.gov (United States)

    Knoepp, Fenja; Bettmer, Joerg; Fronius, Martin

    2017-05-01

    Gadolinium-based-contrast-agents (GBCAs) are used for magnetic-resonance-imaging and associated with renal and cardiovascular adverse reactions caused by released Gd 3+ ions. Gd 3+ is also a modulator of mechano-gated ion channels, including the epithelial Na + channel (ENaC) that is expressed in kidney epithelium and the vasculature. ENaC is important for salt-/water homeostasis and blood pressure regulation and a likely target of released Gd 3+ from GBCAs causing the above-mentioned adverse reactions. Therefore this study examined the effect of Gd 3+ and GBCAs on ENaC's activity. Human αβγENaC was expressed in Xenopus laevis oocytes and exposed to Gd 3+ , linear (Gd-DTPA, Magnevist) or cyclic (Dotarem) GBCAs. Transmembrane ion-currents (I M ) were recorded by the two-electrode-voltage-clamp technique and Gd 3+ -release by Gd-DTPA was confirmed by inductively coupled plasma-mass spectrometry. Gd 3+ exerts biphasic effects on ENaC's activity: ≤0.3mmol/l decreased I M which was preventable by DEPC (modifies histidines). Strikingly Gd 3+ ≥0.4mmol/l increased I M and this effect was prevented by cysteine-modifying MTSEA. Linear Gd-DTPA and Magnevist mimicked the effect of ≤0.3mmol/l Gd 3+ , whereas the chelator DTPA showed no effect. Gd 3+ and Gd-DTPA increased the IC 50 for amiloride, but did not affect ENaC's self-inhibition. Interestingly, cyclic Gd-DOTA (Dotarem) increased I M to a similar extent as its chelator DOTA, suggesting that the chelator rather than released Gd 3+ is responsible for this effect. These results confirm Gd 3+ -release from linear Gd-DTPA and indicate that the released Gd 3+ amount is sufficient to interfere with ENaC's activity to provide putative explanations for GBCA-related adverse effects. Copyright © 2017 Elsevier B.V. All rights reserved.

  6. A pyrophosphate-responsive gadolinium(III) MRI contrast agent.

    Science.gov (United States)

    Surman, Andrew J; Bonnet, Célia S; Lowe, Mark P; Kenny, Gavin D; Bell, Jimmy D; Tóth, Eva; Vilar, Ramon

    2011-01-03

    This study shows that the relaxivity and optical properties of functionalised lanthanide-DTPA-bis-amide complexes (lanthanide=Gd(3+) and Eu(3+) , DTPA=diethylene triamine pentaacetic acid) can be successfully modulated by addition of specific anions, without direct Ln(3+) /anion coordination. Zinc(II)-dipicolylamine moieties, which are known to bind strongly to phosphates, were introduced in the amide "arms" of these ligands, and the interaction of the resulting Gd-Zn(2) complexes with a range of anions was screened by using indicator displacement assays (IDAs). Considerable selectivity for polyphosphorylated species (such as pyrophosphate and adenosine-5'-triphosphate (ATP)) over a range of other anions (including monophosphorylated anions) was apparent. In addition, we show that pyrophosphate modulates the relaxivity of the gadolinium(III) complex, this modulation being sufficiently large to be observed in imaging experiments. To establish the binding mode of the pyrophosphate and gain insight into the origin of the relaxometric modulation, a series of studies including UV/Vis and emission spectroscopy, luminescence lifetime measurements in H(2) O and D(2) O, (17) O and (31) P NMR spectroscopy and nuclear magnetic resonance dispersion (NMRD) studies were carried out. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  7. 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)

  8. Nephrogenic systemic fibrosis after application of gadolinium-based contrast agents - a status paper

    International Nuclear Information System (INIS)

    Heinrich, M.; Uder, M.

    2007-01-01

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

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

    International Nuclear Information System (INIS)

    Fujimoto, T.; Ichikawa, H.; Akisue, T.; Fujita, I.; Kishimoto, K.; Hara, H.; Imabori, M.; Kawamitsu, H.; Sharma, P.; Brown, S.C.; Moudgil, B.M.; Fujii, M.; Yamamoto, T.; Kurosaka, M.; Fukumori, Y.

    2009-01-01

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

  10. Long-term retention of gadolinium in the skin of rodents following the administration of gadolinium-based contrast agents

    International Nuclear Information System (INIS)

    Pietsch, Hubertus; Jost, Gregor; Frenzel, Thomas; Huetter, Joachim; Sieber, Martin A.; Lengsfeld, Philipp

    2009-01-01

    Several publications suggest a potential association between the administration of Gadolinium-based contrast agents (GBCAs) and the onset of a rare but serious disease, Nephrogenic Systemic Fibrosis (NSF). The aim of this study was to determine the elimination time-course of Gadolinium (Gd) from skin tissue after application of GBCAs in rats. Seven different marketed GBCAs were injected on five consecutive days at a dose of 2.5 mmol/kg bodyweight into the tail vein of Han-Wistar rats and the Gd concentrations were determined by Inductively Coupled Plasma Mass Spectrometry (ICP-MS) in skin biopsies taken at various time-points up to a year after the last injection. Most of the administered Gd was eliminated from the skin within a time-period of about 2 months. However, the repeated administration of linear GBCAs resulted in long-term retention of a small portion of the administered Gd in the skin tissue of rats, with substantially higher values observed in animals treated with non-ionic linear agents than in those that received ionic linear GBCAs. Following treatment with macrocyclic GBCAs, Gd values in the skin were in the same range as observed in the controls from day 24 post-injection onwards. In summary, we observed a correlation between the complex stability of GBCAs and the amount of residual Gd in the skin up to a year after application of GBCAs. (orig.)

  11. Long-term retention of gadolinium in the skin of rodents following the administration of gadolinium-based contrast agents

    Energy Technology Data Exchange (ETDEWEB)

    Pietsch, Hubertus; Jost, Gregor; Frenzel, Thomas; Huetter, Joachim; Sieber, Martin A. [Media Research, Bayer Schering Pharma AG Contrast, Berlin (Germany); Lengsfeld, Philipp [Bayer Schering Pharma AG, Global Medical Affairs Diagnostic Imaging, Berlin (Germany)

    2009-06-15

    Several publications suggest a potential association between the administration of Gadolinium-based contrast agents (GBCAs) and the onset of a rare but serious disease, Nephrogenic Systemic Fibrosis (NSF). The aim of this study was to determine the elimination time-course of Gadolinium (Gd) from skin tissue after application of GBCAs in rats. Seven different marketed GBCAs were injected on five consecutive days at a dose of 2.5 mmol/kg bodyweight into the tail vein of Han-Wistar rats and the Gd concentrations were determined by Inductively Coupled Plasma Mass Spectrometry (ICP-MS) in skin biopsies taken at various time-points up to a year after the last injection. Most of the administered Gd was eliminated from the skin within a time-period of about 2 months. However, the repeated administration of linear GBCAs resulted in long-term retention of a small portion of the administered Gd in the skin tissue of rats, with substantially higher values observed in animals treated with non-ionic linear agents than in those that received ionic linear GBCAs. Following treatment with macrocyclic GBCAs, Gd values in the skin were in the same range as observed in the controls from day 24 post-injection onwards. In summary, we observed a correlation between the complex stability of GBCAs and the amount of residual Gd in the skin up to a year after application of GBCAs. (orig.)

  12. 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.

  13. Gadolinium-DTPA (Magnevist) as a contrast medium for arterial DSA

    International Nuclear Information System (INIS)

    Schild, H.H.; Weber, W.; Boeck, E.; Mildenberger, P.; Strunk, H.; Dueber, C.; Grebe, P.; Schadmand-Fischer, S.; Thelen, M.

    1994-01-01

    16 DSA investigations using intra-arterial Gd-DTPA were performed on 12 patients. The contrast medium was administered either as a 0.5 molar gadolinium solution (commercially available) or diluted with distilled water to a 0.2 -0.4 molar gadolinium solution. The injection was made either by pressure injector or by hand. The aortic arch, abdominal aorta and pelvic and lower limb arteries were examined. 14 of the 16 procedures were diagnostically adequate, but compared with iodinated contrast materials, contrast was less marked. There were no cardiovascular, neurological or allergic side effects. Three patients suffered a feeling of heat and one patient had mild pain during the injection. Even large volumes rapidly injected (up to 20 ml/s of the commercially available solution) were well tolerated. DSA with intra-arterial Gd-DTPA seems to be a suitable alternative for vascular imaging if iodine-containing contrast materials are contraindicated. (orig.) [de

  14. Impact of Impaired Renal Function on Gadolinium Retention After Administration of Gadolinium-Based Contrast Agents in a Mouse Model.

    Science.gov (United States)

    Kartamihardja, A Adhipatria P; Nakajima, Takahito; Kameo, Satomi; Koyama, Hiroshi; Tsushima, Yoshito

    2016-10-01

    The aim of this study was to investigate the impact of impaired renal function on gadolinium (Gd) retention in various organs after Gd-based contrast agent injection. After local animal care and review committee approval, 23 normal mice and 26 with renal failure were divided into 4 treatment groups (Gd-DTPA-BMA, 5 mmol/kg; Gd-DOTA, 5 mmol/kg; GdCl3, 0.02 mmol/kg; and saline, 250 μL). Each agent was intravenously administered on weekdays for 4 weeks. Samples were collected on days 3 (short-term) and 45 (long-term) after the last injection. Gadolinium concentrations were quantified by inductively coupled plasma-mass spectrometry. Three mice with renal failure and 2 normal mice in the GdCl3 group and 1 mouse with renal failure in the Gd-DTPA-BMA group died. In the Gd-DTPA-BMA group, impaired renal function increased short-term Gd retention in the liver, bone, spleen, skin, and kidney (P DTPA-BMA showed higher Gd retention than Gd-DOTA. Although Gd retention in the Gd-DOTA group was generally low, impaired renal function increased only long-term hepatic Gd retention. Hepatic and splenic Gd retentions were significantly higher than other organs' Gd retention in the GdCl3 group (P DTPA-BMA administration, long-term Gd retention for Gd-based contrast agents was almost unaffected by renal function, suggesting that the chemical structures of retained Gd may not be consistent and some Gd is slowly eliminated after initially being retained.

  15. Porphyrin-containing polyaspartamide gadolinium complexes as potential magnetic resonance imaging contrast agents.

    Science.gov (United States)

    Yan, Guo-Ping; Li, Zhen; Xu, Wei; Zhou, Cheng-Kai; Yang, Lian; Zhang, Qiao; Li, Liang; Liu, Fan; Han, Lin; Ge, Yuan-Xing; Guo, Jun-Fang

    2011-04-04

    Porphyrin-containing polyaspartamide ligands (APTSPP-PHEA-DTPA) were synthesized by the incorporation of diethylenetriaminepentaacetic acid (DTPA) and 5-(4'-aminophenyl)-10,15,20-tris(4'-sulfonatophenyl) porphyrin, trisodium salt (APTSPP) into poly-α,β-[N-(2-hydroxyethyl)-l-aspartamide] (PHEA). These ligands were further reacted with gadolinium chloride to produce macromolecule-gadolinium complexes (APTSPP-PHEA-DTPA-Gd). Experimental data of (1)H NMR, IR, UV and elemental analysis evidenced the formation of the polyaspartamide ligands and gadolinium complexes. In vitro and in vivo property tests indicated that APTSPP-PHEA-DTPA-Gd possessed noticeably higher relaxation effectiveness, less toxicity to HeLa cells, and significantly higher enhanced signal intensities (SI) of the VX2 carcinoma in rabbits with lower injection dose requirement than that of Gd-DTPA. Moreover, APTSPP-PHEA-DTPA-Gd was found to greatly enhance the contrast of MR images of the VX2 carcinoma, providing prolonged intravascular duration, and distinguished the VX2 carcinoma and normal tissues in rabbits according to MR image signal enhancements. These porphyrin-containing polyaspartamide gadolinium complexes can be used as the candidates of contrast agents for targeted MRI to tumors. Crown Copyright © 2011. Published by Elsevier B.V. All rights reserved.

  16. 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.

  17. Pineapple juice labeled with gadolinium: a convenient oral contrast for magnetic resonance cholangiopancreatography

    International Nuclear Information System (INIS)

    Coppens, Emmanuel; Metens, Thierry; Winant, Catherine; Matos, Celso

    2005-01-01

    The aim of our study was to prepare in vitro a pineapple juice (PJ) solution labeled with a minimal gadolinium concentration working as a negative contrast agent in heavily T2-weighted imaging and to assess that solution in vivo as a negative oral contrast agent for magnetic resonance cholangiopancreatography (MRCP). Three PJs were compared in vitro according to their T2. Increasing concentrations of gadolinium (Gd)-DOTA in PJ were assessed in vitro for T2 reduction. Single-shot turbo spin echo T2-weighted MR cholangiopancreatograms were obtained for 35 patients with suspected biliopancreatic duct disease, before and after ingestion of the PJ/Gd-DOTA solution. Signal intensity (SI) measurements of gastroduodenal lumens, pancreatobiliary ducts, and image quality scores were obtained systematically before and after contrast ingestion. The in vitro selected Gd-DOTA concentration in the PJ was 2.76 mmol/l. Ingestion of 180 ml of PJ labeled with 1 ml of Gd-DOTA eliminated efficiently the gastroduodenal SI in MRCP, improving significantly the rates of complete visualization of the pancreatobiliary ducts (P<0.01) and the MRCP image quality scores (P<0.05). All patients easily ingested the contrast solution and found the solution palatable. PJ labeled with gadolinium constituted an efficient and convenient negative oral contrast agent for MRCP. (orig.)

  18. Pineapple juice labeled with gadolinium: a convenient oral contrast for magnetic resonance cholangiopancreatography

    Energy Technology Data Exchange (ETDEWEB)

    Coppens, Emmanuel; Metens, Thierry; Winant, Catherine; Matos, Celso [Hopital Erasme, Universite Libre de Bruxelles, Department of Radiology, Division of Magnetic Resonance, Brussels (Belgium)

    2005-10-01

    The aim of our study was to prepare in vitro a pineapple juice (PJ) solution labeled with a minimal gadolinium concentration working as a negative contrast agent in heavily T2-weighted imaging and to assess that solution in vivo as a negative oral contrast agent for magnetic resonance cholangiopancreatography (MRCP). Three PJs were compared in vitro according to their T2. Increasing concentrations of gadolinium (Gd)-DOTA in PJ were assessed in vitro for T2 reduction. Single-shot turbo spin echo T2-weighted MR cholangiopancreatograms were obtained for 35 patients with suspected biliopancreatic duct disease, before and after ingestion of the PJ/Gd-DOTA solution. Signal intensity (SI) measurements of gastroduodenal lumens, pancreatobiliary ducts, and image quality scores were obtained systematically before and after contrast ingestion. The in vitro selected Gd-DOTA concentration in the PJ was 2.76 mmol/l. Ingestion of 180 ml of PJ labeled with 1 ml of Gd-DOTA eliminated efficiently the gastroduodenal SI in MRCP, improving significantly the rates of complete visualization of the pancreatobiliary ducts (P<0.01) and the MRCP image quality scores (P<0.05). All patients easily ingested the contrast solution and found the solution palatable. PJ labeled with gadolinium constituted an efficient and convenient negative oral contrast agent for MRCP. (orig.)

  19. Gadolinium-DTPA and gadodiamide as an alternative contrast medium for CT

    International Nuclear Information System (INIS)

    Engelbrecht, V.; Koch, J.A.; Rassek, M.; Moedder, U.

    1996-01-01

    To evaluate the effect of intravenously applied gadolinium-based contrast medium in computed tomographic (CT) studies. Serial dilutions of iohexol 300, Gd-DTPA and gadodiamide were scanned with CT in a phantom study using water filled tubes. For quantification of X-ray attenuation, the mean Hounsfield units (HU) were calculated from the CT scans. Five patients with contraindications against iodine contrast agents were examined with abdominal or thoracic CT before and after application of 0.2 mmol/kg body weight of a gadolinium-based contrast agent. In these patients attenuation values were obtained in ROI from unenhanced and enhanced CT scans. The phantom study revealed a 38,4% enhancement for Gd-DTPA and a 35.7% enhancement for gadodiamide scaled on the reference measurements with iohexol 300. Thus, 130.2 ml Gd-DTPA or 140.1 ml gadodiamide are needed to achieve the same attenuation as an i.v. injection of 50 ml iohexol 300. Consequently the corresponding dose of 1 mmol/kg body weight would exceed the manufacturer's recommended dose. In four patients with complete thoracic or abdominal CT, i.v. applied gadolinium-based contrast medium (0.2 mmol/kg) yielded no visible advantage. In these patients parenchymal enhancement did not exceed 25%. Dynamic CT of a patient with focal liver lesion revealed an arterial enhancement peak of 75%. Sufficient parenchymal enhancement in CT studies cannot be achieved with the available gadolinium-based contrast mediums. They might be helpful if only short time vascular enhancement is required. (orig.) [de

  20. Nuclear magnetic resonance diagnosis of cerebral tumours with the use of the contrast medium gadolinium-DTPA

    International Nuclear Information System (INIS)

    Schoerner, W.; Felix, R.; Claussen, C.; Fiegler, W.; Kazner, E.; Speck, U.; Niendorf, H.P.

    1984-01-01

    This study examines the effect of the NMR contrast medium gadolinium-DTPA on image contrast in cerebral tumours. Sixteen patients with space-occupying cerebral lesions were examined on a 0.35 Tesla superconducting scanner, using a T1-weighted spinecho sequence prior to and after the intravenous application of gadolinium-DTPA. In 8 patients T2-weighted spinecho-sequences were obtained before the administration of contrast. The tomograms were evaluated visually and according to quantitative criteria. The use of gadolinium-DTPA helps to evaluate the blood-brain barrier and improves diagnosis by differentiating tumour tissue from edema and from normal brain tissue. (orig.) [de

  1. 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.

  2. Quantitative structure-property relationship (correlation analysis) of phosphonic acid-based chelates in design of MRI contrast agent.

    Science.gov (United States)

    Tiwari, Anjani K; Ojha, Himanshu; Kaul, Ankur; Dutta, Anupama; Srivastava, Pooja; Shukla, Gauri; Srivastava, Rakesh; Mishra, Anil K

    2009-07-01

    Nuclear magnetic resonance imaging is a very useful tool in modern medical diagnostics, especially when gadolinium (III)-based contrast agents are administered to the patient with the aim of increasing the image contrast between normal and diseased tissues. With the use of soft modelling techniques such as quantitative structure-activity relationship/quantitative structure-property relationship after a suitable description of their molecular structure, we have studied a series of phosphonic acid for designing new MRI contrast agent. Quantitative structure-property relationship studies with multiple linear regression analysis were applied to find correlation between different calculated molecular descriptors of the phosphonic acid-based chelating agent and their stability constants. The final quantitative structure-property relationship mathematical models were found as--quantitative structure-property relationship Model for phosphonic acid series (Model 1)--log K(ML) = {5.00243(+/-0.7102)}- MR {0.0263(+/-0.540)}n = 12 l r l = 0.942 s = 0.183 F = 99.165 quantitative structure-property relationship Model for phosphonic acid series (Model 2)--log K(ML) = {5.06280(+/-0.3418)}- MR {0.0252(+/- .198)}n = 12 l r l = 0.956 s = 0.186 F = 99.256.

  3. Design and Optimization of Gadolinium Based Contrast Agents for Magnetic Resonance Imaging

    International Nuclear Information System (INIS)

    Pereira, G.A.; Geraldes, C.F.G.C.; University of Coimbra

    2007-01-01

    The role of Gd 3+ chelates as contrast agents in Magnetic Resonance Imaging is discussed. The theory describing the different contributions to paramagnetic relaxation relevant to the understanding of the molecular parameters determining the relativity of those Gd 3+ chelates, is presented. The experimental techniques used to obtain those parameters are also described. Then, the various approaches taken to optimize those parameters, leading to maximum relativity (efficiency) of the contrast agents, are also illustrated with relevant examples taken from the literature. The various types of Gd 3+ -based agents, besides non-specific and hepatobiliary agents, are also discussed, namely blood pool, targeting, responsive and paramagnetic chemical shift saturation transfer (PARACEST) agents. Finally, a perspective is presented of some of the challenges lying ahead in the optimization of MRI contrast agents to be useful in Molecular Imaging. (author)

  4. 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

  5. Gadolinium Deposition in Human Brain Tissues after Contrast-enhanced MR Imaging in Adult Patients without Intracranial Abnormalities.

    Science.gov (United States)

    McDonald, Robert J; McDonald, Jennifer S; Kallmes, David F; Jentoft, Mark E; Paolini, Michael A; Murray, David L; Williamson, Eric E; Eckel, Laurence J

    2017-11-01

    Purpose To determine whether gadolinium deposits in neural tissues of patients with intracranial abnormalities following intravenous gadolinium-based contrast agent (GBCA) exposure might be related to blood-brain barrier integrity by studying adult patients with normal brain pathologic characteristics. Materials and Methods After obtaining antemortem consent and institutional review board approval, the authors compared postmortem neuronal tissue samples from five patients who had undergone four to 18 gadolinium-enhanced magnetic resonance (MR) examinations between 2005 and 2014 (contrast group) with samples from 10 gadolinium-naive patients who had undergone at least one MR examination during their lifetime (control group). All patients in the contrast group had received gadodiamide. Neuronal tissues from the dentate nuclei, pons, globus pallidus, and thalamus were harvested and analyzed with inductively coupled plasma mass spectrometry (ICP-MS), transmission electron microscopy with energy-dispersive x-ray spectroscopy, and light microscopy to quantify, localize, and assess the effects of gadolinium deposition. Results Tissues from the four neuroanatomic regions of gadodiamide-exposed patients contained 0.1-19.4 μg of gadolinium per gram of tissue in a statistically significant dose-dependent relationship (globus pallidus: ρ = 0.90, P = .04). In contradistinction, patients in the control group had undetectable levels of gadolinium with ICP-MS. All patients had normal brain pathologic characteristics at autopsy. Three patients in the contrast group had borderline renal function (estimated glomerular filtration rate the contrast group was localized to the capillary endothelium and neuronal interstitium and, in two cases, within the nucleus of the cell. Conclusion Gadolinium deposition in neural tissues after GBCA administration occurs in the absence of intracranial abnormalities that might affect the permeability of the blood-brain barrier. These findings

  6. 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 deep learning method, gadolinium dose can be reduced 10-fold while preserving contrast information and avoiding significant image quality degradation. 3 Technical Efficacy: Stage 5 J. Magn. Reson. Imaging 2018. © 2018 International Society for Magnetic Resonance in Medicine.

  7. Utility of gadolinium as a contrast medium in endovascular therapeutic procedures; Utilidad del gadolinio como medio de contraste en procedimientos terapeuticos endovasculares

    Energy Technology Data Exchange (ETDEWEB)

    Reyes, R.; Pardo, M. D.; Gorriz, E.; Gallardo, L. (Hospital de Gran Canaria Dr. Negrin); Carreira, J. M. (Universidad de Santiago de Compostela)

    2001-07-01

    To assess the utility of gadolinium associated with CO{sub 2}, as a contrast medium in angiographic studies related to endovascular therapeutic procedures in patients with suboptimal renal function. Between January 2000 and June 2001, endovascular treatments using CO{sub 2} and gadolinium as contrast medium were performed in 10 patients presenting renal function deterioration (creatinine>1.5 mg/ml). A mean dose of 42 ml of gadolinium was administered. The images acquired in diagnostic and therapeutic studied were satisfactory in every case. There was no evidence of significant increases in the previous urea and creatine levels when measured 24, 48 and 72 hours after the procedure. In combination with CO{sub 2} gadolinium is a useful contrast medium for endovascular therapeutic procedures in patients with suboptimal renal function. (Author) 21 refs.

  8. Correlation of contrast agent kinetics between iodinated contrast-enhanced spectral tomosynthesis and gadolinium-enhanced MRI of breast lesions

    International Nuclear Information System (INIS)

    Froeling, Vera; Diekmann, Felix; Renz, Diane M.; Fallenberg, Eva M.; Steffen, Ingo G.; Diekmann, Susanne; Schmitzberger, Florian F.; Lawaczeck, Ruediger

    2013-01-01

    Assessment of contrast agent kinetics in contrast-enhanced MRI (CE-MRI) with gadolinium-containing contrast agents offers the opportunity to predict breast lesion malignancy. The goal of our study was to determine if similar patterns exist for spectral contrast-enhanced digital breast tomosynthesis (CE-DBT) using an iodinated contrast agent. The protocol of our prospective study was approved by the relevant institutional review board and the German Federal Office for Radiation Protection. All patients provided written informed consent. We included 21 women with a mean age of 62.4 years. All underwent ultrasound-guided biopsy of a suspect breast lesion, spectral CE-DBT and CE-MRI. For every breast lesion, contrast agent kinetics was assessed by signal intensity-time curves for spectral CE-DBT and CE-MRI. Statistical comparison used Cohen's kappa and Spearman's rho test. Spearman's rho of 0.49 showed significant (P = 0.036) correlation regarding the contrast agent kinetics in signal intensity-time curves for spectral CE-DBT and CE-MRI. Cohen's kappa indicated moderate agreement (kappa = 0.438). There is a statistically significant correlation between contrast agent kinetics in the signal intensity-time curves for spectral CE-DBT and CE-MRI. Observing intralesional contrast agent kinetics in spectral CE-DBT may aid evaluation of malignant breast lesions. (orig.)

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

    International Nuclear Information System (INIS)

    Kubaska, Samantha; Sahani, Dushyant V.; Saini, Sanjay; Hahn, Peter F.; Halpern, Elkan

    2001-01-01

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

  10. Effects of gadolinium-based MRI contrast agents on liver tissue.

    Science.gov (United States)

    Mercantepe, Tolga; Tümkaya, Levent; Çeliker, Fatma Beyazal; Topal Suzan, Zehra; Çinar, Seda; Akyildiz, Kerimali; Mercantepe, Filiz; Yilmaz, Adnan

    2018-04-01

    MRI with contrast is often used clinically. However, recent studies have reported a high accumulation of gadolinium-based contrast agents (GBCAs) in kidney, liver, and spleen tissues in several mouse models. To compare the effects on liver tissue of gadolinium-based MRI contrast agents in the light of biochemical and histopathological evaluation. Institutional Review Board (IRB)-approved controlled longitudinal study. In all, 32 male Sprague-Dawley rats were divided into a healthy control group subjected to no procedure (Group 1), a sham group (Group 2), a gadodiamide group (Group 3), and a gadoteric acid group (Group 4). Not applicable. Liver tissues removed at the end of the fifth week and evaluated pathologically (scored Knodell's histological activity index [HAI] method by two histopathologists) immunohistochemical (caspase-3 and biochemical tests (AST, ALT, TAS, TOS, and OSI method by Erel et al) were obtained. Differences between groups were analyzed using the nonparametric Kruskal-Wallis test followed by the Tamhane test, and one-way analysis of variance (ANOVA) followed by Turkey's HSD test. An increase was observed in histological activity scores in sections from rats administered gadodiamide and gadoteric acid, and in caspase-3, AST and ALT values (P total antioxidant and antioxidant capacity. 1 Technical Efficacy: Stage 4 J. Magn. Reson. Imaging 2018. © 2018 International Society for Magnetic Resonance in Medicine.

  11. Rapid MR measurements of contrast medium dilution kinetics (gadolinium-DTPA) in a flow phantom

    International Nuclear Information System (INIS)

    Boeck, J.C.; Sander, B.; Frank, J.; Schoerner, W.

    1991-01-01

    We studied first-pass MRI-contrast dilution to compute flow and volume of distribution in a realistic flow phantom. Pulsatile flow was provided by a one-chamber artificial heart. Physiological stroke volume, rate, pressure, and flow were adjustable. An elastic tube with dimensions similar to that of the human aorta was imaged at a rate of 2.4 Hz. After contrast injection, an initial increase in signal intensity was followed by a decrease. Signal-intensity-time plots demonstrated slightly skewed curves as expected from dispersion theory. After calibration at different gadolinium-DTPA concentrations, signal intensities were converted into true gadolinium concentrations, and flow was calculated from the concentration-time curves. Flow was varied between 2.5 and 10.0 l/min and a significant correlation was found between the MRI-estimate and true flow. Volume of distribution between injection and detection site was reliably estimated. This study demonstrates rapid 2-D imaging of a paramagnetic contrast bolus in a realistic flow phantom. Reliable estimates of flow and volume are obtained. (orig.) [de

  12. Synthesis and characterization of Gadolinium-Lectin conjugates as selective blood-vessel contrast agents for magnetic resonance imaging (MRI)

    International Nuclear Information System (INIS)

    Pashkunova-Martic, I.

    2004-11-01

    Molecular imaging without use of ionizing radiation has recently been developed for both magnetic resonance and ultrasound imaging (MRI, US) and is expected to play a major future role in diagnosis and monitoring of tumours. In MRI, targeted nanoparticle contrast media (CM) with high relaxivities are required in order to obtain adequate signal-to-noise ratios, due to the low number of target sites. The size, charge and chemical constitution of the targeted nanoparticle CM are expected to influence nanoparticle interactions with cells and tissue elements significantly, and hence the targeting, the accumulation and dwell time at the targeted site, and the type and rate of clearance of the nanoparticles. The work reported here aims to characterise and optimise these parameters in mouse and human models, using nanoparticles targeted to a major carbohydrate determinant of the endothelial cell surface which is present in all blood vessels. Specific binding to the endothelium was demonstrated in both living and chemically fixed human vessels and in mice. Long-standing spin-echo and FLASH-3D images were obtained in the vasculature of living mice, in strong contrast to the rapid renal clearance of gadolinium-DTPA chelates which are widely used in the clinic. Nanoparticle size was found to be a major determinant of the biological response, and our data indicate that an optimal nanoparticle size lies between 50-100 nm diameter. We expect that hyperpermeable vessels present in tumours will permit targeting of optimised nanoparticles to the tumour cells, permitting MRI monitoring of the tumour. (author)

  13. Fatal anaphylactic reaction to intravenous gadobutrol, a gadolinium-based MRI contrast agent

    Directory of Open Access Journals (Sweden)

    Sabine Franckenberg, MD

    2018-02-01

    Full Text Available We present the rare case of a fatal anaphylactic reaction to gadobutrol, a magnetic resonance imaging contrast agent, in a 42-year-old man. The patient underwent elective magnetic resonance imaging for diagnostic clarification of a suspicious finding in the abdomen. The patient had undergone contrast-enhanced computed tomography previously without the occurrence of any adverse effects. Adverse drug reactions in gadobutrol have a very low prevalence of 0.32%-3.5%, with serious adverse drug reactions in <0.1%. There are only a few cases of fatal anaphylactoid reactions to gadolinium-based contrast agents in general. However, if an anaphylactoid reaction occurs, it can present itself with a fulminant course within minutes.

  14. Diethylenetriaminepentaacetic acid-gadolinium (DTPA-Gd)-conjugated polysuccinimide derivatives as magnetic resonance imaging contrast agents.

    Science.gov (United States)

    Lee, Ha Young; Jee, Hye Won; Seo, Sung Mi; Kwak, Byung Kook; Khang, Gilson; Cho, Sun Hang

    2006-01-01

    Biocompatible polysuccinimide (PSI) derivatives conjugated with diethylenetriaminepentaacetic acid gadolinium (DTPA-Gd) were prepared as magnetic resonance imaging (MRI) contrast agents. In this study, we synthesized PSI derivatives incorporating methoxy-poly(ethylene glycol) (mPEG) as hydrophilic ligand, hexadecylamine as hydrophobic ligand, and DTPA-Gd as contrast agent. PSI was synthesized by the polycondensation polymerization of aspartic acid. All the synthesized materials were characterized by proton nuclear magnetic resonance (1H NMR). Critical micellization concentrations were determined using fluorescent probes (pyrene). Micelle size and shape were measured by electro-photometer light scattering (ELS) and atomic force microscopy (AFM). The formed micelle size ranged from 100 to 300 nm. The T1-weighted MR images of the phantom prepared with PSI-mPEG-C16-(DTPA-Gd) were obtained in a 3.0 T clinical MR imager, and the conjugates showed a great potential as MRI contrast agents.

  15. Gadolinium-DTPA as an oral contrast medium for MR tomography of the abdomen

    International Nuclear Information System (INIS)

    Krahe, T.; Doelken, W.; Lackner, K.; Houselog, M.

    1990-01-01

    150 MR examinations of the upper abdomen were carried out after the oral administration of 5 ml/kg body weight of a gadolinium DTPA formulation (1.0 mmol/l, 15 g/l manitol), with reference to the delineation of the pancreas, the liver and intra-abdominal fat. For comparison, 100 MR examinations without oral opacification of the G.I. tract were evaluated. Contrast administration resulted in a signal-intensive demonstration of the G.I tract for all measurement sequences. The intraluminal contrast improved the distinction between normal and abnormal structures, T 1 and T 2 sequences and the demonstration of fat on T 2 -weighted series. T 1 -weighted series showed the best diagnostic results. In 25% there was meteorism and diarrhoea within 24 hours of the administration of the oral contrast. (orig.) [de

  16. 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

  17. 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.

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

    International Nuclear Information System (INIS)

    Lundin, B.; Berntorp, E.; Pettersson, H.; Wirestam, R.; Jonsson, K.; Staahlberg, F.; Ljung, R.

    2007-01-01

    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

  19. Polydisulfide Manganese(II) Complexes as Non-Gadolinium Biodegradable Macromolecular MRI Contrast Agents

    Science.gov (United States)

    Ye, Zhen; Jeong, Eun-Kee; Wu, Xueming; Tan, Mingqian; Yin, Shouyu; Lu, Zheng-Rong

    2011-01-01

    Purpose To develop safe and effective manganese(II) based biodegradable macromolecular MRI contrast agents. Materials and Methods In this study, we synthesized and characterized two polydisulfide manganese(II) complexes, Mn-DTPA cystamine copolymers and Mn-EDTA cystamine copolymers, as new biodegradable macromolecular MRI contrast agents. The contrast enhancement of the two manganese based contrast agents were evaluated in mice bearing MDA-MB-231 human breast carcinoma xenografts, in comparison with MnCl2. Results The T1 and T2 relaxivities were 4.74 and 10.38 mM−1s−1 per manganese at 3T for Mn-DTPA cystamine copolymers (Mn=30.50 kDa) and 6.41 and 9.72 mM−1s−1 for Mn-EDTA cystamine copolymers (Mn= 61.80 kDa). Both polydisulfide Mn(II) complexes showed significant liver, myocardium and tumor enhancement. Conclusion The manganese based polydisulfide contrast agents have a potential to be developed as alternative non-gadolinium contrast agents for MR cancer and myocardium imaging. PMID:22031457

  20. 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.)

  1. 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

  2. Enhanced conjugation stability and blood circulation time of macromolecular gadolinium-DTPA contrast agent

    Energy Technology Data Exchange (ETDEWEB)

    Jenjob, Ratchapol [Department of New Drug Development, School of Medicine, Inha University, 2F A-dong, Jeongseok Bldg., Sinheung-dong 3-ga, Jung-gu, Incheon 400-712 (Korea, Republic of); Kun, Na [Department of Biotechnology, The Catholic University of Korea, 43 Jibong-ro, Wonmi-gu, Bucheon-si, Gyeonggi-do 420-743 (Korea, Republic of); Ghee, Jung Yeon [Utah-Inha DDS and Advanced Therapeutics, B-403 Meet-You-All Tower, SongdoTechnopark, 7–50, Songdo-dong, Yeonsu-gu, Incheon 406-840 (Korea, Republic of); Shen, Zheyu; Wu, Xiaoxia [Division of Functional Materials and Nano-Devices, Ningbo Institute of Materials Technology & Engineering (NIMTE), Chinese Academy of Sciences, 519 Zhuangshi Street, Zhenhai District, Ningbo, Zhejiang 315201 (China); Cho, Steve K., E-mail: scho@gist.ac.kr [Division of Liberal Arts and Science, GIST College, Gwangju Institute of Science and Technology, Gwangju 500-712 (Korea, Republic of); Lee, Don Haeng [Utah-Inha DDS and Advanced Therapeutics, B-403 Meet-You-All Tower, SongdoTechnopark, 7–50, Songdo-dong, Yeonsu-gu, Incheon 406-840 (Korea, Republic of); Department of Internal Medicine, School of Medicine, Inha University Hospital, Incheon 420-751 (Korea, Republic of); Yang, Su-Geun, E-mail: Sugeun.Yang@Inha.ac.kr [Department of New Drug Development, School of Medicine, Inha University, 2F A-dong, Jeongseok Bldg., Sinheung-dong 3-ga, Jung-gu, Incheon 400-712 (Korea, Republic of)

    2016-04-01

    In this study, we prepared macromolecular MR T1 contrast agent: pullulan-conjugated Gd diethylene triamine pentaacetate (Gd-DTPA-Pullulan) and estimated residual free Gd{sup 3+}, chelation stability in competition with metal ions, plasma and tissue pharmacokinetics, and abdominal MR contrast on rats. Residual free Gd{sup 3+} in Gd-DTPA-Pullulan was measured using colorimetric spectroscopy. The transmetalation of Gd{sup 3+} incubated with Ca{sup 2+} was performed by using a dialysis membrane (MWCO 100–500 Da) and investigated by ICP-OES. The plasma concentration profiles of Gd-DTPA-Pullulan were estimated after intravenous injection at a dose 0.1 mmol/kg of Gd. The coronal-plane abdominal images of normal rats were observed by MR imaging. The content of free Gd{sup 3+}, the toxic residual form, was less than 0.01%. Chelation stability of Gd-DTPA-Pullulan was estimated, and only 0.2% and 0.00045% of Gd{sup 3+} were released from Gd-DTPA-Pullulan after 2 h incubation with Ca{sup 2+} and Fe{sup 2+}, respectively. Gd-DTPA-Pullulan displayed the extended plasma half-life (t{sub 1/2,α} = 0.43 h, t{sub 1/2,β} = 2.32 h), much longer than 0.11 h and 0.79 h of Gd-EOB-DTPA. Abdominal MR imaging showed Gd-DTPA-Pullulan maintained initial MR contrast for 30 min. The extended plasma half-life of Gd-DTPA-Pullulan probably allows the prolonged MR acquisition time in clinic with enhanced MR contrast. - Highlights: • Macromolecule (pullulan) conjugated Gd contrast agent (Gd-DTPA-Pullulan) showed the extended plasma half-life (t{sub 1/2,α} = 0.43 h, t{sub 1/2,β} = 2.32 h) in comparison with Gd-EOB-DTPA • Gd-DTPA-pullulan T1 contrast agent exhibited strong chelation stability against Gd. • The extended blood circulation attributed the enhanced and prolonged MR contrast on abdominal region of rats. • The extended blood circulation may provide prolonged MR acquisition time window in clinics.

  3. Gadolinium DTPA as oral contrast medium for MRT of the pancreas

    International Nuclear Information System (INIS)

    Neumann, K.; Kaminsky, S.; Gogoll, M.; Langer, M.; Felix, R.

    1991-01-01

    52 patients with normal pancreas, pancreatitis and pancreatic tumors were examined by magnetic resonance imaging (Magnetom 0,5 T). Using T 1 -, proton density- and T 2 -weighted spin-echo sequences images were obtained before and after oral administration of Gadolinium-DTPA (Gd-DTPA, 1 mM, 15 g/l Mannit, 5-13 ml/kg). Gd-DTPA resulted in hyperintense labeling of small bowel in all sequences and improved visualization of pancreatic head, body and tail in 15, 14 and 7 of 27 patients with normal pancreas and in 17, 8 and 6 of 25 patients with diseased pancreas. Better delineation of pseudocysts and tumorous gut wall invasion were diagnostically profitable. With regard to motion artifact reduced MRI of the intestine using fast sequences Gd-DTPA may be a suitable oral contrast agent to improve the imaging of the pancreas. (orig.) [de

  4. T(2) relaxation time of hyaline cartilage in presence of different gadolinium-based contrast agents.

    Science.gov (United States)

    Wiener, Edzard; Settles, Marcus; Diederichs, Gerd

    2010-01-01

    The transverse relaxation time, T(2), of native cartilage is used to quantify cartilage degradation. T(2) is frequently measured after contrast administration, assuming that the impact of gadolinium-based contrast agents on cartilage T(2) is negligible. To verify this assumption the depth-dependent variation of T(2) in the presence of gadopentetate dimeglumine, gadobenate dimeglumine and gadoteridol was investigated. Furthermore, the r(2)/r(1) relaxivity ratios were quantified in different cartilage layers to demonstrate differences between T(2) and T(1) relaxation effects. Transverse high-spatial-resolution T(1)- and T(2)-maps were simultaneously acquired on a 1.5 T MR scanner before and after contrast administration in nine bovine patellae using a turbo-mixed sequence. The r(2)/r(1) ratios were calculated for each contrast agent in cartilage. Profiles of T(1), T(2) and r(2)/r(1) across cartilage thickness were generated in the absence and presence of contrast agent. The mean values in different cartilage layers were compared for global variance using the Kruskal-Wallis test and pairwise using the Mann-Whitney U-test. T(2) of unenhanced cartilage was 98 +/- 5 ms at 1 mm and 65 +/- 4 ms at 3 mm depth. Eleven hours after contrast administration significant differences (p cartilage thickness were close to 1.0 (range 0.9-1.3). At 1.5 T, T(2) decreased significantly in the presence of contrast agents, more pronounced in superficial than in deep cartilage. The change in T(2) relaxation rate was similar to the change in T(1). Cartilage T(2) measurements after contrast administration will lead to systematic errors in the quantification of cartilage degradation. 2010 John Wiley & Sons, Ltd.

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

    International Nuclear Information System (INIS)

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

    2016-01-01

    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. (paper)

  6. 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.

  7. Magnetic resonance imaging of urinary bladder carcinoma: tumor staging and gadolinium contrast-enhanced imaging

    International Nuclear Information System (INIS)

    Doringer, E.; Joos, H.; Forstner, R.; Schmoller, H.

    1992-01-01

    Forty-nine patients with urinary bladder carcinomas underwent pre-operative examinations using magnetic resonance (MR) imaging. The results of the MR examinations were correlated with the clinical-pathological findings following transurethral resection (TUR) and bimanual palpation (n = 47) or radical cystectomy (n = 2). The results of pre-contrast MR tumor staging (T1, T2), viewing stages Tis-T2 collectively, and subsequent to separate assessments of stages T3b-T4b, were correct 76.6% of the time. Gadolinium-DTPA (Gd-DTPA) contrast-enhanced examinations (pre-contrast T1 and after Gd-DTPA) showed a staging accuracy rate of 85.7%. T2-weighted images did not indicate any advantage when compared to T1-weighted images following Gd-DTPA. The signal intensity ratios of tumor/fat and tumor/muscle tissue were measured on T1-weighted pre-contrast images and following Gd-DTPA and then evaluated statistically, whereby the increased tumor signal intensity was statistically significant (Wilcoxon test, P < 0.01). Due to the relatively short examination time needed for T1-weighted images and the specific tumor enhancement, the administration of Gd-DTPA proves valuable in the diagnosis of bladder carcinomas. T2-weighted images are not necessary. (orig.)

  8. Contrast-enhanced NMR imaging: animal studies using gadolinium-DTPA complex

    International Nuclear Information System (INIS)

    Brasch, R.C.; Weinmann, H.J.; Wesbey, G.E.

    1984-01-01

    Gadolinium (Gd)-DTPA complex was assessed as a nuclear magnetic resonance (NMR) contrast-enhancing agent by experimentally imaging normal and diseased animals. After intravenous injection, Gd-DTPA, a strongly paramagnetic complex by virtue of unpaired electrons, was rapidly excreted into the urine of rats, producing an easily observable contrast enhancement on NMR images in kidney parenchyma and urine. Sterile soft-tissue abscesses demonstrated an obvious rim pattern of enhancement. A focus of radiation-induced brain damage in a canine model was only faintly detectable on spin-echo NMR images before contrast administration; after 0.5 mmol/kg Gd-DTPA administration, the lesion intensity increased from 3867 to 5590. In comparison, the normal brain with an intact blood-brain barrier remained unchanged in NMR characterization. Gd-DTPA is a promising new NMR contrast enhancer for the clinical assessment of renal function, of inflammatory lesions, and of focal disruption of the blood-brain barrier

  9. The value of paramagnetic contrast agent gadolinium-DTPA in the diagnosis of pituitary adenomas

    International Nuclear Information System (INIS)

    Nakamura, T.; Schoerner, W.; Bittner, R.C.; Felix, R.

    1988-01-01

    The purpose of this study was to assess the role of MR imaging and the paramagnetic contrast agent Gadolinium-DYPA(Gd-DTPA) in the diagnosis of pituitary macroadenomas. 44 macroadenomas were examined with MRI before and after intravenous application of Gd-DTPA. Gd-DTPA produced excellent enhancement of solid adenoma. The best contrast between adenoma and surrounding structures could be gained on post-Gd T1-weighted images. Post-Gd images were equivalent to pre-Gd images in the evaluation of supra- and infrasellar extensions of macroadenomas. Post-Gd images had advantages in the evaluation of cavernous sinus invasion by adenoma. The difference in degree of contrast enhancement between adenoma and cavernous sinus facilitated the exact evaluation of lateral extension by adenoma in 18 cases. Almost equal degree of enhancement of both structures impaired tumor-sinus contrast in 2 cases. In the other 24 cases the tumor filled the cavernous sinus completely. It is our opinion that Gd-DTPA can be used on a widerspread basis because of its excellent capability to highlight and delineate pituitary adenomas. (orig.)

  10. Enhanced conjugation stability and blood circulation time of macromolecular gadolinium-DTPA contrast agent.

    Science.gov (United States)

    Jenjob, Ratchapol; Kun, Na; Ghee, Jung Yeon; Shen, Zheyu; Wu, Xiaoxia; Cho, Steve K; Lee, Don Haeng; Yang, Su-Geun

    2016-04-01

    In this study, we prepared macromolecular MR T1 contrast agent: pullulan-conjugated Gd diethylene triamine pentaacetate (Gd-DTPA-Pullulan) and estimated residual free Gd(3+), chelation stability in competition with metal ions, plasma and tissue pharmacokinetics, and abdominal MR contrast on rats. Residual free Gd(3+) in Gd-DTPA-Pullulan was measured using colorimetric spectroscopy. The transmetalation of Gd(3+) incubated with Ca(2+) was performed by using a dialysis membrane (MWCO 100-500 Da) and investigated by ICP-OES. The plasma concentration profiles of Gd-DTPA-Pullulan were estimated after intravenous injection at a dose 0.1 mmol/kg of Gd. The coronal-plane abdominal images of normal rats were observed by MR imaging. The content of free Gd(3+), the toxic residual form, was less than 0.01%. Chelation stability of Gd-DTPA-Pullulan was estimated, and only 0.2% and 0.00045% of Gd(3+) were released from Gd-DTPA-Pullulan after 2h incubation with Ca(2+) and Fe(2+), respectively. Gd-DTPA-Pullulan displayed the extended plasma half-life (t1/2,α=0.43 h, t1/2,β=2.32 h), much longer than 0.11h and 0.79 h of Gd-EOB-DTPA. Abdominal MR imaging showed Gd-DTPA-Pullulan maintained initial MR contrast for 30 min. The extended plasma half-life of Gd-DTPA-Pullulan probably allows the prolonged MR acquisition time in clinic with enhanced MR contrast. Copyright © 2016 Elsevier B.V. All rights reserved.

  11. 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.

  12. Contrast enhanced magnetic resonance imaging of the brain using gadolinium-DTPA

    International Nuclear Information System (INIS)

    Valk, J.; Slegte, R.G.M. de; Crezee, F.C.; Hazenberg, G.J.; Thjaha, S.I.; Nauta, J.J.P.; Vrije Univ., Amsterdam; Vrije Univ., Amsterdam; Vrije Univ., Amsterdam

    1987-01-01

    This report concerns a clinical trial with gadolinium-DTPA (Gd-DTPA) as an intravenous contrast medium for magnetic resonance imaging (MRI) in patients with disorders of the central nervous system. Fifty patients, 30 females and 20 males, were examined without and with Gd-GTPA. The contrast medium was well tolerated by all patients. The results of MRI scanning without and with Gd-DTPA and those obtained with computed tomography (CT) using intravenous contrast enhancement were compared. This investigation comprised mainly patients with intracranial tumors, multiple sclerosis, and nasopharyngeal tumors. The results may be summarized as follows: 1) MRI with Gd-DTPA (MRI+) gave better results than MRI without Gd as regards delineation of the lesion, blood vessels and edema in cerebral tumors, pituitary adenomas and acute forms of multiple sclerosis (MS). MRI+ was better than CT in 32 of the 50 cases examined; with intracerebral tumors it was better in 15 out of 18 cases. 3) MRI+ was always better than CT in patients with MS. In 3 out of 7 cases MRI demonstrated the acute MS lesions. 4) MRI+ seemed to have advantages also in nasopharyngeal tumors as ascertained from this limited experience. (orig.)

  13. 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

  14. Clinical, biological, and skin histopathologic effects of ionic macrocyclic and nonionic linear gadolinium chelates in a rat model of nephrogenic systemic fibrosis.

    Science.gov (United States)

    Fretellier, Nathalie; Idée, Jean-Marc; Guerret, Sylviane; Hollenbeck, Claire; Hartmann, Daniel; González, Walter; Robic, Caroline; Port, Marc; Corot, Claire

    2011-02-01

    the purpose of this study was to compare the clinical, pathologic, and biochemical effects of repeated administrations of ionic macrocyclic or nonionic linear gadolinium chelates (GC) in rats with impaired renal function. rats submitted to subtotal nephrectomy were allocated to single injections of 2.5 mmol/kg of gadodiamide (nonionic linear chelate), nonformulated gadodiamide (ie, without the free ligand caldiamide), gadoterate (ionic macrocyclic chelate), or saline for 5 consecutive days. Blinded semi-quantitative histopathologic and immunohistochemical examinations of the skin were performed, as well as clinical, hematological, and biochemical follow-up. Rats were killed at day 11. Long-term (up to day 32) follow-up of rats was also performed in an auxiliary study. epidermal lesions (ulcerations and scabs) were found in 4 of the 10 rats treated with nonformulated gadodiamide. Two rats survived the study period. Inflammatory signs were observed in this group. No clinical, hematological, or biochemical signs were observed in the saline and gadoterate- or gadodiamide-treated groups. Plasma fibroblast growth factor-23 levels were significantly higher in the gadodiamide group than in the gadoterate group (day 11). Decreased plasma transferrin-bound iron levels were measured in the nonformulated gadodiamide group. Histologic lesions were in the range: nonformulated gadodiamide (superficial epidermal lesions, inflammation, necrosis, and increased cellularity in papillary dermis) > gadodiamide (small superficial epidermal lesions and signs of degradation of collagen fibers in the dermis) > gadoterate (very few pathologic lesions, similar to control rats). repeated administration of the nonionic linear GC gadodiamide to renally impaired rats is associated with more severe histologic lesions and higher FGF-23 plasma levels than the macrocyclic GC gadoterate.

  15. Gd (III) chelates adsorbed on TiO2 nanoparticles - promising MRI contrast agent

    International Nuclear Information System (INIS)

    Rehor, Ivan; Lukes, Ivan; Peters, Joop A.; Jirak, Daniel

    2009-01-01

    Full text: The project deals with a new contrast agent (CA) for magnetic resonance imaging (MRI). The CA consists of two main parts - diamagnetic core (TiO 2 nanoparticle) and Gd (III) chelates grafted on its surface. The presence of the nanoparticle core is responsible for significant increase of r1 millimolar relaxivity (which corresponds to the efficiency of the CA) due to the slowing down the rotation of the complex in solution. It also affects the biodistribution characteristics of the CA - the ability to penetrate through cell membranes is well known for nanoparticles, making them useful for cell labeling. The structure of the chelate is derived from DOTA ligand, whose Gd (III) complexes are commercially used as MRI CA in human medicine. The connection of the complex to the surface is realized via penylphosphonate, which is attached to the pendant arm of the ligand. Strong interaction of the phosphonate with the TiO 2 surface results in the full surface coverage. The complexation and MRI properties of Gd chelate were studied and exhibit analogy to the complexes of DOTA, The millimolar relaxivity (r1) of the Gd (III) complex significantly increases upon adsorption on the TiO 2 nanoparticles. PVA was added to the colloidal solutions of CA to stabilize them under biological conditions and such stabilized CA was utilized for MRI visualization of rat pancreatic islets (P1). The labeled islets were detected on MR images as hyperintense area and therefore our CA seems to be promising material for cellular MRI

  16. Controlled intracellular self-assembly of gadolinium nanoparticles as smart molecular MR contrast agents.

    Science.gov (United States)

    Cao, Chun-Yan; Shen, Ying-Ying; Wang, Jian-Dong; Li, Li; Liang, Gao-Lin

    2013-01-01

    Herein we developed a new "smart" Gd-based MR contrast agent (i.e., 1) which is susceptive to furin, a protease overexpressed in tumor. Under the action of furin, 1 condenses to form dimers (1-Ds) and the latter self-assemble into gadolinium nanparticles (Gd-NPs). Relaxivity of 1-D is more than 2 folds of those of 1 and magnevist at 1.5 T, and 1.4 folds of that of 1 at 3 T. Intracellular condensation of 1 in furin-overexpressed MDA-MB-468 cells was proven with direct two-photon laser microscopy (TPLM) fluorescence imaging of the cells incubated with the europium analog of 1 (i.e., 2). Intracellular Gd-NPs of 1 were uncovered and characterized for the first time. MRI of MDA-MB-468 tumors showed that 1 has enhanced MR contrast within the tumors than that of its scrambled control 1-Scr.

  17. Gadolinium labeled pharmaceuticals as potential MRI contrast agents for liver and biliary tract

    International Nuclear Information System (INIS)

    Najafi, A.; Amparo, E.G.; Johnson, R.F. Jr.

    1987-01-01

    Three gadolinium-labeled compounds, potential nuclear magnetic resonance (NMR) imaging contrast agents for liver and biliary tract, were studied: 1) Gd-DISIDA, 2) Gd-DTPA-Liposomes, and 3) Gd-DTPA dihexadecylamide (Gd-diamide). In each case, ''Carrier Added'' Gd-153 with specific activity of about 5uCi/mg was used. Each labeled compound was evaluated in experimental animals. Gd-DISIDA proved unsatisfactory because of in vivo instability. Gd-DTPA-Liposomes demonstrated strong toxic effects probably due to pulmonary embolism when large amounts of this compound was administered intravenously. Gd-diamide showed good uptake in the hepatocytes with subsequent excretion into the biliary tract. Several rabbits were imaged in a 0.6T NMR imaging system before and after injection of Gd-diamide. Pulse sequences were chosen that would yield T1-weighted images and permit calculation of T1 relaxation times. This compound produced significant shortening of the T1 relaxation times of the liver and observable increase in intensity on the T1-weighted images. Gd-diamide shows promise as potential NMR contrast agent for liver and biliary tract imaging. (author)

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

    International Nuclear Information System (INIS)

    Veldhoen, Simon; Sauer, Alexander; Gassenmaier, Tobias; Petritsch, Bernhard; Herz, Stefan; Blanke, Philipp; Bley, Thorsten A.; Wirth, Clemens; Derlin, Thorsten

    2015-01-01

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

  19. Role of chelates in magnetic resonance imaging studies

    Directory of Open Access Journals (Sweden)

    Tripathi Laxmi

    2009-01-01

    Full Text Available Imaging studies are tests performed with a variety of techniques that produce pictures of the inside of a patient′s body. Magnetic resonance imaging (MRI is an imaging technique based on the principles of nuclear magnetic resonance. MRI uses a powerful magnetic field, radio waves, and a computer to produce detailed pictures of organs, soft tissues, bone, and virtually all other internal body structures. Chelates have a wide application in such imaging techniques. Chelates in imaging studies are used alone as radioactive agents or conjugated to monoclonal antibodies or to DNA as radioactive agents. Technetium chelates and gadolinium chelates are being widely used as magnetic resonance contrast media.

  20. Acute myocardial ischemia: magnetic resonance contrast enhancement with gadolinium-DTPA

    International Nuclear Information System (INIS)

    McNamara, M.T.; Higgins, C.B.; Ehman, R.L.; Revel, D.; Sievers, R.; Brasch, R.C.

    1984-01-01

    Gadolinium-DTPA (Gd-DTPA) was used to improve the diagnostic utility of magnetic resonance (MR) in detecting early ischemia, before the onset of infarction. Following one minute of left anterior descending coronary artery occlusion, 9 dogs were intraveneously injected with either 0.5 mM/kg of Gd-DTPA (6 dogs) or normal saline (3 dogs). There was no visible difference in intensity or alterations in magnetic relaxation times between normal and ischemic myocardium in the control (saline-injected) animals. The Gd-DTPA-injected dogs had a well-defined segment of high intensity representing the ischemic myocardium in the anterior wall of the left ventricle. Both T1 and T2 were significantly shortened in the normal myocardium of the Gd-DTPA animals, but relatively greater T2 relaxation rate enhancement resulted in reduced intensity of normal myocardium, thus increasing contrast with ischemic myocardium. It is concluded that Gd-DTPA has the potential to expand the sensitivity and diagnostic utility of MR in the study of occlusive coronary artery disease

  1. Gadolinium as a CT contrast agent: an experimental study for the effects of injection parameters in the rabbit brain model

    International Nuclear Information System (INIS)

    Kim, Hyun Jin; Choi, Hye Young; Lee, Sun Wha; Hwang, Ji Young

    2005-01-01

    We wanted to investigate the use of gadolinium based contrast agent (Gd-DTPA) for computed tomography (CT), and we also wanted to assess the effects of valuable injection parameters on enhancement in an experimental rabbit brain model. In vitro, attenuation measurements of serial dilutions of Gd-DTPA and iopromide were compared. In five rabbits, single level dynamic gadolinium-enhanced brain CT studies were obtained using different injection parameters. A comparision CT scan after iopromide administration was performed. The time-attenuation curves of the brain vessel and parenchyma were obtained and the magnitude of enhancement (Hmax) and the time to peak enhancement (Tmax) were analyzed. In vitro, the attenuation coefficient of undiluted Gd-DTPA (2,578 HU) was higher than that of iopromide (1,761 HU) at equimolar concentrations. In 5 rabbits, the time-attenuation curve demonstrated a distinct pattern with peak enhancement only in the brain vessel, but not in the brain parenchyma. There was increasing linear relationship between the injection rate of Gd-DTPA and Hmax, and a declining linear relationship with Tmax. The higher the concentration of Gd-DTPA, the higher Hmax was, but no significant difference was found for the Tmax. Higher volumes of Gd-DTPA revealed a higher Hmax and a delayed Tmax. Enhancement of the brain parenchyma on gadolinium-enhanced CT is minimal, while enhancement of the brain vessels is distinctive. The most important factor affecting Hmax of the vessel is the concentration of the contrast medium and the most important factor affecting Tmax of the vessel is volume of the contrast medium. The gadolinium-based contrast agent may be an reasonable alternative contrast agent for brain CT, and especially in cerebral vessels, and it may also be advantageous for brain parenchyma of those patients with BBB dysfunction

  2. 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.

  3. Pediatric Patients Demonstrate Progressive T1-Weighted Hyperintensity in the Dentate Nucleus following Multiple Doses of Gadolinium-Based Contrast Agent.

    Science.gov (United States)

    Roberts, D R; Chatterjee, A R; Yazdani, M; Marebwa, B; Brown, T; Collins, H; Bolles, G; Jenrette, J M; Nietert, P J; Zhu, X

    2016-12-01

    While there have been recent reports of brain retention of gadolinium following gadolinium-based contrast agent administration in adults, a retrospective series of pediatric patients has not previously been reported, to our knowledge. We investigated the relationship between the number of prior gadolinium-based contrast agent doses and increasing T1 signal in the dentate nucleus on unenhanced T1-weighted MR imaging. We hypothesized that despite differences in pediatric physiology and the smaller gadolinium-based contrast agent doses that pediatric patients are typically administered based on weighted-adjusted dosing, the pediatric brain would also demonstrate dose-dependent increasing T1 signal in the dentate nucleus. We included children with multiple gadolinium-based contrast agent administrations at our institution. A blinded reader placed ROIs within the dentate nucleus and adjacent cerebellar white matter. To eliminate reader bias, we also performed automated ROI delineation of the dentate nucleus, cerebellar white matter, and pons. Dentate-to-cerebellar white matter and dentate-to pons ratios were compared with the number of gadolinium-based contrast agent administrations. During 20 years at our institution, 280 patients received at least 5 gadolinium-based contrast agent doses, with 1 patient receiving 38 doses. Sixteen patients met the inclusion/exclusion criteria for ROI analysis. Blinded reader dentate-to-cerebellar white matter ratios were significantly associated with gadolinium-based contrast agent doses (r s = 0.77, P = .001). The dentate-to-pons ratio and dentate-to-cerebellar white matter ratios based on automated ROI placement were also significantly correlated with gadolinium-based contrast agent doses (t = 4.98, P contrast agent doses is significantly correlated with progressive T1-weighted dentate hyperintensity. Definitive confirmation of gadolinium deposition requires tissue analysis. Any potential clinical sequelae of gadolinium retention in

  4. 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.

  5. Gadolinium-Hematoporphyrin: new potential MRI contrast agent for detection of breast cancer cell line (MCF-7

    Directory of Open Access Journals (Sweden)

    D Shahbazi Gahrouei

    2005-09-01

    Full Text Available Background: Gadolinium-porphyrins have been synthesized and are currently being investigated as magnetic resonance imaging (MRI contrast agents. This study aimed to synthesize Gd-hematoporphyrin and applicate it for in vitro detection of breast cancer cell line (MCF-7. Methods: The naturally occurring porphyrin (hematoporphyrin was inserted with gadolinium (III nitrate hexahydrate to yield Gd-H. T1 relaxation times and signal enhancement of the contrast agents were presented, and the results were compared. UV spectrophotometer measured the attachment of Gd to the cell membrane of MCF-7. Results: Most of gadolinium chloride (GdCl3 was found in the washing solution, indicate that it didn`t fixed to the breast cell membranes during incubation. Gd-DTPA showed some uptake into the MCF-7 cell membranes with incubation, however, its uptake was significantly lower than Gd-H. Conclusion: Good cell memberan uptake of Gd-porphyrin is comparable to controls, indicating selective delivery it to the breast cell line and considerable potency in diagnostic MR imaging for detection of breast cancer. Key Words: Porphyrin, Contrast agent, MRI, Hematoporphyrin, Breast cancer cell (MCF-7

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

    International Nuclear Information System (INIS)

    Rees, O.; Agarwal, S.K.

    2010-01-01

    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.

  7. 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

  8. 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.

  9. 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.

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

    Directory of Open Access Journals (Sweden)

    Matthias Ceulemans

    2015-11-01

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

  11. A smart T(1)-weighted MRI contrast agent for uranyl cations based on a DNAzyme-gadolinium conjugate.

    Science.gov (United States)

    Xu, Weichen; Xing, Hang; Lu, Yi

    2013-11-07

    Rational design of smart MRI contrast agents with high specificity for metal ions remains a challenge. Here, we report a general strategy for the design of smart MRI contrast agents for detecting metal ions based on conjugation of a DNAzyme with a gadolinium complex. The 39E DNAzyme, which has high selectivity for UO2(2+), was conjugated to Gd(III)-DOTA and streptavidin. The binding of UO2(2+) to its 39E DNAzyme resulted in the dissociation of Gd(III)-DOTA from the large streptavidin, leading to a decrease of the T1 correlation time, and a change in the MRI signal.

  12. Use of gadolinium chloride as a contrast agent for imaging spruce knots by magnetic resonance

    Science.gov (United States)

    Thomas L. Eberhardt; Chi-Leung So; Amy H. Herlihy; Po-Wah So

    2006-01-01

    Treatments of knot-containing spruce wood blocks with a paramagnetic salt, gadolinium (III) chloride, in combination with solvent pretreatments, were evaluated as strategies to enhance the visualization of wood features by magnetic resonance imaging (MRI). Initial experiments with clear wood and excised knot samples showed differences in moisture uptake after...

  13. Delayed Gadolinium-Enhanced MRI of Cartilage (dGEMRIC) of Cadaveric Shoulders: Comparison of Contrast Dynamics in Hyaline and Fibrous Cartilage after Intraarticular Gadolinium Injection

    Energy Technology Data Exchange (ETDEWEB)

    Wiener, E. (Dept. of Radiology, Charite Universitaetsmedizin Berlin (Germany)); Hodler, J.; Pfirrmann, C.W.A. (Dept. of Radiology, Orthopedic Univ. Hospital Balgrist, Zuerich (Switzerland))

    2009-01-15

    Background: Delayed gadolinium-enhanced magnetic resonance imaging of cartilage (dGEMRIC) is a novel method to investigate cartilaginous and fibrocartilaginous structures. Purpose: To investigate the contrast dynamics in hyaline and fibrous cartilage of the glenohumeral joint after intraarticular injection of gadopentetate dimeglumine. Material and Methods: Transverse T1 maps were acquired on a 1.5T scanner before and after intraarticular injection of 2.0 mmol/l gadopentetate dimeglumine in five cadaveric shoulders using a dual flip angle three-dimensional gradient echo (3D-GRE) sequence. The acquisition time for the T1 maps was 5 min 5 s for the whole shoulder. Measurements were repeated every 15 min over 2.5 hours. Regions of interest (ROIs) covering the glenoid cartilage and the labrum were drawn to assess the temporal evolution of the relaxation parameters. Results: T1 of unenhanced hyaline cartilage of the glenoid was 568+-34 ms. T1 of unenhanced fibrous cartilage of the labrum was 552+-38 ms. Significant differences (P=0.002 and 0.03) in the relaxation parameters were already measurable after 15 min. After 2 to 2.5 hours, hyaline and fibrous cartilage still demonstrated decreasing relaxation parameters, with a larger range of the T1(Gd) values in fibrous cartilage. T1 and ?R1 values of hyaline and fibrous cartilage after 2.5 hours were 351+-16 ms and 1.1+-0.09/s, and 332+-31 ms and 1.2+-0.1/s, respectively. Conclusion: A significant decrease in T1(Gd) was found 15 min after intraarticular contrast injection. Contrast accumulation was faster in hyaline than in fibrous cartilage. After 2.5 hours, contrast accumulation showed a higher rate of decrease in hyaline cartilage, but neither hyaline nor fibrous cartilage had reached equilibrium

  14. Delayed gadolinium-enhanced MRI of cartilage (dGEMRIC) of cadaveric shoulders: comparison of contrast dynamics in hyaline and fibrous cartilage after intraarticular gadolinium injection.

    Science.gov (United States)

    Wiener, E; Hodler, J; Pfirrmann, C W A

    2009-01-01

    Delayed gadolinium-enhanced magnetic resonance imaging of cartilage (dGEMRIC) is a novel method to investigate cartilaginous and fibrocartilaginous structures. To investigate the contrast dynamics in hyaline and fibrous cartilage of the glenohumeral joint after intraarticular injection of gadopentetate dimeglumine. Transverse T(1) maps were acquired on a 1.5T scanner before and after intraarticular injection of 2.0 mmol/l gadopentetate dimeglumine in five cadaveric shoulders using a dual flip angle three-dimensional gradient echo (3D-GRE) sequence. The acquisition time for the T(1) maps was 5 min 5 s for the whole shoulder. Measurements were repeated every 15 min over 2.5 hours. Regions of interest (ROIs) covering the glenoid cartilage and the labrum were drawn to assess the temporal evolution of the relaxation parameters. T(1) of unenhanced hyaline cartilage of the glenoid was 568+/-34 ms. T(1) of unenhanced fibrous cartilage of the labrum was 552+/-38 ms. Significant differences (P=0.002 and 0.03) in the relaxation parameters were already measurable after 15 min. After 2 to 2.5 hours, hyaline and fibrous cartilage still demonstrated decreasing relaxation parameters, with a larger range of the T(1)(Gd) values in fibrous cartilage. T(1) and triangle Delta R(1) values of hyaline and fibrous cartilage after 2.5 hours were 351+/-16 ms and 1.1+/-0.09 s(-1), and 332+/-31 ms and 1.2+/-0.1 s(-1), respectively. A significant decrease in T(1)(Gd) was found 15 min after intraarticular contrast injection. Contrast accumulation was faster in hyaline than in fibrous cartilage. After 2.5 hours, contrast accumulation showed a higher rate of decrease in hyaline cartilage, but neither hyaline nor fibrous cartilage had reached equilibrium.

  15. 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

  16. MRI with intrathecal MRI gadolinium contrast medium administration: a possible method to assess glymphatic function in human brain.

    Science.gov (United States)

    Eide, Per Kristian; Ringstad, Geir

    2015-11-01

    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. Comparison of blood pool and extracellular gadolinium chelate for functional MR evaluation of vascular thoracic outlet syndrome

    Energy Technology Data Exchange (ETDEWEB)

    Lim, Ruth P., E-mail: ruthplim74@gmail.com [New York University School of Medicine, Bernard and Irene Schwartz Center for Biomedical Imaging, Department of Radiology, 660 1st Avenue, New York, NY 10016 (United States); Austin Health, Department of Radiology, Heidelberg, Victoria 3084 (Australia); The University of Melbourne, School of Medicine, Parkville, Victoria 3010 (Australia); Bruno, Mary, E-mail: mary.bruno@nyumc.org [New York University School of Medicine, Bernard and Irene Schwartz Center for Biomedical Imaging, Department of Radiology, 660 1st Avenue, New York, NY 10016 (United States); Rosenkrantz, Andrew B., E-mail: Andrew.rosenkrantz@nyumc.org [New York University School of Medicine, Bernard and Irene Schwartz Center for Biomedical Imaging, Department of Radiology, 660 1st Avenue, New York, NY 10016 (United States); Kim, Danny C., E-mail: danny.kim@nyumc.org [New York University School of Medicine, Bernard and Irene Schwartz Center for Biomedical Imaging, Department of Radiology, 660 1st Avenue, New York, NY 10016 (United States); Mulholland, Thomas, E-mail: Thomas.mulholland@nyumc.org [New York University School of Medicine, Bernard and Irene Schwartz Center for Biomedical Imaging, Department of Radiology, 660 1st Avenue, New York, NY 10016 (United States); Kwon, Jane, E-mail: jane.kwon@nyumc.org [New York University School of Medicine, Bernard and Irene Schwartz Center for Biomedical Imaging, Department of Radiology, 660 1st Avenue, New York, NY 10016 (United States); Palfrey, Amy P., E-mail: amy.pastva10@stjohns.edu [St John' s University, Department of Psychology, 8000 Utopia Parkway, Jamaica-Queens, NY 11439 (United States); Ogedegbe, Olugbenga, E-mail: Olugbenga.Ogedegbe@nyumc.org [New York University School of Medicine, Clinical and Translational Science Institute, 227 E30th St, 8th Floor, New York, NY 10016 (United States)

    2014-07-15

    Objective: To compare performance of single-injection blood pool agent (gadofosveset trisodium, BPA) against dual-injection extracellular contrast (gadopentetate dimeglumine, ECA) for MRA/MRV in assessment of suspected vascular TOS. Materials and methods: Thirty-one patients referred for vascular TOS evaluation were assessed with BPA (n = 18) or ECA (n = 13) MRA/MRV in arm abduction and adduction. Images were retrospectively assessed for: image quality (1 = non-diagnostic, 5 = excellent), vessel contrast (1 = same signal as muscle, 4 = much brighter than muscle) and vascular pathology by two independent readers, with a separate experienced reader providing reference assessment of vascular pathology. Results: Median image quality was diagnostic or better (score ≥3) for ECA and BPA at all time points, with BPA image quality superior at abduction late (BPA 4.5, ECA 4, p = 0.042) and ECA image quality superior at adduction-early (BPA 4.5; ECA 4.0, p = 0.018). High qualitative vessel contrast (mean score ≥3) was observed at all time points with both BPA and ECA, with superior BPA vessel contrast at abduction-late (BPA 3.97 ± 0.12; ECA 3.73 ± 0.26, p = 0.007) and ECA at adduction-early (BPA 3.42 ± 0.52; ECA 3.96 ± 0.14, p < 0.001). Readers readily identified arterial and venous pathology with BPA, similar to ECA examinations. Conclusion: Single-injection BPA MRA/MRV for TOS evaluation demonstrated diagnostic image quality and high vessel contrast, similar to dual-injection ECA imaging, enabling identification of fixed and functional arterial and venous pathology.

  18. Gadolinium DTPA-monoamide complexes incorporated into mixed micelles as possible MRI contrast agents

    OpenAIRE

    Parac-Vogt, Tatjana; Kimpe, Kristof; Laurent, Sophie; Pierart, Corinne; Vander Elst, Luce; Muller, Robert N.; Binnemans, Koen

    2004-01-01

    Four monoamide derivatives of Gd-DTPA with alkyl chains consisting of 12, 14, 16, or 18 carbon atoms were synthesized. The gadolinium(III) complexes with chain lengths of 14, 16 or 18 carbon atoms were efficiently incorporated into mixed micelles whereas the complex with a chain length of 12 carbon atoms was not incorporated into a micellar structure. The size distribution of the micelles was measured by photon correlation spectroscopy. The mean sizes of the micelles for all the complexes lay...

  19. Comparison between immediate and delayed imaging after gadolinium chelate injection for detecting enhanced lesions in multiple sclerosis

    International Nuclear Information System (INIS)

    Alizadeh, A.; Roudbari, A.; Heidarzadeh, A.; Kouhsari, M.

    2010-01-01

    Magnetic resonance imaging is a noninvasive and valuable method in the diagnosis of Multiple Sclerosis. Compared with other modalities, the sensitivity of Magnetic resonance imaging for detection of the lesion increases using magnetization transfer and delayed imaging. Our aim was to compare the two methods in detecting Multiple Sclerosis lesions. Patients and Methods: In this double-blind clinical trial, twenty-one patients with the definite diagnosis of Multiple Sclerosis referred to Poursina Hospital, Rasht were included. Two radiologists evaluated all the images. First, images without contrast were conducted, then 0.1 mmol/kg contrast material (Dotarem, single dose) was injected and after 30 minutes, T1W and magnetization transfer images were obtained. Seventy-two hours later, T1W images were obtained immediately after injection of 0.2 mmol/kg contrast material (double dose). The data were analyzed using Fisher's and McNemar tests by SPSS for Windows. Results: Delayed magnetization transfer showed 44 enhanced lesions using magnetization transfer (69.84%) and 29 lesions using T1 (46.03%). In addition, the number of enhanced lesions in the delayed method were significantly more than those in the immediate method (p value=0.003). Conclusion: The use of single dose in combination with magnetization transfer and delayed images after 20-30 minutes enables us to detect more enhanced lesions.

  20. Preclinical investigation to compare different gadolinium-based contrast agents regarding their propensity to release gadolinium in vivo and to trigger nephrogenic systemic fibrosis-like lesions

    International Nuclear Information System (INIS)

    Sieber, Martin A.; Frenzel, Thomas; Golfier, Sven; Weinmann, Hanns-Joachim; Pietsch, Hubertus; Lengsfeld, Philipp; Schmitt-Willich, Heribert; Siegmund, Fred; Walter, Jakob

    2008-01-01

    Recent reports suggest that nephrogenic systemic fibrosis (NSF) is associated with the administration of gadolinium (Gd)-based contrast agents (GBCAs) and in particular with the stability of the Gd-complex. The aim of this investigation was to compare GBCAs and their potential to trigger NSF. Forty-two healthy male rats received repeated intravenous injections of six different GBCAs at high doses to simulate the exposure seen in patients with severe renal dysfunction. Histopathological and immunohistochemical analysis of the skin was performed, and the concentrations of Gd, zinc and copper were measured in several tissues by inductive coupled plasma atomic emission spectroscopy. Macroscopic and histological skin changes similar to those seen in NSF patients were only observed in rats receiving Omniscan. In addition, very high concentrations of Gd were observed in the animals treated with Omniscan, and, to a lesser extent, in animals treated with OptiMARK. Significantly lower levels of Gd were found after the treatment with ionic linear agents and even less after the treatment with macrocyclic agents. The data in this investigation strongly suggest that the stability of the Gd-complex is a key factor for the development of NSF-like symptoms in this experimental setting. (orig.)

  1. Preclinical investigation to compare different gadolinium-based contrast agents regarding their propensity to release gadolinium in vivo and to trigger nephrogenic systemic fibrosis-like lesions

    Energy Technology Data Exchange (ETDEWEB)

    Sieber, Martin A.; Frenzel, Thomas; Golfier, Sven; Weinmann, Hanns-Joachim; Pietsch, Hubertus [Bayer Schering Pharma AG, TRG Diagnostic Imaging, Berlin (Germany); Lengsfeld, Philipp [Bayer Schering Pharma AG, GMA DG Diagnostic Imaging, Berlin (Germany); Schmitt-Willich, Heribert [Bayer Schering Pharma AG, GDD Diagnostic Imaging, Berlin (Germany); Siegmund, Fred; Walter, Jakob [Bayer Schering Pharma AG, Nonclinical Drug Safety, Berlin (Germany)

    2008-10-15

    Recent reports suggest that nephrogenic systemic fibrosis (NSF) is associated with the administration of gadolinium (Gd)-based contrast agents (GBCAs) and in particular with the stability of the Gd-complex. The aim of this investigation was to compare GBCAs and their potential to trigger NSF. Forty-two healthy male rats received repeated intravenous injections of six different GBCAs at high doses to simulate the exposure seen in patients with severe renal dysfunction. Histopathological and immunohistochemical analysis of the skin was performed, and the concentrations of Gd, zinc and copper were measured in several tissues by inductive coupled plasma atomic emission spectroscopy. Macroscopic and histological skin changes similar to those seen in NSF patients were only observed in rats receiving Omniscan. In addition, very high concentrations of Gd were observed in the animals treated with Omniscan, and, to a lesser extent, in animals treated with OptiMARK. Significantly lower levels of Gd were found after the treatment with ionic linear agents and even less after the treatment with macrocyclic agents. The data in this investigation strongly suggest that the stability of the Gd-complex is a key factor for the development of NSF-like symptoms in this experimental setting. (orig.)

  2. 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

  3. Brain MR post-gadolinium contrast in multiple sclerosis: the role of magnetization transfer and image subtraction in detecting more enhancing lesions

    Energy Technology Data Exchange (ETDEWEB)

    Gavra, M.M.; Gouliamos, A.D.; Vlahos, L.J. [Department of Radiology, ' ' Aretaieion' ' Hospital,University of Athens Medical School, Athens (Greece); Voumvourakis, C.; Sfagos, C. [Department of Neurology, ' ' Eginiteion' ' Hospital, University of Athens Medical School, Athens (Greece)

    2004-03-01

    Our purpose was to evaluate the role of magnetization transfer and image subtraction in detecting more enhancing lesions in brain MR imaging of patients with multiple sclerosis (MS). Thirty-one MS patients underwent MR imaging of the brain with T1-weighted spin echo sequences without and with magnetization transfer (MT) using a 1.5 T imager. Both sequences were acquired before and after intravenous injection of a paramagnetic contrast agent. Subtraction images in T1-weighted sequences were obtained by subtracting the pre-contrast images from the post-contrast ones. A significant difference was found between the numbers of enhanced areas in post-gadolinium T1-weighted images without and with MT (p=0.020). The post-gadolinium T1-weighted images with MT allowed the detection of an increased (13) number of enhancing lesions compared with post-gadolinium T1-weighted images without MT. A significant difference was also found between the numbers of enhanced areas in post-gadolinium T1-weighted images without MT and subtraction images without MT (p=0.020). The subtraction images without MT allowed the detection of an increased (10) number of enhancing lesions compared with post-gadolinium T1-weighted images without MT. Magnetization transfer contrast and subtraction techniques appear to be the simplest and least time-consuming applications to improve the conspicuity and detection of contrast-enhancing lesions in patients with MS. (orig.)

  4. Brain MR post-gadolinium contrast in multiple sclerosis: the role of magnetization transfer and image subtraction in detecting more enhancing lesions

    International Nuclear Information System (INIS)

    Gavra, M.M.; Gouliamos, A.D.; Vlahos, L.J.; Voumvourakis, C.; Sfagos, C.

    2004-01-01

    Our purpose was to evaluate the role of magnetization transfer and image subtraction in detecting more enhancing lesions in brain MR imaging of patients with multiple sclerosis (MS). Thirty-one MS patients underwent MR imaging of the brain with T1-weighted spin echo sequences without and with magnetization transfer (MT) using a 1.5 T imager. Both sequences were acquired before and after intravenous injection of a paramagnetic contrast agent. Subtraction images in T1-weighted sequences were obtained by subtracting the pre-contrast images from the post-contrast ones. A significant difference was found between the numbers of enhanced areas in post-gadolinium T1-weighted images without and with MT (p=0.020). The post-gadolinium T1-weighted images with MT allowed the detection of an increased (13) number of enhancing lesions compared with post-gadolinium T1-weighted images without MT. A significant difference was also found between the numbers of enhanced areas in post-gadolinium T1-weighted images without MT and subtraction images without MT (p=0.020). The subtraction images without MT allowed the detection of an increased (10) number of enhancing lesions compared with post-gadolinium T1-weighted images without MT. Magnetization transfer contrast and subtraction techniques appear to be the simplest and least time-consuming applications to improve the conspicuity and detection of contrast-enhancing lesions in patients with MS. (orig.)

  5. Tissue gadolinium deposition in renally impaired rats exposed to different gadolinium-based MRI contrast agents: evaluation with inductively coupled plasma mass spectrometry (ICP-MS).

    Science.gov (United States)

    Sato, Tomohiro; Ito, Katsuyoshi; Tamada, Tsutomu; Kanki, Akihiko; Watanabe, Shigeru; Nishimura, Hirotake; Tanimoto, Daigo; Higashi, Hiroki; Yamamoto, Akira

    2013-10-01

    To quantify tissue gadolinium (Gd) deposition in renally impaired rats exposed to Gd-EOB-DTPA and other Gd-based MRI contrast agents by means of inductively coupled plasma mass spectrometry (ICP-MS), and to compare the differences in distribution among major organs as possible triggers for nephrogenic systemic fibrosis (NSF). A total of 15 renally impaired rats were injected with Gd-EOB-DTPA, Gd-DTPA-BMA and Gd-HP-DO3A. Gd contents of skin, liver, kidney, lung, heart, spleen, diaphragm and femoral muscle were measured by inductively coupled plasma mass spectrometry (ICP-MS). Histological assessment was also conducted. Tissue Gd deposition in all organs was significantly higher (P=0.005~0.009) in the Gd-DTPA-BMA group than in the Gd-HP-DO3A and Gd-EOB-DTPA groups. In the Gd-DTPA-BMA group, Gd was predominantly deposited in kidney (1306±605.7μg/g), followed by skin, liver, lung, spleen, femoral muscle, diaphragm and heart. Comparing Gd-HP-DO3A and Gd-EOB-DTPA groups, Gd depositions in the kidney, liver and lung were significantly lower (P=0.009~0.011) in the Gd-EOB-DTPA group than in the Gd-HP-DO3A group although no significant differences were seen for any other organs. Gd-EOB-DTPA is a stable and safe Gd-based contrast agent (GBCA) showing lower Gd deposition in major organs in renally impaired rats, compared with other GBCAs. This fact suggests that the risk of NSF onset would be low in the use of Gd-EOB-DTPA. Copyright © 2013 Elsevier Inc. All rights reserved.

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

    International Nuclear Information System (INIS)

    Lingott, Jana

    2016-01-01

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

  7. 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

    compromises the differentiation of synovium from joint fluid. OBJECTIVE: To determine the time period after IV MRI contrast (gadolinium-DTPA (Gd)) injection in which synovial membrane volume determination is reliable. METHODS: MRI of five RA knees with clinical synovitis was carried out, with axial, T(1...... 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...

  8. 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.

  9. Nephrogenic systemic fibrosis and class labeling of gadolinium-based contrast agents by the Food and Drug Administration.

    Science.gov (United States)

    Yang, Lucie; Krefting, Ira; Gorovets, Alex; Marzella, Louis; Kaiser, James; Boucher, Robert; Rieves, Dwaine

    2012-10-01

    In 2007, the Food and Drug Administration requested that manufacturers of all approved gadolinium-based contrast agents (GBCAs), drugs widely used in magnetic resonance imaging, use nearly identical text in their product labeling to describe the risk of nephrogenic systemic fibrosis (NSF). Accumulating information about NSF risks led to revision of the labeling text for all of these drugs in 2010. The present report summarizes the basis and purpose of this class-labeling approach and describes some of the related challenges, given the evolutionary nature of the NSF risk evidence. The class-labeling approach for presentation of product risk is designed to decrease the occurrence of NSF and to enhance the safe use of GBCAs in radiologic practice. © RSNA, 2012.

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

    DEFF Research Database (Denmark)

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

    2008-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2007-06-15

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

  12. 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 islet s Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 3.046, year: 2013

  13. Gadolinium-Encapsulating Iron Oxide Nanoprobe as Activatable NMR/MRI Contrast Agent

    Science.gov (United States)

    Santra, Santimukul; Jativa, Samuel D.; Kaittanis, Charalambos; Normand, Guillaume; Grimm, Jan; Perez, J. Manuel

    2012-01-01

    Herein we report a novel gadolinium-encapsulating iron oxide nanoparticle-based activatable NMR/MRI nanoprobe. In our design, Gd-DTPA is encapsulated within the polyacrylic acid (PAA) polymer coating of a superparamagnetic iron oxide nanoparticle (IO-PAA) yielding a composite magnetic nanoprobe (IO-PAA-Gd-DTPA) with quenched longitudinal spin-lattice magnetic relaxation (T1). Upon release of the Gd-DTPA complex from the nanoprobe's polymeric coating in acidic media, an increase in the T1 relaxation rate (1/T1) of the composite magnetic nanoprobe was observed, indicating a dequenching of the nanoprobe with a corresponding increase in the T1-weighted MRI signal. When a folate-conjugated nanoprobe was incubated in HeLa cells, a cancer cell line overexpressing folate receptors, an increase in the 1/T1 signal was observed. This result suggests that upon receptor-mediated internalization, the composite magnetic nanoprobe degraded within the cell's lysosome acidic (pH = 5.0) environment, resulting in an intracellular release of Gd-DTPA complex with subsequent T1 activation. No change in T1 was observed when the Gd-DTPA complex was chemically conjugated on the surface of the nanoparticle's polymeric coating or when encapsulated in the polymeric coating of a non-magnetic nanoparticle. These results confirmed that the observed (T1) quenching of the composite magnetic nanoprobe is due to the encapsulation and close proximity of the Gd ion to the nanoparticles superparamagnetic iron oxide (IO) core. In addition, when an anticancer drug (Taxol) was co-encapsulated with the Gd-DTPA within the folate receptor targeting composite magnetic nanoprobe, the T1 activation of the probe coincide with the rate of drug release and corresponding cytotoxic effect in cell culture studies. Taken together, these results suggest that our activatable T1 nanoagent could be of great importance for the detection of acidic tumors and assessment of drug targeting and release by MRI. PMID:22809405

  14. 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

  15. 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

  16. Combined use of contrast media containing iodine and gadolinium for imaging and intervention. A hitherto widely ignored topic in radiological practice

    International Nuclear Information System (INIS)

    Golder, W.

    2012-01-01

    The synchronous use of chemically different contrast media in the same body compartment is a challenge for the radiologist, whether it is scheduled or unexpected. However, to inject contrast media containing iodine and gadolinium at the same time can be a prerequisite for the examination of several organs or organ systems. Unlike other topics of contrast-enhanced imaging procedures, the difficulties encountered with double contrast injections have been widely ignored in the literature. In the absence of reliable data from experimental and clinical studies the radiologist is dependent on case reports, information provided by the contrast media manufacturers, personal communications, mostly scanty personal experiences and a skilful time management, in order to overcome the situation. Only the combination of X-ray, computed tomography and magnetic resonance arthrography can be performed without another thought. However, the more or less synchronous vascular application of contrast media containing iodine and gadolinium requires vigilance. The more seriously ill the patient is, the more caution is advised even if the decision on the combined administration has to be reached urgently. The following overview gives a description of the properties of contrast media containing iodine and gadolinium as far as interactions following simultaneous administration are concerned. Subsequently, the clinically relevant situations and constellations are outlined and analyzed. (orig.) [de

  17. 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.

  18. Gadolinium heteropoly complex K 17[Gd(P 2W 17O 61) 2] as a potential MRI contrast agent

    Science.gov (United States)

    Sun, Guoying; Feng, Jianghua; Wu, Huifeng; Pei, Fengkui; Fang, Ke; Lei, Hao

    2004-10-01

    Gadolinium heteropoly complex K17[Gd(P2W17O61)2] has been evaluated by in vitro and in vivo experiments as a potential contrast agent for magnetic resonance imaging (MRI). The thermal analysis and conductivity study indicate that this complex has good thermal stability and wide pH stability range. The T1 relaxivity is 7.59 mM-1 s-1 in aqueous solution and 7.97 mM-1 s-1 in 0.725 mmol l-1 bovine serum albumin (BSA) solution at 25 °C and 9.39 T, respectively. MR imaging of three male Sprague-Dawley rats showed remarkable enhancement in rat liver after intravenous injection, which persisted longer than with Gd-DTPA. The signal intensity increased by 57.1±16.9% during the whole imaging period at 0.082 mmol kg-1dose. Our preliminary in vitro and in vivo studies indicate that K17[Gd(P2W17O61)2] is a potential liver-specific MRI contrast agent.

  19. Quantification and Assessment of the Chemical Form of Residual Gadolinium in the Brain After Repeated Administration of Gadolinium-Based Contrast Agents

    Science.gov (United States)

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

    2017-01-01

    Objective 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. Materials and Methods 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. Results 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

  20. 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

  1. Retrospective analysis of patients for development of nephrogenic systemic fibrosis following conventional angiography using gadolinium-based contrast agents.

    Science.gov (United States)

    Hoppe, Hanno; Spagnuolo, Sara; Froehlich, Johannes M; Nievergelt, Helga; Dinkel, Hans-Peter; Gretener, Silvia; Thoeny, Harriet C

    2010-03-01

    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(2)). Mean eGFR pre-angiography was 26 ml/min/1.73 m(2) and 33 ml/min/1.73 m(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(2) angiography or rather the use of low doses of iodinated contrast agents, should be considered in these patients.

  2. Retrospective analysis of patients for development of nephrogenic systemic fibrosis following conventional angiography using gadolinium-based contrast agents

    International Nuclear Information System (INIS)

    Hoppe, Hanno; Spagnuolo, Sara; Froehlich, Johannes M.; Thoeny, Harriet C.; Nievergelt, Helga; Dinkel, Hans-Peter; Gretener, Silvia

    2010-01-01

    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 2 ). Mean eGFR pre-angiography was 26 ml/min/1.73 m 2 and 33 ml/min/1.73 m 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 2 angiography or rather the use of low doses of iodinated contrast agents, should be considered in these patients. (orig.)

  3. 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.)

  4. Gadolinium-porphyrins: new potential magnetic resonance imaging contrast agents for melanoma detection

    Directory of Open Access Journals (Sweden)

    Daryoush Shahbazi-Gahrouei

    2006-11-01

    Full Text Available BACKGROUND: Two new porphyrin-based magnetic resonance imaging (MRI contrast agents, Gd-hematoporphyrin (Gd-H and Gd-tetra-carboranylmethoxyphenyl-porphyrin (Gd-TCP were synthesized and tested in nude mice with human melanoma (MM-138 xenografts as new melanoma contrast agents. METHODS: Subcutaneous xenografts of human melanoma cells (MM-138 were studied in 30 (five groups of six nude mice. The effect of different contrast agents (Gd-TCP, Gd-H, GdCl3 and Gd-DTPA on proton relaxation times was measured in tumors and other organs. T1 values, signal enhancement and the Gd concentration for different contrast agent solutions were also investigated. RESULTS: The porphyrin agents showed higher relaxivity compared to the clincal agent, Gd-DTPA. A significant 16% and 21% modification in T1 relaxation time of the water in human melanoma tumors grafted in the nude mice was revealed 24 hours after injection of Gd-TCP and Gd-H, respectively. The percentage of injected Gd localized to the tumor measured by inductively coupled plasma atomic emission spectrometry (ICP-AES was approximately 21% for Gd-TCP and 28% for Gd-H which were higher than that of Gd-DTPA (10%. CONCLUSIONS: The high concentration of Gd in the tumor is indicative of a selective retention of the compounds and indicates that Gd-TCP and Gd-H are promising MR imaging contrast agents for melanoma detection. Gd-porphyrins have considerable promise for further diagnostic applications in magnetic resonance imaging. KEY WORDS: MRI, porphyrin-based contrast agent, hematoporphyrin, melanoma.

  5. 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.

  6. Potential of gadolinium as contrast material in second generation dual energy computed tomography - An ex vivo phantom study.

    Science.gov (United States)

    Bongers, Malte N; Schabel, Christoph; Krauss, Bernhard; Claussen, Claus D; Nikolaou, Konstantin; Thomas, Christoph

    To evaluate the potential of gadolinium (Gd) as contrast material (CM) in second generation dual energy computed tomography (DECT). In a phantom model, DECT post-processing was used to increase Gd attenuation using advanced monoenergetic extrapolation (MEI), to create virtual non-contrast images (Gd-VNC) and Gd maps and to quantify Gd content. Dilutions of Gd and iodinated CM (7-296 HU) were filled in syringes, placed in an attenuation phantom and scanned with standard DECT protocols (80 &100/Sn140 kV). MEI (40-190 keV) and VNC images as well as Gd maps were computed. The amount of Gd was quantified and the accuracy was compared to iodine images. Linear regression models were calculated to evaluate Gd attenuation of equivolume CM doses and clinical MRI doses. Applying monoenergetic reconstructions and using Gd as contrast agent (Gd MEI 40 keV) doubled Hounsfield-Units (HU) and 90% of the SNR (averaged: 225 HU, SNR3.1) are achievable, as compared to iodinated CM at 120 kV (averaged:110 HU, SNR3.5), at Gd doses of 1.0mmol/kg BW. The accuracies of Gd-VNC (deviation, 6±12 HU) images and Gd quantification (measurement error, 17%) were not significantly different to those of iodine enhanced images (VNC:deviation, 2±11 HU; measurement error,14%). Using monoenergetic extrapolation at 40keV, it is possible to increase Gd-CM attenuation significantly. Thus, equivalent HU and half the SNR in comparison to a standard dose of ICM at 120kV can be expected at a Gd-CM dose of 0.5mmol/kg BW. Post-processing features of iodine based DECT like monoenergetic or VNC images, iodine maps or quantification of CM are feasible with the use of Gd-CM. Copyright © 2017 Elsevier Inc. All rights reserved.

  7. MRI contrast agent for targeting glioma: interleukin-13 labeled liposome encapsulating gadolinium-DTPA.

    Science.gov (United States)

    Liu, Xiaoli; Madhankumar, Achuthamangalam B; Miller, Patti A; Duck, Kari A; Hafenstein, Susan; Rizk, Elias; Slagle-Webb, Becky; Sheehan, Jonas M; Connor, James R; Yang, Qing X

    2016-05-01

    Detection of glioma with MRI contrast agent is limited to cases in which the blood-brain barrier (BBB) is compromised as contrast agents cannot cross the BBB. Thus, an early-stage infiltrating tumor is not detectable. Interleukin-13 receptor alpha 2 (IL-13Rα2), which has been shown to be overexpressed in glioma, can be used as a target moiety. We hypothesized that liposomes conjugated with IL-13 and encapsulating MRI contrast agent are capable of passing through an intact BBB and producing MRI contrast with greater sensitivity. The targeted MRI contrast agent was created by encapsulating Magnevist (Gd-DTPA) into liposomes conjugated with IL-13 and characterized by particle size distribution, cytotoxicity, and MRI relaxivity. MR image intensity was evaluated in the brain in normal mice post injection of Gd-DTPA and IL-13-liposome-Gd-DTPA one day apart. The specificity for glioma detection by IL-13-liposome-Gd-DTPA was demonstrated in an intracranial glioma mouse model and validated histologically. The average size of IL-13-liposome-Gd-DTPA was 137 ± 43 nm with relaxivity of 4.0 ± 0.4 L/mmole-s at 7 Tesla. No significant cytotoxicity was observed with MTS assay and serum chemistry in mice. The MRI signal intensity was enhanced up to 15% post injection of IL-13-liposome-Gd-DTPA in normal brain tissue following a similar time course as that for the pituitary gland outside of the BBB. MRI enhanced by IL-13-liposome-Gd-DTPA detected small tumor masses in addition to those seen with Magnevist-enhanced MRI. IL-13-liposome-Gd-DTPA is able to pass through the uncompromised BBB and detect an early stage glioma that cannot be seen with conventional contrast-enhanced MRI. © The Author(s) 2015. Published by Oxford University Press on behalf of the Society for Neuro-Oncology. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

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

    Science.gov (United States)

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

    2015-04-01

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

  9. Impact of gadolinium-based contrast agent in the assessment of Crohn's disease activity: Is contrast agent injection necessary?

    Science.gov (United States)

    Quaia, Emilio; Sozzi, Michele; Gennari, Antonio Giulio; Pontello, Michele; Angileri, Roberta; Cova, Maria Assunta

    2016-03-01

    To determine whether magnetic resonance enterography (MRE) performed without intravenous contrast injection is diagnostically noninferior to conventional contrast-enhanced MRE (CE-MRE) in patients with Crohn's disease (CD). This was an Institutional Review Board (IRB)-approved retrospective study. Ninety-six patients (52 male and 44 female; 47.18 years ± 13.6) with a diagnosis of CD underwent MRE at 1.5T including T2 -weighted single-shot turbo-spin-echo, T2 -weighted spectral fat presaturation with inversion recovery (SPAIR), T1 -weighted balanced fast-field-echo MR sequences, and CE-MRE consisting in T1 -weighted breath-hold THRIVE 3D MRI sequences after administration of gadobenate dimeglumine (0.2 mL/kg of body weight). Unenhanced MRE, CE-MRE, and unenhanced MRE plus CE-MRE were reviewed in separate sessions with blinding by two readers in consensus, and subsequently by two other readers independently considering a subgroup of 20 patients. Crohn's Disease Endoscopic Index of Severity (CDEIS) and/or histologic analysis of the surgical specimen were considered as reference standards for the assessment of inflammatory activity. Patients revealed prevalently active (n = 55 patients) or quiescent CD (n = 41 patients). The agreement between unenhanced MRE vs. CE-MRE in interpreting active bowel inflammation was 96% (123/128 bowel segments; one-sided 95% confidence interval [CI], >94.4%). Unenhanced MRE vs. CE-MRE vs. unenhanced MRE plus CE-MRE revealed a diagnostic accuracy of 93% [90/96] vs. 92% [88/96] vs. 97% [93/96] (P > 0.05) in the diagnosis of active CD. Interreader agreement was very good for all variables (κ value = 0.8-0.9) except for the measurement of the length of disease (κ value = 0.45). Unenhanced MRE was noninferior to CE-MRE in diagnosing active inflammation in patients with CD. © 2015 Wiley Periodicals, Inc.

  10. Prevalence and signal characteristics of late gadolinium enhancement on contrast-enhanced magnetic resonance imaging in patients with takotsubo cardiomyopathy

    International Nuclear Information System (INIS)

    Nakamori, Shiro; Matsuoka, Koji; Onishi, Katsuya

    2012-01-01

    The background of this study was to determine the prevalence and signal intensity (SI) characteristics of late gadolinium enhancement (LGE) on magnetic resonance imaging (MRI) in takotsubo cardiomyopathy (TC). Cine, black-blood T2-weighted and LGE MR images were acquired in 23 patients with TC within 72h of onset. Wall motion abnormality (WMA), edema and LGE were evaluated with a 16-segment model. The SI characteristics of LGE were analyzed using SI distribution in remote normal segments as reference. Follow-up MRI was performed 3 months later. Retrospective analysis of LGE MRI was also performed in 10 patients with acute myocardial infarction (AMI) to compare the SI characteristics between TC and AMI. In acute phase, WMA and edema were observed in 236 (64%) and 205 (56%) of 368 segments. LGE was observed in 10 (2.7%) of 368 segments and in 5 (22%) of 23 patients. All LGE lesions in TC exhibited transmural enhancement. The contrast-to-noise ratio (CNR) in TC was significantly lower than that of AMI (3.1±0.3 standard deviations (SD) vs. 6.1±1.2 SD, P<0.01), and CNR value of 4 was useful for distinguishing TC from AMI. Both LGE and WMA disappeared within 12 months. Grey myocardial signal on LGE MRI may be observed in patients with TC. However, the extent of LGE is substantially less than that of WMA and edema, and disappears within 12 months. (author)

  11. Slow clearance gadolinium-based extracellular and intravascular contrast media for three-dimensional MR angiography.

    Science.gov (United States)

    Bremerich, J; Colet, J M; Giovenzana, G B; Aime, S; Scheffler, K; Laurent, S; Bongartz, G; Muller, R N

    2001-04-01

    The objective of this study was to assess two new slow-clearance contrast media with extracellular and intravascular distribution for magnetic resonance angiography (MRA). Extracellular Gd-DTPA-BC(2)glucA and intravascular Gd(DO3A)(3)-lys(16) were developed within the European Biomed2 MACE Program and compared with two reference compounds, intravascular CMD-A2-Gd-DOTA and extracellular GdDOTA, in 12 rats. Pre- and post-contrast three-dimensional MR (TR/TE = 5 msec/2.2 msec; isotropic voxel size 0.86 mm(3)) was acquired for 2 hours. Signal-to-noise enhancement (DeltaSNR) was calculated. Two minutes after injection, all contrast media provided strong vascular signal enhancement. The DeltaSNR for Gd-DTPA-BC(2)glucA, Gd(DO3A)(3)-lys(16), CMD-A2-Gd-DOTA, and GdDOTA were 13.0 +/- 1.8, 25.0 +/- 3.2, 25.0 +/- 4.0, and 18.0 +/- 3.4, respectively. Gd-DTPA-BC(2)glucA, Gd(DO3A)(3)-lys(16), and CMD-A2-Gd-DOTA cleared slowly from the circulation, whereas GdDOTA cleared rapidly. Vascular DeltaSNR at 2 hours were 2.9 +/- 0.6, 25.0 +/- 3.2, 25.0 +/- 4.0, and 0.4 +/- 1.0. Gd(DO3A)(3)-lys(16) provided strong vascular and minor background enhancement, and thus may be useful for MRA or perfusion imaging. Gd-DTPA-BC(2)glucA produces persistent enhancement of extracellular water, and thus may allow quantification of extracellular distribution volume and assessment of myocardial viability.

  12. Comparison of gadolinium polylysine and gadopentetate in contrast enhanced MR imaging of myocardial ischemia-reperfusion in cats

    International Nuclear Information System (INIS)

    Lim, Tae Hwan; Lee, Jung Hee; Lee, Tae Keun; Mun, Chi Woong

    1995-01-01

    To assess the signal enhancement by gadolinium-DTPA-polylysine (Gd-polylysine) as compared to gadopentetate (Gd-DTPA) in MR imaging of heart that have undergone ischemia-reperfusion, and to estimate the extent of myocardial damage covered by the MR signal enhancement. A series of contrast enhanced cardiac MR images were obtained from 17 cats subjected to a 90 minutes of occlusion of the left anterior descending coronary artery (LAD) followed by a 90 minutes of reperfusion. Time courses of changes in the signal intensity (SI) of the ischemic area were measured in Gd-polylysine group (8 cats) and Gd-DTPA group (9 cats). The size of MR signal enhanced area was then compared to the sizes of infarction and the area at risk revealed by TTC histochemical staining. Maximum SIs were obtained at 60 minutes and 30 minutes after injection of the contrast material, respectively for Gd-polylysine group and Gd-DTPA group. Signal enhancement was stronger and persistent for a longer period in Gd-polylysine group than in GD-DTPA group. Sizes of the enhanced are, the infarction, and the area at risk were about 30%, 15%, and 50% of the total left ventricle (LV) area; the difference between the groups was statistically insignificant. Gd-polylysine can be used better for a blood pool marker than Gd-DTPA in MR imaging of myocardial ischemia, due to its strong and persistent signal enhancement. The MR signal enhanced area includes both the infarcted area and a portion of the area at risk

  13. Contrast enhanced renal MR angiography at 7 Tesla: How much gadolinium do we need?

    Energy Technology Data Exchange (ETDEWEB)

    Beiderwellen, Karsten, E-mail: karsten.beiderwellen@uni-due.de [Department of Diagnostic and Interventional Radiology and Neuroradiology, University Hospital Essen, Essen (Germany); Erwin L. Hahn Institute for Magnetic Resonance Imaging, University Duisburg-Essen, Essen (Germany); Kraff, Oliver, E-mail: Oliver.kraff@uni-due.de [Erwin L. Hahn Institute for Magnetic Resonance Imaging, University Duisburg-Essen, Essen (Germany); Laader, Anja, E-mail: anja.laader@uk-essen.de [Department of Diagnostic and Interventional Radiology and Neuroradiology, University Hospital Essen, Essen (Germany); Erwin L. Hahn Institute for Magnetic Resonance Imaging, University Duisburg-Essen, Essen (Germany); Maderwald, Stefan, E-mail: Stefan.maderwald@uni-due.de [Erwin L. Hahn Institute for Magnetic Resonance Imaging, University Duisburg-Essen, Essen (Germany); Orzada, Stephan, E-mail: Stephan.orzada@uni-due.de [Erwin L. Hahn Institute for Magnetic Resonance Imaging, University Duisburg-Essen, Essen (Germany); Ladd, Mark E., E-mail: mark.ladd@dkfz-heidelberg.de [Medical Physics in Radiology, German Cancer Research Center (DKFZ), Heidelberg (Germany); Forsting, Michael, E-mail: Michael.forsting@uk-essen.de [Department of Diagnostic and Interventional Radiology and Neuroradiology, University Hospital Essen, Essen (Germany); Erwin L. Hahn Institute for Magnetic Resonance Imaging, University Duisburg-Essen, Essen (Germany); Lauenstein, Thomas C., E-mail: Thomas.Lauenstein@uni-due.de [Department of Diagnostic and Interventional Radiology and Neuroradiology, University Hospital Essen, Essen (Germany); Umutlu, Lale, E-mail: Lale.umutlu@uk-essen.de [Department of Diagnostic and Interventional Radiology and Neuroradiology, University Hospital Essen, Essen (Germany); Erwin L. Hahn Institute for Magnetic Resonance Imaging, University Duisburg-Essen, Essen (Germany)

    2017-01-15

    Objectives: To investigate whether a dose reduction of Gadobutrol for renal magnetic resonance angiography (MRA) at 7 Tesla (T) is feasible while preserving diagnostic image quality. Methods: Ten healthy volunteers were enrolled for a renal MRA on a 7 T scanner. Fast low angle shot (FLASH) MRA data sets were obtained utilizing three different doses of Gadobutrol (0.1, 0.05 and 0.025 mmol/kg body weight [BW]). Contrast ratios (CR) were measured in the aorta as well as in the intra- and extraparenchymal arteries compared to the psoas muscle. Qualitative analysis regarding the delineation of vessel structures was performed using a four-point-scale. Results: All doses of Gadobutrol allowed for a good delineation of the aorta and renal arteries. For the extra- and intraparenchymal segmental arteries higher values were observed for full and half dose in comparison to quarter dose. No significant difference was observed for full and half dose. A lower CR was observed for quarter compared to half dose (p < 0.05) for the renal arteries. Conclusions: While best results were observed for half and full dose, a dose reduction to 0.025 mmol/kg BW is justifiable, maintaining a diagnostic image quality. This may be of high interest considering patients with renal impairment.

  14. Penetration and distribution of gadolinium-based contrast agents into the cerebrospinal fluid in healthy rats: a potential pathway of entry into the brain tissue.

    Science.gov (United States)

    Jost, Gregor; Frenzel, Thomas; Lohrke, Jessica; Lenhard, Diana Constanze; Naganawa, Shinji; Pietsch, Hubertus

    2017-07-01

    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. • Gadolinium-based contrast agents can cross the blood-CSF barrier. • Fluid-attenuated MRI shows GBCA distribution with CSF flow. • GBCA structure and physicochemical properties do not impact CSF penetration and distribution. • GBCA clearance from CSF was almost complete within 24 h in rats. • CSF is a potential pathway of GBCA entry into the brain.

  15. 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

  16. 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

  17. 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.

  18. 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.)

  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

    International Nuclear Information System (INIS)

    Jost, Gregor; Frenzel, Thomas; Lohrke, Jessica; Pietsch, Hubertus; Lenhard, Diana Constanze; Naganawa, Shinji

    2017-01-01

    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 three-dimensional gadolinium-enhanced MR angiography using the timing monitoring function of contrast material (Smart Prep technique)

    International Nuclear Information System (INIS)

    Tsuchihashi, Toshio; Sasaki, Sadayuki; Yoshizawa, Satoshi; Maki, Toshio; Kitagawa, Matsuo; Suzuki, Takeshi

    1998-01-01

    The Smart Prep technique for gadolinium-enhanced three-dimensional MR angiography (3D-MRA) was evaluated in clinical practice. By monitoring signal intensity in the region of interest (tracking volume) in the target vessel, start timing after contrast injection can be optimized using the Smart Prep technique. Successful triggering was obtained in the chest, abdomen, and pelvic areas in about 80% of the cases in this study. Failures with this technique were mainly due to changes in tracking volume caused by patient motion and respiration. We noted that the scan started earlier than expected in the thoracic aorta when part of the heart or pulmonary artery was included in the tracking volume. Thus, care must be taken in defining the size and location of the tracking volume in gadolinium-enhanced 3D-MRA using the Smart Prep technique. (author)

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2011-10-15

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

  2. 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...

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2011-03-15

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

  4. Perbedaan Intensitas Penyengatan Meningeal Hasil MRI antara Sekuens T2 FLAIR Post Contrast dan T1WI Post Contrast Gadolinium-DTPA dalam Mendeteksi Penyangatan Meningeal pada Kasus Meningitis Tuberkulosis

    Directory of Open Access Journals (Sweden)

    Arie Hendarin

    2017-09-01

    Full Text Available Diagnosis meningitis TB terutama pada kasus possible dan probable sulit ditegakkan. Pemeriksaan MRI kepala dengan kontras Gadolinium-DTPA adalah modalitas radiologi yang paling sensitif untuk membantu mendiagnosis penyakit ini. Penyangatan meningeal di daerah basal merupakan gambaran MRI yang paling banyak ditemukan pada meningitis TB. Tujuan penelitian ini adalah mengetahui perbedaan peningkatan intensitas sinyal meningen sekuens T2-FLAIR dengan T1WI pada pasien meningitis tuberkulosis menggunakan pemeriksaan MRI kepala dengan kontras Gadolinium-DTPA di RSUP Dr. Hasan Sadikin Bandung pada bulan Januari 2015–Juni 2016. Subjek penelitian sebanyak 21 orang dengan meningitis TB dilakukan pemeriksaan MRI kepala dengan kontras Gadolinium-DTPA. Analisis statistik komparatif dilakukan untuk menguji perbedaan peningkatan intensitas sinyal meningen sekuens T2-FLAIR post contrast dengan T1WI post contrast. Hasil penelitian menujukkan rerata peningkatan intensitas sinyal meningen sekuen T2-FLAIR (∆T2-FLAIR sebesar 360,59±182,19 aμ sedangkan T1WI (∆T1WI sebesar 126,47±72,57 aμ. Hasil uji statistik menggunakan uji T pada derajat kepercayaan 95% menunjukkan perbedaan yang bermakna ∆T2-FLAIR dengan ∆T1WI pada nilai p=0,000. Sebagai simpulan didapatkan peningkatan intensitas sinyal meningen sekuens T2-FLAIR post contrast lebih besar daripada T1WI post contrast pada kasus meningitis TB.  [MKB. 2017;49(3:172–78] Kata kunci: Meningitis tuberkulosis, MRI sekuens T1WI dan T2-FLAIR, penyangatan meningeal Difference between Gadolinium-DTPA Enhanced T2 FLAIR Sequence and T1WI Sequence MRI in Detecting Meningeal Enhancement in Tuberculous Meningitis The diagnosis of TB meningitis, especially in possible and probable cases, is difficult. Contrast-enhanced MRI of the head with Gadolinium-DTPA is the most sensitive imaging modality that supports diagnosis of this disease. The most common presentation of TB meningitis in MRI is basal meningeal enhancement

  5. Dual modal ultra-bright nanodots with aggregation-induced emission and gadolinium-chelation for vascular integrity and leakage detection.

    Science.gov (United States)

    Feng, Guangxue; Li, Jackson Liang Yao; Claser, Carla; Balachander, Akhila; Tan, Yingrou; Goh, Chi Ching; Kwok, Immanuel Weng Han; Rénia, Laurent; Tang, Ben Zhong; Ng, Lai Guan; Liu, Bin

    2018-01-01

    The study of blood brain barrier (BBB) functions is important for neurological disorder research. However, the lack of suitable tools and methods has hampered the progress of this field. Herein, we present a hybrid nanodot strategy, termed AIE-Gd dots, comprising of a fluorogen with aggregation-induced emission (AIE) characteristics as the core to provide bright and stable fluorescence for optical imaging, and gadolinium (Gd) for accurate quantification of vascular leakage via inductively-coupled plasma mass spectrometry (ICP-MS). In this report, we demonstrate that AIE-Gd dots enable direct visualization of brain vascular networks under resting condition, and that they form localized punctate aggregates and accumulate in the brain tissue during experimental cerebral malaria, indicative of hemorrhage and BBB malfunction. With its superior detection sensitivity and multimodality, we hereby propose that AIE-Gd dots can serve as a better alternative to Evans blue for visualization and quantification of changes in brain barrier functions. Copyright © 2017. Published by Elsevier Ltd.

  6. 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.)

  7. Survey of gadolinium-based contrast agent utilization among the members of the Society for Pediatric Radiology: a Quality and Safety Committee report.

    Science.gov (United States)

    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; Swenson, David W; Slovis, Thomas L; Iyer, Ramesh S

    2017-05-01

    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.

  8. 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.)

  9. Equilibrium-phase MR angiography: Comparison of unspecific extracellular and protein-binding gadolinium-based contrast media with respect to image quality.

    Science.gov (United States)

    Erb-Eigner, Katharina; Taupitz, Matthias; Asbach, Patrick

    2016-01-01

    The purpose of this study was to compare contrast and image quality of whole-body equilibrium-phase high-spatial-resolution MR angiography using a non-protein-binding unspecific extracellular gadolinium-based contrast medium with that of two contrast media with different protein-binding properties. 45 patients were examined using either 15 mL of gadobutrol (non-protein-binding, n = 15), 32 mL of gadobenate dimeglumine (weakly protein binding, n = 15) or 11 mL gadofosveset trisodium (protein binding, n = 15) followed by equilibrium-phase high-spatial-resolution MR-angiography of four consecutive anatomic regions. The time elapsed between the contrast injection and the beginning of the equilibrium-phase image acquisition in the respective region was measured and was up to 21 min. Signal intensity was measured in two vessels per region and in muscle tissue. Relative contrast (RC) values were calculated. Vessel contrast, artifacts and image quality were rated by two radiologists in consensus on a five-point scale. Compared with gadobutrol, gadofosveset trisodium revealed significantly higher RC values only when acquired later than 15 min after bolus injection. Otherwise, no significant differences between the three contrast media were found regarding vascular contrast and image quality. Equilibrium-phase high-spatial-resolution MR-angiography using a weakly protein-binding or even non-protein-binding contrast medium is equivalent to using a stronger protein-binding contrast medium when image acquisition is within the first 15 min after contrast injection, and allows depiction of the vasculature with high contrast and image quality. The protein-binding contrast medium was superior for imaging only later than 15 min after contrast medium injection. Copyright © 2015 John Wiley & Sons, Ltd.

  10. A gadolinium(III) complex of a carboxylic-phosphorus acid derivative of diethylenetriamine covalently bound to inulin, a potential macromolecular MRI contrast agent.

    Science.gov (United States)

    Lebdusková, Petra; Kotek, Jan; Hermann, Petr; Vander Elst, Luce; Muller, Robert N; Lukes, Ivan; Peters, Joop A

    2004-01-01

    A novel conjugate of a polysaccharide and a Gd(III) chelate with potential as contrast agent for magnetic resonance imaging (MRI) was synthesized. The structure of the chelate was derived from H5DTPA by replacing the central pendant arm by a phosphinic acid functional group, which was covalently bound to the polysaccharide inulin. On the average, each monosaccharide unit of the inulin was attached to approximately one (0.9) chelate moiety. The average molecular weight is 23110 and the average number of Gd3+ ions per molecule is 24. The ligand binds the Gd3+ ion in an octadentate fashion via three nitrogen atoms, four carboxylate oxygen atoms, and one P-O oxygen atom, and its first coordination sphere is completed by a water molecule. This compound shows promising properties for application as a contrast agent for MRI thanks to a favorable residence lifetime of this water molecule (170 ns at 298 K), a relatively long rotational correlation time (866 ps at 298 K), and the presence of two water molecules in the second coordination sphere of the Gd3+ ion. Furthermore, its stability toward transmetalation with Zn(II) is as high as that of the clinically used [Gd(DTPA)(H2O)]2-.

  11. Synthesis route and three different core-shell impacts on magnetic characterization of gadolinium oxide-based nanoparticles as new contrast agents for molecular magnetic resonance imaging

    Science.gov (United States)

    Azizian, Gholamreza; Riyahi-Alam, Nader; Haghgoo, Soheila; Moghimi, Hamid Reza; Zohdiaghdam, Reza; Rafiei, Behrooz; Gorji, Ensieh

    2012-10-01

    Despite its good resolution, magnetic resonance imaging intrinsically has low sensitivity. Recently, contrast agent nanoparticles have been used as sensitivity and contrast enhancer. The aim of this study was to investigate a new controlled synthesis method for gadolinium oxide-based nanoparticle preparation. For this purpose, diethyleneglycol coating of gadolinium oxide (Gd2O3-DEG) was performed using new supervised polyol route, and small particulate gadolinium oxide (SPGO) PEGylation was obtained with methoxy-polyethylene-glycol-silane (550 and 2,000 Da) coatings as SPGO-mPEG-silane550 and 2,000, respectively. Physicochemical characterization and magnetic properties of these three contrast agents in comparison with conventional Gd-DTPA were verified by dynamic light scattering transmission electron microscopy, Fourier transform infrared spectroscopy, inductively coupled plasma, X-ray diffraction, vibrating sample magnetometer, and the signal intensity and relaxivity measurements were performed using 1.5-T MRI scanner. As a result, the nanoparticle sizes of Gd2O3-DEG, SPGO-mPEG-silane550, and SPGO-mPEG-silane2000 could be reached to 5.9, 51.3, 194.2 nm, respectively. The image signal intensity and longitudinal ( r 1) and transverse relaxivity ( r 2) measurements in different concentrations (0.3 to approximately 2.5 mM), revealed the r 2/ r 1 ratios of 1.13, 0.89, 33.34, and 33.72 for Gd-DTPA, Gd2O3-DEG, SPGO-mPEG-silane550, and SPGO-mPEG-silane2000, respectively. The achievement of new synthesis route of Gd2O3-DEG resulted in lower r 2/ r 1 ratio for Gd2O3-DEG than Gd-DTPA and other previous synthesized methods by this and other groups. The smaller r 2/ r 1 ratios of two PEGylated-SPGO contrast agents in our study in comparison with r 2/ r 1 ratio of previous PEGylation ( r 2/ r 1 = 81.9 for mPEG-silane 6,000 MW) showed that these new three introduced contrast agents could potentially be proper contrast enhancers for cellular and molecular MR imaging.

  12. Sequential gadolinium-enhanced magnetic resonance angiography of the aortoiliac and the femoropopliteal arteries with repetitive administration of low-dose contrast agent

    International Nuclear Information System (INIS)

    Ito, Koichiro; Kumazaki, Tatsuo

    2000-01-01

    To obtain a wide-range contrast MR angiography in a single examination, we performed two sequential administrations of low-dose (0.08 mmol/kg) gadolinium diethylenetriaminepentaacetic acid (Gd-DTPA) with three dimensional inversion recovery prepared fast spoiled gradient recalled acquisition in the steady-state (3D IR-fast SPGR) sequence. Signal characteristics of the sequence were estimated by computed simulations and an in vitro study. A clinical study of 19 examinations was done with sequential MR angiography of the aortoiliac and femoropopliteal arteries. Great signal differences were observed between the high and low Gd concentrations. Higher Gd concentrations generated significantly stronger signals. Greater signals were produced at TIs of longer than 150 msec than at shorter than 100 msec. In the clinical study, the arteries were visualized with sufficient signals even with a small amount of contrast agent. Contrast-to-noise ratios between the arteries and surrounding skeletal muscles or fat tissues ranged from 10.5±9.6 to 4.7±2.2 and 6.6±2.8 to -3.1±11.2, respectively. No venous enhancement was found with diluted contrast agent on the second MR angiography. Two consecutive contrast MR angiographies can be obtained with repetitive administration of low-dose contrast agent. (author)

  13. Sequential gadolinium-enhanced magnetic resonance angiography of the aortoiliac and the femoropopliteal arteries with repetitive administration of low-dose contrast agent

    Energy Technology Data Exchange (ETDEWEB)

    Ito, Koichiro [Nippon Medical School, Inba, Chiba (Japan). Chiba Hokusoh Hospital; Kumazaki, Tatsuo

    2000-12-01

    To obtain a wide-range contrast MR angiography in a single examination, we performed two sequential administrations of low-dose (0.08 mmol/kg) gadolinium diethylenetriaminepentaacetic acid (Gd-DTPA) with three dimensional inversion recovery prepared fast spoiled gradient recalled acquisition in the steady-state (3D IR-fast SPGR) sequence. Signal characteristics of the sequence were estimated by computed simulations and an in vitro study. A clinical study of 19 examinations was done with sequential MR angiography of the aortoiliac and femoropopliteal arteries. Great signal differences were observed between the high and low Gd concentrations. Higher Gd concentrations generated significantly stronger signals. Greater signals were produced at TIs of longer than 150 msec than at shorter than 100 msec. In the clinical study, the arteries were visualized with sufficient signals even with a small amount of contrast agent. Contrast-to-noise ratios between the arteries and surrounding skeletal muscles or fat tissues ranged from 10.5{+-}9.6 to 4.7{+-}2.2 and 6.6{+-}2.8 to -3.1{+-}11.2, respectively. No venous enhancement was found with diluted contrast agent on the second MR angiography. Two consecutive contrast MR angiographies can be obtained with repetitive administration of low-dose contrast agent. (author)

  14. Structural, kinetic, and thermodynamic characterization of the interconverting isomers of MS-325, a gadolinium(III)-based magnetic resonance angiography contrast agent.

    Science.gov (United States)

    Tyeklar, Zoltan; Dunham, Stephen U; Midelfort, Katarina; Scott, Daniel M; Sajiki, Hirano; Ong, Karen; Lauffer, Randall B; Caravan, Peter; McMurry, Thomas J

    2007-08-06

    The amphiphilic gadolinium complex MS-325 ((trisodium-{(2-(R)-[(4,4-diphenylcyclohexyl) phosphonooxymethyl] diethylenetriaminepentaacetato) (aquo)gadolinium(III)}) is a contrast agent for magnetic resonance angiography (MRA). MS-325 comprises a GdDTPA core with an appended phosphodiester moiety linked to a diphenylcyclohexyl group to facilitate noncovalent binding to serum albumin and extension of the plasma half-life in vivo. The chiral DTPA ligand (R) was derived from L-serine, and upon complexation with gadolinium, forms two interconvertible diastereomers, denoted herein as isomers A and B. X-ray crystallography of the tris(ethylenediamine)cobalt(III) salt derivative of isomer A revealed a structure in the polar acentric space group P32. The structure consisted of three independent molecules of the gadolinium complex in the asymmetric unit along with three Delta-[Co(en)3]3+ cations, and it represents an unusual example of spontaneous Pasteur resolution of the cobalt cation. The geometry of the coordination core was best described as a distorted trigonal prism, and the final R factor was 5.6%. The configuration of the chiral central nitrogen of the DTPA core was S. The Gd-water (2.47-2.48 A), the Gd-acetate oxygens (2.34-2.42 A), and the Gd-N bond distances (central N, 2.59-2.63 A; terminal N, 2.74-2.80 A) were similar to other reported GdDTPA structures. The structurally characterized single crystal was one of two interconvertable diastereomers (isomers A and B) that equilibrated to a ratio of 1.81 to 1 at pH 7.4 and were separable at elevated pH by ion-exchange chromatography. The rate of isomerization was highly pH dependent: k1 = (1.45 +/- 0.08) x 102[H+] + (4.16 +/- 0.30) x 105[H+]2; k-1 = (2.57 +/- 0.17) x 102[H+] + (7.54 +/- 0.60) x 105[H+]2.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2016-05-15

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

  16. Comparison of half-dose and full-dose gadolinium MR contrast on the enhancement of bone and soft tissue tumors

    Energy Technology Data Exchange (ETDEWEB)

    Costelloe, Colleen M. [University of Texas M. D. Anderson Cancer Center, Department of Diagnostic Radiology, Houston, Texas (United States); University of Texas M. D. Anderson Cancer Center, Houston, Texas (United States); Murphy, William A.; Haygood, Tamara M.; Kumar, Rajendra; McEnery, Kevin W.; Madewell, John E. [University of Texas M. D. Anderson Cancer Center, Department of Diagnostic Radiology, Houston, Texas (United States); Stafford, R.J. [University of Texas M. D. Anderson Cancer Center, Department of Imaging Physics, Houston, Texas (United States); Roy, Anjali [Cancer Treatment Centers of America Medical Diagnostic Imaging Group, Arizona (United States); Bassett, Roland L.; Harrell, Robyn K. [University of Texas M. D. Anderson Cancer Center, Department of Biostatistics, Houston, Texas (United States)

    2011-03-15

    To evaluate the effect of half-dose intravenous gadolinium contrast on the enhancement of bone and soft tissue tumors. This study is HIPAA compliant and informed consent was waived by the institutional review board. An institutional database search was performed over a 1-year period for patients with full- and half-dose MR examinations performed for musculoskeletal oncologic indications. Examination pairs that were identical with regard to field strength and presence or absence of fat saturation were included, resulting in 29 paired examinations. When multiple, the lesion that was best delineated and enhanced well on the first examination in the pair was chosen, yielding 17 bone and 12 soft tissue. Five musculoskeletal radiologists blinded to dosages were asked to assess for a difference in enhancement when comparing the lesion on both examinations and to rate the degree of difference on a three-point scale. They were also asked to identify the examination on which the lesion enhanced less (tallied as low dose). Results were analyzed with the exact binomial test. The readers perceived an enhancement difference in 41% (59/145) of studies (p = 0.03) and the majority were rated as ''mild'' (66%, 39/59). The readers did not accurately identify the low-dose examinations (54% correctly identified, 32/59, p = 0.60). Half-dose gadolinium enhancement of lesions could not be accurately distinguished from full-dose enhancement upon review of the same lesion imaged at both concentrations. (orig.)

  17. Metabolomic Analysis of N-acetylcysteine Protection of Injury from Gadolinium-DTPA Contrast Agent in Rats with Chronic Renal Failure.

    Science.gov (United States)

    Wan, Chuanling; Xue, Rong; Zhan, Youyang; Wu, Yijie; Li, Xiaojing; Pei, Fengkui

    2017-09-01

    Gadolinium-based contrast agents (GBCAs) are frequently used to enhance the diagnostic efficacy of magnetic resonance imaging. On the other hand, the association between GBCA administration in patients with advanced renal disease and nephrogenic systemic fibrosis (NSF) was also noted. NSF is a systemic disorder characterized by widespread tissue fibrosis that may lead to death. N-acetylcysteine (NAC) protects rats from injury induced by gadolinium-based contrast agents, but the underlying mechanisms remain unclear. In this study, a nuclear magnetic resonance-based metabolomic approach was used to systematically investigate the protective effects of NAC on Gd-DTPA-induced injury. Thirty-two male Sprague-Dawley rats were given adenine (200 mg·kg -1 body weight) by oral gavage once a day for 3 weeks to induce chronic renal failure (CRF). NAC (600 mg/L in drinking water for 9 days) pretreatment was initiated 2 days before Gd-DTPA injection (a single tail vein injection, 2 mmol/kg body weight). Serum and liver samples were collected on day 7 after Gd-DTPA injection. By study design, the serum and hepatic metabolic changes of rats were measured in four groups of eight each: CRF, CRF-Gd, CRF-Gd-NAC, and CRF-NAC. Gd-DTPA administration to rats with CRF resulted in disturbances of several metabolic pathways, including glucose, lipid, glutamate, choline, gut microbiota, one-carbon, and purine metabolism. NAC pretreatment reversed the abundance changes of high-density lipoprotein, low-density lipoprotein, very low-density lipoprotein, glutamate, glutamine, oxidized glutathione, choline, phosphocholine, glycerophosphocholine, trimethylamine, and trimethylamine-N-oxide induced by Gd-DTPA. It is noteworthy, however, that the ameliorating effects of NAC on the disturbance of glutamate, choline, and gut microbiota metabolism may be specific to Gd-DTPA. In all, these findings could be potentially useful to decipher the underlying mechanisms of NAC protective effects from the

  18. Dual-mode T_1 and T_2 magnetic resonance imaging contrast agent based on ultrasmall mixed gadolinium-dysprosium oxide nanoparticles: synthesis, characterization, and in vivo application

    International Nuclear Information System (INIS)

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

    2015-01-01

    A new type of dual-mode T_1 and T_2 magnetic resonance imaging (MRI) contrast agent based on mixed lanthanide oxide nanoparticles was synthesized. Gd"3"+ ("8S_7_/_2) plays an important role in T_1 MRI contrast agents because of its large electron spin magnetic moment resulting from its seven unpaired 4f-electrons, and Dy"3"+ ("6H_1_5_/_2) has the potential to be used in T_2 MRI contrast agents because of its very large total electron magnetic moment: among lanthanide oxide nanoparticles, Dy_2O_3 nanoparticles have the largest magnetic moments at room temperature. Using these properties of Gd"3"+ and Dy"3"+ and their oxide nanoparticles, ultrasmall mixed gadolinium-dysprosium oxide (GDO) nanoparticles were synthesized and their potential to act as a dual-mode T_1 and T_2 MRI contrast agent was investigated in vitro and in vivo. The D-glucuronic acid coated GDO nanoparticles (d_a_v_g = 1.0 nm) showed large r_1 and r_2 values (r_2/r_1 ≈ 6.6) and as a result clear dose-dependent contrast enhancements in R_1 and R_2 map images. Finally, the dual-mode imaging capability of the nanoparticles was confirmed by obtaining in vivo T_1 and T_2 MR images. (paper)

  19. Gadolinium-Loaded Solid Lipid Nanoparticles as a Tumor-Absorbable Contrast Agent for Early Diagnosis of Colorectal Tumors Using Magnetic Resonance Colonography.

    Science.gov (United States)

    Sun, Jihong; Zhang, Shizheng; Jiang, Shaojie; Bai, Weixian; Liu, Fei; Yuan, Hong; Ji, Jiansong; Luo, Jingfeng; Han, Guocan; Chen, Lumin; Jin, Yin; Hu, Peng; Yu, Lei; Yang, Xiaoming

    2016-09-01

    Magnetic resonance (MR) contrast agents focusing on special functions are required to improve cancer diagnosis, particularly in the early stages. Here, we designed multifunctional solid lipid nanoparticles (SLNs) with simultaneous loading of gadolinium (Gd) diethylenetriaminepentaacetic acid (Gd-DTPA) and octadecylamine fluorescein isothiocyanate (FITC) to obtain Gd-FITC-SLNs as a tumor-absorbable nanoparticle contrast agent for the histological confirmation of MR imaging (MRI) findings. Colorectal tumors were evaluated in vitro and in vivo via direct uptake of this contrast agent, which displayed reasonable T1 relaxivity and no significant cytotoxicity at the experimental concentrations in human colon carcinoma cells (HT29) and mouse colon carcinoma cells (CT26). In vitro cell uptake experiments demonstrated that contrast agent absorption by the two types of cancer cells was concentration-dependent in the safe concentration range. During in vivo MRI, transrectal infusion of Gd-FITC-SLNs showed more significant enhancement at the tumor site compared with the infusion of Gd-DTPA in female C57/BL mice with azoxymethane/dextran sulfate sodium-induced colorectal highgrade intraepithelial neoplasia. Subsequent confocal fluorescence microscopy demonstrated Gd-FITC-SLNs as highly concentrated green fluorescent spots distributed from the tumor capsule into the tumor. This study establishes the "proof-of-principle" of a new MRI technique wherein colorectal tumors are enhanced via direct absorption or uptake of the nanoparticle contrast agent.

  20. 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.

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

    International Nuclear Information System (INIS)

    Lee, Mi Jung; Kim, Myung Joon; Yoon, Choon Sik; Song, Si Young; Park, Kyung Soo; Kim, Woo Sun

    2011-01-01

    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.

  2. Towards the Rational Design of MRI Contrast Agents: Electron Spin Relaxation Is Largely Unaffected by the Coordination Geometry of Gadolinium(III)–DOTA-Type Complexes

    Science.gov (United States)

    Bean, Jonathan F.; Clarkson, Robert B.; Helm, Lothar; Moriggi, Loïck; Sherry, A. Dean

    2009-01-01

    Electron-spin relaxation is one of the determining factors in the efficacy of MRI contrast agents. Of all the parameters involved in determining relaxivity it remains the least well understood, particularly as it relates to the structure of the complex. One of the reasons for the poor understanding of electron-spin relaxation is that it is closely related to the ligand-field parameters of the Gd3+ ion that forms the basis of MRI contrast agents and these complexes generally exhibit a structural isomerism that inherently complicates the study of electron spin relaxation. We have recently shown that two DOTA-type ligands could be synthesised that, when coordinated to Gd3+, would adopt well defined coordination geometries and are not subject to the problems of intramolecular motion of other complexes. The EPR properties of these two chelates were studied and the results examined with theory to probe their electron-spin relaxation properties. PMID:18283704

  3. Caspase-responsive smart gadolinium-based contrast agent for magnetic resonance imaging of drug-induced apoptosis.

    Science.gov (United States)

    Ye, Deju; Shuhendler, Adam J; Pandit, Prachi; Brewer, Kimberly D; Tee, Sui Seng; Cui, Lina; Tikhomirov, Grigory; Rutt, Brian; Rao, Jianghong

    2014-10-01

    Non-invasive detection of caspase-3/7 activity in vivo has provided invaluable predictive information regarding tumor therapeutic efficacy and anti-tumor drug selection. Although a number of caspase-3/7 targeted fluorescence and positron emission tomography (PET) imaging probes have been developed, there is still a lack of gadolinium (Gd)-based magnetic resonance imaging (MRI) probes that enable high spatial resolution detection of caspase-3/7 activity in vivo . Here we employ a self-assembly approach and develop a caspase-3/7 activatable Gd-based MRI probe for monitoring tumor apoptosis in mice. Upon reduction and caspase-3/7 activation, the caspase-sensitive nano-aggregation MR probe (C-SNAM: 1 ) undergoes biocompatible intramolecular cyclization and subsequent self-assembly into Gd-nanoparticles (GdNPs). This results in enhanced r 1 relaxivity-19.0 (post-activation) vs. 10.2 mM -1 s -1 (pre-activation) at 1 T in solution-and prolonged accumulation in chemotherapy-induced apoptotic cells and tumors that express active caspase-3/7. We demonstrate that C-SNAM reports caspase-3/7 activity by generating a significantly brighter T 1 -weighted MR signal compared to non-treated tumors following intravenous administration of C-SNAM, providing great potential for high-resolution imaging of tumor apoptosis in vivo .

  4. Chiral DOTA chelators as an improved platform for biomedical imaging and therapy applications.

    Science.gov (United States)

    Dai, Lixiong; Jones, Chloe M; Chan, Wesley Ting Kwok; Pham, Tiffany A; Ling, Xiaoxi; Gale, Eric M; Rotile, Nicholas J; Tai, William Chi-Shing; Anderson, Carolyn J; Caravan, Peter; Law, Ga-Lai

    2018-02-27

    Despite established clinical utilisation, there is an increasing need for safer, more inert gadolinium-based contrast agents, and for chelators that react rapidly with radiometals. Here we report the syntheses of a series of chiral DOTA chelators and their corresponding metal complexes and reveal properties that transcend the parent DOTA compound. We incorporated symmetrical chiral substituents around the tetraaza ring, imparting enhanced rigidity to the DOTA cavity, enabling control over the range of stereoisomers of the lanthanide complexes. The Gd chiral DOTA complexes are shown to be orders of magnitude more inert to Gd release than [GdDOTA] - . These compounds also exhibit very-fast water exchange rates in an optimal range for high field imaging. Radiolabeling studies with (Cu-64/Lu-177) also demonstrate faster labelling properties. These chiral DOTA chelators are alternative general platforms for the development of stable, high relaxivity contrast agents, and for radiometal complexes used for imaging and/or therapy.

  5. The utility of gadoteric acid in contrast-enhanced MRI: a review

    Directory of Open Access Journals (Sweden)

    Tartaro A

    2015-02-01

    Full Text Available Armando Tartaro, Marica Tina Maccarone Department of Neuroscience, Imaging and Clinical Sciences, and Institute for Advanced Biomedical Technologies (ITAB, “G d’Annunzio” University, Chieti-Pescara, Italy Abstract: Gadoteric acid (Dotarem® is a macrocyclic, paramagnetic, gadolinium-based contrast agent. It is used in the magnetic resonance imaging (MRI of the brain, spine, and associated tissues. Particularly, it is able to detect and visualize areas with disruption of the blood–brain barrier and/or abnormal vascularity. Gadoteric acid has been also approved for MR angiography of supraaortic vessels, cardiac MR (to detect myocardial infarctions, as well as whole-body MRI including abdominal, renal, pelvic, breast, and osteoarticular diseases. Cyclic chelates are more stable compared to linear chelates, and ionic chelates are more stable compared to nonionic chelates. Linear chelates have a greater likelihood of releasing free Gd3+ compared to cyclic chelates. Non-ionic chelates are more likely, compared to ionic chelates, to release Gd3+ from their chelates. Gadoteric acid is a cyclic ionic chelate and has the greatest kinetic stability among gadolinium-based contrast agents. In patients with chronic reduced kidney function, the use of gadolinium-based contrast agents leads to acute kidney injury and dialysis. The risk of acute kidney injury may increase with increasing dose of the contrast agents. Therefore, it is recommended to administer the lowest dose necessary for adequate imaging. The dose reduction allows protection the patients form potential risk of nephrogenic systemic fibrosis, a systemic reaction that is probably due to unbound Gd3+ ions deposited in body tissues. The dose of gadoteric acid should not exceed 0.1 mmol/kg body weight. More than one dose should not be used during a scan. Because of the lack of information on repeated administration, Dotarem® injections should not be repeated unless the interval between

  6. Accumulation of Bile in the Gallbladder: Evaluation by means of Serial Dynamic Contrast-Enhanced Magnetic Resonance Cholangiography with Gadolinium Ethoxybenzyl Diethylenetriaminepentaacetic Acid

    Directory of Open Access Journals (Sweden)

    Tsutomu Tamada

    2014-01-01

    Full Text Available The aim of this study was to evaluate the process of biliary excretion of gadolinium ethoxybenzyl diethylenetriaminepentaacetic acid (Gd-EOB-DTPA into the biliary tract and to assess the accumulation patterns in the gallbladder using MR cholangiography obtained with Gd-EOB-DTPA which is a liver-specific hepatobiliary contrast agent. Seventy-five patients underwent Gd-EOB-DTPA enhanced MR imaging. Serial multiphasic hepatobiliary phase imaging was qualitatively reviewed to evaluate the process of the biliary excretion of contrast agent into the bile duct and the gallbladder. The accumulation pattern of contrast agent into gallbladder was classified into two groups (group 1 = orthodromic type and group 2 = delayed type. Furthermore, the results in differences of the presence of T1 hyperintense bile or sludge of gallbladder, gall stones, wall thickening of gallbladder, chronic liver disease, and liver cirrhosis between two groups were compared. Forty-eight of 75 patients (64% were included in group 1, and remaining 27 (36% were in group 2. The frequency of the presence of T1 hyperintense bile or sludge of gallbladder was significantly higher in patients with group 2 than that in patients with group 1 (P=0.041. MR cholangiography obtained with Gd-EOB-DTPA showed that there may be an association between the biliary accumulation pattern in the gallbladder and the pathological condition.

  7. In vivo magnetic resonance imaging of atherosclerotic lesions with a newly developed Evans blue-DTPA-gadolinium contrast medium in apolipoprotein-E-deficient mice.

    Science.gov (United States)

    Yasuda, Satoshi; Ikuta, Kenjiro; Uwatoku, Toyokazu; Oi, Keiji; Abe, Kohtaro; Hyodo, Fuminori; Yoshimitsu, Kengo; Sugimura, Kohtaro; Utsumi, Hideo; Katayama, Yoshiki; Shimokawa, Hiroaki

    2008-01-01

    Magnetic resonance imaging (MRI) contrast agents that specifically detect atherosclerotic plaque may be useful for the noninvasive detection of the plaque. We have recently developed a new contrast agent, Evans blue-DTPA-gadolinium (EB-DTPA-Gd), which selectively accumulates vascular lesions with endothelial removal. In this study, we examined whether EB-DTPA-Gd is also useful for in vivo imaging of atherosclerotic plaques. We used male apolipoprotein-E-deficient (ApoE-/-) mice of different ages (3, 6 and 12 months old) and age-matched male wild-type mice. After a single intravenous administration of EB-DTPA-Gd (160 microM/kg body weight), MRI T(1) signal was obtained in vivo. Increased signal intensity in the aortic wall was noted within 10-20 min after intravenous injection of EB-DTPA-Gd and was maintained for 30 min. The MRI enhancement in the aorta of ApoE-/- mice was increased in accordance with age, whereas no such enhancement was noted in wild-type mice. Histological examination demonstrated that there was a topological correlation between the site of MRI enhancement and that of atherosclerotic plaque. These results indicate that EB-DTPA-Gd is a useful MRI contrast medium for the in vivo detection of atherosclerotic plaques. Copyright (c) 2007 S. Karger AG, Basel.

  8. Cardiac MRI. Estimation of changes in normalized myocardial gadolinium accumulation over time after contrast injection in patients with acute myocarditis and healthy volunteers

    International Nuclear Information System (INIS)

    Breuckmann, F.; Buhr, C.; Maderwald, S.; Bruder, O.; Schlosser, T.; Nassenstein, K.; Erbel, R.; Barkhausen, J.

    2011-01-01

    An increased normalized gadolinium accumulation (NGA) in the myocardium during early washout has been used for the diagnosis of acute myocarditis (AM). Due to the fact that the pharmacokinetics of contrast agents are complex, time-related changes in NGA after contrast injection are likely. Because knowledge about time-related changes of NGA may improve the diagnostic accuracy of MR, our study aimed to estimate the time course of NGA after contrast injection in patients as well as in healthy volunteers. An ECG-triggered inversion recovery SSFP sequence with incrementally increasing inversion times was repetitively acquired over the 15 minutes after injection of 0.2 Gd-DTPA per kg body weight in a 4-chamber view in 15 patients with AM and 20 volunteers. The T 1relaxation times and the longitudinal relaxation rates (R1) of the myocardium and skeletal musculature were calculated for each point in time after contrast injection. The time course of NGA was estimated based on the linear relationship between R 1 and tissue Gd concentration. NGA decreased over time in the form of a negative power function in patients with AM and in healthy controls. NGA in AM tended to be higher than in controls (p > 0.05). NGA rapidly changes after contrast injection, which must be considered when measuring NGA. Although we observed a trend towards higher NGA values in patients with AM with a maximum difference one minute after contrast injection, NGA did not allow us to differentiate patients with AM from healthy volunteers, because the observed differences did not reach a level of significance. (orig.)

  9. Does the application of gadolinium-DTPA have an impact on magnetic resonance phase contrast velocity measurements? Results from an in vitro study

    International Nuclear Information System (INIS)

    Heverhagen, J.T.; Hoppe, M.; Klose, K.-J.; Wagner, H.-J.

    2002-01-01

    Introduction/objective: To evaluate the potential influence of various concentrations of gadolinium (Gd)-DTPA on magnetic resonance phase contrast (MR PC) velocimetry. Material and methods: Imaging was done with a 1.0 T scanner using a standard Flash 2D sequence and a circular polarized extremity coil. In a validated flow phantom with a defined 75% area stenosis different concentrations of Gd-DTPA, diluted in a 10:1 water-yogurt mixture, MR PC measurements were correlated with a Doppler guide wire as gold standard. Results: MR PC measurements correlated well with the Doppler derived data (r=0.99; P 0.05; Student's t-test) flow measurement changes were noted (maximum pre-stenotic velocity: 21.3±1.3 cm/s; maximum intra-stenotic velocity: 84.0±3.6 cm/s). However, delineation of the perfused lumen was enhanced after the application of Gd-DTPA. Discussions and conclusion: The application of Gd-DTPA does not affect MR PC velocimetry. However, the application of contrast media allowed a more accurate vessel segmentation. MR PC measurements can be reliably carried out after application of Gd-DTPA

  10. Does the application of gadolinium-DTPA have an impact on magnetic resonance phase contrast velocity measurements? Results from an in vitro study

    Energy Technology Data Exchange (ETDEWEB)

    Heverhagen, J.T. E-mail: heverhag@post.med.uni-marburg.de; Hoppe, M.; Klose, K.-J.; Wagner, H.-J

    2002-10-01

    Introduction/objective: To evaluate the potential influence of various concentrations of gadolinium (Gd)-DTPA on magnetic resonance phase contrast (MR PC) velocimetry. Material and methods: Imaging was done with a 1.0 T scanner using a standard Flash 2D sequence and a circular polarized extremity coil. In a validated flow phantom with a defined 75% area stenosis different concentrations of Gd-DTPA, diluted in a 10:1 water-yogurt mixture, MR PC measurements were correlated with a Doppler guide wire as gold standard. Results: MR PC measurements correlated well with the Doppler derived data (r=0.99; P<0.01; maximum pre-stenotic velocity: 21.6{+-}0.5 cm/s; maximum intra-stenotic velocity: 81.7{+-}0.6 cm/s). Following Gd-DTPA administration no significant (P>0.05; Student's t-test) flow measurement changes were noted (maximum pre-stenotic velocity: 21.3{+-}1.3 cm/s; maximum intra-stenotic velocity: 84.0{+-}3.6 cm/s). However, delineation of the perfused lumen was enhanced after the application of Gd-DTPA. Discussions and conclusion: The application of Gd-DTPA does not affect MR PC velocimetry. However, the application of contrast media allowed a more accurate vessel segmentation. MR PC measurements can be reliably carried out after application of Gd-DTPA.

  11. A smart magnetic resonance imaging contrast agent responsive to adenosine based on a DNA aptamer-conjugated gadolinium complex.

    Science.gov (United States)

    Xu, Weichen; Lu, Yi

    2011-05-07

    We report a general strategy for developing a smart MRI contrast agent for the sensing of small molecules such as adenosine based on a DNA aptamer that is conjugated to a Gd compound and a protein streptavidin. The binding of adenosine to its aptamer results in the dissociation of the Gd compound from the large protein, leading to decreases in the rotational correlation time and thus change of MRI contrast. © The Royal Society of Chemistry 2011

  12. Visualization of endolymphatic hydrops in meniere's disease after single-dose intravenous gadolinium-based contrast medium. Timing of optimal enhancement

    International Nuclear Information System (INIS)

    Naganawa, Shinji; Yamazaki, Masahiro; Kawai, Hisashi; Bokura, Kiminori; Sone, Michihiko; Nakashima, Tsutomu

    2012-01-01

    Visualization of endolymphatic hydrops (EH) in patients with Meniere's disease (MD) is now possible by heavily T 2 -weighted 3-dimensional fluid-attenuated inversion recovery (h T 2 W-3D-FLAIR) obtained 4 hours after intravenous (IV) administration of single dose gadolinium-based contrast medium (GBCM). Although maximum enhancement has been reported 4 hours after contrast administration in healthy volunteers, the timing of optimal enhancement in patients with MD is not reported. We investigated if that optimal timing is earlier or later than 4 hours. We evaluated 10 consecutive patients with suspected MD whom we randomly divided into 2 groups. We obtained h T 2 W-3D-FLAIR before GBCM administration and 10 min, 3.5 hours, and 4 hours after GBCM administration in Group A and before and 10 min, 4 hours, and 4.5 hours after GBCM administration in Group B. We compared signal intensity ratio (SIR) values of the perilymph and pons between 3.5 and 4 hours in Group A and between 4 and 4.5 hours in Group B and evaluated grades of EH at 3.5 and 4 hours in Group A and at 4 and 4.5 hours in Group B. SIR values did not differ significantly between 3.5 and 4 hours in Group A and between 4 and 4.5 hours in Group B. However, SIR values at 4 hours were significantly higher in Group A than Group B. Grades of EH agreed between 3.5 and 4 hours in Group A and between 4 and 4.5 hours in Group B. The optimal timing of contrast enhancement in patients with suspected MD remains unclear, but evaluation of EH may be possible from 3.5 to 4.5 hours after contrast administration. (author)

  13. Gadolinium-ethoxybenzyl-DTPA as a hepatobiliary contrast agent for use in MR cholangiography: results of an in vivo phase-I clinical evaluation

    International Nuclear Information System (INIS)

    Bollow, M.; Taupitz, M.; Hamm, B.; Staks, T.; Wolf, K.J.; Weinmann, H.J.

    1997-01-01

    The purpose of this study was to investigate the time course of contrast enhancement in bile ducts and the gallbladder (GB) after injection of gadolinium-ethoxybenzyl-DTPA (Gd-EOB-DTPA). In a clinical phase-I study, MR imaging at 1.5T was performed in 16 healthy volunteers with four different doses of Gd-EOB-DTPA (10, 25, 50, and 100 μmol/kg b. w., four volunteers per dosage). The study protocol comprised a heavily T1-weighted fast multiplanar gradient-echo (GE) sequence before and at increasing intervals for up to 360 min after injection of Gd-EOB-DTPA. The signal enhancement was evaluated in extra-and intrahepatic bile ducts as well as in the GB. In all 16 volunteers the common bile duct showed intense signal enhancement beginning 5-16 min after injection (mean 10 min) and persisting for at least 120 min in 4 subjects and for 360 min in 12 subjects. The duration of signal enhancement was significantly (p < 0.05) longer for higher doses (50, 100 μmol/kg) than for lower doses (10, 25 μmol/kg). Intrahepatic bile ducts were hyperintense as compared with liver parenchyma in all subjects receiving 10 μmol/kg from approximately 50-120 min after contrast agent application. Intrahepatic bile ducts were not displayed using the higher doses, probably because of the strong enhancement of the liver parenchyma. Gallbladder contrasting was achieved in all cases beginning 7-33 min after injection (mean 19 min) and remained visible for up to 360 min in 94 %. Hyperintense visualization of normal extrahepatic bile ducts as well as the GB is regularly achieved with the hepatobiliary contrast agent Gd-EOB-DTPA. The dosage for hyperintense visualization of intrahepatic bile ducts is 10 μmol/kg. (orig.). With 8 figs., 2 tabs

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

    Science.gov (United States)

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

    2013-11-26

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

  15. Digital subtraction in gadolinium-enhanced MR imaging of the brain: a method to reduce contrast dosage

    International Nuclear Information System (INIS)

    Chan, J.H.M.; Tsui, E.Y.K.; Chan, C.Y.; Lai, K.F.; Cheung, Y.K.; Wong, K.P.C.; Yuen, M.K.; Chau, L.F.; Fong, D.; Mok, C.K.

    2002-01-01

    The aim of the study was to investigate the feasibility of using digital subtraction in contrast-enhanced MR imaging of the brain to reduce the MR contrast dosage without jeopardizing patient care. Fifty-two patients with intracranial lesions, either intra-axial or extra-axial, detected by computerized tomography were selected for contrast-enhanced MR imaging with half-dose and full-dose of gadopentetate dimeglumine. The half-dose unsubtracted, full-dose unsubtracted, and half-dose subtracted MR images were visually assessed by counting the number of enhancing brain lesions in the images and quantitatively analyzed by computing their lesion contrast-to-background ratios (CBR). The visual conspicuity of the half-dose subtracted MR images was comparable to that of the full-dose unsubtracted MR images (p>0.05), whereas the CBR of the half-dose subtracted images was approximately two to three times higher than that of the full-dose unsubtracted images. The half-dose subtracted T1-weighted spin-echo images might be able to replace the conventional standard-dose T1-weighted spin-echo images in MR imaging of the brain. (orig.)

  16. Heavy metal staining, a comparative assessment of gadolinium chloride and osmium tetroxide for inner ear labyrinthine contrast enhancement using X-ray microtomography.

    Science.gov (United States)

    Wong, Christopher C; Curthoys, Ian S; O'Leary, Stephen J; Jones, Allan S

    2013-01-01

    The use of both gadolinium chloride (GdCl(3)) and osmium tetroxide (OsO(4)) allowed for the visualization of the membranous labyrinth and other intralabyrinthine structures, at different intensities, as compared with the control sample. This initial comparison shows the advantages of GdCl(3) in radiological assessments and OsO(4) in more detailed anatomical studies and pathways of labyrinthine pathogenesis using X-ray microtomography (microCT). To assess an improved OsO(4) staining protocol and compare the staining affinities against GdCl(3). Guinea pig temporal bones were stained with either GdCl(3) (2% w/v) for 7 days or OsO(4) (2% w/v) for 3 days, and scanned in a microCT system. The post-scanned datasets were then assessed in a 3D rendering program. The enhanced soft tissue contrast as presented in the temporal bones stained with either GdCl(3) or OsO(4) allowed for the membranous labyrinth to be visualized throughout the whole specimen. GdCl(3)-stained specimens presented more defined contours of the bone profile in the radiographs, while OsO(4)-stained specimens provided more anatomical detail of individual intralabyrinthine structures, hence allowing spatial relationships to be visualized with ease in a 3D rendering context and 2D axial slice images.

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

    International Nuclear Information System (INIS)

    Langer, R.D.; Lorke, D.E.; Neidl van Gorkom, K.F.; Petroianu, G.; Azimullah, S.; Nurulain, S.M.; Singh, S.; Fuchsjäger, M.

    2012-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2012-10-15

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

  19. Gadolinium Accumulation in the Deep Cerebellar Nuclei and Globus Pallidus After Exposure to Linear but Not Macrocyclic Gadolinium-Based Contrast Agents in a Retrospective Pig Study With High Similarity to Clinical Conditions.

    Science.gov (United States)

    Boyken, Janina; Frenzel, Thomas; Lohrke, Jessica; Jost, Gregor; Pietsch, Hubertus

    2018-05-01

    The aim of this retrospective study was to determine the gadolinium (Gd) concentration in different brain areas in a pig cohort that received repeated administration of Gd-based contrast agents (GBCAs) at standard doses over several years, comparable with a clinical setting. Brain tissue was collected from 13 Göttingen mini pigs that had received repeated intravenous injections of gadopentetate dimeglumine (Gd-DTPA; Magnevist) and/or gadobutrol (Gadovist). The animals have been included in several preclinical imaging studies since 2008 and received cumulative Gd doses ranging from 7 to 129 mmol per animal over an extended period. Two animals with no history of administration of GBCA were included as controls. Brain autopsies were performed not earlier than 8 and not later than 38 months after the last GBCA application. Tissues from multiple brain areas including cerebellar and cerebral deep nuclei, cerebellar and cerebral cortex, and pons were analyzed for Gd using inductively coupled plasma mass spectrometry. Of the 13 animals, 8 received up to 48 injections of gadobutrol and Gd-DTPA and 5 received up to 29 injections of gadobutrol only. In animals that had received both Gd-DTPA and gadobutrol, a median (interquartile range) Gd concentration of 1.0 nmol/g tissue (0.44-1.42) was measured in the cerebellar nuclei and 0.53 nmol/g (0.29-0.62) in the globus pallidus. The Gd concentration in these areas in gadobutrol-only animals was 50-fold lower with median concentrations of 0.02 nmol/g (0.01-0.02) for cerebellar nuclei and 0.01 nmol/g (0.01-0.01) for globus pallidus and was comparable with control animals with no GBCA history. Accordingly, in animals that received both GBCAs, the amount of residual Gd correlated with the administered dose of Gd-DTPA (P ≤ 0.002) but not with the total Gd dose, consisting of Gd-DTPA and gadobutrol. The Gd concentration in cortical tissue and in the pons was very low (≤0.07 nmol/g tissue) in all animals analyzed. Multiple exposure

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

    Directory of Open Access Journals (Sweden)

    Marta Tibiletti

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

  1. Pharmacokinetic and in vivo evaluation of a self-assembled gadolinium(III)-iron(II) contrast agent with high relaxivity.

    Science.gov (United States)

    Parac-Vogt, Tatjana N; Vander Elst, Luce; Kimpe, Kristof; Laurent, Sophie; Burtéa, Carmen; Chen, Feng; Van Deun, Rik; Ni, Yicheng; Muller, Robert N; Binnemans, Koen

    2006-01-01

    A high-molecular weight tetrametallic supramolecular complex [(Ln-DTPA-phen)3Fe]- (Ln = Gd, Eu, La) has been obtained upon self-assembly around one iron(II) ion of three 1,10-phenantroline-based molecules substituted in 5'-position with the polyaminocarboxylate diethylenetriamine-N,N,N',N',N'-pentaacetate, DTPA-phen(4-). The ICP-MS measurements indicated that the lanthanide:iron ratio is 3:1. Photoluminescence spectra of [Eu-DTPA-phen](-) and of [(Eu-DTPA-phen)3Fe]- are nearly identical, implying that the first coordination sphere of the lanthanide(III) ion has not been changed upon coordination of phenantroline unit to iron(II) ion. NMRD measurements revealed that at 20 MHz and 310 K the relaxivity of the [(Gd-DTPA-phen)3Fe]- is equal to 9.5 +/- 0.3 s(-1) mM(-1) of Gd (28.5 s(-1) per millimole per liter of complex) which is significantly higher than that for Gd-DTPA (3.9 s(-1) mM(-1)). The pharmacokinetic parameters of [(Gd-DTPA-phen)3Fe]- in rats indicate that the elimination of [(Gd-DTPA-phen)3Fe]- is significantly slower than that of Gd-DTPA and is correlated with a reduced volume of distribution. The low volume of distribution and the longer elimination time (T(e1/2)) suggest that the agent is confined to the blood compartment, so it could have an important potential as a blood pool contrast agent. The biodistribution profile of [(Gd-DTPA-phen)3Fe]- 2 h after injection indicates significantly higher concentrations of [(Gd-DTPA-phen)3Fe]- as compared with Gd-DTPA in kidney, liver, lungs, heart and spleen. The images obtained on rats by MR angiography show the enhancement of the abdominal blood vessels. The signal intensity reaches a maximum of 55% at 7 min post-contrast and remains around 25% after 90 min. MRI-histomorphological correlation studies of [Gd-DTPA-phen]- and [(Gd-DTPA-phen)3Fe]- showed that both agents displayed potent contrast enhancement in organs including the liver. The necrosis avidity tests indicated that, in contrast to the [Gd

  2. MRI cisternography with gadolinium-containing contrast medium: its role, advantages and limitations in the investigation of rhinorrhoea.

    Science.gov (United States)

    Aydin, K; Guven, K; Sencer, S; Jinkins, J R; Minareci, O

    2004-01-01

    Our purpose was to evaluate the utility of intrathecal gadopentetate dimeglumine -enhanced magnetic resonance cisternography (GdMRC). We injected 0.5 ml contrast medium into the subarachnoid space via lumbar puncture in 20 patients with suspected cerebrospinal fluid (CSF) rhinorrhoea. MRC showed CSF leakage in 14 patients with rhinorrhoea at the time of the examination, into the ethmoid air cells in nine, the sphenoid sinus in three and the frontal sinus in two cases. In 12 of these the site leakage was confirmed during surgical repair of the fistula. No leakage was observed in four patients with intermittent rhinorrhoea, not present at the time of the examination. GdMRC showed leakage in two patients with negative CT cisternography. GdMRC may prove better than CT cisternography, especially with slow CSF flow. We also showed low-dose GdMRC to be a feasible and relative safe way of confirming the presence of and localising active CSF leaks prior to surgical repair.

  3. MRI cisternography with gadolinium-containing contrast medium: its role, advantages and limitations in the investigation of rhinorrhoea

    International Nuclear Information System (INIS)

    Aydin, K.; Guven, K.; Sencer, S.; Minareci, O.; Jinkins, J.R.

    2004-01-01

    Our purpose was to evaluate the utility of intrathecal gadopentetate dimeglumine -enhanced magnetic resonance cisternography (GdMRC). We injected 0.5 ml contrast medium into the subarachnoid space via lumbar puncture in 20 patients with suspected cerebrospinal fluid (CSF) rhinorrhoea. MRC showed CSF leakage in 14 patients with rhinorrhoea at the time of the examination, into the ethmoid air cells in nine, the sphenoid sinus in three and the frontal sinus in two cases. In 12 of these the site leakage was confirmed during surgical repair of the fistula. No leakage was observed in four patients with intermittent rhinorrhoea, not present at the time of the examination. GdMRC showed leakage in two patients with negative CT cisternography. GdMRC may prove better than CT cisternography, especially with slow CSF flow. We also showed low-dose GdMRC to be a feasible and relative safe way of confirming the presence of and localising active CSF leaks prior to surgical repair. (orig.)

  4. Appearance of high signal intensity and gadolinium-DTPA contrast enhancement in hypertrophied myocardium by magnetic resonance imaging

    International Nuclear Information System (INIS)

    Nishimura, Tsunehiko; Yamada, Naoaki; Nagata, Seiki

    1989-01-01

    This study was undertaken to examine the potential role of magnetic resonance imaging (MRI) for evaluating myocardial tissue characterization in hypertrophic cardiomyopathy (HCM). ECG-gated MRI images were acquired in 32 HCM patients and 30 patients with hypertensive heart disease (HHD), using a 1.5 T superconducting magnet system. The thickened areas were depicted as high signal intensities in the septum of 12 HCM patients (38%) and the endocardium of 5 HHD patients (17%). Echocardiography revealed that MRI appearance of high signal intensity was associated with more thickened myocardial wall. For evaluable 16 patients receiving i.v. injection of Gd-DTPA in a dose of 0.1 mM/kg, enhancement effects were observed in 10 patients (63%). High signal intensity appearing in the hypertrophied myocardium, as well as contrast enhancement, may not be characteristic of HCM, but reflect the likelihood of myocardial degeneration associated with the hypertrophied myocardium. Although MRI may not be capable of differentiating tissue characterization in HCM from that in HHD, it may provide different information about tissue characterization in the hypertrophied myocardium from that obtained by other techniques. (N.K.)

  5. MR imaging in recurrent pain after back surgery. A comparative study using standard and high doses of gadolinium contrast agents

    Energy Technology Data Exchange (ETDEWEB)

    Aakeson, P. [Univ. Hospital, Lund (Sweden). Dept. of Radiology; Annertz, M. [Univ. Hospital, Lund (Sweden). Dept. of Radiology; Kristoffersen, D.T. [Nycomed Imaging AS, Oslo (Norway); Jonsson, E. [Nycomed AB, Stockholm (Sweden); Holtaas, S. [Univ. Hospital, Lund (Sweden). Dept. of Radiology

    1996-11-01

    Purpose: To compare the diagnostic results following injection of (a) a high dose (0.3 mmol/kg b.w.) of gadodiamide injection and (b) the standard dose (0.1 mmol/kg b.w.) of Gd-DTPA, in patients with recurrent symptoms after surgery for lumbar disc herniation. Material and Methods: Twenty patients with recurrent or sustained symptoms after surgery for lumbar disc herniations were examined. MR imaging (0.3 T) was first performed before and after Gd-DTPA at 0.1 mmol/kg b.w., and then within one month (17 patients) or within 3 months (3 patients) before and after gadodiamide injection at 0.3 mmol/kg b.w. The examinations were first evaluated by 2 neuroradiologists blinded to dose but not to patient as the images were presented in pairs. Six months later the same investigators evaluated the examinations again, this time blinded to both dose and patient. Results: At the evaluation in pairs (with the investigators blinded to dose only) the high-dose examinations were considered the most informative (p=0.05). However, at the later evaluation (with the investigators blinded both to dose and patient) no significant difference between high and standard dose was found regarding diagnosis or diagnostic certainty. Conclusion: In this study the high-dose contrast enhancement of MR imaging at 0.3 T did not increase the diagnostic information for differentiating between scar and recurrent hernia. The high-dose images were considered more informative when evaluated in pairs, but gave no additional or different information when evaluated separately. The study also indicated that comparisons in pairs should be interpreted with caution. (orig.).

  6. MR imaging in recurrent pain after back surgery. A comparative study using standard and high doses of gadolinium contrast agents

    International Nuclear Information System (INIS)

    Aakeson, P.; Jonsson, E.; Holtaas, S.

    1996-01-01

    Purpose: To compare the diagnostic results following injection of (a) a high dose (0.3 mmol/kg b.w.) of gadodiamide injection and (b) the standard dose (0.1 mmol/kg b.w.) of Gd-DTPA, in patients with recurrent symptoms after surgery for lumbar disc herniation. Material and Methods: Twenty patients with recurrent or sustained symptoms after surgery for lumbar disc herniations were examined. MR imaging (0.3 T) was first performed before and after Gd-DTPA at 0.1 mmol/kg b.w., and then within one month (17 patients) or within 3 months (3 patients) before and after gadodiamide injection at 0.3 mmol/kg b.w. The examinations were first evaluated by 2 neuroradiologists blinded to dose but not to patient as the images were presented in pairs. Six months later the same investigators evaluated the examinations again, this time blinded to both dose and patient. Results: At the evaluation in pairs (with the investigators blinded to dose only) the high-dose examinations were considered the most informative (p=0.05). However, at the later evaluation (with the investigators blinded both to dose and patient) no significant difference between high and standard dose was found regarding diagnosis or diagnostic certainty. Conclusion: In this study the high-dose contrast enhancement of MR imaging at 0.3 T did not increase the diagnostic information for differentiating between scar and recurrent hernia. The high-dose images were considered more informative when evaluated in pairs, but gave no additional or different information when evaluated separately. The study also indicated that comparisons in pairs should be interpreted with caution. (orig.)

  7. Development of a conjugated gadolinium and cisplatin-gelatin possessing properties as an intravascular contrast agent for MR imaging

    International Nuclear Information System (INIS)

    Sonoda, Akinaga; Nitta, Norihisa; Ohta, Shinichi; Seko, Ayumi; Jo, Jun-ichiro; Morikawa, Shigehiro; Tabata, Yasuhiko; Takahashi, Masashi; Murata, Kiyoshi

    2009-01-01

    Purpose: The purpose of this study is to create a Gd-DTPA-Gel-Cis compound, which made from gadolinum (Gd), diethylenetriaminepentaacetic acid (DTPA)-dianhydride, cis-diamminedichloroplatinum (Cis) and bovine gelatin (Gel), that makes it possible to visualize Cis as intravascular agent under magnetic resonance imaging (MRI). Materials and methods: The amount of DTPA, Gd, and Cis were titrated to determine the new compound's conjugation ratio with gelatin. Considering these functions, Gd-DTPA-Gel-Cis was synthesized, and its stability in bovine serum was evaluated. In addition, the signal intensity of the diluted sample was measured under 1.5 Tesla MRI. Results: The synthesized 10 mg/ml of Gd-DTPA-Gel-Cis contained 42.84 μg/ml of Gd and 1.53 μg/ml of platinum. Gd-DTPA-Gel-Cis (100 mg/10 ml) enclosed into the cellulose dialysis tubing was placed in 90 ml of bovine serum and shaken reciprocally at 72 stroke/min at 37 deg. C. Partial release of free Pt was shown at 6 and 24 h, but no release of Gd occurred for a 24-h period. And high stability of Gd conjugated to DTPA-Gel-Cis. This result suggests possible anti-tumor effectiveness and high stability of Gd conjugated to DTPA-Gel-Cis. The diluted sample presented high signal intensity under 1.5 Tesla MRI. Conclusion: Gd-DTPA-Gel-Cis has been developed successfully and we have proven its stability and contrast ability in MRI.

  8. Prevalence of NSF following intravenous gadolinium-contrast media administration in dialysis patients with endstage renal disease

    Energy Technology Data Exchange (ETDEWEB)

    Heinz-Peer, Gertraud, E-mail: gertraud.heinz@meduniwien.ac.a [Department of Radiology, Medical University of Vienna (Austria); Neruda, Anita [Department of Radiology, Medical University of Vienna (Austria); Watschinger, Bruno; Vychytil, Andreas [Department of Nephrology, Medical University of Vienna (Austria); Geusau, Alexandra [Department of Dermatology, Medical University of Vienna (Austria); Haumer, Markus [Department of Internal Medicine II, Medical University of Vienna (Austria); Weber, Michael [Department of Radiology, Medical University of Vienna (Austria)

    2010-10-15

    Purpose: To evaluate the prevalence of nephrogenic systemic fibrosis (NSF) in a patient population being at highest risk for developing this disease and to evaluate possible risk factors. Materials and methods: The radiological records of 552 patients with ESRD being on hemodialysis (HD) or peritoneal dialysis (PD) were retrospectively reviewed to identify whether the patients underwent MR-examinations with or without intravenous administration of GBCA. In case of exposure to GBCA, the number of contrast injections, the benchmark and the cumulative doses of GBCA, and possible cofactors regarding pathogenesis of NSF were recorded. Diagnosis of NSF was confirmed either by deep skin biopsy or by review of medical and histopathological records. Data of NSF patients were compared with data of dialysis patients who did not develop NSF after MR-examinations. Results: 146 dialysis patients underwent MRI without i.v.-administration of GBCA. No case of NSF was observed in this patient population. 195/552 patients proved to have a total number of 325 well-documented exposures to GBCA. Seven different types of GBCA were used during these MR-examinations. NSF prevalence rate was 1.6%. One patient died of NSF. Three different types of GBCA were involved in 6 NSF cases. 4/6 proved to be confounded cases. The cumulative dose of GBCA, history of thrombosis, recent surgery, and the combination of HD and PD proved to be significant cofactors for the development of NSF (p < .05). No significant difference regarding residual renal clearance (p = .898) and residual urine volume (p = .083) was found between NSF and non-NSF patients. Conclusion: The prevalence of NSF proved to be much lower in this high risk patient group being exposed to GBCA compared to the literature. NSF was not observed in ESRD patients undergoing MRI without administration of GBCA. Our data support a positive association between cumulative dose of GBCA and development of NSF. No positive association was found

  9. Target binding improves relaxivity in aptamer-gadolinium conjugates.

    Science.gov (United States)

    Bernard, Elyse D; Beking, Michael A; Rajamanickam, Karunanithi; Tsai, Eve C; Derosa, Maria C

    2012-12-01

    MRI contrast agents (CA) have been heavily used over the past several decades to enhance the diagnostic value of the obtained images. From a design perspective, two avenues to improve the efficacy of contrast agents are readily evident: optimization of magnetic properties of the CA, and optimization of the pharmacokinetics and distribution of the CA in the patient. Contrast agents consisting of DNA aptamer-gadolinium(III) conjugates provide a single system in which these factors can be addressed simultaneously. In this proof-of-concept study, the 15mer thrombin aptamer was conjugated to diethylenetriaminepentaacetic (DTPA) dianhydride to form a monoamide derivative of the linear open-chain chelate present in the commonly used contrast agent Magnevist(®). The stability of the conjugated DNA aptamer-DTPA-Gd(III) chelate in a transmetallation study using Zn(II) was found to be similar to that reported for DTPA-Gd(III). Relaxivity enhancements of 35 ± 4 and 20 ± 1 % were observed in the presence of thrombin compared to a control protein at fields of 9.4 and 1.5 T, respectively. The inclusion of spacers between the aptamer and the DTPA to eliminate possible steric effects was also investigated but not found to improve the relaxation enhancement achieved in comparison to the unaltered aptamer conjugate.

  10. Usefulness of combining gadolinium-ethoxybenzyl-diethylenetriamine pentaacetic acid-enhanced magnetic resonance imaging and contrast-enhanced ultrasound for diagnosing the macroscopic classification of small hepatocellular carcinoma

    Energy Technology Data Exchange (ETDEWEB)

    Kobayashi, Tomoki; Aikata, Hiroshi; Hatooka, Masahiro; Morio, Kei; Morio, Reona; Kan, Hiromi; Fujino, Hatsue; Fukuhara, Takayuki; Masaki, Keiichi; Ohno, Atsushi; Naeshiro, Noriaki; Nakahara, Takashi; Honda, Yohji; Murakami, Eisuke; Kawaoka, Tomokazu; Tsuge, Masataka; Hiramatsu, Akira; Imamura, Michio; Kawakami, Yoshiiku; Hyogo, Hideyuki; Takahashi, Shoichi [Hiroshima University Hospital, Department of Gastroenterology and Metabolism, Hiroshima (Japan); Chayama, Kazuaki [Hiroshima University Hospital, Department of Gastroenterology and Metabolism, Hiroshima (Japan); Hiroshima University, Liver Research Project Center, Hiroshima (Japan)

    2015-11-15

    Non-simple nodules in hepatocellular carcinoma (HCC) correlate with poor prognosis. Therefore, we examined the diagnostic ability of gadolinium-ethoxybenzyl-diethylenetriamine pentaacetic acid-enhanced magnetic resonance imaging (EOB-MRI) and contrast-enhanced ultrasound (CEUS) for diagnosing the macroscopic classification of small HCCs. A total of 85 surgically resected nodules (≤30 mm) were analyzed. HCCs were pathologically classified as simple nodular (SN) and non-SN. By evaluating hepatobiliary phase (HBP) of EOB-MRI and Kupffer phase of CEUS, the diagnostic abilities of both modalities to correctly distinguish between SN and non-SN were compared. Forty-six nodules were diagnosed as SN and the remaining 39 nodules as non-SN. The area under the ROC curve (AUROCs, 95 % confidence interval) for the diagnosis of non-SN were EOB-MRI, 0.786 (0.682-0.890): CEUS, 0.784 (0.679-0.889), in combination, 0.876 (0.792-0.959). The sensitivity, specificity, and accuracy were 64.1 %, 95.7 %, and 81.2 % in EOB-MRI, 56.4 %, 97.8 %, and 78.8 % in CEUS, and 84.6 %, 95.7 %, and 90.6 % in combination, respectively. High diagnostic ability was obtained when diagnosed in both modalities combined. The sensitivity was especially statistically significant compared to CEUS. Combined diagnosis by EOB-MRI and CEUS can provide high-quality imaging assessment for determining non-SN in small HCCs. (orig.)

  11. Usefulness of combining gadolinium-ethoxybenzyl-diethylenetriamine pentaacetic acid-enhanced magnetic resonance imaging and contrast-enhanced ultrasound for diagnosing the macroscopic classification of small hepatocellular carcinoma.

    Science.gov (United States)

    Kobayashi, Tomoki; Aikata, Hiroshi; Hatooka, Masahiro; Morio, Kei; Morio, Reona; Kan, Hiromi; Fujino, Hatsue; Fukuhara, Takayuki; Masaki, Keiichi; Ohno, Atsushi; Naeshiro, Noriaki; Nakahara, Takashi; Honda, Yohji; Murakami, Eisuke; Kawaoka, Tomokazu; Tsuge, Masataka; Hiramatsu, Akira; Imamura, Michio; Kawakami, Yoshiiku; Hyogo, Hideyuki; Takahashi, Shoichi; Chayama, Kazuaki

    2015-11-01

    Non-simple nodules in hepatocellular carcinoma (HCC) correlate with poor prognosis. Therefore, we examined the diagnostic ability of gadolinium-ethoxybenzyl-diethylenetriamine pentaacetic acid-enhanced magnetic resonance imaging (EOB-MRI) and contrast-enhanced ultrasound (CEUS) for diagnosing the macroscopic classification of small HCCs. A total of 85 surgically resected nodules (≤30 mm) were analyzed. HCCs were pathologically classified as simple nodular (SN) and non-SN. By evaluating hepatobiliary phase (HBP) of EOB-MRI and Kupffer phase of CEUS, the diagnostic abilities of both modalities to correctly distinguish between SN and non-SN were compared. Forty-six nodules were diagnosed as SN and the remaining 39 nodules as non-SN. The area under the ROC curve (AUROCs, 95% confidence interval) for the diagnosis of non-SN were EOB-MRI, 0.786 (0.682-0.890): CEUS, 0.784 (0.679-0.889), in combination, 0.876 (0.792-0.959). The sensitivity, specificity, and accuracy were 64.1%, 95.7%, and 81.2% in EOB-MRI, 56.4%, 97.8%, and 78.8% in CEUS, and 84.6%, 95.7%, and 90.6% in combination, respectively. High diagnostic ability was obtained when diagnosed in both modalities combined. The sensitivity was especially statistically significant compared to CEUS. Combined diagnosis by EOB-MRI and CEUS can provide high-quality imaging assessment for determining non-SN in small HCCs. • Non-SN has a higher frequency of MVI and intrahepatic metastasis than SN. • Macroscopic classification is useful to choose the treatment strategy for small HCCs. • Diagnostic ability for macroscopic findings of EOB-MRI and CEUS were statistically equal. • The diagnosis of macroscopic findings by individual modality has limitations. • Combined diagnosis of EOB-MRI and CEUS provides high diagnostic ability.

  12. Objective evaluation of acute adverse events and image quality of gadolinium-based contrast agents (gadobutrol and gadobenate dimeglumine) by blinded evaluation. Pilot study.

    Science.gov (United States)

    Semelka, Richard C; Hernandes, Mateus de A; Stallings, Clifton G; Castillo, Mauricio

    2013-01-01

    The purpose was to objectively evaluate a recently FDA-approved gadolinium-based contrast agent (GBCA) in comparison to our standard GBCA for acute adverse events and image quality by blinded evaluation. Evaluation was made of a recently FDA-approved GBCA, gadobutrol (Gadavist; Bayer), in comparison to our standard GBCA, gadobenate dimeglumine (MultiHance; Bracco), in an IRB- and HIPAA-compliant study. Both the imaging technologist and patient were not aware of the brand of the GBCA used. A total of 59 magnetic resonance studies were evaluated (59 patients, 31 men, 28 women, age range of 5-85 years, mean age of 52 years). Twenty-nine studies were performed with gadobutrol (22 abdominal and 7 brain studies), and 30 studies were performed with gadobenate dimeglumine (22 abdominal and 8 brain studies). Assessment was made of acute adverse events focusing on objective observations of vomiting, hives, and moderate and severe reactions. Adequacy of enhancement was rated as poor, fair and good by one of two experienced radiologists who were blinded to the type of agent evaluated. No patient experienced acute adverse events with either agent. The target minor adverse events of vomiting or hives, and moderate and severe reactions were not observed in any patient. Adequacy of enhancement was rated as good for both agents in all patients. Objective, blinded evaluation is feasible and readily performable for the evaluation of GBCAs. This proof-of-concept study showed that both GBCAs evaluated exhibited consistent good image quality and no noteworthy adverse events. Copyright © 2013 Elsevier Inc. All rights reserved.

  13. Contrast enhanced liver MRI in patients with primary sclerosing cholangitis: inverse appearance of focal confluent fibrosis on delayed phase MR images with hepatocyte specific versus extracellular gadolinium based contrast agents.

    Science.gov (United States)

    Husarik, Daniela B; Gupta, Rajan T; Ringe, Kristina I; Boll, Daniel T; Merkle, Elmar M

    2011-12-01

    To assess the enhancement pattern of focal confluent fibrosis (FCF) on contrast-enhanced hepatic magnetic resonance imaging (MRI) using hepatocyte-specific (Gd-EOB-DTPA) and extracellular (ECA) gadolinium-based contrast agents in patients with primary sclerosing cholangitis (PSC). After institutional review board approval, 10 patients with PSC (6 male, 4 female; 33-61 years) with 13 FCF were included in this retrospective study. All patients had a Gd-EOB-DTPA-enhanced liver MRI exam, and a comparison ECA-enhanced MRI. On each T1-weighted dynamic dataset, the signal intensity (SI) of FCF and the surrounding liver as well as the paraspinal muscle (M) were measured. In the Gd-EOB-DTPA group, hepatocyte phase images were also included. SI FCF/SI M, SI liver/SI M, and [(SI liver - SI FCF)/SI liver] were compared between the different contrast agents for each dynamic phase using the paired Student's t-test. There was no significant difference in SI FCF/SI M in all imaging phases. SI liver/SI M was significantly higher for the Gd-EOB-DTPA group in the delayed phase (P DTPA group, mean [(SI liver - SI FCF)/SI liver] were as follows (values for ECA group in parentheses): unenhanced phase: 0.26 (0.26); arterial phase: 0.01 (-0.31); portal venous phase (PVP): -0.05 (-0.26); delayed phase (DP): 0.14 (-0.54); and hepatocyte phase: 0.26. Differences were significant for the DP (P DTPA-enhanced images. Copyright © 2011 AUR. Published by Elsevier Inc. All rights reserved.

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

    Directory of Open Access Journals (Sweden)

    Noriyuki Koibuchi

    2016-08-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

    Lingott, Jana

    2016-01-05

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

  16. Subcellular SIMS imaging of gadolinium isotopes in human glioblastoma cells treated with a gadolinium containing MRI agent

    Science.gov (United States)

    Smith, Duane R.; Lorey, Daniel R.; Chandra, Subhash

    2004-06-01

    Neutron capture therapy is an experimental binary radiotherapeutic modality for the treatment of brain tumors such as glioblastoma multiforme. Recently, neutron capture therapy with gadolinium-157 has gained attention, and techniques for studying the subcellular distribution of gadolinium-157 are needed. In this preliminary study, we have been able to image the subcellular distribution of gadolinium-157, as well as the other six naturally abundant isotopes of gadolinium, with SIMS ion microscopy. T98G human glioblastoma cells were treated for 24 h with 25 mg/ml of the metal ion complex diethylenetriaminepentaacetic acid Gd(III) dihydrogen salt hydrate (Gd-DTPA). Gd-DTPA is a contrast enhancing agent used for MRI of brain tumors, blood-brain barrier impairment, diseases of the central nervous system, etc. A highly heterogeneous subcellular distribution was observed for gadolinium-157. The nuclei in each cell were distinctly lower in gadolinium-157 than in the cytoplasm. Even within the cytoplasm the gadolinium-157 was heterogeneously distributed. The other six naturally abundant isotopes of gadolinium were imaged from the same cells and exhibited a subcellular distribution consistent with that observed for gadolinium-157. These observations indicate that SIMS ion microscopy may be a viable approach for subcellular studies of gadolinium containing neutron capture therapy drugs and may even play a major role in the development and validation of new gadolinium contrast enhancing agents for diagnostic MRI applications.

  17. 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)

  18. Influence of delayed gadolinium enhanced MRI of cartilage (dGEMRIC) protocol on T2-mapping: is it possible to comprehensively assess knee cartilage composition in one post-contrast MR examination at 3 Tesla?

    Science.gov (United States)

    Verschueren, J; van Tiel, J; Reijman, M; Bron, E E; Klein, S; Verhaar, J A N; Bierma-Zeinstra, S M A; Krestin, G P; Wielopolski, P A; Oei, E H G

    2017-09-01

    To evaluate the possibility of assessing knee cartilage with T2-mapping and delayed gadolinium enhanced magnetic resonance imaging (MRI) of cartilage (dGEMRIC) in one post-contrast MR examination at 3 Tesla (T). T2 mapping was performed in 10 healthy volunteers at baseline; directly after baseline; after 10 min of cycling; and after 90 min delay, and in 16 osteoarthritis patients before and after intravenous administration of a double dose gadolinium dimeglumine contrast agent, reflecting key dGEMRIC protocol elements. Differences in T2 relaxation times between each timepoint and baseline were calculated for 6 cartilage regions using paired t tests or Wilcoxon signed-rank tests and the smallest detectable change (SDC). After cycling, a significant change in T2 relaxation times was found in the lateral weight-bearing tibial plateau (+1.0 ms, P = 0.04). After 90 min delay, significant changes were found in the lateral weight-bearing femoral condyle (+1.2 ms, P = 0.03) and the lateral weight-bearing tibial plateau (+1.3 ms, P = 0.01). In these regions of interests (ROIs), absolute differences were small and lower than the corresponding SDCs. T2-mapping after contrast administration only showed statistically significantly lower T2 relaxation times in the medial posterior femoral condyle (-2.4 ms, P T2 relaxation times that were not consistent and lower than the SDC in the majority of regions, our results suggest that T2-mapping and dGEMRIC can be performed reliably in a single imaging session to assess cartilage biochemical composition in knee osteoarthritis (OA) at 3 T. Copyright © 2017 Osteoarthritis Research Society International. Published by Elsevier Ltd. All rights reserved.

  19. Enrichment of gadolinium-157 and gadolinium-155 by laser method

    International Nuclear Information System (INIS)

    Xinjun, Su; Xiaowei, Zhang; Zhiquan, Li

    2008-01-01

    Laser isotope separation experiments of gadolinium by atomic vapor method have been performed. Gadolinium-157 and gadolinium-155 were selectively photoionized by means of three linearly polarized dye lasers, the excitation process of which is based on the polarization selection rules. Gramme-magnitude of enriched gadolinium was obtained and the total abundance of gadolinium-157 and gadolinium-155 was in excess of 80%, and the product rating exceeded 200 mg/h. (author)

  20. Improved paramagnetic chelate for molecular imaging with MRI

    International Nuclear Information System (INIS)

    Winter, Patrick; Athey, Phillip; Kiefer, Garry; Gulyas, Gyongyi; Frank, Keith; Fuhrhop, Ralph; Robertson, David; Wickline, Samuel; Lanza, Gregory

    2005-01-01

    The relaxivity and transmetallation of two lipophilic paramagnetic chelates incorporated onto perfluorocarbon nanoparticles, i.e., gadolinium-methoxy-tetraazacyclododecane-tetraacetic acid phosphatidylethanolamine (Gd-MeO-DOTA-PE) and gadolinium-methoxy-tetraazacyclododecane-tetraacetic acid triglycine phosphatidylethanolamine (Gd-MeO-DOTA-triglycine-PE (Gd-MeO-DOTA-triglycine-PE)), were compared to a prototypic gadolinium-diethylene-triamine-pentaacetic acid bis-oleate (Gd-DTPA-BOA) paramagnetic formulation. Nanoparticles with MeO-DOTA-based chelates demonstrated higher relaxivity (40% higher for Gd-MeO-DOTA-PE and 55% higher for Gd-MeO-DOTA-triglycine-PE) and less transmetallation than the original Gd-DTPA-BOA-based agent

  1. Improved paramagnetic chelate for molecular imaging with MRI

    Science.gov (United States)

    Winter, Patrick; Athey, Phillip; Kiefer, Garry; Gulyas, Gyongyi; Frank, Keith; Fuhrhop, Ralph; Robertson, David; Wickline, Samuel; Lanza, Gregory

    2005-05-01

    The relaxivity and transmetallation of two lipophilic paramagnetic chelates incorporated onto perfluorocarbon nanoparticles, i.e., gadolinium-methoxy-tetraazacyclododecane-tetraacetic acid phosphatidylethanolamine (Gd-MeO-DOTA-PE) and gadolinium-methoxy-tetraazacyclododecane-tetraacetic acid triglycine phosphatidylethanolamine (Gd-MeO-DOTA-triglycine-PE (Gd-MeO-DOTA-triglycine-PE)), were compared to a prototypic gadolinium-diethylene-triamine-pentaacetic acid bis-oleate (Gd-DTPA-BOA) paramagnetic formulation. Nanoparticles with MeO-DOTA-based chelates demonstrated higher relaxivity (40% higher for Gd-MeO-DOTA-PE and 55% higher for Gd-MeO-DOTA-triglycine-PE) and less transmetallation than the original Gd-DTPA-BOA-based agent.

  2. Chelating polymeric membranes

    KAUST Repository

    Peinemann, Klaus-Viktor; Villalobos Vazquez de la Parra, Luis Francisco; Hilke, Roland

    2015-01-01

    microporous chelating polymeric membrane. Embodiments include, but are not limited to, microporous chelating polymeric membranes, device comprising the membranes, and methods of using and making the same.

  3. Magnetic Resonance Imaging Contrast Agents: A Review of Literature

    Directory of Open Access Journals (Sweden)

    Zahra Sahraei

    2015-10-01

    Full Text Available  Magnetic Resonance Imaging (MRI contrast agents most commonly agents used in diagnosing different diseases. Several agents have been ever introduced with different peculiar characteristics. They vary in potency, adverse reaction and other specification, so it is important to select the proper agent in different situations. We conducted a systematic literature search in MEDLINE/PUBMED, Web of Science (ISI, Scopus,Google Scholar by using keywords "gadolinium" and "MRI contrast Medias", "Gadofosvest", "Gadobenate" and "Gadoxetate". The most frequent contrast media agents made based on gadolinium (Gd. These are divided into two categories based on the structure of their chelating parts, linear agents and macrocyclic agents. All characteristics of contrast media factors, including efficiency, kinetic properties, stability, side effects and the rate of resolution are directly related to the structure of chelating part of that formulation.In vitro data has shown that the macrocyclic compounds are the most stable Gd-CA as they do not bind to serum proteins, they all possess similar and relatively low relaxivity and the prevalence of Nephrogenic Systemic Fibrosis (NSF has decreased by increasing the use of macrocyclic agents in recent years. No cases of NSF have been recorded after the administration of any of the high-relaxivity protein interacting agents, the vascular imaging agent gadofosveset trisodium (Ablavar, the hepatic imaging agent gadoxetate meglumine (Eovist, and the multipurpose agent gadobenate dimeglumine (MultiHance. In pregnancy and lactating women, stable macrocyclic agent is recommended.

  4. A basic research of gadolinium hydrogen [alpha], [alpha]', [alpha]'', [alpha]'''-tetramethly- 1,4,7,10-tetraazacyclododecane- 1,4,7,10-tetraacetate with high complex stability as a contrast agent for MRI

    Energy Technology Data Exchange (ETDEWEB)

    Seri, Shigemi; Hashiguchi, Yuji; Kubomura, Kan; Abe, Yukiko; Iguchi, Toshio; Iwai, Kumiko [Nihon Medi-Physics Co., Ltd., Sodegaura, Chiba (Japan); Watanabe, Tokuko

    1993-05-01

    Gadolinium hydrogen [alpha], [alpha]', [alpha]'', [alpha]'''-tetramethyl- 1,4,7,10-tetraazacyclododecane- 1,4,7,10-tetraacetate (abbreviated Gd-DOTMA) was developed as a new contrast agent for magnetic resonance imaging. Our study focused on the evaluation of the pharmaceutical properties as in vivo agent. The new modified process by which Gd-DOTMA was synthesized resulted in high yields of this agent. A high stability constant of 10[sup 26] fro Gd-DOTMA was determined at physiological pH. It is more stable than Gd complex with tetraazacyclododecanetetraacetic acid (which is regarded as the most stable Gd complex). The strong T[sub 1] relaxivities of 4.0 and 3.7 (mM [center dot] s)[sup -1] at 0.5 tesla and 1.5 tesla were measured in the aqueous solution. The osmolarity of 0.5 M solution, dissolved with equal amounts of meglumine as a solubilizer is 1020 mOsmol/kg. This contrasting agent was studied in vivo by using rats as the experimental group. The agent showed strong enhancement of transplanted tumors within the rat population studied. This compound is rapidly excreted by the kidneys, and has a half-life of 26 min in blood. The median lethal dose (LD[sub 50] value) of the stable Gd-DOTMA has a favorable tolerance of over 12.3 mmol/kg. (author).

  5. A basic research of gadolinium hydrogen α, α', α'', α'''-tetramethly- 1,4,7,10-tetraazacyclododecane- 1,4,7,10-tetraacetate with high complex stability as a contrast agent for MRI

    International Nuclear Information System (INIS)

    Seri, Shigemi; Hashiguchi, Yuji; Kubomura, Kan; Abe, Yukiko; Iguchi, Toshio; Iwai, Kumiko; Watanabe, Tokuko.

    1993-01-01

    Gadolinium hydrogen α, α', α'', α'''-tetramethyl- 1,4,7,10-tetraazacyclododecane- 1,4,7,10-tetraacetate (abbreviated Gd-DOTMA) was developed as a new contrast agent for magnetic resonance imaging. Our study focused on the evaluation of the pharmaceutical properties as in vivo agent. The new modified process by which Gd-DOTMA was synthesized resulted in high yields of this agent. A high stability constant of 10 26 fro Gd-DOTMA was determined at physiological pH. It is more stable than Gd complex with tetraazacyclododecanetetraacetic acid (which is regarded as the most stable Gd complex). The strong T 1 relaxivities of 4.0 and 3.7 (mM · s) -1 at 0.5 tesla and 1.5 tesla were measured in the aqueous solution. The osmolarity of 0.5 M solution, dissolved with equal amounts of meglumine as a solubilizer is 1020 mOsmol/kg. This contrasting agent was studied in vivo by using rats as the experimental group. The agent showed strong enhancement of transplanted tumors within the rat population studied. This compound is rapidly excreted by the kidneys, and has a half-life of 26 min in blood. The median lethal dose (LD 50 value) of the stable Gd-DOTMA has a favorable tolerance of over 12.3 mmol/kg. (author)

  6. Room temperature ferromagnetic gadolinium silicide nanoparticles

    Science.gov (United States)

    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.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2014-08-15

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

  8. Exact monitoring of aortic diameters in Marfan patients without gadolinium contrast: intraindividual comparison of 2D SSFP imaging with 3D CE-MRA and echocardiography

    International Nuclear Information System (INIS)

    Veldhoen, Simon; Behzadi, Cyrus; Derlin, Thorsten; Henes, Frank Oliver; Adam, Gerhard; Bannas, Peter; Rybczinsky, Meike; Kodolitsch, Yskert von; Sheikhzadeh, Sara; Bley, Thorsten Alexander

    2015-01-01

    To assess whether ECG-gated non-contrast 2D steady-state free precession (SSFP) imaging allows for exact monitoring of aortic diameters in Marfan syndrome (MFS) patients using non-ECG-gated contrast-enhanced 3D magnetic resonance angiography (CE-MRA) and echocardiography for intraindividual comparison. Non-ECG-gated CE-MRA and ECG-gated non-contrast SSFP at 1.5 T were prospectively performed in 50 patients. Two readers measured aortic diameters on para-sagittal images identically aligned with the aortic arch at the sinuses of Valsalva, sinotubular junction, ascending/descending aorta and aortic arch. Image quality was assessed on a three-point scale. Aortic root diameters acquired by echocardiography were used as reference. Intra- and interobserver variances were smaller for SSFP at the sinuses of Valsalva (p = 0.002; p = 0.002) and sinotubular junction (p = 0.014; p = 0.043). Image quality was better in SSFP than in CE-MRA at the sinuses of Valsalva (p < 0.0001), sinotubular junction (p < 0.0001) and ascending aorta (p = 0.02). CE-MRA yielded higher diameters than SSFP at the sinuses of Valsalva (mean bias, 2.5 mm; p < 0.0001), and comparison with echocardiography confirmed a higher bias for CE-MRA (7.2 ± 3.4 mm vs. SSFP, 4.7 ± 2.6 mm). ECG-gated non-contrast 2D SSFP imaging provides superior image quality with higher validity compared to non-ECG-gated contrast-enhanced 3D imaging. Since CE-MRA requires contrast agents with potential adverse effects, non-contrast SSFP imaging is an appropriate alternative for exact and riskless aortic monitoring of MFS patients. (orig.)

  9. Exact monitoring of aortic diameters in Marfan patients without gadolinium contrast: intraindividual comparison of 2D SSFP imaging with 3D CE-MRA and echocardiography

    Energy Technology Data Exchange (ETDEWEB)

    Veldhoen, Simon [University Medical Center Wuerzburg, Department of Diagnostic and Interventional Radiology, Bavaria (Germany); University Medical Center Hamburg-Eppendorf, Department of Diagnostic and Interventional Radiology, Hamburg (Germany); Behzadi, Cyrus; Derlin, Thorsten; Henes, Frank Oliver; Adam, Gerhard; Bannas, Peter [University Medical Center Hamburg-Eppendorf, Department of Diagnostic and Interventional Radiology, Hamburg (Germany); Rybczinsky, Meike; Kodolitsch, Yskert von; Sheikhzadeh, Sara [University Medical Center Hamburg-Eppendorf, Department of General and Interventional Cardiology, Hamburg (Germany); Bley, Thorsten Alexander [University Medical Center Wuerzburg, Department of Diagnostic and Interventional Radiology, Bavaria (Germany)

    2014-10-15

    To assess whether ECG-gated non-contrast 2D steady-state free precession (SSFP) imaging allows for exact monitoring of aortic diameters in Marfan syndrome (MFS) patients using non-ECG-gated contrast-enhanced 3D magnetic resonance angiography (CE-MRA) and echocardiography for intraindividual comparison. Non-ECG-gated CE-MRA and ECG-gated non-contrast SSFP at 1.5 T were prospectively performed in 50 patients. Two readers measured aortic diameters on para-sagittal images identically aligned with the aortic arch at the sinuses of Valsalva, sinotubular junction, ascending/descending aorta and aortic arch. Image quality was assessed on a three-point scale. Aortic root diameters acquired by echocardiography were used as reference. Intra- and interobserver variances were smaller for SSFP at the sinuses of Valsalva (p = 0.002; p = 0.002) and sinotubular junction (p = 0.014; p = 0.043). Image quality was better in SSFP than in CE-MRA at the sinuses of Valsalva (p < 0.0001), sinotubular junction (p < 0.0001) and ascending aorta (p = 0.02). CE-MRA yielded higher diameters than SSFP at the sinuses of Valsalva (mean bias, 2.5 mm; p < 0.0001), and comparison with echocardiography confirmed a higher bias for CE-MRA (7.2 ± 3.4 mm vs. SSFP, 4.7 ± 2.6 mm). ECG-gated non-contrast 2D SSFP imaging provides superior image quality with higher validity compared to non-ECG-gated contrast-enhanced 3D imaging. Since CE-MRA requires contrast agents with potential adverse effects, non-contrast SSFP imaging is an appropriate alternative for exact and riskless aortic monitoring of MFS patients. (orig.)

  10. Use of gadolinium-DTPA

    International Nuclear Information System (INIS)

    Bydder, G.

    1990-01-01

    Early in the development of magnetic resonance imaging (MRI) it was apparent that a high level of soft tissue contrast was available de novo and it was thought that the need for externally administered contrast agents might be small. This observation was tempered by the fact that separation of tumor from edema was frequently better with contrast-enhanced X-ray computed tomography (CT) than with unenhanced MRI. It was therefore felt that a contrast agent might be needed for MRI. At the end of 1983 the first parenteral agent, gadolinium diethylene triamine pentaacetic acid (Gd-DTPA) was used in volunteers, and clinical studies began in 1984. This paper discusses how, at present, Gd-DTPA, oral, and intravenous iron compounds are in clinical use

  11. Enhancement effects and relaxivities of gadolinium-DTPA at 1.5 versus 3 tesla. A phantom study

    International Nuclear Information System (INIS)

    Sasaki, Makoto; Shibata, Eri; Kanbara, Yoshiyuki; Ehara, Shigeru

    2005-01-01

    The purpose of this study was to investigate the difference in enhancement effects and relaxivities of the gadolinium chelate at 1.5 and 3 Tesla (T) and to elucidate the contribution of the high magnetic field to contrast enhancement in spin-echo (SE) and gradient-echo (GRE) images. Phantoms containing water with or without gadopentetate dimeglumine (Gd-DTPA) at different concentrations were scanned using 1.5T and 3T MRI scanners of the same manufacturer and under the same temperature conditions and scanning parameters. Relaxivities of gadolinium, R 1 and R 2 , were estimated from serial T 1 and T 2 values of the phantoms using linear regression. Contrast enhancement ratios in SE and GRE T 1 -weighted images were compared at 1.5 and 3T. The R 1 and R 2 of Gd-DTPA at 1.5 and 3T were 4.79 and 5.14, and 4.50 and 5.09, respectively. Although the relaxivities at 3T were slightly lower than those at 1.5T, the contrast enhancement ratio improved in both SE and GRE images as a result of T 1 prolongation of the water at 3T. The decrease in relaxivities of the Gd-DTPA at 3T appears to be so small that T 1 prolongation of the water improves contrast enhancement, suggesting a potential clinical advantage in administration of Gd-DTPA at high field strength. (author)

  12. Evaluation of the in vitro stability of gadolinium (III) polyoxometalates

    International Nuclear Information System (INIS)

    Crooks, William J.; Choppin, Gregory R.; Rogers, Buck E.; Welch, Michael

    1997-01-01

    The gadolinium chelates of lacunary polyoxometalates were evaluated for in vitro stability against rat serum, diethylenetriaminepentaacetic acid (DTPA), endogenous metal cations, and DTPA-doped rat serum. The chelates dissociated rapidly in rat serum. Challenges by DTPA gave relatively slower dissociation rates, whereas challenges by endogenous metal cations (Fe(III), Zn(II), and Cu(II)) occurred at a rate comparable to the serum challenge, suggesting the instability in serum is due to a transmetalation mechanism. Challenges by DTPA-doped serum gave slower rates of dissociation than in native serum, verifying the transmetalation mechanism

  13. Lectin conjugates as biospecific contrast agents for MRI. Coupling of Lycopersicon esculentum agglutinin to linear water-soluble DTPA-loaded oligomers.

    Science.gov (United States)

    Pashkunova-Martic, Irena; Kremser, Christian; Galanski, Markus; Schluga, Petra; Arion, Vladimir; Debbage, Paul; Jaschke, Werner; Keppler, Bernhard

    2011-06-01

    Magnetic resonance imaging (MRI) requires synthesis of contrast media bearing targeting groups and numerous gadolinium chelating groups generating high relaxivity. This paper explores the results of linking the gadolinium chelates to the targeting group, a protein molecule, via various types of linkers. Polycondensates of diethylenetriaminepentaacetic acid (DTPA) with either diols or diamines were synthesised and coupled to the targeting group, a lectin (Lycopersicon esculentum agglutinin, tomato lectin) which binds with high affinity to specific oligosaccharide configurations in the endothelial glycocalyx. The polycondensates bear up to four carboxylic groups per constitutive unit. Gd-chelate bonds are created through dative interactions with the unshared pair of electrons on each oxygen and nitrogen atom on DTPA. This is mandatory for complexation of Gd(III) and avoidance of the severe toxicity of free gadolinium ions. The polymer-DTPA compounds were characterised by (1)H NMR and mass spectrometry. The final lectin-DTPA-polycondensate conjugates were purified by fast protein liquid chromatography (FPLC). The capacity for specific binding was assessed, and the MRI properties were examined in order to evaluate the use of these oligomers as components of selective perfusional contrast agents.

  14. Gadolinium photoionization process

    Science.gov (United States)

    Paisner, Jeffrey A.; Comaskey, Brian J.; Haynam, Christopher A.; Eggert, Jon H.

    1993-01-01

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

  15. Investigating tumor perfusion by hyperpolarized (13) C MRI with comparison to conventional gadolinium contrast-enhanced MRI and pathology in orthotopic human GBM xenografts

    DEFF Research Database (Denmark)

    Park, Ilwoo; von Morze, Cornelius; Lupo, Janine M

    2016-01-01

    glioblastoma (GBM) model for the characterization of tumor perfusion and compared with standard Gd-based dynamic susceptibility contrast (DSC) MRI data and immunohistochemical analysis from resected brains. Distinct HMCP perfusion characteristics were observed within the GBM tumors compared with contralateral...... for tumor that exhibited high levels of hyperpolarized HMCP signal. The results from this study have demonstrated that hyperpolarized HMCP data can be used as an indicator of tumor perfusion in an orthotopic xenograft model for GBM. Magn Reson Med, 2016. © 2016 Wiley Periodicals, Inc....

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

    Directory of Open Access Journals (Sweden)

    Nima Kasraie

    2011-01-01

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

  17. Optimal gadolinium dose level for magnetic resonance imaging (MRI) contrast enhancement of U87-derived tumors in athymic nude rats for the assessment of photodynamic therapy

    Science.gov (United States)

    Cross, Nathan; Varghai, Davood; Flask, Chris A.; Feyes, Denise K.; Oleinick, Nancy L.; Dean, David

    2009-02-01

    This study aims to determine the effect of varying gadopentetate dimeglumine (Gd-DTPA) dose on Dynamic Contrast Enhanced-Magnetic Resonance Imaging (DCE-MRI) tracking of brain tumor photodynamic therapy (PDT) outcome. Methods: We injected 2.5 x 105 U87 cells (derived from human malignant glioma) into the brains of six athymic nude rats. After 9, 12, and 13 days DCE-MRI images were acquired on a 9.4 T micro-MRI scanner before and after administration of 100, 150, or 200 μL of Gd-DTPA. Results: Tumor region normalized DCE-MRI scan enhancement at peak was: 1.217 over baseline (0.018 Standard Error [SE]) at the 100 μL dose, 1.339 (0.013 SE) at the 150 μL dose, and 1.287 (0.014 SE) at the 200 μL dose. DCE-MRI peak tumor enhancement at the 150 μL dose was significantly greater than both the 100 μL dose (p DTPA dose provided the greatest T1 weighted contrast enhancement, while minimizing negative T2* effects, in DCE-MRI scans of U87-derived tumors. Maximizing Gd-DTPA enhancement in DCE-MRI scans may assist development of a clinically robust (i.e., unambiguous) technique for PDT outcome assessment.

  18. Method validation for determination of gadolinium (III) and diethyl tetraamine pentaacetic acid (DTPA) ligand amount determination in Gd-DTPA contrast agent

    International Nuclear Information System (INIS)

    Rien Ritawidya; Martalena Ramli; Cecep Taufik Rustendi

    2014-01-01

    Gd-DTPA is one of the contrast agent which is important in Magnetic Resonance Imaging (MRI) application. The presence of free Gd (III) ion and free DTPA ligand is extremely toxic in human body. Therefore, it needs a method in order to determine free ion Gd (III) and free DTPA ligand concentration which then MRI would be applicable for clinical purpose. The analytical method that selected for the research was complexometric titration. The research was carried out in order to make validation method of free ion Gd (III) and free DTPA ligand determination, then validation criteria such as % recovery, % coefisien of variance and linearity could be obtained. Some experiments that had been done on determination of free Gd (III) with DTPA resulted in % recovery between 30,33% - 183,59%, the precision from %CV between 2,34% - 35,25% and linearity showed with value of R = 0,9525. Meanwhile on determination of DTPA with Gd (III) resulted in % recovery between 105.15% - 139,12%, %CV between 6,78% - 10,96% and R = 0,9525. Validation result indicates that determination method can not be used as a method to determine free ion Gd(III) and free DTPA ligand in contrast agent. (author)

  19. 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.

  20. Indication-related dosing for magnetic resonance contrast media

    International Nuclear Information System (INIS)

    Yuh, W.T.C.; Parker, J.R.; Carvlin, M.J.

    1997-01-01

    This presentation reviews the issue of contrast media dosing and imaging protocols for the optimal MR imaging detection and characterization of pathology. The cumulative clinical experience gained in performing contrast-enhanced MR examinations with gadolinium chelates indicates that a dose of 0.1 mmol/kg body weight provides safe and effective enhancement of most CNS pathology. Doses lower than 0.1 mmol/kg have been shown to be inadequate for delineating all but selected types of CNS pathology, such as masses with a high lesion to background ratio on post-contrast images (acoustic neuromas) or lesions located in areas in which the normal tissue very rapidly takes up contrast agent (e. g. microadenomas in the pituitary gland). Recent clinical studies have suggested a role for high dose gadolinium administration (up to 0.3 mmol/kg) for the optimal detection and delineation of cerebral metastases or other small or poorly enhancing lesions. Differences in the histopathologic characteristics (capillary permeability, vascularity, location, size) of specific diseased tissues may require varying doses or even a different contrast agent to be used for optimal imaging results. As new MR contrast agents and new scanning techniques are introduced, the specific diagnostic question posed will likely determine the choice of pulse sequence, contrast agent and dose used. (orig.)

  1. 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

  2. SIMS imaging of gadolinium isotopes in tissue from Nephrogenic Systemic Fibrosis patients: Release of free Gd from magnetic resonance imaging (MRI) contrast agents

    Energy Technology Data Exchange (ETDEWEB)

    Abraham, Jerrold L. [Department of Pathology, SUNY Upstate Medical University, Syracuse, New York (United States); Chandra, Subhash [Cornell SIMS Laboratory, Department of Earth and Atmospheric Sciences, Cornell University, Ithaca, NY 14853 (United States)], E-mail: sc40@cornell.edu; Thakral, Charu [Department of Pathology, SUNY Upstate Medical University, Syracuse, New York (United States); Abraham, Joshua M. [Cornell SIMS Laboratory, Department of Earth and Atmospheric Sciences, Cornell University, Ithaca, NY 14853 (United States)

    2008-12-15

    Recently, Gd-based magnetic resonance imaging (MRI) contrast agents (GBMCA) have been linked to a new disease, Nephrogenic Systemic Fibrosis (NSF), with skin and systemic toxicity and death in certain patients with renal failure. Due to widespread use of GBMCA in diagnostic MRI, it is essential to study their excretion, metabolism, and target sites in cells and tissues. A CAMECA IMS-3f SIMS ion microscope and scanning electron microscopy (SEM) with energy dispersive X-ray spectroscopy (EDS) were used for imaging Gd isotopes in relation to calcium distributions in histologic sections of human tissues. SIMS imaging revealed two types of Gd localization in skin biopsies of patients who received GBMCA. The Gd was present in micrometer size deposits in association with calcium, and in detectable amounts in a more diffuse cellular distribution. Only the Gd-containing deposits associated with Ca and P were detectable using SEM/EDS. As only insoluble deposits remain in the biopsy tissues after aqueous and organic solvent processing of the tissue, our observations support release of free Gd from the GBMCA and selective localization of insoluble Gd in the target tissue from patients with NSF. This study opens new novel applications of SIMS for characterization of the safety of GBMCA.

  3. Using T2-Exchange from Ln3+DOTA-Based Chelates for Contrast-Enhanced Molecular Imaging of Prostate Cancer with MRI

    Science.gov (United States)

    2016-04-01

    thereby performing disease staging entirely non-invasively. Also, in contrast to PET/CT or SPECT/CT, disease diagnostics and therapy monitoring would...2011;6.e27370. 11. Zhang SR, Sherry AD. Physical characteristics of lanthanide com- plexes that act as magnetization transfer (MT) contrast agents. J...reper- fused and nonreperfused myocardial infarctions - MR imaging with dysprosium-DTPA-BMA in the pig. Acta Radiol 1996;37:18–26. 28. Nilsson S

  4. Diffusion-weighted imaging for assessment of synovial inflammation in juvenile idiopathic arthritis. A promising imaging biomarker as an alternative to gadolinium-based contrast agents

    Energy Technology Data Exchange (ETDEWEB)

    Barendregt, Anouk M.; Gulik, E.C. van [Academic Medical Center/University of Amsterdam, Department of Radiology, Amsterdam (Netherlands); Academic Medical Center/University of Amsterdam, Department of Pediatric Hematology, Immunology, Rheumatology and Infectious Disease, Emma Children' s Hospital, Amsterdam (Netherlands); Lavini, Cristina; Nusman, Charlotte M.; Hemke, Robert; Maas, Mario [Academic Medical Center/University of Amsterdam, Department of Radiology, Amsterdam (Netherlands); Berg, J.M. van den; Schonenberg-Meinema, Dieneke; Kuijpers, Taco W. [Academic Medical Center/University of Amsterdam, Department of Pediatric Hematology, Immunology, Rheumatology and Infectious Disease, Emma Children' s Hospital, Amsterdam (Netherlands); Dolman, Koert M. [Reade, Department of Pediatric Rheumatology, Amsterdam (Netherlands); Onze Lieve Vrouwe Gasthuis West, Department of Pediatric Rheumatology, Amsterdam (Netherlands); Onze Lieve Vrouwe Gasthuis Oost, Department of Pediatric Rheumatology, Amsterdam (Netherlands)

    2017-11-15

    To compare dynamic-contrast-enhanced MRI (DCE) and diffusion-weighted imaging (DWI) in quantifying synovial inflammation in juvenile idiopathic arthritis (JIA). Regions of interest (ROI) were drawn in the synovium of JIA patients on T1 DCE and T2 DWI, followed by extraction of the maximum enhancement (ME), maximum initial slope (MIS), time to peak (TTP), % of different time intensity curve shapes (TIC) and apparent diffusion coefficient (ADC) of the ROIs. Mann-Whitney-U test was used for comparing parameters between MRI-active and -inactive patients (defined by the juvenile arthritis MRI scoring system). Spearman's rank was used to analyse the correlation between DCE and DWI. Thirty-five JIA patients (18 MRI active and 17 MRI inactive) were included. Median age was 13.1 years and 71% were female. ME, MIS, TTP, % TIC 5 and ADC were significantly different in MRI-active versus MRI-inactive JIA with median ADC 1.49 x 10{sup -3} mm{sup 2}/s in MRI-active and 1.25 x 10{sup -3} mm{sup 2}/s in MRI-inactive JIA, p = 0.001, 95% confidence interval of difference in medians =0.11-0.53 x 10{sup -3} mm{sup 2}/s. ADC correlated to ME, MIS and TIC 5 shapes (r = 0.62, r = 0.45, r = -0.51, respectively, all p < 0.05). Similar to DCE parameters, DWI-derived ADC is significantly different in MRI-active JIA as compared to MRI-inactive JIA. The non-invasiveness of DWI combined with its possibility to detect synovial inflammation shows the potential of DWI. (orig.)

  5. Diffusion-weighted imaging for assessment of synovial inflammation in juvenile idiopathic arthritis. A promising imaging biomarker as an alternative to gadolinium-based contrast agents

    International Nuclear Information System (INIS)

    Barendregt, Anouk M.; Gulik, E.C. van; Lavini, Cristina; Nusman, Charlotte M.; Hemke, Robert; Maas, Mario; Berg, J.M. van den; Schonenberg-Meinema, Dieneke; Kuijpers, Taco W.; Dolman, Koert M.

    2017-01-01

    To compare dynamic-contrast-enhanced MRI (DCE) and diffusion-weighted imaging (DWI) in quantifying synovial inflammation in juvenile idiopathic arthritis (JIA). Regions of interest (ROI) were drawn in the synovium of JIA patients on T1 DCE and T2 DWI, followed by extraction of the maximum enhancement (ME), maximum initial slope (MIS), time to peak (TTP), % of different time intensity curve shapes (TIC) and apparent diffusion coefficient (ADC) of the ROIs. Mann-Whitney-U test was used for comparing parameters between MRI-active and -inactive patients (defined by the juvenile arthritis MRI scoring system). Spearman's rank was used to analyse the correlation between DCE and DWI. Thirty-five JIA patients (18 MRI active and 17 MRI inactive) were included. Median age was 13.1 years and 71% were female. ME, MIS, TTP, % TIC 5 and ADC were significantly different in MRI-active versus MRI-inactive JIA with median ADC 1.49 x 10 -3 mm 2 /s in MRI-active and 1.25 x 10 -3 mm 2 /s in MRI-inactive JIA, p = 0.001, 95% confidence interval of difference in medians =0.11-0.53 x 10 -3 mm 2 /s. ADC correlated to ME, MIS and TIC 5 shapes (r = 0.62, r = 0.45, r = -0.51, respectively, all p < 0.05). Similar to DCE parameters, DWI-derived ADC is significantly different in MRI-active JIA as compared to MRI-inactive JIA. The non-invasiveness of DWI combined with its possibility to detect synovial inflammation shows the potential of DWI. (orig.)

  6. Gadolinium-enhanced MR angiography of the thoracoabdominal aorta diseases

    International Nuclear Information System (INIS)

    D'Ippolito, Giuseppe; Wolosker, Nelson; Galvao Filho, Mario; Kalil, Jorge A.; Wolosker, Angela; Borri, Maria Lucia

    1998-01-01

    Gadolinium-enhanced MR angiography (GEMRA) of the thoracoabdominal aorta is a noninvasive technique that can rapidly delineate the branch vessels diseases, without flow or respiration artifacts, obtained with non contrast MRA. The objective of this paper is to show the main clinical applications of GEMRA, compared to non contrast sequences. We have evaluated 30 patients with thorocoabdominal aorta diseases. These patients have been examined with GEMRA (3D, FFE sequences) obtained after 30 mlIV contrast injection and non contrast MRA (2D-TOF sequences). In our experience, gadolinium-enhanced MRA is a high resolution and speedy technique with advantages over non contrast MRA. (author)

  7. Signal intensity at unenhanced T1-weighted magnetic resonance in the globus pallidus and dentate nucleus after serial administrations of a macrocyclic gadolinium-based contrast agent in children

    Energy Technology Data Exchange (ETDEWEB)

    Rossi Espagnet, Maria Camilla; Bernardi, Bruno; Figa-Talamanca, Lorenzo [Ospedale Pediatrico Bambino Gesu, IRCCS, Neuroradiology Unit, Imaging Department, Rome (Italy); Pasquini, Luca [Ospedale Pediatrico Bambino Gesu, IRCCS, Neuroradiology Unit, Imaging Department, Rome (Italy); University Sapienza, Neuroradiology Unit, Azienda Ospedaliera Sant' Andrea, Rome (Italy); Toma, Paolo [Ospedale Pediatrico Bambino Gesu, IRCCS, Department of Imaging, Rome (Italy); Napolitano, Antonio [Ospedale Pediatrico Bambino Gesu, IRCCS, Enterprise Risk Management, Medical Physics Department, Rome (Italy)

    2017-09-15

    Few studies have been conducted on the relations between T1-weighted signal intensity changes in the pediatric brain following gadolinium-based contrast agent (GBCA) exposure. The purpose of this study is to investigate the effect of multiple administrations of a macrocyclic GBCA on signal intensity in the globus pallidus and dentate nucleus of the pediatric brain on unenhanced T1-weighted MR images. This retrospective study included 50 patients, mean age: 8 years (standard deviation: 4.8 years), with normal renal function exposed to ≥6 administrations of the same macrocyclic GBCA (gadoterate meglumine) and a control group of 59 age-matched GBCA-naive patients. The globus pallidus-to-thalamus signal intensity ratio and dentate nucleus-to-pons signal intensity ratio were calculated from unenhanced T1-weighted images for both patients and controls. A mixed linear model was used to evaluate the effects on signal intensity ratios of the number of GBCA administrations, the time interval between administrations, age, radiotherapy and chemotherapy. T-test analyses were performed to compare signal intensity ratio differences between successive administrations and baseline MR signal intensity ratios in patients compared to controls. P-values were considered significant if <0.05. A significant effect of the number of GBCA administrations on relative signal intensities globus pallidus-to-thalamus (F[8]=3.09; P=0.002) and dentate nucleus-to-pons (F[8]=2.36; P=0.021) was found. The relative signal intensities were higher at last MR examination than at baseline (P<0.001). Quantitative analysis evaluation of globus pallidus:thalamus and dentate nucleus:pons of the pediatric brain demonstrated an increase after serial administrations of macrocyclic GBCA. Further research is necessary to fully understand GBCA pharmacokinetic in children. (orig.)

  8. Comparison of MRI properties between derivatized DTPA and DOTA gadolinium-dendrimer conjugates.

    Science.gov (United States)

    Nwe, K; Bernardo, M; Regino, C A S; Williams, M; Brechbiel, M W

    2010-08-15

    In this report we directly compare the in vivo and in vitro MRI properties of gadolinium-dendrimer conjugates of derivatized acyclic diethylenetriamine-N,N',N',N'',N''-pentaacetic acid (1B4M-DTPA) and macrocyclic 1,4,7,10-tetraazacyclododecane-N,N',N'',N'''-tetraacetic acid (C-DOTA). The metal-ligand chelates were pre-formed in alcohol prior to conjugation to the generation 4 PAMAM dendrimer (G4D), and the dendrimer-based agents were purified by Sephadex(R) G-25 column. The analysis and SE-HPLC data indicated chelate to dendrimer ratios of 30:1 and 28:1, respectively. Molar relaxivity measured at pH 7.4, 22 degrees C, and 3T are comparable (29.5 vs 26.9 mM(-1)s(-1)), and both conjugates are equally viable as MRI contrast agents based on the images obtained. The macrocyclic agent however exhibits a faster rate of clearance in vivo (t(1/2)=16 vs 29 min). Our conclusion is that the macrocyclic-based agent is the more suitable agent for in vivo use for these reasons combined with kinetic inertness associated with the Gd(III) DOTA complex stability properties. Published by Elsevier Ltd.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2008-01-15

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

  10. 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

  11. Use of gadolinium-DTPA in inflammatory skeletal diseases

    International Nuclear Information System (INIS)

    Mueller-Miny, H.; Reiser, M.; Erlemann, R.; Peters, P.E.

    1989-01-01

    In bacterial osteomyelitis and arthritis paraossal spreading is sensitively detected by gadolinium-DTPA. Abscessous cavities and membranes are better imaged than with T1- and T2-weighted MRT sequences without contrast medium. In chronic osteomylitis it is of advantage, that also florid inflammatory processes can be detected. Gadolinium-DTPA selectively induces a signal increase in the synovitic pannus, that allows the differentiation from articular effusion. In inflammed particular soft tissue only a retarded signal increase is detectable. (author)

  12. Gadolinium contrast-enhanced MRI sequence does not have an incremental value in the assessment of sacroiliitis in patients with early inflammatory back pain by using MRI in combination with pelvic radiographs: a 2-year follow-up study

    NARCIS (Netherlands)

    van Onna, M.; van Tubergen, A.; van der Heijde, D.; Jurik, A. G.; Landewé, R.

    2014-01-01

    To evaluate the potential incremental value in detecting sacroiliitis of the T1 post-gadolinium diethylenetriaminepenta-acetic acid (Gd-DTPA) MRI sequence of the sacroiliac joints (SIJ) compared with the combination of short tau inversion recovery (STIR) MRI sequence and pelvic radiographs in

  13. Chelation in Metal Intoxication

    Directory of Open Access Journals (Sweden)

    Swaran J.S. Flora

    2010-06-01

    Full Text Available Chelation therapy is the preferred medical treatment for reducing the toxic effects of metals. Chelating agents are capable of binding to toxic metal ions to form complex structures which are easily excreted from the body removing them from intracellular or extracellular spaces. 2,3-Dimercaprol has long been the mainstay of chelation therapy for lead or arsenic poisoning, however its serious side effects have led researchers to develop less toxic analogues. Hydrophilic chelators like meso-2,3-dimercaptosuccinic acid effectively promote renal metal excretion, but their ability to access intracellular metals is weak. Newer strategies to address these drawbacks like combination therapy (use of structurally different chelating agents or co-administration of antioxidants have been reported recently. In this review we provide an update of the existing chelating agents and the various strategies available for the treatment of heavy metals and metalloid intoxications.

  14. 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)

  15. An experimental phantom study of the effect of gadolinium-based MR contrast agents on PET attenuation coefficients and PET quantification in PET-MR imaging: application to cardiac studies.

    Science.gov (United States)

    O' Doherty, Jim; Schleyer, Paul

    2017-12-01

    Simultaneous cardiac perfusion studies are an increasing trend in PET-MR imaging. During dynamic PET imaging, the introduction of gadolinium-based MR contrast agents (GBCA) at high concentrations during a dual injection of GBCA and PET radiotracer may cause increased attenuation effects of the PET signal, and thus errors in quantification of PET images. We thus aimed to calculate the change in linear attenuation coefficient (LAC) of a mixture of PET radiotracer and increasing concentrations of GBCA in solution and furthermore, to investigate if this change in LAC produced a measurable effect on the image-based PET activity concentration when attenuation corrected by three different AC strategies. We performed simultaneous PET-MR imaging of a phantom in a static scenario using a fixed activity of 40 MBq [18 F]-NaF, water, and an increasing GBCA concentration from 0 to 66 mM (based on an assumed maximum possible concentration of GBCA in the left ventricle in a clinical study). This simulated a range of clinical concentrations of GBCA. We investigated two methods to calculate the LAC of the solution mixture at 511 keV: (1) a mathematical mixture rule and (2) CT imaging of each concentration step and subsequent conversion to LAC at 511 keV. This comparison showed that the ranges of LAC produced by both methods are equivalent with an increase in LAC of the mixed solution of approximately 2% over the range of 0-66 mM. We then employed three different attenuation correction methods to the PET data: (1) each PET scan at a specific millimolar concentration of GBCA corrected by its corresponding CT scan, (2) each PET scan corrected by a CT scan with no GBCA present (i.e., at 0 mM GBCA), and (3) a manually generated attenuation map, whereby all CT voxels in the phantom at 0 mM were replaced by LAC = 0.1 cm -1 . All attenuation correction methods (1-3) were accurate to the true measured activity concentration within 5%, and there were no trends in image

  16. Obligatory reduction of ferric chelates in iron uptake by soybeans.

    Science.gov (United States)

    Chaney, R L; Brown, J C; Tiffin, L O

    1972-08-01

    The contrasting Fe(2+) and Fe(3+) chelating properties of the synthetic chelators ethylenediaminedi (o-hydroxyphenylacetate) (EDDHA) and 4,7-di(4-phenylsulfonate)-1, 10-phenanthroline (bathophenanthrolinedisulfonate) (BPDS) were used to determine the valence form of Fe absorbed by soybean roots supplied with Fe(3+)-chelates. EDDHA binds Fe(3+) strongly, but Fe(2+) weakly; BPDS binds Fe(2+) strongly but Fe(3+) weakly. Addition of an excess of BPDS to nutrient solutions containing Fe(3+)-chelates inhibited soybean Fe uptake-translocation by 99+%; [Fe(II) (BPDS)(3)](4-) accumulated in the nutrient solution. The addition of EDDHA caused little or no inhibition. These results were observed with topped and intact soybeans. Thus, separation and absorption of Fe from Fe(3+)-chelates appear to require reduction of Fe(3+)-chelate to Fe(2+)-chelate at the root, with Fe(2+) being the principal form of Fe absorbed by soybean.

  17. Cell-permeable Ln(III) chelate-functionalized InP quantum dots as multimodal imaging agents.

    Science.gov (United States)

    Stasiuk, Graeme J; Tamang, Sudarsan; Imbert, Daniel; Poillot, Cathy; Giardiello, Marco; Tisseyre, Céline; Barbier, Emmanuel L; Fries, Pascal Henry; de Waard, Michel; Reiss, Peter; Mazzanti, Marinella

    2011-10-25

    Quantum dots (QDs) are ideal scaffolds for the development of multimodal imaging agents, but their application in clinical diagnostics is limited by the toxicity of classical CdSe QDs. A new bimodal MRI/optical nanosized contrast agent with high gadolinium payload has been prepared through direct covalent attachment of up to 80 Gd(III) chelates on fluorescent nontoxic InP/ZnS QDs. It shows a high relaxivity of 900 mM(-1) s(-1) (13 mM(-1 )s(-1) per Gd ion) at 35 MHz (0.81 T) and 298 K, while the bright luminescence of the QDs is preserved. Eu(III) and Tb(III) chelates were also successfully grafted to the InP/ZnS QDs. The absence of energy transfer between the QD and lanthanide emitting centers results in a multicolor system. Using this convenient direct grafting strategy additional targeting ligands can be included on the QD. Here a cell-penetrating peptide has been co-grafted in a one-pot reaction to afford a cell-permeable multimodal multimeric MRI contrast agent that reports cellular localization by fluorescence and provides high relaxivity and increased tissue retention with respect to commercial contrast agents.

  18. Macromolecular and dendrimer-based magnetic resonance contrast agents

    Energy Technology Data Exchange (ETDEWEB)

    Bumb, Ambika; Brechbiel, Martin W. (Radiation Oncology Branch, National Cancer Inst., National Inst. of Health, Bethesda, MD (United States)), e-mail: pchoyke@mail.nih.gov; Choyke, Peter (Molecular Imaging Program, National Cancer Inst., National Inst. of Health, Bethesda, MD (United States))

    2010-09-15

    Magnetic resonance imaging (MRI) is a powerful imaging modality that can provide an assessment of function or molecular expression in tandem with anatomic detail. Over the last 20-25 years, a number of gadolinium-based MR contrast agents have been developed to enhance signal by altering proton relaxation properties. This review explores a range of these agents from small molecule chelates, such as Gd-DTPA and Gd-DOTA, to macromolecular structures composed of albumin, polylysine, polysaccharides (dextran, inulin, starch), poly(ethylene glycol), copolymers of cystamine and cystine with GD-DTPA, and various dendritic structures based on polyamidoamine and polylysine (Gadomers). The synthesis, structure, biodistribution, and targeting of dendrimer-based MR contrast agents are also discussed

  19. 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.

  20. Contrast agents and cardiac MR imaging of myocardial ischemia: from bench to bedside

    International Nuclear Information System (INIS)

    Croisille, Pierre; Revel, Didier; Saeed, Maythem

    2006-01-01

    This review paper presents, in the first part, the different classes of contrast media that are already used or are in development for cardiac magnetic resonance imaging. A classification of the different types of contrast media is proposed based on the distribution of the compounds in the body, their type of relaxivity and their potential affinity to particular molecules. In the second part, the different uses of the extracellular type of T1-enhancing contrast agent for myocardial imaging is covered from the detection of stable coronary artery disease to the detection and characterization of chronic infarction. A particular emphasis is placed on the clinical use of gadolinium-chelates, which are the universally used type of MRI contrast agent in the clinical routine. Both approaches, first-pass magnetic resonance imaging (FP-MRI) as well as delayed-enhanced magnetic resonance imaging (DE-MRI), are covered in the different situations of acute and chronic myocardial infarction. (orig.)

  1. Combined use of contrast media containing iodine and gadolinium for imaging and intervention. A hitherto widely ignored topic in radiological practice; Kombinierter zeitnaher Einsatz jod- und gadoliniumhaltiger Kontrastmittel in der diagnostischen und interventionellen Radiologie. Ein bisher vernachlaessigtes Kapitel der radiologischen Praxis

    Energy Technology Data Exchange (ETDEWEB)

    Golder, W.

    2012-02-15

    The synchronous use of chemically different contrast media in the same body compartment is a challenge for the radiologist, whether it is scheduled or unexpected. However, to inject contrast media containing iodine and gadolinium at the same time can be a prerequisite for the examination of several organs or organ systems. Unlike other topics of contrast-enhanced imaging procedures, the difficulties encountered with double contrast injections have been widely ignored in the literature. In the absence of reliable data from experimental and clinical studies the radiologist is dependent on case reports, information provided by the contrast media manufacturers, personal communications, mostly scanty personal experiences and a skilful time management, in order to overcome the situation. Only the combination of X-ray, computed tomography and magnetic resonance arthrography can be performed without another thought. However, the more or less synchronous vascular application of contrast media containing iodine and gadolinium requires vigilance. The more seriously ill the patient is, the more caution is advised even if the decision on the combined administration has to be reached urgently. The following overview gives a description of the properties of contrast media containing iodine and gadolinium as far as interactions following simultaneous administration are concerned. Subsequently, the clinically relevant situations and constellations are outlined and analyzed. (orig.) [German] Die kombinierte Gabe zweier chemisch verschiedener Kontrastmittel stellt fuer den Radiologen eine Herausforderung dar. Der mehr oder weniger zeitgleiche Einsatz jod- und gadoliniumhaltiger Kontrastmittel kann sowohl geplant sein als auch bei der Untersuchung einer Reihe von Organen/Organsystemen unvorhergesehen notwendig werden. Im Gegensatz zu anderen Themen der kontrastverstaerkten Diagnostik ist dem Problem der Doppelinjektion in der Literatur bisher wenig Aufmerksamkeit geschenkt worden

  2. Use of contrast agents for liver MRI

    International Nuclear Information System (INIS)

    Ward, Janice

    2007-01-01

    Contrast-enhanced MRI is recognised as one of the most accurate imaging methods for investigating diseases of the liver. Uniquely several different types of contrast agents are available for liver MRI. They can be divided into non-specific extracellular fluid space (ECF), hepatocyte specific and reticulo-endothelial system (RES) specific agents. They are used to improve the detection of focal liver lesions by increasing normal-abnormal tissue contrast and to assist in lesion characterisation by demonstrating tissue perfusion and cellular function. ECF-gadolinium (Gd) chelates have been widely used in abdominal MRI for many years. They provide valuable information regarding the vascularisation and perfusion characteristics of lesions and assist in lesion detection, particularly of hypervascular lesions. The hepatocyte and RES-specific agents further improve lesion detection, provide important functional information and allow the distinction between hepatocellular and non-hepatocellular tumours. This article describes the different MR contrast agents and discusses their current status for diagnosing focal liver lesions. The importance of optimised technique and appropriate selection of contrast agent is emphasised

  3. 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.

  4. Contrast agents for MRI

    International Nuclear Information System (INIS)

    Bonnemain, B.

    1994-01-01

    Contrast agents MRI (Magnetic Resonance Imaging) have been developed to improve the diagnostic information obtained by this technic. They mainly interact on T1 and T2 parameters and increase consequently normal to abnormal tissues contrast. The paramagnetic agents which mainly act on longitudinal relaxation rate (T1) are gadolinium complexes for which stability is the main parameter to avoid any release of free gadolinium. The superparamagnetic agents that decrease signal intensity by an effect on transversal relaxation rate (T2) are developed for liver, digestive and lymph node imaging. Many area of research are now opened for optimal use of present and future contrast agents in MRI. (author). 28 refs., 4 tabs

  5. Chelating polymeric membranes

    KAUST Repository

    Peinemann, Klaus-Viktor

    2015-01-22

    The present application offers a solution to the current problems associated with recovery and recycling of precious metals from scrap material, discard articles, and other items comprising one or more precious metals. The solution is premised on a microporous chelating polymeric membrane. Embodiments include, but are not limited to, microporous chelating polymeric membranes, device comprising the membranes, and methods of using and making the same.

  6. Chelation in metal intoxication

    DEFF Research Database (Denmark)

    Aaseth, Jan; Skaug, Marit Aralt; Cao, yang

    2015-01-01

    The present review provides an update of the general principles for the investigation and use of chelating agents in the treatment of intoxications by metals. The clinical use of the old chelators EDTA (ethylenediamine tetraacetate) and BAL (2,3-dimercaptopropanol) is now limited due to the incon......The present review provides an update of the general principles for the investigation and use of chelating agents in the treatment of intoxications by metals. The clinical use of the old chelators EDTA (ethylenediamine tetraacetate) and BAL (2,3-dimercaptopropanol) is now limited due...... to the inconvenience of parenteral administration, their own toxicity and tendency to increase the neurotoxicity of several metals. The hydrophilic dithiol chelators DMSA (meso-2,3-dimercaptosuccinic acid) and DMPS (2,3-dimercapto-propanesulphonate) are less toxic and more efficient than BAL in the clinical treatment...... of heavy metal poisoning, and available as capsules for oral use. In copper overload, DMSA appears to be a potent antidote, although d-penicillamine is still widely used. In the chelation of iron, the thiols are inefficient, since iron has higher affinity for ligands with nitrogen and oxygen, but the new...

  7. Chelation Therapy for Mercury Poisoning

    Directory of Open Access Journals (Sweden)

    Rong Guan

    2009-01-01

    Full Text Available Chelation therapy has been the major treatment for heavy metal poisoning. Various chelating agents have been developed and tested for treatment of heavy metal intoxications, including mercury poisoning. It has been clearly shown that chelating agents could rescue the toxicity caused by heavy metal intoxication, but the potential preventive role of chelating agents against heavy metal poisoning has not been explored much. Recent paper by Siddiqi and colleagues has suggested a protective role of chelating agents against mercury poisoning, which provides a promising research direction for broader application of chelation therapy in prevention and treatment of mercury poisoning.

  8. Comments on chelation therapy

    International Nuclear Information System (INIS)

    Wrenn, M.E.

    1981-01-01

    The primary purpose of actinide chelation is to decrease the risk from radiation-induced cancer. While occupational exposures in the past have mainly involved low specific activity 239 Pu, future exposures will increasingly involve high specific activity plutonium, americium, and curium - all of which clear more rapidly from the lung. This will tend to shift the cancer risk from lung to bone and liver. Although therapy with Ca- or Zn-DTPA rapidly removes 241 Am from the canine, the sub-human primate, and the human liver, improved methods for removal from bone and lung are needed. DTPA can remove 241 Am more easily from the growing skeleton of a child than from the mature skeleton of an adult. Investigators at Karlsruhe are developing chelation agents for oral administration and are investigating the reduction in local dose to bone resulting from chelation therapy

  9. The fate of Gd and chelate following intravenous injection of gadodiamide in rats

    International Nuclear Information System (INIS)

    Moerk Kindberg, Grete; Uran, Steinar; Friisk, Grete; Martinsen, Ivar; Skotland, Tore

    2010-01-01

    The biodistribution of gadolinium (Gd) and chelate was studied in rats injected intravenously with a commercially available gadodiamide magnetic resonance contrast agent spiked with trace amounts of 14 C-labelled GdDTPA-BMA. Biodistribution of the 14 C-labelled ligand in whole animals was visualised using quantitative whole-body autoradiography, and quantified in individual tissue samples by analysing for radioactivity using beta-counting. Biodistribution of Gd was measured by inductively coupled plasma atomic emission spectroscopy (ICP-AES) and inductively coupled plasma sector field mass spectrometry (ICP-SF-MS). The injected dose was rapidly excreted, with only 1.0% remaining in the body at 24 h. The radioactivity thereafter was mainly associated with kidney cortex, liver, lung, muscle and skin, with a similar rate of clearance for both ligand and Gd from these tissues. The ratio between 14 C-labelled substance and Gd was not significantly different from that of the injected substance in most tissue samples up to 24 h after injection; the ratio then slowly decreased. The data clearly show that measurements of Gd concentration alone in tissue samples from animals injected with Gd-based contrast agents (GBCAs) cannot be used as a measure of Gd released from the ligand. To our knowledge, such measurements comparing Gd and ligand concentrations and distribution in tissue samples have not been published previously for any of the commercial GBCAs. (orig.)

  10. Magnetic resonance ventriculography with gadolinium DTPA: report of two cases

    International Nuclear Information System (INIS)

    Siebner, H.R.; Einsiedel, H. von; Conrad, B.

    1997-01-01

    We report intrathecal use of gadolinium DTPA for MRI of the cerebrospinal fluid (CSF). In two patients with leptomeningeal carcinomatosis, we injected 0.01 mmol gadolinium DTPA into the lateral ventricle via an Ommaya device. Coronal T1-weighted images of the head were obtained at 0.2 T prior to and after injection. There was pronounced enhancement of CSF close to the injection site, allowing good delineation of CSF and surrounding brain tissue. No side effects occurred. MRI with intrathecal administration of highly diluted gadolinium DTPA may be a promising alternative to conventional investigation of CSF-filled cavities using iodinated X-ray contrast media or radionuclides. (orig.). With 3 figs

  11. Preclinical studies on gadolinium neutron capture therapy

    International Nuclear Information System (INIS)

    Akine, Yasuyuki

    1994-01-01

    Gadolinium neutron capture therapy is based on radiations (photons and electrons) produced in the tumor by a nuclear reaction between gadolinium and lower-energy neutrons. Studies with Chinese hamster cells have shown that the radiation effect resulting from gadolinium neutron capture reactions is mostly of low LET and that released electrons are the significant component in the over-all dose. Biological dosimetry revealed that the dose does not seem to increase in proportion to the gadolinium concentration, leading to a conclusion that there is a range of gadolinium concentrations most efficient for gadolinium neutron capture therapy. The in vivo studies with transplantable tumors in mice and rabbits have revealed that close contact between gadolinium and the cell is not necessarily required for cell inactivation and that gadolinium delivery selective to tumors is crucial. The results show that the potential of gadolinium neutron capture therapy as a therapeutic modality appears very promising. (author)

  12. Chelation Therapy for Mercury Poisoning

    OpenAIRE

    Rong Guan; Han Dai

    2009-01-01

    Chelation therapy has been the major treatment for heavy metal poisoning. Various chelating agents have been developed and tested for treatment of heavy metal intoxications, including mercury poisoning. It has been clearly shown that chelating agents could rescue the toxicity caused by heavy metal intoxication, but the potential preventive role of chelating agents against heavy metal poisoning has not been explored much. Recent paper by Siddiqi and colleagues has suggested a protective role o...

  13. Giant cisterna chyli: MRI depiction with gadolinium-DTPA enhancement

    International Nuclear Information System (INIS)

    Lee, K.C.Y.; Cassar-Pullicino, V.N.

    2000-01-01

    AIM: To demonstrate the use of MRI with Gadolinium-DTPA enhancement in the diagnosis of giant cisterna chyli. MATERIALS AND METHODS: The study consisted of contrast enhanced MRI with ultrasound and CT correlation in three patients with a giant cisterna chyli. An analysis of the morphology, location and post-contrast MR signal characteristics in relation to time was performed. RESULTS: Cisterna chyli has a characteristic lobulated morphology and location but the unenhanced MRI appearances are not specific. The post-Gadolinium-DTPA MRI appearances are critically dependent on the time elapsed after injection of contrast medium. Within the first 5 min, there is no enhancement at all, but by 10 min there is early layering of contrast medium evident, which by 30 min produces a clear fluid-fluid level. Delayed images at 4-5 h demonstrate a uniform enhancement of the cisternal contents producing a homogeneous intermediate signal. All of these features are best visualized on T1 fast saturation sequences. CONCLUSION: MRI with Gadolinium-DTPA enhancement is valuable in confirming the nature of the lymphatic ducts in the retroperitoneal space and helps to differentiate these normal structures from alternative lesions such as lymphadenopathy and tumour recurrence. Lee, K.C.Y., Cassar-Pullicino, V.N. (2000)

  14. Quantitative Molecular Imaging with a Single Gd-Based Contrast Agent Reveals Specific Tumor Binding and Retention in Vivo.

    Science.gov (United States)

    Johansen, Mette L; Gao, Ying; Hutnick, Melanie A; Craig, Sonya E L; Pokorski, Jonathan K; Flask, Chris A; Brady-Kalnay, Susann M

    2017-06-06

    Magnetic resonance imaging (MRI) has become an indispensable tool in the diagnosis and treatment of many diseases, especially cancer. However, the poor sensitivity of MRI relative to other imaging modalities, such as PET, has hindered the development and clinical use of molecular MRI contrast agents that could provide vital diagnostic information by specifically locating a molecular target altered in the disease process. This work describes the specific and sustained in vivo binding and retention of a protein tyrosine phosphatase mu (PTPμ)-targeted, molecular magnetic resonance (MR) contrast agent with a single gadolinium (Gd) chelate using a quantitative MRI T 1 mapping technique in glioma xenografts. Quantitative T 1 mapping is an imaging method used to measure the longitudinal relaxation time, the T 1 relaxation time, of protons in a magnetic field after excitation by a radiofrequency pulse. T 1 relaxation times can in turn be used to calculate the concentration of a gadolinium-containing contrast agent in a region of interest, thereby allowing the retention or clearance of an agent to be quantified. In this context, retention is a measure of molecular contrast agent binding. Using conventional peptide chemistry, a PTPμ-targeted peptide was linked to a chelator that had been conjugated to a lysine residue. Following complexation with Gd, this PTPμ-targeted molecular contrast agent containing a single Gd ion showed significant tumor enhancement and a sustained increase in Gd concentration in both heterotopic and orthotopic tumors using dynamic quantitative MRI. This single Gd-containing PTPμ agent was more effective than our previous version with three Gd ions. Differences between nonspecific and specific agents, due to specific tumor binding, can be determined within the first 30 min after agent administration by examining clearance rates. This more facile chemistry, when combined with quantitative MR techniques, allows for widespread adoption by academic

  15. 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

    OBJECTIVES: The aim of this study was to determine whether early gadolinium enhancement (EGE) by cardiac magnetic resonance (CMR) in a canine model of reperfused myocardial infarction depicts the area at risk (AAR) as determined by microsphere blood flow analysis. BACKGROUND: It remains controver......OBJECTIVES: The aim of this study was to determine whether early gadolinium enhancement (EGE) by cardiac magnetic resonance (CMR) in a canine model of reperfused myocardial infarction depicts the area at risk (AAR) as determined by microsphere blood flow analysis. BACKGROUND: It remains...... 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...... on native T1 and T2 maps. The size of EGE was significantly greater than the infarct by triphenyltetrazolium chloride (44.1 ± 15.8% vs. 20.7 ± 14.4%; p gadolinium enhancement (44.1 ± 15.8% vs. 23.5 ± 12.7%; p

  16. Correlation between late gadolinium enhancement and diastolic function in hypertrophic cardiomyopathy assessed by magnetic resonance imaging

    International Nuclear Information System (INIS)

    Motoyasu, Munenobu; Kurita, Tairo; Onishi, Katsuya

    2008-01-01

    Diastolic dysfunction is common in patients with overt hypertrophic cardiomyopathy (HCM). Steady-state cine magnetic resonance imaging (MRI) enables measurement of the diastolic function of the left ventricle (LV), and late gadolinium enhanced MRI can delineate the presence and extent of fibrosis in HCM. The purpose of this study was to determine the relationship between the extent of myocardial fibrosis demonstrated by late gadolinium-enhanced MRI and diastolic dysfunction. Seventeen patients (13 men, mean age 57.7±9.8 years) with HCM were studied. The severity index of late gadolinium enhancement was determined by scoring the extent of enhanced tissue in 30 myocardial segments. The peak filling rate (PFR), LV ejection fraction and LV mass were determined by cine MRI. Contrast-enhanced MRI demonstrated late gadolinium enhancement in 97 of 510 segments (19%) and 13 of the 17 patients (77%). The severity index of late gadolinium enhancement demonstrated a significant negative correlation with PFR (r=-0.86, p<0.01) and with the LV ejection fraction (r=-0.59, p<0.05). No significant correlation was observed between the severity index of late gadolinium enhancement and LV mass (r=0.23, p=0.30). The extent of myocardial fibrosis revealed by late gadolinium-enhanced MRI has a strong relationship to diastolic dysfunction in patients with HCM. (author)

  17. Clinical experience of gadolinium-DTPA

    International Nuclear Information System (INIS)

    Takemoto, Kazumasa; Inoue, Yuichi; Hashimoto, Hiromi

    1986-01-01

    Magnetic resonance imaging was performed before and after intravenous administration of gadolinium-DTPA (Gd-DTPA) in 9 patients with intracranial tumors (8) and a spinal tumor (1). In this study IR (2100/600) and short SE (600/40) were used. After administration of Gd-DTPA, signal intensity of tumors increased in all cases. Contrast enhanced MRI with Gd-DTPA was useful in metastatic brain tumor, cerebeller astrocytoma and glioblastoma to differentiate the tumor from edema. Since meningiomas were clearly demonstrated and differentiated from edema. Gd-DTPA seems to be not required for the diagnosis of meningiomas. No severe side effect were encountered after injection of Gd-DTPA. (author)

  18. Studies of MRI relaxivities of gadolinium-labeled dendrons

    Science.gov (United States)

    Pan, Hongmu; Daniel, Marie-Christine

    2011-05-01

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

  19. Characteristics of Gadolinium Oxide Nanoparticles Using Terahertz Spectroscopy

    International Nuclear Information System (INIS)

    Lee, Dongkyu; Maeng, Inhee; Son, Joo-Hiuk; Oh, Seung Jae; Kim, Taekhoon; Cho, Byung Kyu; Lee, Kwangyeol

    2009-01-01

    The penetration property of the terahertz electromagnetic (THz) wave is relevant to its use. We used the THz wave spectroscopy system which easily penetrates some materials that do not contain water, e.g., plastic and ceramics. The system has been developed for several purposes, including measuring the properties of semiconductors and bio-materials, and detecting plastic bombs and ceramic knives at airports. It is also used for medical imaging systems, such as magnetic resonance imaging (MRI), at some research institutes. It can show not only the difference in amplitude, but also the difference of the phase of each point of sample. MRI technology usually uses contrast agents to enhance the quality of the image. Gadolinium diethylenetriamine pentaacetic acid (Gd-DTPA), made with a heavy metal ion, is commonly used as a clinical MRI contrast agent. Gadolinium oxide (Gd 2 O 3 ) nanoparticle is a new contrast agent. It serves to equip the core of each particle with antibodies or ligands. It can freely circulate in blood vessels without amassing in the liver or lungs. This study shows the characteristics of gadolinium oxide nanoparticles to further advance terahertz medical imaging.

  20. Demonstration of pulmonary embolism with gadolinium-enhanced spiral CT

    Energy Technology Data Exchange (ETDEWEB)

    Coche, E.E.; Hammer, F.D.; Goffette, P.P. [Dept. of Radiology, St. Luc University Hospital, Brussels (Belgium)

    2001-11-01

    The authors report a case of successful detection of pulmonary embolism using gadolinium-enhanced spiral CT (Gadodiamide, 0.4 mmol/kg, 2 ml/s, delay 18 s) in a 77-year-old woman, with previous allergy to iodinated contrast medium, and renal failure, who presented with pulmonary arterial hypertension. Doppler ultrasound of the lower limbs was first performed and revealed a deep venous thrombosis of the right lower limb. To establish if venous thrombosis was the cause of pulmonary hypertension and to confirm that pulmonary endarterectomy was not indicated in this situation, several imaging modalities were performed. Lung scintigraphy and MRI were non-diagnostic. Gadolinium-enhanced spiral CT demonstrated a large thrombus located proximally and in a segmental artery of the right lower lobe. This case illustrates the potential usefulness of gadolinium as alternative contrast agent with spiral CT to diagnose pulmonary embolism and elucidate the cause of pulmonary arterial hypertension in a patient with some contraindications for iodinated contrast medium injection. (orig.)

  1. Demonstration of pulmonary embolism with gadolinium-enhanced spiral CT

    International Nuclear Information System (INIS)

    Coche, E.E.; Hammer, F.D.; Goffette, P.P.

    2001-01-01

    The authors report a case of successful detection of pulmonary embolism using gadolinium-enhanced spiral CT (Gadodiamide, 0.4 mmol/kg, 2 ml/s, delay 18 s) in a 77-year-old woman, with previous allergy to iodinated contrast medium, and renal failure, who presented with pulmonary arterial hypertension. Doppler ultrasound of the lower limbs was first performed and revealed a deep venous thrombosis of the right lower limb. To establish if venous thrombosis was the cause of pulmonary hypertension and to confirm that pulmonary endarterectomy was not indicated in this situation, several imaging modalities were performed. Lung scintigraphy and MRI were non-diagnostic. Gadolinium-enhanced spiral CT demonstrated a large thrombus located proximally and in a segmental artery of the right lower lobe. This case illustrates the potential usefulness of gadolinium as alternative contrast agent with spiral CT to diagnose pulmonary embolism and elucidate the cause of pulmonary arterial hypertension in a patient with some contraindications for iodinated contrast medium injection. (orig.)

  2. Characteristics of Gadolinium Oxide Nanoparticles Using Terahertz Spectroscopy (abstract)

    Science.gov (United States)

    Lee, Dongkyu; Maeng, Inhee; Oh, Seung Jae; Kim, Taekhoon; Cho, Byung Kyu; Lee, Kwangyeol; Son, Joo-Hiuk

    2009-04-01

    The penetration property of the terahertz electromagnetic (THz) wave is relevant to its use. We used the THz wave spectroscopy system which easily penetrates some materials that do not contain water, e.g., plastic and ceramics. The system has been developed for several purposes, including measuring the properties of semiconductors and bio-materials, and detecting plastic bombs and ceramic knives at airports. It is also used for medical imaging systems, such as magnetic resonance imaging (MRI), at some research institutes. It can show not only the difference in amplitude, but also the difference of the phase of each point of sample. MRI technology usually uses contrast agents to enhance the quality of the image. Gadolinium diethylenetriamine pentaacetic acid (Gd-DTPA), made with a heavy metal ion, is commonly used as a clinical MRI contrast agent. Gadolinium oxide (Gd2O3) nanoparticle is a new contrast agent. It serves to equip the core of each particle with antibodies or ligands. It can freely circulate in blood vessels without amassing in the liver or lungs. This study shows the characteristics of gadolinium oxide nanoparticles to further advance terahertz medical imaging.

  3. A neutral polydisulfide containing Gd(III) DOTA monoamide as a redox-sensitive biodegradable macromolecular MRI contrast agent.

    Science.gov (United States)

    Ye, Zhen; Zhou, Zhuxian; Ayat, Nadia; Wu, Xueming; Jin, Erlei; Shi, Xiaoyue; Lu, Zheng-Rong

    2016-01-01

    This work aims to develop safe and effective gadolinium (III)-based biodegradable macromolecular MRI contrast agents for blood pool and cancer imaging. A neutral polydisulfide containing macrocyclic Gd-DOTA monoamide (GOLS) was synthesized and characterized. In addition to studying the in vitro degradation of GOLS, its kinetic stability was also investigated in an in vivo model. The efficacy of GOLS for contrast-enhanced MRI was examined with female BALB/c mice bearing 4T1 breast cancer xenografts. The pharmacokinetics, biodistribution, and metabolism of GOLS were also determined in mice. GOLS has an apparent molecular weight of 23.0 kDa with T1 relaxivities of 7.20 mM(-1) s(-1) per Gd at 1.5 T, and 6.62 mM(-1) s(-1) at 7.0 T. GOLS had high kinetic inertness against transmetallation with Zn(2+) ions, and its polymer backbone was readily cleaved by L-cysteine. The agent showed improved efficacy for blood pool and tumor MR imaging. The structural effect on biodistribution and in vivo chelation stability was assessed by comparing GOLS with Gd(HP-DO3A), a negatively charged polydisulfide containing Gd-DOTA monoamide GODC, and a polydisulfide containing Gd-DTPA-bisamide (GDCC). GOLS showed high in vivo chelation stability and minimal tissue deposition of gadolinium. The biodegradable macromolecular contrast agent GOLS is a promising polymeric contrast agent for clinical MR cardiovascular imaging and cancer imaging. Copyright © 2015 John Wiley & Sons, Ltd.

  4. Dynamic contrast enhanced MRI in prostate cancer

    Energy Technology Data Exchange (ETDEWEB)

    Alonzi, Roberto [Marie Curie Research Wing, Mount Vernon Cancer Centre, Rickmansworth Road, Northwood, Middlesex, HA6 2RN (United Kingdom)], E-mail: robertoalonzi@btinternet.com; Padhani, Anwar R. [Paul Strickland Scanner Centre, Mount Vernon Cancer Centre, Rickmansworth Road, Northwood, Middlesex, HA6 2RN (United Kingdom); Synarc Inc. 575 Market Street, San Francisco, CA 94105 (United States)], E-mail: anwar.padhani@paulstrickland-scannercentre.org.uk; Allen, Clare [Department of Imaging, University College Hospital, London, 235 Euston Road, NW1 2BU (United Kingdom)], E-mail: clare.allen@uclh.nhs.uk

    2007-09-15

    Angiogenesis is an integral part of benign prostatic hyperplasia (BPH), is associated with prostatic intraepithelial neoplasia (PIN) and is key to the growth and for metastasis of prostate cancer. Dynamic contrast enhanced magnetic resonance imaging (DCE-MRI) using small molecular weight gadolinium chelates enables non-invasive imaging characterization of tissue vascularity. Depending on the technique used, data reflecting tissue perfusion, microvessel permeability surface area product, and extracellular leakage space can be obtained. Two dynamic MRI techniques (T{sub 2}*-weighted or susceptibility based and T{sub 1}-weighted or relaxivity enhanced methods) for prostate gland evaluations are discussed in this review with reference to biological basis of observations, data acquisition and analysis methods, technical limitations and validation. Established clinical roles of T{sub 1}-weighted imaging evaluations will be discussed including lesion detection and localisation, for tumour staging and for the detection of suspected tumour recurrence. Limitations include inadequate lesion characterisation particularly differentiating prostatitis from cancer, and in distinguishing between BPH and central gland tumours.

  5. Gadolinium enhancement of cerebrospinal fluid in a patient with renal failure

    International Nuclear Information System (INIS)

    Erbay, S.H.; Bhadelia, R.A.

    2001-01-01

    Gadolinium based MRI contrast agents are considered very safe due to their well known pharmacologic properties and elimination mechanisms. In this paper, we present a unique case in whom transient enhancement of CSF with contrast is seen. Severe renal failure is demonstrated to be responsible for this finding. The diagnostic criteria for everyday clinical setting and possible clinical implications are discussed. (orig.)

  6. Investigation of gadolinium monophosphide at high temperatures

    International Nuclear Information System (INIS)

    Gordienko, S.P.; Gol'nik, V.F.; Mironov, K.E.

    1982-01-01

    Gadolinium monophosphide has been studied in vacuum at high temperatures using mass-spectrometric, chemical, X-ray phase and derivatographical analyses. It is established that gadolinium monophosphide at 2080-2465 K dissociates into atomic gadolinium, phosphorus and, P 2 molecules. According to Vant-Hoff and Gibbs-Helmholtz equations standard enthalpy of atomization ΔHsub(at) deg (298)=1027.3 kJ/mol and of formation ΔHsub(f) deg (298)=313.8 kJ/mol of gadolinium monophosphide are determined

  7. Serial MRI studies using gadolinium DTPA in active multiple sclerosis

    International Nuclear Information System (INIS)

    Miller, D.H.; Johnson, G.; Barnes, D.; Rudge, P.; McDonald, W.I.

    1988-01-01

    It has been suggested that blood brain barrier (BBB) impairment is a necessary early event in the pathogenesis of the multiple sclerosis (MS) lesions. To evaluate such an hypothesis in vivo would require: (1) serial imaging studies using a modality with high sensitivity for detecting plaques; (2) a contrast enhancing agent which demonstrates BBB impairment. A serial magnetic resonance imaging (MRI) study was undertaken of a group of MS patients using the contrast agent gadolinium-DTPA. As it has been suggested that T 1 and T 2 relaxation times are longer in acute than chronic MS lesions, these were also measured. 3 refs.; 1 figure

  8. Clinical impact of gadolinium in the MRI diagnosis of musculoskeletal infection in children

    Energy Technology Data Exchange (ETDEWEB)

    Kan, J.H.; Young, Robert S.; Hernanz-Schulman, Marta [Vanderbilt University, Department of Radiology and Radiological Sciences, Vanderbilt Children' s Hospital, Nashville, TN (United States); Yu, Chang [Vanderbilt University, Department of Biostatistics, Nashville, TN (United States)

    2010-07-15

    The incremental value of gadolinium in the diagnosis of musculoskeletal infection by MRI is controversial. To compare diagnostic utility of noncontrast with contrast MRI in the evaluation of pediatric musculoskeletal infections. We reviewed 90 gadolinium-enhanced MRIs in children with suspected musculoskeletal infection. Noncontrast and contrast MRI scans were evaluated to determine sensitivity and specificity in the diagnosis of musculoskeletal infection and identification of abscesses. Pre- and post-contrast diagnosis of osteomyelitis sensitivity was 89% and 91% (P = 1.00) and specificity was 96% and 96% (P = 1.00), respectively; septic arthritis sensitivity was 50% and 67% (P = 1.00) and specificity was 98% and 98% (P = 1.00), respectively; cellulitis/myositis sensitivity was 100% and 100% (P = 1.00) and specificity was 84% and 88% (P = 0.59), respectively; abscess for the total group was 22 (24.4%) and 42 (46.6%), respectively (P < 0.0001). Abscesses identified only on contrast sequences led to intervention in eight additional children. No child with a final diagnosis of infection had a normal pre-contrast study. Intravenous gadolinium should not be routinely administered in the imaging work-up of nonspinal musculoskeletal infections, particularly when pre-contrast images are normal. However, gadolinium contrast significantly increases the detection of abscesses, particularly small ones that might not require surgical intervention. (orig.)

  9. Clinical impact of gadolinium in the MRI diagnosis of musculoskeletal infection in children

    International Nuclear Information System (INIS)

    Kan, J.H.; Young, Robert S.; Hernanz-Schulman, Marta; Yu, Chang

    2010-01-01

    The incremental value of gadolinium in the diagnosis of musculoskeletal infection by MRI is controversial. To compare diagnostic utility of noncontrast with contrast MRI in the evaluation of pediatric musculoskeletal infections. We reviewed 90 gadolinium-enhanced MRIs in children with suspected musculoskeletal infection. Noncontrast and contrast MRI scans were evaluated to determine sensitivity and specificity in the diagnosis of musculoskeletal infection and identification of abscesses. Pre- and post-contrast diagnosis of osteomyelitis sensitivity was 89% and 91% (P = 1.00) and specificity was 96% and 96% (P = 1.00), respectively; septic arthritis sensitivity was 50% and 67% (P = 1.00) and specificity was 98% and 98% (P = 1.00), respectively; cellulitis/myositis sensitivity was 100% and 100% (P = 1.00) and specificity was 84% and 88% (P = 0.59), respectively; abscess for the total group was 22 (24.4%) and 42 (46.6%), respectively (P < 0.0001). Abscesses identified only on contrast sequences led to intervention in eight additional children. No child with a final diagnosis of infection had a normal pre-contrast study. Intravenous gadolinium should not be routinely administered in the imaging work-up of nonspinal musculoskeletal infections, particularly when pre-contrast images are normal. However, gadolinium contrast significantly increases the detection of abscesses, particularly small ones that might not require surgical intervention. (orig.)

  10. Evaluation of a gadolinium-based nanoparticle (AGuIX) for contrast-enhanced MRI of the liver in a rat model of hepatic colorectal cancer metastases at 9.4 tesla

    Energy Technology Data Exchange (ETDEWEB)

    Fries, P.; Morr, D.; Mueller, A.; Massmann, A.; Seidel, R.; Schneider, G.; Buecker, A. [Saarland University Medical Center, Homburg (Germany). Clinic of Diagnostic and Interventional Radiology; Lux, F.; Tillement, O. [Universite Claude Bernard, Lyon (France). Laboratoire de Physico-Chimie des Materiaux Luminescents; Schaefer, T. [Saarland University Medical Center, Homburg (Germany). Dept. of General, Visceral and Pediatric Surgery; Menger, M.D. [Saarland University Medical Center, Homburg (Germany). Inst. for Clinical and Experimental Surgery

    2015-12-15

    The aim of this study was to compare a Gd-based nanoparticle (AGuIX) with a standard extracellular Gd-based contrast agent (Gd-DOTA) for MRI at 9.4 T in rats with hepatic colorectal cancer metastases. 12 rats with hepatic metastases were subjected to MRI using a 9.4 T animal scanner. T1w self-gated FLASH sequences (TR/TE=45/2.5 ms, alpha = 45 , TA=1: 23 min, FOV=5.12 x 5.12 cm{sup 2}, matrix = 256 x 256) were acquired before and at 10 time points after contrast injection. Each animal received 0.1 mmol/kg BW Gd-DOTA i.v. 2 days later AGuIX was applied at 0.01 mmol/kg BW (representing equal Gd doses). The SNR of normal liver (SNRliver), hyper- and hypoenhancing parts of tumors (SNRtumor, hyperenh/SNRtumor, hypoenhanc), erector spinae muscle (SNRmuscle), CNR and lesion enhancement (LE) were calculated based on ROI measurements. Mean SNRliver (Gd-DOTA: 14.6 ± 0.7; AGuIX: 28.2 ± 2.6, p < 0.001), SNRtumor, hyperenhanc (Gd-DOTA: 18.6 ± 1.2; AGuIX: 29.6 ± 2.8, p < 0.001), SNRtumor, hypoenhanc (Gd-DOTA: 12.0 ± 0.7; AGuIX: 15.4 ± 0.7, p < 0.001), SNRmuscle (Gd-DOTA: 12.3 ± 0.3; AGuIX: 14.0 ± 0.7, p < 0.001), mean CNR (Gd-DOTA: -2.5 ± 0.2; AGuIX: -7.5 ± 1.0, p < 0.001) and LE (Gd-DOTA: 3.8 ± 0.7; AGuIX: 14.9 ± 2.8, p=0.001) were significantly higher using AGuIX. Regardless of the larger molecular size, AGuIX demonstrates an early peak enhancement followed by a continuous washout. AGuIX provides better enhancement at 9.4 T compared to Gd-DOTA for equal doses of applied Gd. This is based on the molecule structure and the subsequent increased interaction with protons leading to a higher relaxivity. AGuIX potentially ameliorates the conspicuity of focal liver lesions and may improve the sensitivity in diagnostic imaging of malignant hepatic tumors.

  11. Evaluation of a gadolinium-based nanoparticle (AGuIX) for contrast-enhanced MRI of the liver in a rat model of hepatic colorectal cancer metastases at 9.4 tesla

    International Nuclear Information System (INIS)

    Fries, P.; Morr, D.; Mueller, A.; Massmann, A.; Seidel, R.; Schneider, G.; Buecker, A.; Lux, F.; Tillement, O.; Schaefer, T.; Menger, M.D.

    2015-01-01

    The aim of this study was to compare a Gd-based nanoparticle (AGuIX) with a standard extracellular Gd-based contrast agent (Gd-DOTA) for MRI at 9.4 T in rats with hepatic colorectal cancer metastases. 12 rats with hepatic metastases were subjected to MRI using a 9.4 T animal scanner. T1w self-gated FLASH sequences (TR/TE=45/2.5 ms, alpha = 45 , TA=1: 23 min, FOV=5.12 x 5.12 cm 2 , matrix = 256 x 256) were acquired before and at 10 time points after contrast injection. Each animal received 0.1 mmol/kg BW Gd-DOTA i.v. 2 days later AGuIX was applied at 0.01 mmol/kg BW (representing equal Gd doses). The SNR of normal liver (SNRliver), hyper- and hypoenhancing parts of tumors (SNRtumor, hyperenh/SNRtumor, hypoenhanc), erector spinae muscle (SNRmuscle), CNR and lesion enhancement (LE) were calculated based on ROI measurements. Mean SNRliver (Gd-DOTA: 14.6 ± 0.7; AGuIX: 28.2 ± 2.6, p < 0.001), SNRtumor, hyperenhanc (Gd-DOTA: 18.6 ± 1.2; AGuIX: 29.6 ± 2.8, p < 0.001), SNRtumor, hypoenhanc (Gd-DOTA: 12.0 ± 0.7; AGuIX: 15.4 ± 0.7, p < 0.001), SNRmuscle (Gd-DOTA: 12.3 ± 0.3; AGuIX: 14.0 ± 0.7, p < 0.001), mean CNR (Gd-DOTA: -2.5 ± 0.2; AGuIX: -7.5 ± 1.0, p < 0.001) and LE (Gd-DOTA: 3.8 ± 0.7; AGuIX: 14.9 ± 2.8, p=0.001) were significantly higher using AGuIX. Regardless of the larger molecular size, AGuIX demonstrates an early peak enhancement followed by a continuous washout. AGuIX provides better enhancement at 9.4 T compared to Gd-DOTA for equal doses of applied Gd. This is based on the molecule structure and the subsequent increased interaction with protons leading to a higher relaxivity. AGuIX potentially ameliorates the conspicuity of focal liver lesions and may improve the sensitivity in diagnostic imaging of malignant hepatic tumors.

  12. First experiences with the application of oral gadolinium-DTPA in MR of the minor pelvis

    International Nuclear Information System (INIS)

    Hoetzinger, H.; Salbeck, R.; Toedt, C.; Beyer, H.K.

    1990-01-01

    The use of an oral contrast medium has so far not become a matter of routine in MR of the abdomen. In the present study the use of orally applied gadolinium-DTPA was examined in respect of tumorous diseases in the minor pelvis. 18 patients with tumours in the minor pelvis were examined before and after oral administration of gadolinium-DTPA (Gd-DTPA). 10 ml/kg body weight of a gadolinium DTPA solution were applied in a concentration of 1.0 mmol/l. T 1 -weighted and T 2 -weighted sequences were carried out before application and T 1 -weighted sequences after application. Oral application of gadolinium-DTPA resulted in enhancing the signals of the filled intestinal portions. In 54% of the cases the sequences showed a sharper delineation between tumour and intestine. In 19% the delineation between pathological tissue and intestine on contrast examination was a well defined as in T 2 -weighted contrast images; in 27% of the cases oral administration of gadolinium-DTPA did not yield any additional information. No significant side effects were seen. (orig.) [de

  13. Gadolinium-DTPA in magnetic resonance tomography

    International Nuclear Information System (INIS)

    Prayer, L.; Imhof, H.; Stiglbauer, R.; Kramer, J.; Wimberger, D.

    1989-01-01

    Magnetic resonance tomography was performed on 158 patients with different indications before and after the administration of contrast medium. The MR examination included various plain T 1 and T 2 weighted spin echo sequences as well as T 1 weighted examinations after intravenous application of gadolinium-DTPA ('Magnevist', Schering AG) in a dosage of 0.1 mmol/kg body weight. The following conclusions were drawn: The sensitivity of MR in detecting brain tumors, acoustic neuromas and pituitary adenomas was improved considerably after the administration of 'Magnevist'. To diagnose the type of tumor, the criteria which apply to Gd-DPTA are similar to those used for iodine-containing contrast medium in CT. In about 2/3 rds of the cases, delineation of pathological tissues from surrounding edema and normal structures was better than in plain films. Hence, accurate, pretherapeutic staging of bronchial carcinomas and an exact definition of the expansion of the malignancies in the muscle-skeleton system were possible. In respect of tumors in the region of the base of the skull, we could omit T 2 -weighted sequences without noticeable loss of diagnostically relevant information; the examination time could thus be shortened by about 12 minutes. (orig.) [de

  14. Gadolinium atom on neutron capture therapy

    International Nuclear Information System (INIS)

    Oda, Y.; Takagaki, M.; Miyatake, S.; Kikuchi, H.

    1994-01-01

    This report describes our measurements of gadolinium concentrations in several brain tumors obtained from fresh surgical specimens, as compared with corresponding concentrations in the blood. Moreover we tried to find out if the gadolinium concentration is high enough to use this compound in the treatment of brain tumors by neutron capture therapy. (J.P.N.)

  15. Retention of contrast media in the history of radiology. Sequelae of the former use of thorotrast and new challenges

    International Nuclear Information System (INIS)

    Kaick, G. van; Delorme, S.

    2016-01-01

    Detection of gadolinium deposits in patients who have repeatedly been administered intravenous gadolinium chelates have given rise to concern regarding the long-term safety of magnetic resonance imaging (MRI) contrast media. Nevertheless, negative long-term clinical effects have not yet been observed. In some publications parallels have been drawn to the sequelae of thorotrast that was formerly used for arterial angiography. In this article the history of thorotrast use is briefly described and in particular why, despite warnings, this substance was used frequently and worldwide. A brief summary of the results of the German Thorotrast Study revealed that high excess rates were only observed for primary malignant liver tumors after a 15-year or longer latency period and to a lesser degree of leukemias, as well as for severe local complications due to paravascular injections, particularly in the neck region. Based on this historical review, we will venture to take stock of the outcome from the ''success story'' of this contrast agent. (orig.) [de

  16. Use of dispersive liquid-liquid microextraction for simultaneous preconcentration of samarium, europium, gadolinium and dysprosium

    International Nuclear Information System (INIS)

    Mallah, M.H.; Atomic Energy Organization of Iran, Tehran; Shemirani, F.; Ghannadi Maragheh, M.

    2008-01-01

    A new preconcentration method of dispersive liquid-liquid microextraction (DLLME) was developed for simultaneous preconcentration of samarium, europium, gadolinium and dysprosium. DLLME technique was successfully used as a sample preparation method. In this preconcentration method, an appropriate mixture of extraction solvent, disperser solvent was injected rapidly into an aqueous solution containing Sm, Eu, Gd and Dy after complex formation using chelating reagent of the 1-(2-pyridylazo)-2-naphthol (PAN). After phase separation, 0.5 mL of the settled phase containing enriched analytes was determined by inductively coupled plasma optical emission spectrometry (ICP-OES). The main factors affected the preconcentration of Sm, Eu, Gd and Dy were extraction and dispersive solvent type and their volume, extraction time, volume of chelating agent (PAN), centrifuge speed and drying temperature of the samples. Under the best operating condition simultaneous preconcentration factors of 80, 100, 103 and 78 were obtained for Sm, Eu, Gd and Dy, respectively. (author)

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

    International Nuclear Information System (INIS)

    Hopkins, K.L.; Li, K.C.P.; Bergman, G.

    1995-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1995-07-01

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

  19. Extended diagnosis of liver tumor with gadolinium DTPA supplementary to routine procedure in nuclear medicine

    International Nuclear Information System (INIS)

    Ehrenheim, C.; Heintz, P.; Schwarzrock, R.; Schober, O.; Hundeshagen, H.

    1988-01-01

    Several imaging methods and especially their combined application are proven to be useful in the diagnosis and differentiation of liver tumors: Ultrasound, roentgen computed tomography, sequential hepatobiliary scintigraphy (HBSS), blood pool scintigraphy and magnetic resonance imaging. 38 patients with liver tumors (hemangioma, hepatocellular carcinoma, focal nodular hyperplasia) underwent MRI of the liver before and after i.v. injection of 0.2 mmol/kg Gadolinium-DTPA in addition to other imaging methods. Written informed consent we achieved in all cases. The normal and pathological findings in MRI were documented in T1- and T2-weighted images, proton density image, calculated T1- and T2-images and a T1-weighted image after application of the contrast agent. The application of Gadolinium-DTPA as contrast agent improves the delimitation of the most intrahepatic lesions. Concerning the hemangiomas of the liver the improved contrast behaviour induced by Gadolinium-DTPA does not reach the contrast and sensitivity of a native T2-weighted SE image. The demarcation of focal nodular hyperplasia is not improved by use of the contrast agent. This finding supports the assumption that the FNH is not basically different from normal liver tissue. Gadolinium-DTPA provides additional information concerning the delineation of internal tumor details in hepatocellular carcinoma (hyperperfused areas, necroses, fibrous capsular structures). (orig.)

  20. Identification and characterization of gadolinium(III) complexes in biological tissue extracts.

    Science.gov (United States)

    Kahakachchi, Chethaka L; Moore, Dennis A

    2010-07-01

    The gadolinium species present in a rat kidney following intravenous administration of a gadolinium-based magnetic resonance contrast agent (Optimark™, Gadoversetamide injection) to a rat was examined in the present study. The major gadolinium species in the supernatant of the rat kidney tissue extracts was determined by reversed-phase liquid chromatography with online inductively coupled plasma optical emission spectrometry (HPLC-ICP-OES). The identity of the compound was established by liquid chromatography electrospray ionization mass spectrometry (LC-ESI-MS) detection. The principal gadolinium(III) complex in a rat kidney tissue extract was identified as Gd-DTPA-BMEA 24 Hrs and 7 days after a single intravenous injection of Optimark™ (gadoversetamide; Gd-DTPA-BMEA) at a dose of 5 mmol Gd/kg body weight. The study demonstrated for the first time the feasibility of the use of two complementary techniques, HPLC-ICP-OES and HPLC-ESI-MS to study the in vivo behavior of gadolinium-based magnetic resonance contrast media.

  1. Albumin microspheres labeled with Ga-67 by chelation: concise communication

    International Nuclear Information System (INIS)

    Hnatowich, D.J.; Schlegel, P.

    1981-01-01

    Albumin microspheres have been synthesized with EDTA and DTPA chelating groups covalently bound to their surface. The microspheres may be labeled with Ga-67 at high yield (97 +- 2%) by transcomplexation from a 0.1 M Ga-67 acetate solution. With EDTA microspheres the resulting label dissociates only slightly after 24 hr in 50% plasma at 37 0 C, whereas with DTPA microspheres the label shows no detectable dissociation over this period. By contrast, microspheres without chelating groups lose their label virtually completely under these conditions. Following intravenous administration of sized Ga-67 DTPA microspheres in mice, about (84 +- 16)% of the activity localizes in the lungs at 5 min, with (60 +- 7)% remaining after 2 h. Since labeling is by chelation, the microspheres may also be tagged with other metallic radionuclides

  2. New MR contrast agent

    International Nuclear Information System (INIS)

    Grossman, C.D.; Subramanian, G.; Schneider, R.; Szeverenyi, N.E.; Rosenbaum, A.M.; Gagne, G.; Tillapaugh-Fay, G.; Berlin, R.; Ritter-Hrncirik, C.; Yu, S.

    1990-01-01

    This paper evaluates an MR contrast agent-meglumine tris-(2,6-dicarboxypyridine) gadolinium (III) or gadolinium dipicolinate (Gd-DPC)-produced in-house. Rats were anesthetized with pentobarbital. For renal imaging, bowel motion artifact was minimized with glucagon (0.014 mg/kg, intravenous (IV)). Enhanced images were generated on a 2-T chemical shift imaging system with a 31-cm horizontal bore magnet after IV injection of Gd-DPC (100 μM/kg). Coronal sections of the kidneys and sagittal sections of the brain, 2 mm thick, were made. Six to eight excitations and 128 or 356 phase-encoding steps were used for each image. Control animals were injected with equivalent doses of gadopentetate dimeglumine

  3. 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)

  4. Article Commentary: Chelation Therapy for Mercury Poisoning

    Directory of Open Access Journals (Sweden)

    Rong Guan

    2009-01-01

    Full Text Available Chelation therapy has been the major treatment for heavy metal poisoning. Various chelating agents have been developed and tested for treatment of heavy metal intoxications, including mercury poisoning. It has been clearly shown that chelating agents could rescue the toxicity caused by heavy metal intoxication, but the potential preventive role of chelating agents against heavy metal poisoning has not been explored much. Recent paper by Siddiqi and colleagues has suggested a protective role of chelating agents against mercury poisoning, which provides a promising research direction for broader application of chelation therapy in prevention and treatment of mercury poisoning.

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

    Indian Academy of Sciences (India)

    solution of higher pH. After complete gelation, an .... between the gadolinium and fumarate ions because at higher ..... Department of Higher Education, Government of Jammu and. Kashmir, for providing and facilitating the teacher fellowship.

  6. MRI with gadolinium DTPA in the diagnosis of spinal intradural masses

    International Nuclear Information System (INIS)

    Kahn, T.; Fuerst, G.; Moedder, U.; Roosen, N.; Lins, E.; Bock, W.J.; Lenard, H.G.

    1989-01-01

    The results of contrast enhanced MRI in 36 patients with suspected spinal intradural tumours are described. All intramedullary tumours showed distinctive enhancement and solid tumors could be delineated clearly, even if they were not clearly visible on unenhanced scans. The differentiation between neoplasm and non-neoplastic syrinx was markedly improved. The sensitivity of MRI for demonstrating intradural extramedullary tumours was greatly improved by gadolinium DTPA and even small lesions or flat meningeal infiltrates could be visualised. In addition, gadolinium DTPA improved the delineation and localisation of larger lesions, even if they had already been seen on unenhanced images. (orig.) [de

  7. Overview of current chelation practices

    Directory of Open Access Journals (Sweden)

    Y. Aydinok

    2011-12-01

    Full Text Available Deferoxamine (DFO is reference standard therapy for transfusional iron overload since the 1980s. Although it is a highly effective iron chelator, the compliance problem to subcutaneous administration of DFO remains as the major problem. The oral chelator Deferiprone (DFP has no marketing licence in North America, however, it has been licensed in India since 1994 and the European Union (EU granted marketing approval for DFP in 1999, specifically for patients with thalassemia major when DFO is inadequate, intolerable or unacceptable. There are still limited data available on the use of DFP in children between 6 and 10 years of age, and no data on DFP use in children under 6 years of age. Subsequently the oral chelator Deferasirox (DFX was approved by FDA and EMA for the treatment of patients with transfusional iron overload -older than 2 years of age- as first line therapy, in 2005 and 2006 respectively. The primary objective of iron chelation is to maintain body iron at safe levels at all times but once iron is accumulated, the objective of iron chelation is to reduce tissue iron to safe levels which is a slow process. The chelation regimen, dose and frequency of administration, of the chelator(s are mainly determined based on body iron burden, presence of myocardial iron and the transfusional iron loading rate. A proper monitoring of chelation is of importance for measuring the response rate to a particular regimen and providing dose adjustments to enhance chelation efficacy and to avoid toxicity. Efficacy of a chelation regimen may exhibit individual variability resulting from factors such as absorbtion and metabolism of the chelator. Tolerability and compliance are also individual variables effecting the response to chelation. Understanding of advantages and limitations of chelators, accurately determining chelation needs of patients with iron overload and designing individualized chelation regimens with less toxicity but optimum efficacy

  8. Hyperintense hepatocellular carcinoma on gadolinium-enhanced hepatic MRI

    International Nuclear Information System (INIS)

    Yoshikawa, Jun; Matsui, Osamu; Kadoya, Masumi; Gabata, Toshifumi; Arai, Kazunori; Takashima, Tsutomu

    1992-01-01

    We reported a phenomenon in which some hepatocellular carcinomas (HHCs) visualized as hypointense on plain T1 weighted MR images became hyperintense on gadolinium-DTPA (Gd-DTPA) (0.06∼0.23 mmol/kg) enhanced delayed images. Gd-DTPA enhanced images (using a super conducting magnet operating at 1.5T) of 44 HCCs were studied in comparison with contrast enhanced CT using 30∼80g of iodine. Six of 44 HCCs (14%) which were visualized as hypointense on plain T1 weighted image became hyperintense on delayed Gd-DTPA enhanced images. Although these were visualized as low intensity areas on both plain and enhanced CT, the contrast between HCC and the surrounding liver was small on post contrast CT. These findings were thought to be due to a stronger enhancement effect of Gd-DTPA than that of iodine. (author)

  9. MR angiography of the carotid arteries and intracranial circulation: advantage of a high relaxivity contrast agent

    International Nuclear Information System (INIS)

    Anzalone, N.; Scotti, R.; Iadanza, A.

    2006-01-01

    Several studies have shown the usefulness of contrast-enhanced MR angiography (CE-MRA) for imaging the supraortic vessels, and, as a consequence, it has rapidly become a routine imaging modality. The main advantage over unenhanced techniques is the possibility to acquire larger volumes, allowing demonstration of the carotid artery from its origin to the intracranial portion. Most published studies on CE-MRA of the carotid arteries have been performed with standard Gd-based chelates whose T1 relaxivity values are similar. Recently new gadolinium chelates such as gadobenate dimeglumine (Gd-BOP-TA, MultiHance; Bracco Imaging, Milan, Italy) have been developed which have markedly higher intravascular T1 relaxivity values. When administered at an equivalent dose to that of a standard agent, these newer contrast agents produce significantly greater intravascular signal enhancement. The availability of an appropriate high-relaxivity contrast agent might also help to overcome some of the intrinsic technical problems (e. g. those related to flow) that affect time-of-flight (TOF) and phase contrast (PC) MR angiography of the intracranial vasculature. To avoid the problem of superimposition of veins, ultrafast gradient echo MRA techniques with very short TR and TE have been developed. Although the precise sequence parameters vary between manufacturers, they are basically similar. The choice between performing a time-resolved or high spatial resolution CE-MRA examination depends upon the precise clinical application. The most common applications include the study of cerebral aneurysms, arteriovenous malformations, dural arteriovenous fistulas and dural venous diseases

  10. Gadolinium-enhanced magnetic resonance angiography in neonates and infants suspected of caval or aortic thrombosis

    Energy Technology Data Exchange (ETDEWEB)

    Greenberg, S. Bruce; Bhutta, Sadaf T.; Buchmann, Robert F. [University of Arkansas for Medical Sciences, Arkansas Children' s Hospital, Little Rock, AR (United States)

    2004-12-01

    Gadolinium-enhanced magnetic resonance angiography (MRA)is a well-established technique in older children and adults. No studies have focused on its use in neonates and small infants. Our objective was to study the use of gadolinium-enhanced MRA in neonates and infants suspected of caval or aortic thrombosis. Materials and Methods:Gadolinium-enhanced MR angiography was performed on seven neonates and small infants for the evaluation of caval or aortic thrombosis. Gadolinium-DTPA at a dose of 0.3 mmol/kg (minimum dose 1 ml) was injected using a power injector (0.2 ml/s). Contrast-enhanced MRA was performed using a 3-D, fast, radiofrequency spoiled gradient-echo sequence (TR/TE: 4.8/1.1, flip angle 45 , matrix 256 x 128, slice thickness 2.6 mm interpolated to 1.3 mm, FOV variable, NEX=1.0). Diagnostic-quality angiograms were obtained in all seven neonates. Superior vena cava thrombosis was identified in two neonates, and abdominal aortic thrombosis was present in one neonate. It is practical to perform gadolinium-enhanced MRA in neonates weighing as little as 600 g for the detection of caval or aortic thrombosis. (orig.)

  11. Gadolinium-enhanced magnetic resonance angiography in neonates and infants suspected of caval or aortic thrombosis

    International Nuclear Information System (INIS)

    Greenberg, S. Bruce; Bhutta, Sadaf T.; Buchmann, Robert F.

    2004-01-01

    Gadolinium-enhanced magnetic resonance angiography (MRA)is a well-established technique in older children and adults. No studies have focused on its use in neonates and small infants. Our objective was to study the use of gadolinium-enhanced MRA in neonates and infants suspected of caval or aortic thrombosis. Materials and Methods:Gadolinium-enhanced MR angiography was performed on seven neonates and small infants for the evaluation of caval or aortic thrombosis. Gadolinium-DTPA at a dose of 0.3 mmol/kg (minimum dose 1 ml) was injected using a power injector (0.2 ml/s). Contrast-enhanced MRA was performed using a 3-D, fast, radiofrequency spoiled gradient-echo sequence (TR/TE: 4.8/1.1, flip angle 45 , matrix 256 x 128, slice thickness 2.6 mm interpolated to 1.3 mm, FOV variable, NEX=1.0). Diagnostic-quality angiograms were obtained in all seven neonates. Superior vena cava thrombosis was identified in two neonates, and abdominal aortic thrombosis was present in one neonate. It is practical to perform gadolinium-enhanced MRA in neonates weighing as little as 600 g for the detection of caval or aortic thrombosis. (orig.)

  12. Demonstration of multiple neurofibromas in gadolinium-DTPA enhanced MRI - a case report

    International Nuclear Information System (INIS)

    Kaminsky, S.; Schulz, B.

    1988-01-01

    Although magnetic resonance imaging has a high sensitivity for cerebral and spinal tumors, demonstration of small lesions can be difficult. In a patient with multiple extra- and intraspinal tumors due to neurofibromatosis generalisata, the use of the MRI contrast agent gadolinium-DTPA resulted in a better differentiation especially of small lesions. High tumor contrast facilitated a safe localisation of the widespread disease using a fast imaging sequence (FLASH). (orig.) [de

  13. Gd-DTPA L-cystine bisamide copolymers as novel biodegradable macromolecular contrast agents for MR blood pool imaging.

    Science.gov (United States)

    Kaneshiro, Todd L; Ke, Tianyi; Jeong, Eun-Kee; Parker, Dennis L; Lu, Zheng-Rong

    2006-06-01

    The purpose of this study was to synthesize biodegradable Gd-DTPA L-cystine bisamide copolymers (GCAC) as safe and effective, macromolecular contrast agents for magnetic resonance imaging (MRI) and to evaluate their biodegradability and efficacy in MR blood pool imaging in an animal model. Three new biodegradable GCAC with different substituents at the cystine bisamide [R = H (GCAC), CH2CH2CH3 (Gd-DTPA L-cystine bispropyl amide copolymers, GCPC), and CH(CH3)2 (Gd-DTPA cystine bisisopropyl copolymers, GCIC)] were prepared by the condensation copolymerization of diethylenetriamine pentaacetic acid (DTPA) dianhydride with cystine bisamide or bisalkyl amides, followed by complexation with gadolinium triacetate. The degradability of the agents was studied in vitro by incubation in 15 microM cysteine and in vivo with Sprague-Dawley rats. The kinetics of in vivo contrast enhancement was investigated in Sprague-Dawley rats on a Siemens Trio 3 T scanner. The apparent molecular weight of the polydisulfide Gd(III) chelates ranged from 22 to 25 kDa. The longitudinal (T1) relaxivities of GCAC, GCPC, and GCIC were 4.37, 5.28, and 5.56 mM(-1) s(-1) at 3 T, respectively. The polymeric ligands and polymeric Gd(III) chelates readily degraded into smaller molecules in incubation with 15 microM cysteine via disulfide-thiol exchange reactions. The in vitro degradation rates of both the polymeric ligands and macromolecular Gd(III) chelates decreased as the steric effect around the disulfide bonds increased. The agents readily degraded in vivo, and the catabolic degradation products were detected in rat urine samples collected after intravenous injection. The agents showed strong contrast enhancement in the blood pool, major organs, and tissues at a dose of 0.1 mmol Gd/kg. The difference of their in vitro degradability did not significantly alter the kinetics of in vivo contrast enhancement of the agents. These novel GCAC are promising contrast agents for cardiovascular and tumor MRI

  14. 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

  15. 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

  16. Chelators for investigating zinc metalloneurochemistry

    OpenAIRE

    Radford, Robert John; Lippard, Stephen J.

    2013-01-01

    The physiology and pathology of mobile zinc signaling has become an important topic in metalloneurochemistry. To study the action of mobile zinc effectively, specialized tools are required that probe the temporal and positional changes of zinc ions within live tissue and cells. In the present article we describe the design and implementation of selective zinc chelators as antagonists to interrogate the function of mobile zinc, with an emphasis on the pools of vesicular zinc in the terminals o...

  17. Imaging transplanted stem cells in real time using an MRI dual-contrast method

    Science.gov (United States)

    Ngen, Ethel J.; Wang, Lee; Kato, Yoshinori; Krishnamachary, Balaji; Zhu, Wenlian; Gandhi, Nishant; Smith, Barbara; Armour, Michael; Wong, John; Gabrielson, Kathleen; Artemov, Dmitri

    2015-01-01

    Stem cell therapies are currently being investigated for the repair of brain injuries. Although exogenous stem cell labelling with superparamagnetic iron oxide nanoparticles (SPIONs) prior to transplantation provides a means to noninvasively monitor stem cell transplantation by magnetic resonance imaging (MRI), monitoring cell death is still a challenge. Here, we investigate the feasibility of using an MRI dual-contrast technique to detect cell delivery, cell migration and cell death after stem cell transplantation. Human mesenchymal stem cells were dual labelled with SPIONs and gadolinium-based chelates (GdDTPA). The viability, proliferation rate, and differentiation potential of the labelled cells were then evaluated. The feasibility of this MRI technique to distinguish between live and dead cells was next evaluated using MRI phantoms, and in vivo using both immune-competent and immune-deficient mice, following the induction of brain injury in the mice. All results were validated with bioluminescence imaging. In live cells, a negative (T2/T2*) MRI contrast predominates, and is used to track cell delivery and cell migration. Upon cell death, a diffused positive (T1) MRI contrast is generated in the vicinity of the dead cells, and serves as an imaging marker for cell death. Ultimately, this technique could be used to manage stem cell therapies. PMID:26330231

  18. Inorganic nanocrystals as contrast agents in MRI:synthesis, coating and introducing multifunctionality

    Science.gov (United States)

    Sanchez-Gaytan, Brenda L.; Mieszawska, Aneta J.; Fayad, Zahi A.

    2013-01-01

    Inorganic nanocrystals have myriad applications in medicine, which includes their use as drug or gene delivery complexes, therapeutic hyperthermia agents, in diagnostic systems and as contrast agents in a wide range of medical imaging techniques. For MRI, nanocrystals can produce contrast themselves, of which iron oxides have been most extensively explored, or be given a coating that generates MR contrast, for example gold nanoparticles coated with gadolinium chelates. These MR-active nanocrystals can be used in imaging of the vasculature, liver and other organs, as well as molecular imaging, cell tracking and theranostics. Due to these exciting applications, synthesizing and rendering these nanocrystals water-soluble and biocompatible is therefore highly desirable. We will discuss aqueous phase and organic phase methods for synthesizing inorganic nanocrystals such as gold, iron oxides and quantum dots. The pros and cons of the various methods will be highlighted. We explore various methods for making nanocrystals biocompatible, i.e. directly synthesizing nanocrystals coated with biocompatible coatings, ligand substitution, amphiphile coating and embedding in carrier matrices that can be made biocompatible. Various examples will be highlighted and their applications explained. These examples signify that synthesizing biocompatible nanocrystals with controlled properties has been achieved by numerous research groups and can be applied for a wide range of applications. Therefore we expect to see reports of preclinical applications of ever more complex MRI-active nanoparticles and their wider exploitation, as well as in novel clinical settings. PMID:23303729

  19. Contrast enhancement by lipid-based MRI contrast agents in mouse atherosclerotic plaques; a longitudinal study

    NARCIS (Netherlands)

    den Adel, Brigit; van der Graaf, Linda M.; Que, Ivo; Strijkers, Gustav J.; Löwik, Clemens W.; Poelmann, Robert E.; van der Weerd, Louise

    2013-01-01

    The use of contrast-enhanced MRI to enable in vivo specific characterization of atherosclerotic plaques is increasing. In this study the intrinsic ability of two differently sized gadolinium-based contrast agents to enhance atherosclerotic plaques in ApoE(-/-) mice was evaluated with MRI. We

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

    International Nuclear Information System (INIS)

    Kang, Sung Gwon; Kang, Ji Hee; Kim, Won Hong; Lim, Myung Kwan; Cho, Young Kook; Cho, Soon Gu; Suh, Chang Hae

    1998-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1998-05-01

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

  2. Dialysis and contrast media

    International Nuclear Information System (INIS)

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

    2002-01-01

    In a previous survey we revealed uncertainty among responders about (a) whether or not to perform hemodialysis in patients with severely reduced renal function who had received contrast medium; and (b) when to perform hemodialysis in patients on regular treatment with hemodialysis or continuous ambulatory dialysis who received contrast medium. Therefore, the Contrast Media Safety Committee of The European Society of Urogenital Radiology decided to review the literature and to issue guidelines. The committee performed a Medline search. Based on this, a report and guidelines were prepared. The report was discussed at the Ninth European Symposium on Urogenital Radiology in Genoa, Italy. Hemodialysis and peritoneal dialysis safely remove both iodinated and gadolinium-based contrast media. The effectiveness of hemodialysis depends on many factors including blood and dialysate flow rate, permeability of dialysis membrane, duration of hemodialysis and molecular size, protein binding, hydrophilicity, and electrical charge of the contrast medium. Generally, several hemodialysis sessions are needed to removal all contrast medium, whereas it takes 3 weeks for continuous ambulatory dialysis to remove the agent completely. There is no need to schedule the dialysis in relation to the injection of iodinated or MR contrast media or the injection of contrast agent in relation to the dialysis program. Hemodialysis does not protect poorly functioning kidneys against contrast-medium-induced nephrotoxicity. Simple guidelines are given. (orig.)

  3. Accurate late gadolinium enhancement prediction by early T1- based quantitative synthetic mapping

    Energy Technology Data Exchange (ETDEWEB)

    Dijk, Randy van; Harst, Pim van der [University of Groningen, University Medical Centre Groningen, Centre for Medical Imaging, Groningen (Netherlands); University of Groningen, University Medical Centre Groningen, Department of Cardiology, Groningen (Netherlands); Kuijpers, Dirkjan [University of Groningen, University Medical Centre Groningen, Centre for Medical Imaging, Groningen (Netherlands); Department of Cardiovascular Imaging HMC-Bronovo, The Hague (Netherlands); Kaandorp, Theodorus A.M.; Dijkman, Paul R.M. van [Department of Cardiovascular Imaging HMC-Bronovo, The Hague (Netherlands); Vliegenthart, Rozemarijn [University of Groningen, University Medical Center Groningen, Department of Radiology, Groningen (Netherlands); Oudkerk, Matthijs [University of Groningen, University Medical Centre Groningen, Centre for Medical Imaging, Groningen (Netherlands); University Medical Center Groningen, Center for Medical Imaging, Groningen (Netherlands)

    2018-02-15

    Early synthetic gadolinium enhancement (ESGE) imaging from post-contrast T1 mapping after adenosine stress-perfusion cardiac magnetic resonance (CMR) was compared to conventional late gadolinium enhancement (LGE) imaging for assessing myocardial scar. Two hundred fourteen consecutive patients suspected of myocardial ischaemia were referred for stress-perfusion CMR. Myocardial infarct volume was quantified on a per-subsegment basis in both synthetic (2-3 min post-gadolinium) and conventional (9 min post-gadolinium) images by two independent observers. Sensitivity, specificity, PPV and NPV were calculated on a per-patient and per-subsegment basis. Both techniques detected 39 gadolinium enhancement areas in 23 patients. The median amount of scar was 2.0 (1.0-3.1) g in ESGE imaging and 2.2 (1.1-3.1) g in LGE imaging (p=0.39). Excellent correlation (r=0.997) and agreement (mean absolute difference: -0.028±0.289 ml) were found between ESGE and LGE images. Sensitivity, specificity, PPV and NPV of ESGE imaging were 96 (78.9-99.9), 99 (97.1-100.0)%, 96 (76.5-99.4) and 99.5 (96.6-99.9) in patient-based and 99 (94.5-100.0), 100 (99.9-100.0)%, 97.0 (91.3-99.0) and 100.0 (99.8-100.0) in subsegment-based analysis. ESGE based on post-contrast T1 mapping after adenosine stress-perfusion CMR imaging shows excellent agreement with conventional LGE imaging for assessing myocardial scar, and can substantially shorten clinical acquisition time. (orig.)

  4. Accurate late gadolinium enhancement prediction by early T1- based quantitative synthetic mapping

    International Nuclear Information System (INIS)

    Dijk, Randy van; Harst, Pim van der; Kuijpers, Dirkjan; Kaandorp, Theodorus A.M.; Dijkman, Paul R.M. van; Vliegenthart, Rozemarijn; Oudkerk, Matthijs

    2018-01-01

    Early synthetic gadolinium enhancement (ESGE) imaging from post-contrast T1 mapping after adenosine stress-perfusion cardiac magnetic resonance (CMR) was compared to conventional late gadolinium enhancement (LGE) imaging for assessing myocardial scar. Two hundred fourteen consecutive patients suspected of myocardial ischaemia were referred for stress-perfusion CMR. Myocardial infarct volume was quantified on a per-subsegment basis in both synthetic (2-3 min post-gadolinium) and conventional (9 min post-gadolinium) images by two independent observers. Sensitivity, specificity, PPV and NPV were calculated on a per-patient and per-subsegment basis. Both techniques detected 39 gadolinium enhancement areas in 23 patients. The median amount of scar was 2.0 (1.0-3.1) g in ESGE imaging and 2.2 (1.1-3.1) g in LGE imaging (p=0.39). Excellent correlation (r=0.997) and agreement (mean absolute difference: -0.028±0.289 ml) were found between ESGE and LGE images. Sensitivity, specificity, PPV and NPV of ESGE imaging were 96 (78.9-99.9), 99 (97.1-100.0)%, 96 (76.5-99.4) and 99.5 (96.6-99.9) in patient-based and 99 (94.5-100.0), 100 (99.9-100.0)%, 97.0 (91.3-99.0) and 100.0 (99.8-100.0) in subsegment-based analysis. ESGE based on post-contrast T1 mapping after adenosine stress-perfusion CMR imaging shows excellent agreement with conventional LGE imaging for assessing myocardial scar, and can substantially shorten clinical acquisition time. (orig.)

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

    Indian Academy of Sciences (India)

    nitrogen atmosphere leads to the formation of gadolinium oxide as the final product. ... from Chengdu Haoxuan Technology Co. Ltd, China ..... by metal cations. A band centered at 1534.78 cm. −1 is due to asymmetric stretching of coordinated carboxylate group vas(COO. −. ). Another absorption band at 1398.38 cm. −1 is.

  6. Morphological imaging and T2 and T2* mapping of hip cartilage at 7 Tesla MRI under the influence of intravenous gadolinium

    International Nuclear Information System (INIS)

    Lazik-Palm, Andrea; Geis, Christina; Goebel, Juliane; Theysohn, Jens M.; Kraff, Oliver; Johst, Soeren; Ladd, Mark E.; Quick, Harald H.

    2016-01-01

    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.)

  7. Novel Gd nanoparticles enhance vascular contrast for high-resolution magnetic resonance imaging.

    Directory of Open Access Journals (Sweden)

    Tot Bui

    2010-09-01

    Full Text Available Gadolinium (Gd, with its 7 unpaired electrons in 4f orbitals that provide a very large magnetic moment, is proven to be among the best agents for contrast enhanced MRI. Unfortunately, the most potent MR contrast agent based on Gd requires relatively high doses of Gd. The Gd-chelated to diethylene-triamine-penta-acetic acid (DTPA, or other derivatives (at 0.1 mmole/kg recommended dose, distribute broadly into tissues and clear through the kidney. These contrast agents carry the risk of Nephrogenic Systemic Fibrosis (NSF, particularly in kidney impaired subjects. Thus, Gd contrast agents that produce higher resolution images using a much lower Gd dose could address both imaging sensitivity and Gd safety.To determine whether a biocompatible lipid nanoparticle with surface bound Gd can improve MRI contrast sensitivity, we constructed Gd-lipid nanoparticles (Gd-LNP containing lipid bound DTPA and Gd. The Gd-LNP were intravenously administered to rats and MR images collected. We found that Gd in Gd-LNP produced a greater than 33-fold higher longitudinal (T(1 relaxivity, r(1, constant than the current FDA approved Gd-chelated contrast agents. Intravenous administration of these Gd-LNP at only 3% of the recommended clinical Gd dose produced MRI signal-to-noise ratios of greater than 300 in all vasculatures. Unlike current Gd contrast agents, these Gd-LNP stably retained Gd in normal vasculature, and are eliminated predominately through the biliary, instead of the renal system. Gd-LNP did not appear to accumulate in the liver or kidney, and was eliminated completely within 24 hrs.The novel Gd-nanoparticles provide high quality contrast enhanced vascular MRI at 97% reduced dose of Gd and do not rely on renal clearance. This new agent is likely to be suitable for patients exhibiting varying degrees of renal impairment. The simple and adaptive nanoparticle design could accommodate ligand or receptor coating for drug delivery optimization and in vivo drug

  8. Modified Gadonanotubes as a Promising Novel MRI Contrasting Agent

    OpenAIRE

    Rouzbeh Jahanbakhsh; Fatemeh Atyabi; Saeed Shanehsazzadeh; Zahra Sobhani; Mohsen Adeli; Rassoul Dinarvand

    2013-01-01

    Background and purpose of the study Carbon nanotubes (CNTs) are emerging drug and imaging carrier systems which show significant versatility. One of the extraordinary characteristics of CNTs as Magnetic Resonance Imaging (MRI) contrasting agent is the extremely large proton relaxivities when loaded with gadolinium ion (Gdn 3+) clusters. Methods In this study equated Gdn 3+ clusters were loaded in the sidewall defects of oxidized multiwalled (MW) CNTs. The amount of loaded gadolinium ion into ...

  9. Recent hot topics in contrast media

    DEFF Research Database (Denmark)

    Thomsen, Henrik S

    2011-01-01

    This editorial reviews the way in which the facts related to the safety of iodinated and gadolinium based contrast agents have emerged over the last two decades. This is especially important given their ever increasing usage in modern computed tomographic (CT) and Magnetic resonance imaging (MRI)...

  10. Contrast agents in magnetic resonance imaging

    International Nuclear Information System (INIS)

    Karadjian, V.

    1987-01-01

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

  11. Recent hot topics in contrast media

    DEFF Research Database (Denmark)

    Thomsen, Henrik S

    2011-01-01

    This editorial reviews the way in which the facts related to the safety of iodinated and gadolinium based contrast agents have emerged over the last two decades. This is especially important given their ever increasing usage in modern computed tomographic (CT) and Magnetic resonance imaging (MRI...

  12. Facile Synthesis of Gd-Functionalized Gold Nanoclusters as Potential MRI/CT Contrast Agents

    Directory of Open Access Journals (Sweden)

    Wenjun Le

    2016-04-01

    Full Text Available Multi-modal imaging plays a key role in the earlier detection of disease. In this work, a facile bioinspired method was developed to synthesize Gd-functionalized gold nanoclusters (Gd-Au NCs. The Gd-Au NCs exhibit a uniform size, with an average size of 5.6 nm in dynamic light scattering (DLS, which is a bit bigger than gold clusters (3.74 nm, DLS, while the fluorescent properties of Gd-Au NCs are almost the same as that of Au NCs. Moreover, the Gd-Au NCs exhibit a high longitudinal relaxivity value (r1 of 22.111 s−1 per mM of Gd in phosphate-buffered saline (PBS, which is six times higher than that of commercial Magnevist (A complex of gadolinium with a chelating agent, diethylenetriamine penta-acetic acid, Gd-DTPA, r1 = 3.56 mM−1·s−1. Besides, as evaluated by nano single photon emission computed tomography (SPECT and computed tomography (CT the Gd-Au NCs have a potential application as CT contrast agents because of the Au element. Finally, the Gd-Au NCs show little cytotoxicity, even when the Au concentration is up to 250 μM. Thus, the Gd-Au NCs can act as multi-modal imaging contrast agents.

  13. The complex fate in plasma of gadolinium incorporated into high-density lipoproteins used for magnetic imaging of atherosclerotic plaques

    NARCIS (Netherlands)

    Barazza, Alessandra; Blachford, Courtney; Even-Or, Orli; Joaquin, Victor A.; Briley-Saebo, Karen C.; Chen, Wei; Jiang, Xian-Cheng; Mulder, Willem J. M.; Cormode, David P.; Fayad, Zahi A.; Fisher, Edward A.

    2013-01-01

    We have previously reported enhancing the imaging of atherosclerotic plaques in mice using reconstituted high density lipoproteins (HDL) as nanocarriers for the MRI contrast agent gadolinium (Gd). This study focuses on the underlying mechanisms of Gd delivery to atherosclerotic plaques. HDL, LDL,

  14. Characterization of antibody-chelator conjugates: Determination of chelator content by terbium fluorescence titration

    Energy Technology Data Exchange (ETDEWEB)

    Brandt, K.D.; Schnobrich, K.E.; Johnson, D.K. (Abbott Laboratories, Department 90M, Abbott Park, IL (United States))

    1991-01-01

    Fluorescence titrations were performed by adding varying mole ratios of terbium(III) to antibody conjugates formed by benzyl isothiocyanate derivatives of three different polyaminopolycarboxylate chelators (NTA, EDTA, and DTPA) and the results compared to values for average chelator content obtained by cobalt-57 binding assays. For two different murine monoclonal antibodies, the average chelator content obtained by terbium fluorescence titration correlated closely with that measured by the cobalt-57 binding assay. It is concluded that lanthanide fluorescence titrations provide a useful alternative to radiometal binding assays for the determination of chelator content in protein-chelator conjugates.

  15. Characterization of antibody-chelator conjugates: Determination of chelator content by terbium fluorescence titration

    International Nuclear Information System (INIS)

    Brandt, K.D.; Schnobrich, K.E.; Johnson, D.K.

    1991-01-01

    Fluorescence titrations were performed by adding varying mole ratios of terbium(III) to antibody conjugates formed by benzyl isothiocyanate derivatives of three different polyaminopolycarboxylate chelators (NTA, EDTA, and DTPA) and the results compared to values for average chelator content obtained by cobalt-57 binding assays. For two different murine monoclonal antibodies, the average chelator content obtained by terbium fluorescence titration correlated closely with that measured by the cobalt-57 binding assay. It is concluded that lanthanide fluorescence titrations provide a useful alternative to radiometal binding assays for the determination of chelator content in protein-chelator conjugates

  16. Beliefs about chelation among thalassemia patients

    Directory of Open Access Journals (Sweden)

    Trachtenberg Felicia L

    2012-12-01

    Full Text Available Abstract Background Understanding patients’ views about medication is crucial to maximize adherence. Thalassemia is a congenital blood disorder requiring chronic blood transfusions and daily iron chelation therapy. Methods The Beliefs in Medicine Questionnaire (BMQ was used to assess beliefs in chelation in thalassemia patients from North America and London in the Thalassemia Longitudinal Cohort (TLC of the Thalassemia Clinical Research Network (TCRN. Chelation adherence was based on patient report of doses administered out of those prescribed in the last four weeks. Results Of 371 patients (ages 5-58y, mean 24y, 93% were transfused and 92% receiving chelation (26% deferoxamine (DFO; a slow subcutaneous infusion via portable pump, 63% oral, 11% combination. Patients expressed high “necessity” for transfusion (96%, DFO chelation (92% and oral chelation (89%, with lower “concern” about treatment (48%, 39%, 19% respectively. Concern about oral chelation was significantly lower than that of DFO (p Conclusions Despite their requirement for multimodal therapy, thalassemia patients have positive views about medicine, more so than in other disease populations. Patients may benefit from education about the tolerability of chelation and strategies to effectively cope with side effects, both of which might be beneficial in lowering body iron burden. Clinicaltrials.gov identifier NCT00661804

  17. Studies on gadolinium precipitation in moderator system of nuclear reactor

    International Nuclear Information System (INIS)

    Joshi, Akhilesh C.; Rajesh, Puspalata; Rufus, A.L.; Velmurugan, S.

    2015-01-01

    Gadolinium is used in the moderator system of many Pressurised Heavy Water Reactors (PHWRs) for start-up, shut-down and reactivity control during operation. It is very much essential to maintain gadolinium concentration in the system as desired. It has been reported that gadolinium gets precipitated in as oxalate in carbonated water under the influence of γ-radiation. Hence, studies were carried out to investigate the effect of dose, presence of other metal ions and metal surfaces on the precipitation of gadolinium. The results showed that the amount of carboxylic acids viz., formic acid and oxalic acid, formed due to radiolysis is dependent on the dose and that the curve passes though a maxima. Gadolinium is added in higher concentration in Advanced Heavy Water Reactor. So, experiments with high concentration of gadolinium were also carried out. Ultra pure water saturated with high purity CO 2 containing gadolinium and desired ion/surface was irradiated with γ-radiation from 60 Co source at 25°C to doses ranging from 2.5-16.6 Mrad. At lower doses, formation of carboxylic acids takes place but as the dose increases, decomposition of these acids starts and hence the concentration Vs dose passes through a maximum. It was found that precipitation of gadolinium as oxalate occurred at lower doses. At higher doses, it was seen that pH of the solution decreases and hence solubility of gadolinium oxalate increases. It was also observed that the amount of gadolinium precipitated varied linearly with the initial concentration of gadolinium varying from 2 ppm to 20 ppm. While for gadolinium concentration from 20 ppm to 400 ppm, gadolinium in particulate form was observed. The amount of carboxylic acids formed depends on the nature of cations present in solution. It was found that the amount of oxalic acid formed in the case of gadolinium was more than that formed in the case of sodium. Presence of metal oxides such as ZrO 2 formed over zircoloy surfaces was found to

  18. Metal-oxo containing polymer nanobeads as potential contrast agents for magnetic resonance imaging

    Science.gov (United States)

    Pablico, Michele Huelar

    Magnetic resonance imaging (MRI) has greatly revolutionized the way diseases are detected and treated, as it is a non-invasive imaging modality solely based on the interaction of radiowaves and hydrogen nuclei in the presence of an external magnetic field. It is widely used today for the diagnosis of diseases as it offers an efficient method of mapping structure and function of soft tissues in the body. Most MRI examinations utilize paramagnetic materials known as contrast agents, which enhance the MR signal by decreasing the longitudinal (T1) and transverse (T2) relaxation times of the surrounding water protons in biological systems. This results into increased signal intensity differences thereby allowing better interpretation and analysis of pathological tissues. Contrast agents function by lowering the T1 or lowering the T2, resulting into bright and dark contrasts, respectively. The most common MRI contrast agents that are in clinical use today are gadolinium chelates and superparamagnetic iron oxide nanoparticles, both of which have their own advantages in terms of contrast enhancement properties. In the past few years, however, there has been interest in utilizing metal-containing clusters for MRI contrast enhancement as these materials bridge the gap between the constrained structure and magnetic properties of the gadolinium chelates with the superparamagnetic behavior of the iron oxide nanoparticles. Recently, metallic clusters containing Mn and Fe metal centers have received increased attention mainly because of their potential for high spin states and benign nature. In the quest to further develop novel imaging agents, this research has focused on investigating the use of metal-oxo clusters as potential contrast agents for MRI. The primary goal of this project is to identify clusters that meet the following criteria: high paramagnetic susceptibility, water-soluble, stable, cheap, contain environmentally benign metals, and easily derivatized. This work is

  19. The Effect of Pressure and Temperature on Separation of Free Gadolinium(III) From Gd-DTPA Complex by Nanofiltration-Complexation Method

    Science.gov (United States)

    Rahayu, Iman; Anggraeni, Anni; Ukun, MSS; Bahti, Husein H.

    2017-05-01

    Nowdays, the utilization of rare earth elements has been carried out widely in industry and medicine, one of them is gadolinium in Gd-DTPA complex is used as a contrast agent in a magnetic resonance imaging (MRI) diagnostic to increase the visual contrast between normal tissue and diseased. Although the stability of a given complex may be high enough, the complexation step couldnot have been completed, so there is possible to gadolinium(III) in the complex compound. Therefore, the function of that compounds should be dangerous because of the toxicity of gadolinium(III) in human body. So, it is necessarry to separate free gadolinium(III) from Gd-DTPA complex by nanofiltration-complexation. The method of this study is complexing of Gd2O3 with DTPA ligand by reflux and separation of Gd-DTPA complex from gadolinium(III) with a nanofiltration membrane on the variation of pressures(2, 3, 4, 5, 6 bars) and temperature (25, 30, 35, 40 °C) and determined the flux and rejection. The results of this study are the higher of pressures and temperatures, permeation flux are increasing and ion rejections are decreasing and gave the free gadolinium(III) rejection until 86.26%.

  20. 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)

  1. Isotope shift studies in gadolinium spectra

    International Nuclear Information System (INIS)

    Ahmad, S.A.; Saksena, G.D.; Venugopalan, A.

    1976-01-01

    Isotope shift studies have been carried out in the gadolinium spectrum using a recording Fabry-Perot spectrometer and gadolinium samples enriched in 156 Gd and 160 Gd isotopes. Isotope shifts Δsigma(156-160) have been recorded in 134 lines in the region 3930-4140 A. Some of these lines involve the recently identified even configuration 4f 8 5d6s of Gd I and the newly classified transition 4f 8 6s-4f 8 6p of Gd II. From the isotope shift measurements of lines involving the 4f 8 6s-4f 8 6p transition in Gd II, the isotope shift, ΔT(156-160)=87 mK, has been obtained for the 4f 8 6s configuration. Electronic configurations have been suggested for a number of energy levels and configuration mixing has been pointed out in certain cases. (Auth.)

  2. The critical thermal expansion of gadolinium

    International Nuclear Information System (INIS)

    Robinson, K.; Lanchester, P.C.

    1978-01-01

    Measurements have been made of the critical thermal expansion of single crystals of gadolinium, prepared by solid state electrotransport processing. Although the expansion data can be fitted to a simple power law with exponents lambda + =-0.25, lambda - =-0.33, these values are not predicted by theory and a discontinuity remains at Tsub(c)=293.620 K. It is suggested that the results relate to a region of crossover to uniaxial dipolar behaviour. (Auth.)

  3. Synthesis and evaluation of nanoglobule-cystamine-(Gd-DO3A, a biodegradable nanosized magnetic resonance contrast agent for dynamic contrast-enhanced magnetic resonance urography

    Directory of Open Access Journals (Sweden)

    Rongzuo Xu

    2010-09-01

    Full Text Available Rongzuo Xu1, Todd Lyle Kaneshiro1, Eun-Kee Jeong2, Dennis L Parker2, Zheng-Rong Lu31Department of Pharmaceutics and Pharmaceutical Chemistry, University of Utah, Salt Lake City, UT, USA; 2Department of Radiology, University of Utah, Salt Lake City, UT, USA; 3Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH, USAAbstract: Dynamic contrast-enhanced magnetic resonance imaging has been recently shown to be effective for diagnostic urography. High-resolution urographic images can be acquired with T1 contrast agents for the kidney and urinary tract with minimal noise in the abdomen. Currently, clinical contrast agents are low molecular weight agents and can rapidly extravasate from blood circulation, leading to slow contrast agent elimination through kidney and consequently providing limited contrast enhancement in urinary tract. In this study, a new biodegradable macromolecular contrast agent, nanoglobule-G4-cystamine-(Gd-DO3A, was prepared by conjugating Gd-DO3A chelates on the surface of a generation 4 nanoglobule, poly-l-lysine octa(3-aminopropylsilsesquioxane dendrimer, via a disulfide spacer, where the carrier had a precisely defined nanosize that is far smaller than the renal filtration threshold. The in vivo contrast enhancement and dynamic imaging of the urinary tract of the agent was evaluated in nude mice using a low molecular weight agent Gd(DTPA-BMA as a control. The agent eliminated rapidly from blood circulation and accumulated more abundantly in urinary tract than Gd(DTPA-BMA. The fast elimination kinetics is ideal for functional evaluation of the kidneys. The morphology of the kidneys and urinary tract was better visualized by the biodegradable nanoglobular contrast agent than Gd(DTPA-BMA. The agent also resulted in low liver contrast enhancement, indicating low nonspecific tissue deposition. These features render the G4 nanoglobule-cystamine-(Gd-DO3A conjugate a promising contrast agent for magnetic

  4. 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

  5. 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

  6. Coupling fast water exchange to slow molecular tumbling in Gd3+ chelates: why faster is not always better.

    Science.gov (United States)

    Avedano, Stefano; Botta, Mauro; Haigh, Julian S; Longo, Dario L; Woods, Mark

    2013-08-05

    The influence of dynamics on solution state structure is a widely overlooked consideration in chemistry. Variations in Gd(3+) chelate hydration with changing coordination geometry and dissociative water exchange kinetics substantially impact the effectiveness (or relaxivity) of monohydrated Gd(3+) chelates as T1-shortening contrast agents for MRI. Theory shows that relaxivity is highly dependent upon the Gd(3+)-water proton distance (rGdH), and yet this distance is almost never considered as a variable in assessing the relaxivity of a Gd(3+) chelate as a potential contrast agent. The consequence of this omission can be seen when considering the relaxivity of isomeric Gd(3+) chelates that exhibit different dissociative water exchange kinetics. The results described herein show that the relaxivity of a chelate with "optimal" dissociative water exchange kinetics is actually lower than that of an isomeric chelate with "suboptimal" dissociative water exchange. When the rate of molecular tumbling of these chelates is slowed, an approach that has long been understood to increase relaxivity, the observed difference in relaxivity is increased with the more rapidly exchanging ("optimal") chelate exhibiting lower relaxivity than the "suboptimally" exchanging isomer. The difference between the chelates arises from a non-field-dependent parameter: either the hydration number (q) or rGdH. For solution state Gd(3+) chelates, changes in the values of q and rGdH are indistinguishable. These parametric expressions simply describe the hydration state of the chelate--i.e., the number and position of closely associating water molecules. The hydration state (q/rGdH(6)) of a chelate is intrinsically linked to its dissociative water exchange rate kex, and the interrelation of these parameters must be considered when examining the relaxivity of Gd(3+) chelates. The data presented herein indicate that the changes in the hydration parameter (q/rGdH(6)) associated with changing dissociative

  7. Phosphinic acid functionalized polyazacycloalkane chelators for radiodiagnostics and radiotherapeutics: unique characteristics and applications.

    Science.gov (United States)

    Notni, Johannes; Šimeček, Jakub; Wester, Hans-Jürgen

    2014-06-01

    Given the wide application of positron emission tomography (PET), positron-emitting metal radionuclides have received much attention recently. Of these, gallium-68 has become particularly popular, as it is the only PET nuclide commercially available from radionuclide generators, therefore allowing local production of PET radiotracers independent of an on-site cyclotron. Hence, interest in optimized bifunctional chelators for the elaboration of (68) Ga-labeled bioconjugates has been rekindled as well, resulting in the development of improved triazacyclononane-triphosphinate (TRAP) ligand structures. The most remarkable features of these ligands are unparalleled selectivity for Ga(III) , rapid Ga(III) complexation kinetics, extraordinarily high thermodynamic stability, and kinetic inertness of the respective Ga(III) chelates. As a result, TRAP chelators exhibit very favorable (68) Ga-labeling properties. Based on the scaffolds NOPO (1,4,7-triazacyclononane-1,4-bis[methylene(hydroxymethyl)phosphinic acid]-7-[methylene(2-carboxyethyl)phosphinic acid]) and TRAP-Pr, tailored for convenient preparation of (68) Ga-labeled monomeric and multimeric bioconjugates, a variety of novel (68) Ga radiopharmaceuticals have been synthesized. These include bisphosphonates, somatostatin receptor ligands, prostate-specific membrane antigen (PSMA)-targeting peptides, and cyclic RGD pentapeptides, for in vivo PET imaging of bone, neuroendocrine tumors, prostate cancer, and integrin expression, respectively. Furthermore, TRAP-based (68) Ga-labeled gadolinium(III) complexes have been proposed as bimodal probes for PET/MRI, and a cyclen-based analogue of TRAP-Pr has been suggested for the elaboration of targeted radiotherapeutics comprising radiolanthanide ions. Thus, polyazacycloalkane-based polyphosphinic acid chelators are a powerful toolbox for pharmaceutical research, particularly for the development of (68) Ga radiopharmaceuticals. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. Chelating agents in pharmacology, toxicology and therapeutics

    International Nuclear Information System (INIS)

    1988-01-01

    The proceedings contain 71 abstracts of papers. Fourteen abstracts were inputted in INIS. The topics covered include: the effects of chelating agents on the retention of 63 Ni, 109 Cd, 203 Hg, 144 Ce, 95 Nb and the excretion of 210 Po, 63 Ni, 48 V, 239 Pu, 241 Am, 54 Mn; the applications of tracer techniques for studies of the efficacy of chelation therapy in patients with heart and brain disorders; and the treatment of metal poisoning with chelating agents. (J.P.)

  9. Enhancement of 67Ga tumor-to-blood ratios by chelating agent

    International Nuclear Information System (INIS)

    Saji, Hideo; Yokoyama, Akira; Hata, Naotaka; Misaki, Atsushi; Tanaka, Hisashi.

    1980-01-01

    Chelating agent, such as, CaEDTA, CaDTPA, D-penicillamine, DMSA, desferoxamine, NTA, cysteine ethyl ester, BAL, α-MPG, phthalein complexone, were tested as a possible contrast enhancing agent for tumor imaging with 67 Ga-citrate. The intravenous administration of a chelating agent to Ehrlich's tumor bearing mice, one hour after the injection of 67 Ga-citrate, accelerated the blood clearance with only a very slight change of activity in the target, increasing the tumor-to-blood ratio, and consequently achieving a better visualization. Among the tested chelating agents, D-penicillamine showed the highest target-to-nontarget ratio at a shorter time: a good tumor-to-blood ratio, performed after 24 hr with non-treated animals, was achieved in only 1-3 hr with post-treated animals. Thus, D-penicillamine hold a considerable promise as a contrast enhancing agent for future clinical use. (author)

  10. A polymeric micelle magnetic resonance imaging (MRI) contrast agent reveals blood-brain barrier (BBB) permeability for macromolecules in cerebral ischemia-reperfusion injury.

    Science.gov (United States)

    Shiraishi, Kouichi; Wang, Zuojun; Kokuryo, Daisuke; Aoki, Ichio; Yokoyama, Masayuki

    2017-05-10

    Blood-brain barrier (BBB) opening is a key phenomenon for understanding ischemia-reperfusion injuries that are directly linked to hemorrhagic transformation. The recombinant human tissue-type plasminogen activator (rtPA) increases the risk of symptomatic intracranial hemorrhages. Recent imaging technologies have advanced our understanding of pathological BBB disorders; however, an ongoing challenge in the pre-"rtPA treatment" stage is the task of developing a rigorous method for hemorrhage-risk assessments. Therefore, we examined a novel method for assessment of rtPA-extravasation through a hyper-permeable BBB. To examine the image diagnosis of rtPA-extravasation for a rat transient occlusion-reperfusion model, in this study we used a polymeric micelle MRI contrast-agent (Gd-micelles). Specifically, we used two MRI contrast agents at 1h after reperfusion. Gd-micelles provided very clear contrast images in 15.5±10.3% of the ischemic hemisphere at 30min after i.v. injection, whereas a classic gadolinium chelate MRI contrast agent provided no satisfactorily clear images. The obtained images indicate both the hyper-permeable BBB area for macromolecules and the distribution area of macromolecules in the ischemic hemisphere. Owing to their large molecular weight, Gd-micelles remained in the ischemic hemisphere through the hyper-permeable BBB. Our results indicate the feasibility of a novel clinical diagnosis for evaluating rtPA-related hemorrhage risks. Copyright © 2017 Elsevier B.V. All rights reserved.

  11. 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

  12. Clinical application of gadolinium-enhanced three-dimensional pulmonary MR angiography

    International Nuclear Information System (INIS)

    Takano, Katsuyuki

    1999-01-01

    Twenty-nine patients with suspected pulmonary lesions, and three normal volunteers, underwent gadolinium-enhanced three-dimensional (3D) pulmonary MR angiography (MRA). The MRA were obtained during intravenous administration of gadolinium-based contrast material, in a single breath-hold. Conspicuity of the normal pulmonary segmental arteries was estimated on the MRA. Abnormal findings such as ''vascular involvement'', ''abnormal connection'', stenosis'', or ''dilatation'' on the MRA were compared with those on conventional angiography or CT. Normal pulmonary segmental arteries, except for A 4,5,6,8and9 of the left pulmonary artery, could be clearly visualized. Blind reading of four different findings lead to characteristic findings for each pulmonary disease that can be aid in their differential diagnoses. This technique shows promise as a noninvasive diagnosis of lung diseases. (author)

  13. 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.)

  14. 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.)

  15. Indications and contraindications for contrast-enhanced MRI and CT during pregnancy

    International Nuclear Information System (INIS)

    Junkermann, H.

    2007-01-01

    There are no reports about negative effects on the fetus of the application of gadolinium-containing contrast media to pregnant mothers. Iodine-containing contrast media may lead to a transient hypothyroidism in the newborn. This will be detected with certainty by the neonatal TSH screening. Iodine- or gadolinium-containing contrast media may be used in pregnant women if indispensable. In the gut of breastfed children less than 1% of the recommended pediatric doses of contrast media are found after both types of contrast media have been given to their mothers. Therefore there are no reasons against the use of contrast media during the nursing period. (orig.) [de

  16. Exogenous contrast agents for thermoacoustic imaging: An investigation into the underlying sources of contrast

    International Nuclear Information System (INIS)

    Ogunlade, Olumide; Beard, Paul

    2015-01-01

    Purpose: Thermoacoustic imaging at microwave excitation frequencies is limited by the low differential contrast exhibited by high water content tissues. To overcome this, exogenous thermoacoustic contrast agents based on gadolinium compounds, iron oxide, and single wall carbon nanotubes have previously been suggested and investigated. However, these previous studies did not fully characterize the electric, magnetic, and thermodynamic properties of these agents thus precluding identification of the underlying sources of contrast. To address this, measurements of the complex permittivity, complex permeability, DC conductivity, and Grüneisen parameter have been made. These measurements allowed the origins of the contrast provided by each substance to be identified. Methods: The electric and magnetic properties of the contrast agents were characterized at 3 GHz using two rectangular waveguide cavities. The DC conductivity was measured separately using a conductivity meter. Thermoacoustic signals were then acquired and compared to those generated in water. Finally, 3D electromagnetic simulations were used to decouple the different contributions to the absorbed power density. Results: It was found that the gadolinium compounds provided appreciable electric contrast but not originating from the gadolinium itself. The contrast was either due to dissociation of the gadolinium salt which increased ionic conductivity or its nondissociated polar fraction which increased dielectric polarization loss or a combination of both. In addition, very high concentrations were required to achieve appreciable contrast, to the extent that the Grüneisen parameter increased significantly and became a source of contrast. Iron oxide particles were found to produce low but measurable dielectric contrast due to dielectric polarization loss, but this is attributed to the coating of the particles not the iron oxide. Single wall carbon nanotubes did not provide measurable contrast of any type

  17. Exogenous contrast agents for thermoacoustic imaging: An investigation into the underlying sources of contrast

    Energy Technology Data Exchange (ETDEWEB)

    Ogunlade, Olumide, E-mail: o.ogunlade@ucl.ac.uk; Beard, Paul [Department of Medical Physics and Biomedical Engineering, University College London, London WC1E 6BT (United Kingdom)

    2015-01-15

    Purpose: Thermoacoustic imaging at microwave excitation frequencies is limited by the low differential contrast exhibited by high water content tissues. To overcome this, exogenous thermoacoustic contrast agents based on gadolinium compounds, iron oxide, and single wall carbon nanotubes have previously been suggested and investigated. However, these previous studies did not fully characterize the electric, magnetic, and thermodynamic properties of these agents thus precluding identification of the underlying sources of contrast. To address this, measurements of the complex permittivity, complex permeability, DC conductivity, and Grüneisen parameter have been made. These measurements allowed the origins of the contrast provided by each substance to be identified. Methods: The electric and magnetic properties of the contrast agents were characterized at 3 GHz using two rectangular waveguide cavities. The DC conductivity was measured separately using a conductivity meter. Thermoacoustic signals were then acquired and compared to those generated in water. Finally, 3D electromagnetic simulations were used to decouple the different contributions to the absorbed power density. Results: It was found that the gadolinium compounds provided appreciable electric contrast but not originating from the gadolinium itself. The contrast was either due to dissociation of the gadolinium salt which increased ionic conductivity or its nondissociated polar fraction which increased dielectric polarization loss or a combination of both. In addition, very high concentrations were required to achieve appreciable contrast, to the extent that the Grüneisen parameter increased significantly and became a source of contrast. Iron oxide particles were found to produce low but measurable dielectric contrast due to dielectric polarization loss, but this is attributed to the coating of the particles not the iron oxide. Single wall carbon nanotubes did not provide measurable contrast of any type

  18. Contrast enhancement by differently sized paramagnetic MRI contrast agents in mice with two phenotypes of atherosclerotic plaque

    NARCIS (Netherlands)

    van Bochove, Glenda S.; Paulis, Leonie E. M.; Segers, Dolf; Mulder, Willem J. M.; Krams, Rob; Nicolay, Klaas; Strijkers, Gustav J.

    2011-01-01

    Interest in the use of contrast-enhanced MRI to enable in vivo specific characterization of atherosclerotic plaques is increasing. In this study the intrinsic ability of three differently sized gadolinium-based contrast agents to permeate different mouse plaque phenotypes was evaluated with MRI. A

  19. Chelation in root canal therapy reconsidered.

    Science.gov (United States)

    Zehnder, Matthias; Schmidlin, Patrick; Sener, Beatrice; Waltimo, Tuomas

    2005-11-01

    The aim of this study was to assess interactions of EDTA and citric acid (CA) with sodium hypochlorite (NaOCl), the indispensable endodontic irrigant. Other chelators were simultaneously evaluated as possible alternatives: sodium triphosphate (STP), amino tris methylenephosphonic acid (ATMA), and 1- hydroxyethylidene-1, 1-bisphosphonate (HEBP). Available chlorine was titrated in chelator-NaOCl solutions. All chelators other than HEBP and STP caused an almost complete, immediate loss of available chlorine in solution. Atomic absorbtion spectrometry and SEM evaluation of root canal walls of instrumented teeth indicated that NaOCl had no negative effect on calcium-complexing ability of chelators. STP was too weak a complexing agent to warrant further studies. Finally, CA-, EDTA-, and HEBP-NaOCl mixtures were evaluated for their antimicrobial capacity. Again, EDTA and CA negatively interfered with NaOCl, while HEBP did not.

  20. Chelates for Micronutrient Nutrition among Crops

    Indian Academy of Sciences (India)

    years, it has been recognised that compounds containing che- lated metals could .... when using small amounts and no build up of harmful levels. ... degradation of iron chelates. .... down by soil microorganisms into much smaller units for ab-.

  1. A new approach in the preparation of dendrimer-based bifunctional diethylenetriaminepentaacetic acid MR contrast agent derivatives.

    Science.gov (United States)

    Nwe, Kido; Xu, Heng; Regino, Celeste Aida S; Bernardo, Marcelino; Ileva, Lilia; Riffle, Lisa; Wong, Karen J; Brechbiel, Martin W

    2009-07-01

    In this paper, we report a new method to prepare and characterize a contrast agent based on a fourth-generation (G4) polyamidoamine (PAMAM) dendrimer conjugated to the gadolinium complex of the bifunctional diethylenetriamine pentaacetic acid derivative (1B4M-DTPA). The method involves preforming the metal-ligand chelate in alcohol prior to conjugation to the dendrimer. The dendrimer-based agent was purified by a Sephadex G-25 column and characterized by elemental analysis. The analysis and SE-HPLC data gave a chelate to dendrimer ratio of 30:1 suggesting conjugation at approximately every other amine terminal on the dendrimer. Molar relaxivity of the agent measured at pH 7.4 displayed a higher value than that of the analogous G4 dendrimer based agent prepared by the postmetal incorporation method (r(1) = 26.9 vs 13.9 mM(-1) s(-1) at 3 T and 22 degrees C). This is hypothesized to be due to the higher hydrophobicity of this conjugate and the lack of available charged carboxylate groups from noncomplexed free ligands that might coordinate to the metal and thus also reduce water exchange sites. Additionally, the distribution populations of compounds that result from the postmetal incorporation route are eliminated from the current product simplifying characterization as quality control issues pertaining to the production of such agents for clinical use as MR contrast agents. In vivo imaging in mice showed a reasonably fast clearance (t(1/2) = 24 min) suggesting a viable agent for use in clinical application.

  2. Radiopharmaceutical chelates and method of external imaging

    International Nuclear Information System (INIS)

    1976-01-01

    The preparation of the following chemicals is described: chelates of technetium-99m, cobalt-57, gallium-67, gallium-68, indium-111 or indium-113m and a substituted iminodiacetic acid or an 8-hydroxyquinoline useful as a radiopharmaceutical external imaging agent. The compounds described are suitable for intravenous injection, have an excellent in vivo stability and are good organ seekers. Tin(II) choride or other tin(II) compounds are used as chelating agents

  3. 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

  4. 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

  5. Hepatocellular carcinoma. Comparison between gadolinium and ironoxide enhanced MR imaging

    International Nuclear Information System (INIS)

    Castoldi, M.C.; Fauda, V.; Scaramuzza, D.; Vergnaghi, D.

    2000-01-01

    Purpose of this work is to compare prospectively dynamic gadolinium (Gd)-enhanced with superparamagnetic iron oxide (SPIO)-enhanced MRI for the detection of hepatocellular carcinoma (HCC). Twenty-five patients with histologically proven HCC and liver cirrhosis (28% of them in B or C Child class) underwent dynamic Gd-enhanced MRI and, a few days later, (mean interval: three days) SPIO-enhanced MRI. Only patients with availability of clinical and imaging follow-up for at least seven months were enrolled in this prospective study. MR images were reviewed by two independent radiologists. The readers scored each lesion for the presence of HCC and assigned confidence levels based on a five-grade scale: 1, definitely or almost definitely absent; 2, possibly present; 3, probably present; 4, definitely present; 5, definitely present with optimal liver/lesion contrast or good liver/lesion contrast and morphological signs (intact capsule, intranodular septa, extracapsular infiltration), useful for locoregional treatment planning. A positive diagnostic value was assessed for scores of 3 or higher. Gd-enhanced and SPIO-enhanced MRI found 44 lesions. Eight of twelve lesions visible with a single contrast agent measured less than 1 cm in diameter. HCC detectability was 75% with Gd-enhanced MRI and 97.7% with SPIO-enhanced MRI. SPIO-enhanced T2-weighted TSE images showed significantly higher diagnostic value than SPIO-enhanced T1-T2*GRE images only in three cases, while nodule morphological characteristics (capsule, septa, different cell differentiation components) were better depicted by TSE images. In thi study the combined use of SPIO-enhanced T2-weighted TSE and T1-T2*-weighted GRE sequences showed higher sensitivity than gadolinium-enhanced GRE dynamic imaging (97.7% versus 75%). These results are at least partly related to our study conditions, that is: 1)MRI was performed with a 1T system, 2) both axial and sagittal SPIO-enhanced imaging were performed with respiratory

  6. Fluid extraction using carbon dioxide and organophosphorus chelating agents

    Science.gov (United States)

    Smart, Neil G.; Wai, Chien M.; Lin, Yuehe; Kwang, Yak Hwa

    1998-01-01

    Methods for extracting metalloid and metal species from a solid or liquid material by exposing the material to a fluid solvent, particularly supercritical CO.sub.2, and a chelating agent are described. The chelating agent forms a chelate with the species, the chelate being soluble in the fluid to allow removal of the species from the material. In preferred embodiments the extraction solvent is supercritical CO.sub.2 and the chelating agent comprises an organophosphorous chelating agent, particularly sulfur-containing organophosphorous chelating agents, including mixtures of chelating agents. Examples of chelating agents include monothiophosphinic acid, di-thiophosphinic acid, phosphine sulfite, phosphorothioic acid, and mixtures thereof. The method provides an environmentally benign process for removing metal and metalloids from industrial waste solutions, particularly acidic solutions. Both the chelate and the supercritical fluid can be regenerated and the contaminant species recovered to provide an economic, efficient process.

  7. Differential diagnosis between adrenal adenomas and non-adenomas with gadolinium MR in delayed scans: another diagnostic possibility

    International Nuclear Information System (INIS)

    Mondello, Eduardo J.; Eyheremendy, Eduardo P.; Stoisa, Daniela

    2001-01-01

    Purpose: To determine the value of measuring delayed post gadolinium signal intensity by displaying a curve, to make the differential diagnosis between adrenal adenomas and non-adenomas, and compare it to chemical shift MR imaging and unenhanced/delayed contrast enhanced CT. Material and methods: Nine adrenal masses have been evaluated by unenhanced/delayed contrast enhanced CT, chemical shift MR imaging and Dynamic Scan at 5, 15, 30 minutes or more, with measurement curves. The 'in phase' imaging have been compared to the 'out phase' ones. Results: Adenomas have shown drop of the curve at 30 minutes of the contrast injection. Non-adenomas have conserved an ascending curve with the same delay. Conclusion: Gadolinium-enhanced MR imaging at delayed scans can characterize adrenal masses as adenomas or non-adenomas. This technique could be considered as a new complementary diagnostic method. (author)

  8. 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)

  9. Contrast-enhanced peripheral MRA

    DEFF Research Database (Denmark)

    Nielsen, Yousef W; Thomsen, Henrik S

    2012-01-01

    MRI contrast agent is injected intravenously and T1-weighted images are acquired in the subsequent arterial first-pass phase. In order to achieve high quality MR angiograms without interfering venous contamination or artifacts, a number of factors need to be taken into account. This includes magnetic......-state MRA. Gadolinium(Gd)-based contrast agents are used for CE-MRA of the peripheral arteries. Extracellular Gd agents have a pharmacokinetic profile similar to iodinated contrast media. Accordingly, these agents are employed for first-pass MRA. Blood-pool Gd-based agents are characterized by prolonged...... intravascular stay, due to macromolecular structure or protein binding. These agents can be used for first-pass, as well as steady-state MRA. Some Gd-based contrast agents with low thermodynamic stability have been linked to development of nephrogenic systemic fibrosis in patients with severe renal...

  10. Present status of PIK gadolinium control

    International Nuclear Information System (INIS)

    Petrov, Yu.V.; Garusov, E.A.; Shustov, V.A.

    1994-01-01

    A liquid control element (LCE) containing a water solution of gadolinium nitrate Gd(NO 3 ) 3 was originally planned for use at the PIK reactor for partial compensation of poisoning and fuel burnup [1-3]. However, a further analysis has shown that quick forcing-out, boiling up or flowing-out of the absorbing solution (though of low probability) can lead to the dangerous prompt overcriticality of the reactor. The results of the analysis are presented as well as the upper limit of the reactivity, quick insertion of which still is safe for the reactor (J.P.N.)

  11. The application of Anthropogenic Gadolinium as a tracer in ground and surface water: examples from France and the Netherlands

    Science.gov (United States)

    Klaver, G.; Verheul, M.; Petelet-Giraud, E.; Negrel, P. J.

    2011-12-01

    Gadolinium chelates have been used since 1988 as contrasts agents in medical imaging (MRI) and produce positive anthropogenic Gd anomalies in rare element shale normalized patterns (REEnasc) of river and lake waters. Both in the Netherlands and France the presence of a positive Gd anomaly in surface and groundwater is used as a common tool in complex surface-surface and surface-groundwater studies. In this poster 3 examples of this common practice are given. The "Ile du Chambon" catchment (100 ha) is located in the Allier Valley, within Oligocene alluvial formations (sand and gravel). The nitrate content in the wells of the drinking water supply is ≥ 50 mg/l and two sources for the origin of the nitrates are hypothesized: agriculture or wastewater from a waste water treatment plant. Widory et al. (2005), using a coupled chemical (Cl and NO3) and isotopic (nitrogen and boron) approach, could show that the wastewater was the main source of the nitrate pollution. The presence of a Gd anomaly in the shale normalized rare earth patterns of wells contaminated by the waste water confirms the findings of Widory et al. (2005). In the second case the Gd anomaly is used to follow the infiltration of river water into a small lake in the Netherlands. During dry periods in this small river, Meuse water with a distinct Gd anomaly is fed into this river. The REE were monitored in the river, in a piezometer installed in the dike between the river and the lake and in the lake before, during and after the Meuse water was fed into this river. With the time series analyses the infiltration of the Meuse water into the dike and the small lake could be clearly followed. In a third case, in the center of the Netherlands, the flow of inlet Meuse water with a distinct Gd anomaly into a polder and subsequently from the larger into the smaller ditches of this polder were followed by analyzing the REEs. In such dry periods the ditches in the polder are also fed by groundwater that does not

  12. The synthesis of a D-glucosamine contrast agent, Gd-DTPA-DG, and its application in cancer molecular imaging with MRI

    International Nuclear Information System (INIS)

    Zhang Wei; Chen Yue; Guo Dajing; Huang Zhanwen; Cai Liang; He Ling

    2011-01-01

    Objective: The purpose of this study is to describe the synthesis of Gadolinium-diethylenetriamine pentaacetic acid-deoxyglucosamine (Gd-DTPA-DG) which is a D-glucosamine metabolic MR imaging contrast agent. We will also discuss its use in a pilot MRI study using a xenograft mouse model of human adenocarcinoma. Methods: This novel contrast agent was specifically studied because of its ability to 'target' metabolically active tumor tissues. In this study Gd-DTPA-DG is used to investigate how tumor tissues would react to a dose of 0.2 mmol Gd/kg over a 120 min exposure in a xenograft mouse model. These experiments used athymic mice implanted with human pulmonary adenocarcinoma (A549) as demonstrated by dynamic MRI. Alternately, another contrast agent that is not specific for targeting, Gd-DTPA, was used as the control at a similar dose of gadolinium. Efficacy of the targeted contrast agent was assessed by measuring relaxation rate in vitro and signal intensity (SI) in vivo. Statistical differences were calculated using one-way analysis of variance. Results: The synthesized Gd-DTPA-DG was shown to improve the contrast of tumor tissue in this model. Gd-DTPA-DG was also shown to have a similar pharmacokinetic rate but generated a higher relaxation rate in tumor tissues relative to the control contrast Gd-DTPA. In comparison to the pre-contrast imaging, the SI of tumor tissue in the experimental group was shown to be significantly increased at 15 min after injection of Gd-DTPA-DG (p < 0.001). The enhanced signal intensity spread from the edge of the tumor to the center and seemed to strengthen the idea that MRI performance would be useful in different tumor tissues. Conclusion: This preliminary study shows that this new chelated contrast agent, Gd-DTPA-DG, can be specifically targeted to accumulation in tumor tissue as compared to normal tissues. This targeted paramagnetic contrast agent has potential for specific cancer molecular imaging with MRI.

  13. Clinical value of MRI liver-specific contrast agents: a tailored examination for a confident non-invasive diagnosis of focal liver lesions

    International Nuclear Information System (INIS)

    Ba-Ssalamah, Ahmed; Uffmann, Martin; Bastati, Nina; Herold, Christian; Schima, Wolfgang; Saini, Sanjai

    2009-01-01

    Screening of the liver for hepatic lesion detection and characterization is usually performed with either ultrasound or CT. However, both techniques are suboptimal for liver lesion characterization and magnetic resonance (MR) imaging has emerged as the preferred radiological investigation. In addition to unenhanced MR imaging techniques, contrast-enhanced MR imaging can demonstrate tissue-specific physiological information, thereby facilitating liver lesion characterization. Currently, the classes of contrast agents available for MR imaging of the liver include non-tissue-specific extracellular gadolinium chelates and tissue-specific hepatobiliary or reticuloendothelial agents. In this review, we describe the MR features of the more common focal hepatic lesions, as well as appropriate imaging protocols. A special emphasis is placed on the clinical use of non-specific and liver-specific contrast agents for differentiation of focal liver lesions. This may aid in the accurate diagnostic workup of patients in order to avoid invasive procedures, such as biopsy, for lesion characterization. A diagnostic strategy that considers the clinical situation is also presented. (orig.)

  14. Coordination chemistry of gadolinium complexes having pyridine carboxylate units in relation with the medical imagery

    International Nuclear Information System (INIS)

    Gateau, C.; Chatterton, N.; Nonat, A.; Mazzanti, M.; Pecaut, J.; Borel, A.; Merbach, A.; Heim, L.

    2005-01-01

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

  15. PAMAM Dendrimers as Potential Carriers of Gadolinium Complexes of Iminodiacetic Acid Derivatives for Magnetic Resonance Imaging

    Directory of Open Access Journals (Sweden)

    Magdalena Markowicz-Piasecka

    2015-01-01

    Full Text Available This is the first study describing the utilization of PAMAM dendrimers as delivery vehicles of novel magnetic resonance imaging (MRI contrast agents. The purpose of this paper was to establish the potential of G4 PAMAM dendrimers as carriers of gadolinium complexes of iminodiacetic acid derivatives and determine imaging properties of synthesized compounds in in vivo studies. Furthermore, we examined the influence of four synthesized complexes on the process of clot formation, stabilization, and lysis and on amidolytic activity of thrombin. Biodistribution studies have shown that the compounds composed of PAMAM G4 dendrimers and gadolinium complexes of iminodiacetic acid derivatives increase signal intensity preferably in liver in range of 59–116% in MRI studies which corresponds with the greatest accumulation of gadolinium after administration of the compounds. Synthesized compounds affect kinetic parameters of the proces of clot formation, its stabilization, and lysis. However, only one synthesized compound at concentration 10-fold higher than potential plasma concentrations contributed to the increase of general parameters such as the overall potential of clot formation and lysis (↑CLAUC and total time of the process (↑T. Results of described studies provide additional insight into delivery properties of PAMAM dendrimers but simultaneously underscore the necessity for further research.

  16. Engineering an antibody with picomolar affinity to DOTA chelates of multiple radionuclides for pretargeted radioimmunotherapy and imaging

    Energy Technology Data Exchange (ETDEWEB)

    Orcutt, Kelly Davis; Slusarczyk, Adrian L. [Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139 (United States); Cieslewicz, Maryelise [Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139 (United States); Ruiz-Yi, Benjamin [Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139 (United States); Bhushan, Kumar R. [Division of Hematology/Oncology, Beth Israel Deaconess Medical Center, Boston, MA 02215 (United States); Frangioni, John V. [Division of Hematology/Oncology, Beth Israel Deaconess Medical Center, Boston, MA 02215 (United States); Department of Radiology, Beth Israel Deaconess Medical Center, Boston, MA 02215 (United States); Wittrup, K. Dane, E-mail: wittrup@mit.ed [Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139 (United States); Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139 (United States); Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, MA 02139 (United States)

    2011-02-15

    Introduction: In pretargeted radioimmunotherapy (PRIT), a bifunctional antibody is administered and allowed to pre-localize to tumor cells. Subsequently, a chelated radionuclide is administered and captured by cell-bound antibody while unbound hapten clears rapidly from the body. We aim to engineer high-affinity binders to 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA) chelates for use in PRIT applications. Methods: We mathematically modeled antibody and hapten pharmacokinetics to analyze hapten tumor retention as a function of hapten binding affinity. Motivated by model predictions, we used directed evolution and yeast surface display to affinity mature the 2D12.5 antibody to DOTA, reformatted as a single chain variable fragment (scFv). Results: Modeling predicts that for high antigen density and saturating bsAb dose, a hapten-binding affinity of 100 pM is needed for near-maximal hapten retention. We affinity matured 2D12.5 with an initial binding constant of about 10 nM to DOTA-yttrium chelates. Affinity maturation resulted in a 1000-fold affinity improvement to biotinylated DOTA-yttrium, yielding an 8.2{+-}1.9 picomolar binder. The high-affinity scFv binds DOTA complexes of lutetium and gadolinium with similar picomolar affinity and indium chelates with low nanomolar affinity. When engineered into a bispecific antibody construct targeting carcinoembryonic antigen, pretargeted high-affinity scFv results in significantly higher tumor retention of a {sup 111}In-DOTA hapten compared to pretargeted wild-type scFv in a xenograft mouse model. Conclusions: We have engineered a versatile, high-affinity, DOTA-chelate-binding scFv. We anticipate it will prove useful in developing pretargeted imaging and therapy protocols to exploit the potential of a variety of radiometals.

  17. Metal-chelating active packaging film enhances lysozyme inhibition of Listeria monocytogenes.

    Science.gov (United States)

    Roman, Maxine J; Decker, Eric A; Goddard, Julie M

    2014-07-01

    Several studies have demonstrated that metal chelators enhance the antimicrobial activity of lysozyme. This study examined the effect of metal-chelating active packaging film on the antimicrobial activity of lysozyme against Listeria monocytogenes. Polypropylene films were surface modified by photoinitiated graft polymerization of acrylic acid (PP-g-PAA) from the food contact surface of the films to impart chelating activity based on electrostatic interactions. PP-g-PAA exhibited a carboxylic acid density of 113 ± 5.4 nmol cm(-2) and an iron chelating activity of 53.7 ± 9.8 nmol cm(-2). The antimicrobial interaction of lysozyme and PP-g-PAA depended on growth media composition. PP-g-PAA hindered lysozyme activity at low ionic strength (2.48-log increase at 64.4 mM total ionic strength) and enhanced lysozyme activity at moderate ionic strength (5.22-log reduction at 120 mM total ionic strength). These data support the hypothesis that at neutral pH, synergy between carboxylate metal-chelating films (pKa(bulk) 6.45) and lysozyme (pI 11.35) is optimal in solutions of moderate to high ionic strength to minimize undesirable charge interactions, such as lysozyme absorption onto film. These findings suggest that active packaging, which chelates metal ions based on ligand-specific interactions, in contrast to electrostatic interactions, may improve antimicrobial synergy. This work demonstrates the potential application of metal-chelating active packaging films to enhance the antimicrobial activity of membrane-disrupting antimicrobials, such as lysozyme.

  18. Olivine-type cathode for rechargeable batteries: Role of chelating agents

    International Nuclear Information System (INIS)

    Kandhasamy, Sathiyaraj; Singh, Pritam; Thurgate, Stephen; Ionescu, Mihail; Appadoo, Dominique; Minakshi, Manickam

    2012-01-01

    Highlights: ► Olivine powder was synthesized by sol–gel method using a range of chelating agents. ► Role of chelating agents in olivine cathode was investigated for battery application. ► Battery was fabricated with olivine cathode, Zn anode and aqueous electrolyte. ► Synergetic effect of additives (CA + TEA + PVP) led to improved storage capacity. - Abstract: Olivine (LiCo 1/3 Mn 1/3 Ni 1/3 PO 4 ) powders were synthesized at 550–600 °C for 6 h in air by a sol–gel method using multiple chelating agents and used as a cathode material for rechargeable batteries. Range of chelating agents like a weak organic acid (citric acid – CA), emulsifier (triethanolamine – TEA) and non-ionic surfactant (polyvinylpyrrolidone – PVP) in sol–gel wet chemical synthesis were used. The dependence of the physicochemical properties of the olivine powders such as particle size, morphology, structural bonding and crystallinity on the chelating agent was extensively investigated. Among the chelating agents used, unique cycling behavior (75 mAh/g after 25 cycles) is observed for the PVP assisted olivine. This is due to volumetric change in trapped organic layer for first few cycles. The trapped organic species in the electrode–electrolyte interface enhances the rate of lithium ion diffusion with better capacity retention. In contrast, CA and TEA showed a gradual capacity fade of 30 and 38 mAh/g respectively after multiple cycles. The combination of all the three mixed chelating agents showed an excellent electrochemical behavior of 100 mAh/g after multiple cycles and the synergistic effect of these agents are discussed.

  19. Biological behaviour of some 67Ga and 64Cu chelates

    International Nuclear Information System (INIS)

    Leonovicova, T.; Angelis, B.; Cifka, J.; Cifkova, I.

    1984-01-01

    Chelates of 67 Ga and 64 Cu with iminodiacetic acid (IDA) and its two phenyl derivatives as well as with nitrilotriacetic acid (NTA) and benzylnitrilotriacetic acid (BNTA) were prepared. All the chelates were found to be negatively charged. A study of the biological distribution of these chelates in rats during time intervals of 3 to 180 min showed that the chelate of 67 Ga with IDA substituted at a phenyl by a hydrophobic substituent is excreted by the kidneys into the urine at a much higher rate than the IDA chelate of 67 Ga. The excretion of NTA and BNTA chelates of 67 Ga is the opposite. Blood clearance of 64 Cu chelates is more rapid than that of 67 Ga chelates. Chelates of 64 Cu accumulate in the liver and with the bile are slowly excreted into the intestines, urinary excretion is negligible. (author)

  20. Antioxidant and mercury chelating activity of Psidium guajava var. pomifera L. leaves hydroalcoholic extract.

    Science.gov (United States)

    Pinho, Antonio Ivanildo; Oliveira, Cláudia Sirlene; Lovato, Fabricio Luís; Waczuk, Emily Pansera; Piccoli, Bruna Candia; Boligon, Aline Augusti; Leite, Nadghia Figueredo; Coutinho, Henrique Douglas Melo; Posser, Thais; Da Rocha, João Batista Teixeira; Franco, Jeferson Luis

    2017-01-01

    Mercury (Hg) is widely distributed in the environment and is known to produce several adverse effects in organisms. The aim of the present study was to examine the in vitro antioxidant activity and Hg chelating ability of the hydroalcoholic extract of Psidium guajava leaves (HEPG). In addition, the potential protective effects of HEPG against Hg(II) were evaluated using a yeast model (Saccharomyces cerevisiae). HEPG was found to exert significant antioxidant activity in 2,2-diphenyl-1-picrylhydrazyl scavenger and inhibition of lipid peroxidation induced by Fe(II) assays in a concentration-dependent manner. The extract also exhibited significant Hg(II) chelating activity. In yeast, Hg(II) induced a significant decrease in cell viability. In contrast, HEPG partially prevented the fall in cell viability induced by Hg(II). In conclusion, HEPG exhibited protective effects against Hg(II)-mediated toxicity, which may be related to both antioxidant and Hg(II)-chelating activities.

  1. Use of trimetasphere metallofullerene MRI contrast agent for the non-invasive longitudinal tracking of stem cells in the lung.

    Science.gov (United States)

    Murphy, Sean V; Hale, Austin; Reid, Tanya; Olson, John; Kidiyoor, Amritha; Tan, Josh; Zhou, Zhiguo; Jackson, John; Atala, Anthony

    2016-04-15

    Magnetic Resonance Imaging (MRI) is a commonly used, non-invasive imaging technique that provides visualization of soft tissues with high spatial resolution. In both a research and clinical setting, the major challenge has been identifying a non-invasive and safe method for longitudinal tracking of delivered cells in vivo. The labeling and tracking of contrast agent labeled cells using MRI has the potential to fulfill this need. Contrast agents are often used to enhance the image contrast between the tissue of interest and surrounding tissues with MRI. The most commonly used MRI contrast agents contain Gd(III) ions. However, Gd(III) ions are highly toxic in their ionic form, as they tend to accumulate in the liver, spleen, kidney and bones and block calcium channels. Endohedral metallofullerenes such as trimetallic nitride endohedral metallofullerenes (Trimetasphere®) are one unique class of fullerene molecules where a Gd3N cluster is encapsulated inside a C80 carbon cage referred to as Gd3N@C80. These endohedral metallofullerenes have several advantages over small chelated Gd(III) complexes such as increased stability of the Gd(III) ion, minimal toxic effects, high solubility in water and high proton relativity. In this study, we describe the evaluation of gadolinium-based Trimetasphere® positive contrast agent for the ​in vitro labeling and in vivo tracking of human amniotic fluid-derived stem cells within lung tissue. In addition, we conducted a 'proof-of-concept' experiment demonstrating that this methodology can be used to track the homing of stem cells to injured lung tissue and provide longitudinal analysis of cell localization over an extended time course. Copyright © 2015 Elsevier Inc. All rights reserved.

  2. Effect of the chelation of metal cation on the antioxidant activity of chondroitin sulfates.

    Science.gov (United States)

    Ajisaka, Katsumi; Oyanagi, Yutaka; Miyazaki, Tatsuo; Suzuki, Yasuhiro

    2016-06-01

    The antioxidant potencies of chondroitin sulfates (CSs) from shark cartilage, salmon cartilage, bovine trachea, and porcine intestinal mucosa were compared by three representative methods for the measurement of the antioxidant activity; DPPH radical scavenging activity, superoxide radical scavenging activity, and hydroxyl radical scavenging activity. CSs from salmon cartilage and bovine trachea showed higher potency in comparison with CSs from shark cartilage and porcine intestinal mucosa. Next, CS from salmon cartilage chelating with Ca(2+), Mg(2+), Mn(2+), or Zn(2+) were prepared, and their antioxidant potencies were compared. CS chelating with Ca(2+) or Mg(2+) ions showed rather decreased DPPH radical scavenging activity in comparison with CS of H(+) form. In contrast, CS chelating with Ca(2+) or Mg(2+) ion showed remarkably enhanced superoxide radical scavenging activity than CS of H(+) or Na(+) form. Moreover, CS chelating with divalent metal ions, Ca(2+), Mg(2+), Mn(2+), or Zn(2+), showed noticeably higher hydroxyl radical scavenging activity than CS of H(+) or Na(+) form. The present results revealed that the scavenging activities of, at least, superoxide radical and hydroxyl radical were enhanced by the chelation with divalent metal ions.

  3. Gadolinium depletion event in a CANDU® moderator - causes and recovery

    Energy Technology Data Exchange (ETDEWEB)

    Evans, D.W.; Price, J.; Swami, D.; Fracalanza, E.; Brett, M.E.; Puzzuoli, F.V.; Garg, A. [Ontario Power Generation, Pickering, Ontario (Canada); Herrmann, O.; Rudolph, A. [Kinectrics Inc., Toronto, Ontario (Canada); Stuart, C.; Glowa, G. [Atomic Energy of Canada Limited, Chalk River, Ontario (Canada); Smee, J. [Niagara Technical Consultants, St. Catharines, Ontario (Canada)

    2010-07-01

    Gadolinium nitrate is added to the moderator of CANDU units to maintain the reactor in a guaranteed shutdown state (GSS). In April 2008, after being in stable GSS for over 30 hours, one of Ontario Power Generation's Pickering-B units showed a gradual depletion of the dissolved gadolinium, despite purification being isolated. Further additions of gadolinium stabilized the moderator gadolinium concentration, however, since the root cause of the depletion was not immediately identified, the unit was placed in the drained shutdown state, per established procedures. The cumulative gadolinium depletion amounted to about 3200 grams, the equivalent of about 12 ppm. Analysis showed the presence of oxalate in the moderator water. It is well-known that gadolinium forms a very insoluble oxalate (log K{sub sp} = -29.1). Although sub-micron filtration of water samples did not show the presence of gadolinium particulate, the measured levels of oxalate, 1.2 to 2 ppm, were sufficient to react with 1.4 to 2.4 ppm of gadolinium. The source of oxalate was traced to radiolysis of dissolved CO{sub 2} species. This unit had been experiencing chronic low-level ingress of CO{sub 2} from the Annulus Gas System. Free oxalate ion is normally susceptible to radiolytic breakdown back to CO{sub 2}, but Gd{sup 3+} provides a stable sink for radiogenic oxalate, 2 Gd{sup 3+} + 3 C{sub 2}O{sub 4}{sup 2-} → Gd{sub 2}(C{sub 2}O{sub 4}){sub 3}. Subsequent testing confirmed that gadolinium oxalate is quite stable with respect to gamma irradiation. Inspections showed well-crystallized gadolinium oxalate deposited on moderator system surfaces. Estimates indicated that about 1200 grams of gadolinium could have deposited on in-core surfaces, including the outside of the calandria tubes. That amount of negative reactivity was a concern, since it would prevent re-start of the unit. OPG, with support from AECL-Chalk River and Kinectrics, embarked on a two-pronged chemistry recovery program aimed at 1

  4. Decomposition rates of radiopharmaceutical indium chelates in serum

    International Nuclear Information System (INIS)

    Yeh, S.M.; Meares, C.F.; Goodwin, D.A.

    1979-01-01

    The rates at which six small aminopolycarboxylate chelates of trivalent 111 In and three protein-bound chelates of 111 In deliver indium to the serum protein transferrin have been studied in sterile human serum at pH 7.3, 37 deg C. Sterically hindered chelates containing a substituent on an ethylene carbon of EDTA decompose with rates in the range 0.03 to 0.11% per day - one to two orders of magnitude slower than other chelates. Only small differences are observed between rates of decomposition for low-molecular-weight chelates and for protein-bound chelates having analogous structures. (author)

  5. Review of actinide decorporation with chelating agents

    Energy Technology Data Exchange (ETDEWEB)

    Ansoborlo, E. [CEA Valrho, Dir. de l' Energie Nucleaire (DEN/DRCP/CETAMA), 30 - Marcoule (France); Amekraz, B.; Moulin, Ch. [CEA Saclay, Dept. de Physico-Chimie (DEN/DPC/SECR), 91 - Gif sur Yvette (France); Moulin, V. [CEA Saclay, Dir. du Developpement et de l' Innovation Nucleares (DEN/DDIN/MR), 91 - Gif Sur Yvette (France); Taran, F. [CEA Saclay (DSV/DBJC/SMMCB), 91 - Gif-sur-Yvette (France); Bailly, Th.; Burgada, R. [Centre National de la Recherche Scientifique (CNRS/LCSB/UMR 7033), 93 - Bobigny (France); Henge-Napoli, M.H. [CEA Valrho, Site de Marcoule (INSTN), 30 (France); Jeanson, A.; Den Auwer, Ch.; Bonin, L.; Moisy, Ph. [CEA Valrho, Dir. de l' Energie Nucleaire (DEN/DRCP/SCPS), 30 - Marcoule (France)

    2007-10-15

    In case of accidental release of radionuclides in a nuclear facility or in the environment, internal contamination (inhalation, ingestion or wound) with actinides represents a severe health risk to human beings. It is therefore important to provide effective chelation therapy or decorporation to reduce acute radiation damage, chemical toxicity, and late radiation effects. Speciation governs bioavailability and toxicity of elements and it is a prerequisite tool for the design and success of new ligands or chelating agents. The purpose of this review is to present the state-of-the-art of actinide decorporation within biological media, to recall briefly actinide metabolism, to list the basic constraints of actinide-ligand for development, to describe main tools developed and used for decorporation studies, to review mainly the chelating agents tested for actinides, and finally to conclude on the future trends in this field. (authors)

  6. Labelling of bacteria with indium chelates

    International Nuclear Information System (INIS)

    Kleinert, P.; Pfister, W.; Endert, G.; Sproessig, M.

    1985-01-01

    The indium chelates were prepared by reaction of radioactive indiumchloride with 10 μg oxine, 15 μg tropolone and 3 mg acetylacetone, resp. The formed chelates have been incubated with 10 9 germs/ml for 5 minutes, with labelling outputs from 90 to 95%. Both gram-positive (Streptococcus, Staphylococcus) and gram-negative bacteria (Escherichia coli) can be labelled. The reproductive capacity of the bacteria was not impaired. The application of indium labelled bacteria allows to show the distribution of microorganisms within the living organism and to investigate problems of bacterial adherence. (author)

  7. 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

  8. 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.

  9. Gadolinium-DTPA in MR imaging of intracranial and spinal tumors

    International Nuclear Information System (INIS)

    Kakitsubata, Yousuke; Harada, Kuniko; Mori, Yukiko; Kihara, Yasushi; Kakitsubata, Sachiko; Watanabe, Katsushi

    1988-01-01

    Magnetic resonance(MR) imaging was performed on 23 patients with intracranial and spinal tumors, before and after intravenous administration of gadolinium-DTPA (Gd-DTPA). Contrast enhancement was observed in 20 of the 23 tumors. Glioblastomas, intracranial metastases, meningiomas and hemangioblastomas were markedly enhanced by Gd-DTPA. In precontrast scan, tumor delineation was best shown by T 2 weighted images. But T 1 weighted images showed better tumor delineation than T 2 weighted images after administration of Gd-DTPA. No side effects were encountered following administration of Gd-DTPA. (author)

  10. Removal of gadolinium nitrate from heavy water

    Energy Technology Data Exchange (ETDEWEB)

    Wilde, E.W.

    2000-03-22

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

  11. 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.)

  12. A multi-slice gradient sequence for contrast enhanced MR diagnosis of intracranial tumours

    International Nuclear Information System (INIS)

    Schoerner, W.; Sander, B.; Kornmesser, W.; Laniado, M.; Nakamura, T.; Felix, R.

    1988-01-01

    A multi-slice gradient echo sequence (FLASH) was compared with a conventional spin-echo (SE) technique with regard to its value for contrast enhanced MR diagnosis. In 28 patients with cerebral tumours, SE images (SE 400/30; four images/3.4 minutes) and FLASH images (FLASH 315/14; 15 images/1.4 minutes) were obtained before and after gadolinium DTPA. After gadolinium-DTPA results were comparable for both techniques with respect to contrast enhancement, tumor contrast and delineation. Because of the higher efficiency of the FLASH 315/14 technique, this sequence is the method of choice for contrast enhanced cerebral MR imaging. (orig.) [de

  13. The optimal use of contrast agents at high field MRI

    International Nuclear Information System (INIS)

    Trattnig, Siegfried; Pinker, Kathia; Ba-Ssalamah, Ahmed; Noebauer-Huhmann, Iris-Melanie

    2006-01-01

    The intravenous administration of a standard dose of conventional gadolinium-based contrast agents produces higher contrast between the tumor and normal brain at 3.0 Tesla (T) than at 1.5 T, which allows reducing the dose to half of the standard one to produce similar contrast at 3.0 T compared to 1.5 T. The assessment of cumulative triple-dose 3.0 T images obtained the best results in the detection of brain metastases compared to other sequences. The contrast agent dose for dynamic susceptibility-weighted contrast-enhanced perfusion MR imaging at 3.0 T can be reduced to 0.1 mmol compared to 0.2 mmol at 1.5 T due to the increased susceptibility effects at higher magnetic field strengths. Contrast agent application makes susceptibility-weighted imaging (SWI) at 3.0 T clinically attractive, with an increase in spatial resolution within the same scan time. Whereas a double dose of conventional gadolinium-based contrast agents was optimal in SWI with respect to sensitivity and image quality, a standard dose of gadobenate dimeglumine, which has a two-fold higher T1-relaxivity in blood, produced the same effect. For MR-arthrography, optimized concentrations of gadolinium-based contrast agents are similar at 3.0 and 1.5 T. In summary, high field MRI requires the optimization of the contrast agent dose in different clinical applications. (orig.)

  14. Cardiac cell damage in hypertrophic cardiomyopathy evaluated by beta-methyl-branched fatty acid analogue, iodine-123-15-(p-iodophenyl)-3-(R,S)-methylpen-tadecanoic acid (BMIPP) myocardial fatty-acid imaging and late gadolinium-enhanced contrast magnetic resonance imaging. Usefulness of combining the two techniques

    International Nuclear Information System (INIS)

    Kawade, Masafumi; Teraoka, Kunihiko; Hirano, Masaharu; Igarashi, Yuko; Yamada, Masao; Chikamori, Taishiro; Takazawa, Kenji; Yamashina, Akira

    2011-01-01

    Late gadolinium-enhanced (LGE) magnetic resonance imaging (MRI) has been found to be a highly valuable imaging modality for myocardial characterization in cases of hypertrophic cardiomyopathy (HCM). In addition, abnormalities of BMIPP uptake have also been recognized in HCM. In this study, we hypothesized that abnormalities of fatty acid uptake and metabolism may be detected before fibrosis can be recognized on cardiovascular MRI in patients with HCM. Twenty-four patients with HCM were examined by both BMIPP myocardial fatty acid imaging and LGE MRI, and the results of the two imaging methods were compared. BMIPP uptake abnormalities were recognized in 23 of the 24 HCM patients (95.8%) and 126 out of the 408 segments (30.9%) examined, and were most frequently located in the interventricular septum and anterior wall of the left ventricle, the inferior wall and apex of the heart. Areas of LGE were recognized in 18 of the 24 HCM patients (75%) and 50 of the 408 segments (12.2%) examined, and were most frequently located in the interventricular septum of the left ventricle. Double-positive results of both BMIPP uptake abnormalities and LGE were recognized in 18 of the 24 cases (75.0%) and 45 of the 408 segments (11.0%) examined. Double-positive results were noted most frequently in the interventricular septum of the left ventricle and the anterior wall. The areas showing BMIPP uptake abnormalities were more extensive than those showing LGE on MRI. In addition, the positivity rate for BMIPP uptake abnormalities in areas showing LGE on MRI was considerably higher than that of LGE positivity in areas positive for BMIPP uptake abnormalities. These results are not contradictory to our hypothesis. Therefore, differences between the examination methods in terms of the extent and positivity rate in cases of HCM may be related to the stage of progression of the cardiac muscle cell damage in cases of HCM. Thus, the use of both examinations together might be useful in the

  15. MRI and CT contrast media extravasation

    Science.gov (United States)

    Heshmatzadeh Behzadi, Ashkan; Farooq, Zerwa; Newhouse, Jeffery H.; Prince, Martin R.

    2018-01-01

    Abstract Background: This systematic review combines data from multiple papers on contrast media extravasation to identify factors contributing to increased extravasation risk. Methods: Data were extracted from 17 papers reporting 2191 extravasations in 1,104,872 patients (0.2%) undergoing computed tomography (CT) or magnetic resonance imaging (MRI). Results: Extravasation rates were 0.045% for gadolinium-based contrast agents (GBCA) and nearly 6-fold higher, 0.26% for iodinated contrast agents. Factors associated with increased contrast media extravasations included: older age, female gender, using an existing intravenous (IV) instead of placing a new IV in radiology, in-patient status, use of automated power injection, high injection rates, catheter location, and failing to warm up the more viscous contrast media to body temperature. Conclusion: Contrast media extravasation is infrequent but nearly 6 times less frequent with GBCA for MRI compared with iodinated contrast used in CT. PMID:29489663

  16. Bone marrow and chelatable iron in patients with protein energy ...

    African Journals Online (AJOL)

    chelatable iron is present and is excreted in the urine of children with kwashiorkor ... venous blood sample was drawn for routine biochemical and haematological .... storage.l.1:m In response to chelation, the kwashiorkor children excrete large ...

  17. Radiopharmaceutical chelates and method of external imaging

    International Nuclear Information System (INIS)

    Loberg, M.D.; Callery, P.S.; Cooper, M.

    1977-01-01

    A chelate of technetium-99m, cobalt-57, gallium-67, gallium-68, indium-111 or indium-113m and a substituted iminodiacetic acid or an 8-hydroxyquinoline useful as a radiopharmaceutical external imaging agent. The invention also includes preparative methods therefor

  18. Use of chelating agents as immovable phase in extraction chromatography

    International Nuclear Information System (INIS)

    Sebesta, F.

    1978-01-01

    Extraction chromatography using chelating agents is reviewed. The theory of element extraction by chelating agents and factors influencing this process (pH, extracting agent concentration in organic phase, masking agent concentration in aqueous phase) are briefly considered. The effect of kinetic factors on the extraction chromatography process is discussed. Ways of preparing columns are emphasized. Examples of using chelating reagents in various extraction chromatography systems are given. β-Diketones, oximes, hydroxamic acids, dithizon, diethyl dithiocarbamic acid are chosen as chelating agents

  19. Production of gadolinium nitrate for TAPS 3 and 4 PHWR

    International Nuclear Information System (INIS)

    Mishra, S.L.; Ramakrishnan, P.; Iyer, N.S.; Singh, Harvinderpal

    2004-01-01

    In India, gadolinium nitrate is being used for the first time in PHWR at Tarapur. Gadolinium is preferred over boron due to high neutron cross section and the water soluble nitrate form works efficiently for reactivity control through moderator liquid poison addition system (MLPS) as well as for reactor shut down system (SDS2). Low concentration of gadolinium (0.1-0.2 g/l) in heavy water is sufficient to shut down the reactor in a very short time. After use, the small amount of gadolinium can be separated quickly from heavy water by ion exchange process. In this paper separation of Gd using of 2-ethyl hexyl phosphoric acid mono 2-ethyl hexyl ester EHEHPA as an extractant has been described

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

    Energy Technology Data Exchange (ETDEWEB)

    Cribier, M

    1999-04-01

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

  1. Chelating agents as stationary phase in extraction chromatography, ch. 11

    International Nuclear Information System (INIS)

    Sebesta, F.

    1975-01-01

    Chelating agents have been used largely in extraction chromatography for separations related to activation analysis, for concentration of metals from dilute solutions, and for preparation of radiochemically pure or carrier-free radionuclides. This review deals with the theory of extraction by chelating agents, the experimental technique, and the chelating agents and systems used (β-diketones, oximes, hydroxamic acid, dithizone and diethyldithiocarbamic acid)

  2. A model to calculate the burn of gadolinium in PWR

    International Nuclear Information System (INIS)

    Sannazzaro, L.R.

    1983-01-01

    A cell model to calculate the burnup of a PWR fuel element with gadolinium as a poison, projected by KWU, is presented. With the model proposed, the burn of the gadolinium isotopes is analyzed, as well as the effect of these isotopes in the fuel element behaviour. The results obtained with this cell model are compared with those obtained by a conventional cell model. (E.G.) [pt

  3. 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.

  4. Magnetic resonance tomography (MR) of intracranial tumours: Multi-echo technique versus gadolinium-DTPA

    International Nuclear Information System (INIS)

    Heindel, W.; Steinbrich, W.; Friedmann, G.

    1986-01-01

    In thirty-seven MR examinations of intracranial tumours equivalent sections were obtained in a multi-echo technique before and after intravenous injection of 0.1 mmol gadolinium DTPA/kg body weight. From this comparison the following preliminary conclusions have been drawn concerning the demonstration of the tumour, its delineation and type: contrast administration does not unequivocally improve the sensitivity. In 55% of the cases, differentiation between tumour and oedema respectively normal brain tissue was easier after Gd-DTPA. Diffusely infiltrating gliomas remain a problem, since their extent is uncertain with or without contrast medium. The structure of the tumour can already be adequately characterized by the multi-echo technique. In order to diagnose the type of tumour, the criteria which apply to Gd-DTPA are similar to those used for iodine-containing contrast media in CT. (orig.) [de

  5. Chelation therapy after the Trial to Assess Chelation Therapy: results of a unique trial

    Science.gov (United States)

    Avila, Maria D.; Escolar, Esteban; Lamas, Gervasio A.

    2014-01-01

    Purpose of review EDTA chelation therapy has been in off-label use for the treatment of atherosclerosis. We review the results of the first large-scale randomized trial of this treatment. Recent findings The trial to assess chelation therapy was a $30 million National Institutes of Health-funded study of the safety and efficacy of EDTA-based chelation infusions in 1708 post-myocardial infarction (MI) patients. The trial to assess chelation therapy demonstrated a significant (P = 0.035) 18% reduction in a combined primary endpoint of death, MI, stroke, coronary revascularization, or hospitalization for angina. In diabetic patients the benefit was more extreme, with a 41% relative reduction in risk (P = 0.0002) and a 43% reduction in total mortality (P = 0.011). Safety data were favorable. A reduction of oxidative stress by chelation of toxic metals has been proposed as a possible mechanism of action. Summary Recent research suggests that EDTA chelation may be a well-tolerated and effective treatment for post-MI patients. Future replication and mechanistic studies are important prior to implementation in all post-MI patients. PMID:25023079

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

    International Nuclear Information System (INIS)

    Al-Saeed, Osama; Sheikh, Mehraj; Ismail, Mohammed; Athyal, Reji

    2011-01-01

    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

  7. Nature of the bifunctional chelating agent used for radioimmunotherapy with yttrium-88 monoclonal antibodies: critical factors in determining in vivo survival and organ toxicity

    Energy Technology Data Exchange (ETDEWEB)

    Kozak, R.W.; Raubitschek, A.; Mirzadeh, S.; Brechbiel, M.W.; Junghaus, R.; Gansow, O.A.; Waldmann, T.A. (Center for Biologics Evaluation and Research, FDA, Bethesda, MD (USA))

    1989-05-15

    One factor that is critical to the potential effectiveness of radioimmunotherapy is the design of radiometal-chelated antibodies that will be stable in vivo. Stability in vivo depends on the condition that both the chelate linkage and radiolabeling procedures not alter antibody specificity and biodistribution. In addition, synthesis and selection of the chelating agent is critical for each radiometal in order to prevent inappropriate release of the radiometal in vivo. In the present study, we compare the in vivo stability of seven radioimmunoconjugates that use different polyaminocarboxylate chelating agents to complex yttrium-88 to the mouse anti-human interleukin-2 receptor monoclonal antibody, anti-Tac. Chelate linkage and radiolabeling procedures did not alter the immunospecificity of anti-Tac. In order to assess whether yttrium was inappropriately released from the chelate-coupled antibody in vivo, iodine-131-labeled and yttrium-88 chelate-coupled antibodies were simultaneously administered to the same animals to correlate the decline in yttrium and radioiodinated antibody activity. The four stable yttrium-88 chelate-coupled antibodies studied displayed similar iodine-131 and yttrium-88 activity, indicating minimal elution of yttrium-88 from the complex. In contrast, the unstable yttrium-88 chelate-coupled antibodies had serum yttrium-88 activities that declined much more rapidly than their iodine-131 activities, suggesting loss of the radiolabel yttrium-88 from the chelate. Furthermore, high rates of yttrium-88 elution correlated with deposition in bone. Four chelating agents emerged as promising immunotherapeutic reagents: isothiocyanate benzyl DTPA and its derivatives 1B3M, MX, and 1M3B.

  8. Molecular engineering of lanthanide ion chelating phospholipids generating assemblies with a switched magnetic susceptibility.

    Science.gov (United States)

    Isabettini, Stéphane; Massabni, Sarah; Hodzic, Arnel; Durovic, Dzana; Kohlbrecher, Joachim; Ishikawa, Takashi; Fischer, Peter; Windhab, Erich J; Walde, Peter; Kuster, Simon

    2017-08-09

    Lanthanide ion (Ln 3+ ) chelating amphiphiles are powerful molecules for tailoring the magnetic response of polymolecular assemblies. Mixtures of 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC) and 1,2-dimyristoyl-sn-glycero-3-phospho-ethanolamine-diethylene triaminepentaacetate (DMPE-DTPA) complexed to Ln 3+ deliver highly magnetically responsive bicelles. Their magnetic properties are readily tuned by changing the bicellar size or the magnetic susceptibility Δχ of the bilayer lipids. The former technique is intrinsically bound to the region of the phase diagram guarantying the formation of bicelles. Methods aiming towards manipulating the Δχ of the bilayer are comparatively more robust, flexible and lacking. Herein, we synthesized a new Ln 3+ chelating phospholipid using glutamic acid as a backbone: DMPE-Glu-DTPA. The chelate polyhedron was specifically engineered to alter the Δχ, whilst remaining geometrically similar to DMPE-DTPA. Planar asymmetric assemblies hundreds of nanometers in size were achieved presenting unprecedented magnetic alignments. The DMPE-Glu-DTPA/Ln 3+ complex switched the Δχ, achieving perpendicular alignment of assemblies containing Dy 3+ and parallel alignment of those containing Tm 3+ . Moreover, samples with chelated Yb 3+ were more alignable than the Tm 3+ chelating counterparts. Such a possibility has never been demonstrated for planar Ln 3+ chelating polymolecular assemblies. The physico-chemical properties of these novel assemblies were further studied by monitoring the alignment behavior at different temperatures and by including 16 mol% of cholesterol (Chol-OH) in the phospholipid bilayer. The DMPE-Glu-DTPA/Ln 3+ complex and the resulting assemblies are promising candidates for applications in numerous fields including pharmaceutical technologies, structural characterization of membrane biomolecules by NMR spectroscopy, as contrasting agents for magnetic resonance imaging, and for the development of smart optical gels.

  9. 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.)

  10. Effect of gadolinium on hepatic fat quantification using multi-echo reconstruction technique with T2* correction and estimation

    International Nuclear Information System (INIS)

    Ge, Mingmei; Wu, Bing; Liu, Zhiqin; Song, Hai; Meng, Xiangfeng; Wu, Xinhuai; Zhang, Jing

    2016-01-01

    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.)

  11. Chelation and stabilization of berkelium in oxidation state +IV

    Science.gov (United States)

    Deblonde, Gauthier J.-P.; Sturzbecher-Hoehne, Manuel; Rupert, Peter B.; An, Dahlia D.; Illy, Marie-Claire; Ralston, Corie Y.; Brabec, Jiri; de Jong, Wibe A.; Strong, Roland K.; Abergel, Rebecca J.

    2017-09-01

    Berkelium (Bk) has been predicted to be the only transplutonium element able to exhibit both +III and +IV oxidation states in solution, but evidence of a stable oxidized Bk chelate has so far remained elusive. Here we describe the stabilization of the heaviest 4+ ion of the periodic table, under mild aqueous conditions, using a siderophore derivative. The resulting Bk(IV) complex exhibits luminescence via sensitization through an intramolecular antenna effect. This neutral Bk(IV) coordination compound is not sequestered by the protein siderocalin—a mammalian metal transporter—in contrast to the negatively charged species obtained with neighbouring trivalent actinides americium, curium and californium (Cf). The corresponding Cf(III)-ligand-protein ternary adduct was characterized by X-ray diffraction analysis. Combined with theoretical predictions, these data add significant insight to the field of transplutonium chemistry, and may lead to innovative Bk separation and purification processes.

  12. Contrast media. Safety issues and ESUR guidelines

    Energy Technology Data Exchange (ETDEWEB)

    Thomsen, H.S. (ed.) [Copenhagen Univ. Hospital, Herlev (Denmark). Dept. of Diagnostic Radiology 54E2

    2006-07-01

    In 1994 the European Society of Urogenital Radiology (ESUR) set up a committee to consider the safety of the contrast media used in radiology departments. Since then, the committee has questioned members, reviewed the literature, proposed guidelines, and discussed these proposals with participants at the annual symposia on urogenital radiology. This book represents the end result of this hard work. It contains all of the agreed guidelines, updated when necessary, and thereby comprehensively covers the many different safety issues relating to the diverse contrast media: barium contrast media, iodinated contrast media, MR contrast media (both gadolinium-based extracellular and organ-specific) and ultrasound contrast media. The prevention and treatment of both acute and delayed non-renal adverse reactions as well as the renal adverse reactions are covered in detail. The inclusion of all the ESUR guidelines within one book will offer an invaluable, unique and unparalleled resource. (orig.)

  13. Contrast media. Safety issues and ESUR guidelines

    International Nuclear Information System (INIS)

    Thomsen, H.S.

    2006-01-01

    In 1994 the European Society of Urogenital Radiology (ESUR) set up a committee to consider the safety of the contrast media used in radiology departments. Since then, the committee has questioned members, reviewed the literature, proposed guidelines, and discussed these proposals with participants at the annual symposia on urogenital radiology. This book represents the end result of this hard work. It contains all of the agreed guidelines, updated when necessary, and thereby comprehensively covers the many different safety issues relating to the diverse contrast media: barium contrast media, iodinated contrast media, MR contrast media (both gadolinium-based extracellular and organ-specific) and ultrasound contrast media. The prevention and treatment of both acute and delayed non-renal adverse reactions as well as the renal adverse reactions are covered in detail. The inclusion of all the ESUR guidelines within one book will offer an invaluable, unique and unparalleled resource. (orig.)

  14. [Susceptibility of enterococci to natural and synthetic iron chelators].

    Science.gov (United States)

    Lisiecki, Paweł; Mikucki, Jerzy

    2002-01-01

    A total of 79 strains of enterococci belonging to 10 species were tested for susceptibility to natural and synthetic iron chelators. All strains produced siderophores. These enterococci were susceptible to three synthetic iron chelators only: 8-hydroxyquinoline, disodium versenate (EDTA) and o-phenanthroline. They were resistant to all other synthetic chelators: ethylenediamine-di(o-hydroxyphenylacetic acid) (EDDHA), nitrilotriacetate, 2,2'-bipiridyl, salicylic acid, 8-hydroxy-5-sulphonic acid and to all natural chelators: ovotransferrine, human apotransferrine, horse apoferritine, desferrioxamine B, ferrichrome and rhodotorulic acid. The relations between susceptibility/resistance, iron assimilation and structure and stability constants of iron chelators were discussed.

  15. In vitro study of novel gadolinium-loaded liposomes guided by GBI-10 aptamer for promising tumor targeting and tumor diagnosis by magnetic resonance imaging

    Directory of Open Access Journals (Sweden)

    Gu MJ

    2015-08-01

    Full Text Available Meng-Jie Gu,1,* Kun-Feng Li,1,* Lan-Xin Zhang,1 Huan Wang,1 Li-Si Liu,2 Zhuo-Zhao Zheng,2 Nan-Yin Han,1 Zhen-Jun Yang,1 Tian-Yuan Fan1 1State Key Laboratory of Natural and Biomimetic Drugs, School of Pharmaceutical Sciences, Peking University, 2Department of Radiology, Peking University Third Hospital, Beijing, People’s Republic of China *These authors contributed equally to this work Abstract: Novel gadolinium-loaded liposomes guided by GBI-10 aptamer were developed and evaluated in vitro to enhance magnetic resonance imaging (MRI diagnosis of tumor. Nontargeted gadolinium-loaded liposomes were achieved by incorporating amphipathic material, Gd (III [N,N-bis-stearylamidomethyl-N'-amidomethyl] diethylenetriamine tetraacetic acid, into the liposome membrane using lipid film hydration method. GBI-10, as the targeting ligand, was then conjugated onto the liposome surface to get GBI-10-targeted gadolinium-loaded liposomes (GTLs. Both nontargeted gadolinium-loaded liposomes and GTLs displayed good dispersion stability, optimal size, and zeta potential for tumor targeting, as well as favorable imaging properties with enhanced relaxivity compared with a commercial MRI contrast agent (CA, gadopentetate dimeglumine. The use of GBI-10 aptamer in this liposomal system was intended to result in increased accumulation of gadolinium at the periphery of C6 glioma cells, where the targeting extracellular matrix protein tenascin-C is overexpressed. Increased cellular binding of GTLs to C6 cells was confirmed by confocal microscopy, flow cytometry, and MRI, demonstrating the promise of this novel delivery system as a carrier of MRI contrast agent for the diagnosis of tumor. These studies provide a new strategy furthering the development of nanomedicine for both diagnosis and therapy of tumor. Keywords: magnetic resonance imaging, gadolinium, liposomes, tenascin-C, GBI-10 aptamer, tumor targeting

  16. Isotope shift studies in gadolinium spectra

    International Nuclear Information System (INIS)

    Ahmad, S.A.; Saksena, G.D.; Venugopalan, A.

    1975-01-01

    Isotope shift studies have been carried out in the gadolinium spectrum using a recording Fabry-Perot spectrometer and gadolinium samples enriched in 156 Gd and 160 Gd isotopes. The source used is a liquid-nitrogen-cooled hollow cathode with Ne as the carrier gas and operating at about 30 mA. Isotope shifts Δsigma (156-160) have been recorded in 350 transitions of Gd I and Gd II. In the case of the Gd I spectrum, the transitions studied presently involve almost all the reported configurations assigned to the energy levels of Gd I. The odd configurations are 4f 7 5d6s 2 , 4f 7 5d 2 6s, 4f 7 5d 3 , 4f 8 6s6p, 4f 7 5d6s7s and 4f 7 6s 2 6p, and the even ones are 4f 8 6s 2 , 4f 7 5d6s6p, 4f 7 6s 2 6p, 4f 8 5d6s and 4f 7 5d 2 6p. In the case of the Gd II spectrum isotope shifts in the lines of the newly classified transition 4f 8 6s - 4f 8 6p have been studied and isotope shift ΔT (156-160) 87 mK has been obtained for the 4f 8 6s configuration. The other transitions of Gd II involve the odd configurations 4f 7 5d6s, 4f 7 6s 2 , 4f 7 5d 2 and 4f 8 6p and the even ones 4f 7 6s6p, 4f 8 5d, 4f 7 5d6p and 4f 8 6p. The ΔT (156-160) of a large number of odd and even levels of Gd I and Gd II have been evaluated. Electronic configurations have been suggested for a number of energy levels and configuration mixing has been pointed out in certain cases. A number of hitherto unreported transitions have been found and using a monoisotopic sample of Gd, that is 160 Gd, their separations from the closest listed transitions have been measured. (author)

  17. 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

  18. Retention of contrast media in the history of radiology. Sequelae of the former use of thorotrast and new challenges; Kontrastmittelretention in der Geschichte der Radiologie. Folgen der frueheren Thorotrastanwendungen und neue Herausforderungen

    Energy Technology Data Exchange (ETDEWEB)

    Kaick, G. van; Delorme, S. [Deutsches Krebsforschungszentrum (DKFZ), Heidelberg (Germany)

    2016-12-15

    Detection of gadolinium deposits in patients who have repeatedly been administered intravenous gadolinium chelates have given rise to concern regarding the long-term safety of magnetic resonance imaging (MRI) contrast media. Nevertheless, negative long-term clinical effects have not yet been observed. In some publications parallels have been drawn to the sequelae of thorotrast that was formerly used for arterial angiography. In this article the history of thorotrast use is briefly described and in particular why, despite warnings, this substance was used frequently and worldwide. A brief summary of the results of the German Thorotrast Study revealed that high excess rates were only observed for primary malignant liver tumors after a 15-year or longer latency period and to a lesser degree of leukemias, as well as for severe local complications due to paravascular injections, particularly in the neck region. Based on this historical review, we will venture to take stock of the outcome from the ''success story'' of this contrast agent. (orig.) [German] Der Nachweis von Gadoliniumablagerungen im Koerper von Patienten nach mehrfacher Injektion von Gadoliniumchelaten hat Irritationen ausgeloest. Gleichwohl gibt es bislang keine Hinweise auf resultierende klinische Spaetfolgen. In verschiedenen Veroeffentlichungen wird auf moegliche Parallelen zu den Folgen der Anwendung des frueheren Roentgenkontrastmittels Thorotrast hingewiesen. In diesem Beitrag wird die Geschichte der Thorotrastanwendung dargelegt, insbesondere weshalb es trotz der Warnungen zur haeufigen, weltweiten Anwendung des Praeparats kam. Aus einer kurzen Zusammenfassung der Ergebnisse der Deutschen Thorotraststudie wird deutlich, dass erst nach einer ueber 15-jaehrigen Latenzzeit hohe Exzessraten an primaeren Lebertumoren und in geringerem Masse auch an Leukaemien auftraten und schwerwiegende Folgen paravasaler Injektionen v. a. im Halsbereich beobachtet wurden. In einem historischen

  19. Hypersensitivity to contrast media and dyes.

    Science.gov (United States)

    Brockow, Knut; Sánchez-Borges, Mario

    2014-08-01

    This article updates current knowledge on hypersensitivity reactions to diagnostic contrast media and dyes. After application of a single iodinated radiocontrast medium (RCM), gadolinium-based contrast medium, fluorescein, or a blue dye, a hypersensitivity reaction is not a common finding; however, because of the high and still increasing frequency of those procedures, patients who have experienced severe reactions are nevertheless frequently encountered in allergy departments. Evidence on allergologic testing and management is best for iodinated RCM, limited for blue dyes, and insufficient for fluorescein. Skin tests can be helpful in the diagnosis of patients with hypersensitivity reactions to these compounds. Copyright © 2014 Elsevier Inc. All rights reserved.

  20. Optimization of the Contrast Mixture Ratio for Simultaneous Direct MR and CT Arthrography: an in Vitro Study

    International Nuclear Information System (INIS)

    Choi, Ja Young; Hong, Sung Hwan; Kim, Na Ra; Jun, Woo Sun; Moon, Sung Gyu; Kang, Heung Sik; Lee, Joon Woo; Choi, Jung Ah

    2008-01-01

    This study was designed to determine the optimal mixture ratio of gadolinium and iodinated contrast agent for simultaneous direct MR arthrography and CT arthrography. An in vitro study was performed utilizing mixtures of gadolinium at six different concentrations (0.625, 1.25, 2.5, 5.0, 10 and 20 mmol/L) and iodinated contrast agent at seven different concentrations (0, 12.5, 25, 37.5, 50, 75 and 92-99.9%). These mixtures were placed in tissue culture plates, and were then imaged with CT and MR (with T1-weighted sequences, proton-density sequences and T2-weighted sequences). CT numbers and signal intensities were measured. Pearson's correlation coefficients were used to assess the correlations between the gadolinium/iodinated contrast agent mixtures and the CT numbers/MR signal intensities. Scatter diagrams were plotted for all gadolinium/iodinated contrast agent combinations and two radiologists in consensus identified the mixtures that yielded the optimal CT numbers and MR signal intensities. The CT numbers showed significant correlation with iodinated contrast concentrations (r = 0.976, p < 0.001), whereas the signal intensities as measured on MR images showed a significant correlation with both gadolinium and iodinated contrast agent concentrations (r = -484 to -0.719, p < 0.001). A review of the CT and MR images, graphs, and scatter diagram of 42 combinations of the contrast agent showed that a concentration of 1.25 mmol/L gadolinium and 25% iodinated contrast agent was the best combination for simultaneous CT and MR imaging. A mixture of 1.25 mmol/L gadolinium and 25% iodinated contrast agent was found to be optimal for simultaneous direct MR arthrography and CT arthrography

  1. Safe Use of Contrast Media: What the Radiologist Needs to Know.

    Science.gov (United States)

    Beckett, Katrina R; Moriarity, Andrew K; Langer, Jessica M

    2015-10-01

    Iodinated and gadolinium-based contrast media are used on a daily basis in most radiology practices. These agents often are essential to providing accurate diagnoses, and are nearly always safe and effective when administered correctly. However, reactions to contrast media do occur and can be life threatening. Therefore, it is critical for faculty and staff to know how reactions to contrast agents manifest and how to treat them promptly. The decline in renal function seen occasionally after intravenous administration of iodinated contrast agents is poorly understood and likely multifactorial, and its association with the contrast medium may be overemphasized. However, it is important that radiologists be aware of current understanding and strategies to decrease the incidence of renal dysfunction. Nephrogenic systemic fibrosis, a skin disease, is an adverse reaction related to use of some gadolinium-based contrast agents in patients with chronic renal failure. The types of gadolinium most often associated with this condition and the indications for withholding gadolinium are important and are discussed in this article. The use of enteric contrast agents and contrast agents during pregnancy and nursing are reviewed briefly. Current knowledge for safe use of contrast media and key concepts that all radiologists should know are summarized in this review. © RSNA, 2015.

  2. Decorporation of metal ions by chelating agents

    International Nuclear Information System (INIS)

    Koenig, T.

    1978-01-01

    Simple model designs to simulate the effect of therapeutical chelating agents on the behaviour of metals in mammal organisms with and without excretion have been derived and analytical solutions given for the corresponding differential equations. The possibilities of these models in the short-term description of plasma kinetics of various metals, the competition of the therapeutical ligands with proteins for the metal and of the metabolism of chelating agents were tested and the properties applying extreme conceivable parameters were analyzed. The simple models were successsively expanded in logical sequence, so that it was possible to qualitatively well describe over a long period of time, the metallic kinetics in plasma, organs and urine, the retention of the ligands and their effect on the metal excretion. Two suggestions were given to describe the so-called after-effect, an increased excretion of the metal at times when the ligand is almost completely excreted and their different behaviour after injecting the metal chelate is given. Calculations on the therapy with several ligand data as well as on dose fractionation are described resting on the ratios in the plutonium-239 chosen model parameters and the determining mechanisms analyzed. (orig./MG) [de

  3. IRON CHELATION THERAPY IN THALASSEMIA SYNDROMES

    Directory of Open Access Journals (Sweden)

    Paolo Cianciulli

    2009-06-01

    Full Text Available Transfusional hemosiderosis is a frequent complication in patients with transfusion dependent chronic diseases such as  thalassemias and severe type of sickle cell diseases. As there are no physiological mechanisms to excrete the iron contained in transfused red cells (1 unit of blood contains approximately 200 mg of iron the excess of iron is stored in various organs. Cardiomyopathy is the most severe complication covering more than 70% of the causes of death of thalassemic patients. Although the current reference standard iron chelator deferoxamine (DFO has been used clinically for over four decades, its effectiveness is limited by a demanding therapeutic regimen that leads to poor compliance. Despite poor compliance, because of the inconvenience of subcutaneous infusion, DFO improved considerably the survival and quality of life of patients with thalassemia. Deferiprone since 1998 and Deferasirox since 2005 were licensed for clinical use. The oral chelators have a better compliance because of oral use, a comparable efficacy to DFO in iron excretion and probably a better penetration to myocardial cells. Considerable increase in iron excretion was documented with combination therapy of DFO and Deferiprone. The proper use of the three chelators will improve the prevention and treatment of iron overload, it will reduce  complications, and improve survival and quality of life of transfused patients

  4. The use of new contrast media agents in radiology

    International Nuclear Information System (INIS)

    Zerbe, M.

    1992-01-01

    The purpose of the document is to present the importance of different categories of contrast media in radiography. Ionic and non-ionic contrast media are presented. Pharmacology and pathophysiology of Iodine contrast media with their effects on special organs of the body like the heart, vessels, lungs and nervous systems are explained. Paramagnetic contrast media used in NMR imaging are presented too. Emphasis is made on contrast media based on Gadolinium like Gd-DTPA, Gd-CL3, Gd-EDTA. Actions of Gd-DTPA applied to images in urography are pointed out

  5. 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.)

  6. 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.

  7. Layered gadolinium hydroxides for simultaneous drug delivery and imaging.

    Science.gov (United States)

    Xu, Yadong; Goyanes, Alvaro; Wang, Yuwei; Weston, Andrew J; So, Po-Wah; Geraldes, Carlos F G C; Fogg, Andrew M; Basit, Abdul W; Williams, Gareth R

    2018-02-27

    The potential of the layered gadolinium hydroxide (LGdH) [Gd 2 (OH) 5 ]Cl·yH 2 O (LGdH-Cl) for simultaneous drug delivery and magnetic resonance imaging was explored in this work. Three non-steroidal anti-inflammatory drugs (diclofenac [dic], ibuprofen [ibu], and naproxen [nap]) were intercalated into LGdH-Cl for the first time, using three different routes (ion exchange intercalation, coprecipitation, and exfoliation-self-assembly). X-ray diffraction, elemental microanalysis and IR spectroscopy confirmed successful incorporation of the drug into the interlayer spaces of the LGdH in all cases. From a comparison of the guest anion sizes and interlayer spacings, the active ingredients are believed to adopt intertwined bilayer configurations between the LGdH layers. The materials prepared by coprecipitation in general have noticeably higher drug loadings than those produced by ion exchange or self-assembly, as a result of the incorporation of some neutral drug into the composites. The LGdH-drug intercalates are stable at neutral pH, but rapidly degrade in acidic conditions to free Gd 3+ into solution. While LGdH-nap releases its drug loading into solution very rapidly (within ca. 1.5 h) at pH 7.4, LGdH-dic shows sustained release over 4 h, and LGdH-ibu extends this to 24 h. The latter composites therefore can be incorporated into enteric-coated tablets to provide sustained release in the small intestine. The drug intercalates are highly biocompatible and retain the proton relaxivity properties of the parent LGdH-Cl, with the materials most promising for use as negative contrast agents in MRI. Overall, the LGdH-drug intercalation compounds appear to have great potential for use in theranostic applications.

  8. Magnetic resonance imaging of local soft tissue inflammation using gadolinium-DTPA

    International Nuclear Information System (INIS)

    Paajanen, H.; Brasch, R.C.; Schmiedl, U.; Ogan, M.

    1987-01-01

    Chemical inflammation was induced subcutaneously in 10 rats using carrageenan mucopolysaccharide. Dual spin echo (SE) imaging of inflammatory loci was performed employing a 0.35 tesla resistive magnet. In addition, gadolinium-DTPA was administrated intravenously into 5 rats to evaluate the potential benefits of paramagnetic contrast medium for the detection and characterization of inflammatory loci. T2 weighted SE images demonstrated the edematous lesions as zones of high intensity. This was attributed to the increased relaxation times of lesions when compared to the adjacent soft tissue. The inflammation was also delineated on T1 weighted SE images, but only after injection of paramagnetic Gd-DTPA. Carrageenan mucopolysaccharide-induced lesions provide a useful experimental model for in viva evaluation of soft tissue inflammation using magnetic resonance imaging. No special benefit of paramagnetic contrast enhancement was demonstrated in this model of local edema. (orig.)

  9. Validation of gadolinium burnout using PWR benchmark specification

    Energy Technology Data Exchange (ETDEWEB)

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

    2014-07-01

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

  10. 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

  11. 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)

  12. Effects of gadolinium oxide nanoparticles on the oxidative burst from human neutrophil granulocytes

    International Nuclear Information System (INIS)

    Abrikossova, Natalia; Skoglund, Caroline; Ahrén, Maria; Uvdal, Kajsa; Bengtsson, Torbjörn

    2012-01-01

    We have previously shown that gadolinium oxide (Gd 2 O 3 ) nanoparticles are promising candidates to be used as contrast agents in magnetic resonance (MR) imaging applications. In this study, these nanoparticles were investigated in a cellular system, as possible probes for visualization and targeting intended for bioimaging applications. We evaluated the impact of the presence of Gd 2 O 3 nanoparticles on the production of reactive oxygen species (ROS) from human neutrophils, by means of luminol-dependent chemiluminescence. Three sets of Gd 2 O 3 nanoparticles were studied, i.e. as synthesized, dialyzed and both PEG-functionalized and dialyzed Gd 2 O 3 nanoparticles. In addition, neutrophil morphology was evaluated by fluorescent staining of the actin cytoskeleton and fluorescence microscopy. We show that surface modification of these nanoparticles with polyethylene glycol (PEG) is essential in order to increase their biocompatibility. We observed that the as synthesized nanoparticles markedly decreased the ROS production from neutrophils challenged with prey (opsonized yeast particles) compared to controls without nanoparticles. After functionalization and dialysis, more moderate inhibitory effects were observed at a corresponding concentration of gadolinium. At lower gadolinium concentration the response was similar to that of the control cells. We suggest that the diethylene glycol (DEG) present in the as synthesized nanoparticle preparation is responsible for the inhibitory effects on the neutrophil oxidative burst. Indeed, in the present study we also show that even a low concentration of DEG, 0.3%, severely inhibits neutrophil function. In summary, the low cellular response upon PEG-functionalized Gd 2 O 3 nanoparticle exposure indicates that these nanoparticles are promising candidates for MR-imaging purposes. (paper)

  13. Contrast Materials

    Science.gov (United States)

    ... is mixed with water before administration liquid paste tablet When iodine-based and barium-sulfate contrast materials ... for patients with kidney failure or allergies to MRI and/or computed tomography (CT) contrast material. Microbubble ...

  14. Efficacy and safety of lanthanoids as X-ray contrast agents

    International Nuclear Information System (INIS)

    Pietsch, Hubertus; Jost, Gregor; Frenzel, Thomas; Raschke, Marian; Walter, Jakob; Schirmer, Heiko; Huetter, Joachim; Sieber, Martin A.

    2011-01-01

    Objective: It has been suggested that elements from the lanthanoid (Ln) series may be well suited for use as absorbing elements in X-ray contrast agents (CA). Because gadolinium, an element of the lanthanoid series, has been identified as being possibly associated with nephrogenic systemic fibrosis (NSF), a rare but potentially severe disease, we sought to determine if other lanthanoids might possess a similar potential. Materials and methods: By computed tomography (CT), we compared the X-ray attenuation of all lanthanoids to that of iodine in vitro. In addition, we injected Han-Wistar rats on five consecutive days with 2.5 mmol Ln/kg bodyweight intravenously to test several Ln-DTPA-BMA complexes (praseodymium, europium, gadolinium, and holmium). Saline solution and a Ca-DTPA-BMA group served as controls. Ln concentrations in the skin and organs were determined by inductively coupled plasma mass spectrometry (ICP-MS). This method measures the total Ln content and cannot differentiate between chelated and unchelated Ln. In addition, serum cytokine levels were measured by Luminex technology. The complex stability of the Ln-DTPA-BMA complexes was also assessed in vitro. Results: Lanthanoids showed up to 50% higher X-ray attenuation than iodine in CT. The highest X-ray attenuation was observed with holmium and erbium. Differences in the in vitro complex stability of Pr-, Eu-, Gd-, and Ho-DTPA-BMA complexes were observed. The complex stability differences were also reflected by differences in the concentrations in tissue of the lanthanoids in vivo. Injections of Ln complexes caused NSF-like skin lesions in rats and a rapid upregulation of pro-fibrotic and inflammatory serum cytokines. The Ca-DTPA-BMA complex did not to induce pro-fibrotic cytokines or skin lesions. Pr-DTPA-BMA appeared to be toxic; all Pr-DTPA-BMA treated animals died within the first four days of the experiment and were therefore excluded from further analyses. Conclusion: Lanthanoids are very well

  15. Efficacy and safety of lanthanoids as X-ray contrast agents

    Energy Technology Data Exchange (ETDEWEB)

    Pietsch, Hubertus, E-mail: Hubertus.Pietsch@bayerhealthcare.com [Contrast Media Research, Bayer Schering Pharma AG, 13353 Berlin (Germany); Jost, Gregor, E-mail: Gregor.Jost@bayerhealthcare.com [Contrast Media Research, Bayer Schering Pharma AG, 13353 Berlin (Germany); Frenzel, Thomas, E-mail: Thomas.Frenzel@bayerhealthcare.com [Contrast Media Research, Bayer Schering Pharma AG, 13353 Berlin (Germany); Raschke, Marian, E-mail: Marian.Raschke@bayerhealthcare.com [Nonclinical Drug Safety, Bayer Schering Pharma AG, Berlin (Germany); Walter, Jakob, E-mail: Jakob.Walter@bayerhealthcare.com [Nonclinical Drug Safety, Bayer Schering Pharma AG, Berlin (Germany); Schirmer, Heiko, E-mail: Heiko.Schirmer@bayerhealthcare.com [Medical Chemistry VI, Bayer Schering Pharma AG, Berlin (Germany); Huetter, Joachim, E-mail: Joachim.Hutter@bayerhealthcare.com [Contrast Media Research, Bayer Schering Pharma AG, 13353 Berlin (Germany); Sieber, Martin A., E-mail: martin.sieber@bayerhealthcare.com [Contrast Media Research, Bayer Schering Pharma AG, 13353 Berlin (Germany)

    2011-11-15

    Objective: It has been suggested that elements from the lanthanoid (Ln) series may be well suited for use as absorbing elements in X-ray contrast agents (CA). Because gadolinium, an element of the lanthanoid series, has been identified as being possibly associated with nephrogenic systemic fibrosis (NSF), a rare but potentially severe disease, we sought to determine if other lanthanoids might possess a similar potential. Materials and methods: By computed tomography (CT), we compared the X-ray attenuation of all lanthanoids to that of iodine in vitro. In addition, we injected Han-Wistar rats on five consecutive days with 2.5 mmol Ln/kg bodyweight intravenously to test several Ln-DTPA-BMA complexes (praseodymium, europium, gadolinium, and holmium). Saline solution and a Ca-DTPA-BMA group served as controls. Ln concentrations in the skin and organs were determined by inductively coupled plasma mass spectrometry (ICP-MS). This method measures the total Ln content and cannot differentiate between chelated and unchelated Ln. In addition, serum cytokine levels were measured by Luminex technology. The complex stability of the Ln-DTPA-BMA complexes was also assessed in vitro. Results: Lanthanoids showed up to 50% higher X-ray attenuation than iodine in CT. The highest X-ray attenuation was observed with holmium and erbium. Differences in the in vitro complex stability of Pr-, Eu-, Gd-, and Ho-DTPA-BMA complexes were observed. The complex stability differences were also reflected by differences in the concentrations in tissue of the lanthanoids in vivo. Injections of Ln complexes caused NSF-like skin lesions in rats and a rapid upregulation of pro-fibrotic and inflammatory serum cytokines. The Ca-DTPA-BMA complex did not to induce pro-fibrotic cytokines or skin lesions. Pr-DTPA-BMA appeared to be toxic; all Pr-DTPA-BMA treated animals died within the first four days of the experiment and were therefore excluded from further analyses. Conclusion: Lanthanoids are very well