WO1991003261A1 - Novel magnetic resonance imaging agents - Google Patents
Novel magnetic resonance imaging agents Download PDFInfo
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- WO1991003261A1 WO1991003261A1 PCT/US1990/001196 US9001196W WO9103261A1 WO 1991003261 A1 WO1991003261 A1 WO 1991003261A1 US 9001196 W US9001196 W US 9001196W WO 9103261 A1 WO9103261 A1 WO 9103261A1
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- iii
- alkyl
- hydrogen
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- 0 C*C1C=CCC1 Chemical compound C*C1C=CCC1 0.000 description 1
Classifications
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- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61K—PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
- A61K49/00—Preparations for testing in vivo
- A61K49/06—Nuclear magnetic resonance [NMR] contrast preparations; Magnetic resonance imaging [MRI] contrast preparations
Definitions
- This application is a continuation-in-part of serial number 321,265, filed March 9, 1989.
- This invention relates to nuclear magnetic resonance (NMR) imaging and, more particularly, to methods and compositions for enhancing NMR imaging.
- the recently developed technique of NMR imaging encompasses the detection of certain atomic nuclei utilizing magnetic fields and radio-frequency radiation. It is similar in some respects to x-ray computed tomography (CT) in providing a cross-sectional display of the body organ anatomy with excellent resolution of soft tissue detail. As currently used, the images produced constitute a map of the proton density distribution and/or their relaxation times in organs and tissues.
- CT computed tomography
- the technique of NMR imaging is advantageously non-invasive as it avoids the use of ionizing radiation. While the phenomenon of NMR was discovered in
- nuclei with appropriate spin when placed in an applied magnetic field (B, expressed generally in units of gauss or
- Tesla (10* gauss) align in the direction of the field.
- these nuclei precess at a frequency, f, of 42.6 MHz at a field strength of 1 Tesla.
- f a frequency
- an RF pulse of radiation will excite the nuclei and can be considered to tip the net magnetization out of the field direction, the extent of this rotation being determined by the pulse duration and energy.
- the nuclei "relax" or return to equilibrium with the magnetic field, emitting radiation at the resonant frequency.
- the decay of the emitted radiation is characterized by two relaxation times, i.e., T x , the spin-lattice relaxation time or longitudinal relaxation time, that is, the time taken by the nuclei to return to equilibrium along the direction of the externally applied magnetic field, and T 2 , the spin-spin relaxation time associated with the dephasing of the initially coherent precession of individual proton spins.
- T x the spin-lattice relaxation time or longitudinal relaxation time
- T 2 the spin-spin relaxation time associated with the dephasing of the initially coherent precession of individual proton spins.
- NMR imaging scanning planes and slice thicknesses can be selected. This selection permits high quality transverse, coronal and sagittal images to be obtained directly. The absence of any moving parts in NMR imaging equipment promotes a high reliability. It is believed that NMR imaging has a greater potential than CT for the selective examination of tissue characteristics in view of the fact that in CT, x-ray attenuation coefficients alone determine image contrast, whereas at least five separate variables (T lf T 2 , proton density, pulse sequence and flow) may contribute to the NMR signal.
- NMR may be capable of differentiating different tissue types and in detecting diseases which induce physicochemical changes that may not be detected by x-ray or CT which are only sensitive to differences in the electron density of tissue.
- T x and T 2 two of the principal imaging parameters are the relaxation times, T x and T 2 .
- these relaxation times are influenced by the environment of the nuclei (e.g., viscosity, temperature, and the like). These two relaxation phenomena are essentially mechanisms whereby the initially imparted radio frequency energy is dissipated to the surrounding environment.
- the rate of this energy loss or relaxation can be influenced by certain other nuclei which are paramagnetic.
- Chemical compounds incorporating these paramagnetic nuclei may substantially alter the Tj. and T 2 values for nearby protons.
- the extent of the paramagnetic effect of a given chemical compound is a function of the environment within which it finds itself. In general, paramagnetic divalent or trivalent ions of elements with an atomic number of 21 to 29, 42 to 44 and 58 to 70 have been found effective as NMR image contrasting agents.
- Suitable such ions include chromium (III), manganese (II), manganese (III), iron (III), iron (II), cobalt (II), nickel (II), copper (II), praseodymium (III), neodymium (III), samarium (III) and ytterbium (III). Because of their very strong magnetic moments, gadolinium (III), terbium (III), dysprosium (III), holmium (III) and erbium (III) are preferred. Gadolinium (III) ions have been particularly preferred as NMR image contrasting agents. Typically, the divalent and trivalent paramagnetic ions have been administered in the form of complexes with organic complexing agents.
- Such complexes provide the paramagnetic ions in a soluble, non-toxic form, and facilitate their rapid clearance from the body following the imaging procedure.
- Gries et al. U.S. patent 4,647,447, disclose complexes of various paramagnetic ions with conventional aminocarboxylic acid complexing agents.
- a preferred complex disclosed by Gries et al. is the complex of gadolinium (III) with diethylenetriaminepentaacetic acid (“DTPA"). This complex may be represented by the formula:
- Paramagnetic ions such as gadolinium (III) have been found to form strong complexes with DTPA. These complexes do not dissociate substantially in physiological aqueous fluids.
- the complexes have a net charge of -2, and generally are administered as soluble salts. Typical such salts are the sodium and N- methylglucamine salts.
- ionizable salts are attended by certain disadvantages. These salts can raise the in vivo ion concentration and cause localized disturbances in osmolality, which in turn, can lead to edema and other undesirable reactions.
- hydrophilic complexes tend to concentrate in the interstitial fluids, whereas lipophilic complexes tend to associate with cells. Thus, differences in hydrophilicity can lead to different applications of the compounds. See, for example, Weinmann et al., JR, 142, 679 (Mar. 1984) and Brasch et al., AJR, 142, 625 (Mar. 1984).
- the present invention provides novel complexing agents and complexes of complexing agents with paramagnetic ions.
- the complexes are represented by either of the following formulae:
- A is -CHR 2 -CHR 3 - or
- M' z is a paramagnetic ion of an element with an atomic number of 21-29, 42-44 or 58-70, and a valence, Z, of
- R 1 groups may be the same or different and are selected from the group consisting of -0" and
- R 4 , R 5 and R 6 may be the same or different and are hydrogen, alkyl, hydroxy, alkoxy, mono- or poly- hydroxyalkyl, alkoxyalkyl, aminoalkyl or acylaminoalkyl wherein the carbon-containing portions contain from 1 to about 6 carbon atoms or R s and R 6 , together with the adjacent nitrogen, can form a heterocyclic ring of five, six or seven members wherein 0 to 1 members other than the nitrogen are
- R 2 and R 3 may be the same or different and are hydrogen, alkyl having from 1 to about 6 carbon atoms, phenyl or benzyl or R 2 and R 3 together with the intervening carbon can form a hydrocarbon ring of 5, 6 or 7 members; and wherein Z of the R 1 groups are -0 " and the remainder of the R 1 groups are
- M *z is a paramagnetic ion of an element with an atomic number of 21-29, 42-44 or 58-70, and a valence Z of +2 or +3, r and s are integers between 1 and 6 and can be the same or different
- the R' groups can be the same or different and are selected from the group consisting of hydrogen, alkyl having from 1 to 6 carbon atoms and mono or poly- hydroxyalkyl, the alkyl portion having from 1 to 6 carbon atoms, the R ' g roU p ⁇ can De the same or different and are selected from the group consisting of -O " and
- R 2 is selected from the group consisting of
- R 3 , R 5 and R 6 can be the same or different and are selected from the group consisting of hydrogen, alkyl, hydroxy, alkoxy, mono- or poly-hydroxyalkyl, alkoxyalkyl, aminoalkyl or acylamino-alkyl, wherein the carbon- containing portions contain from 1 to about 6 carbon atoms or R s and R 6 , together with the adjacent nitrogen, can form a heterocyclic ring of five, six or seven members wherein 0 to 1 members other than the nitrogen are -0-, -S-, O
- R 4 substituted by hydroxy, alkyl, aryl, hydroxyalkyl, aminoalkyl, aminoaryl, alkylamino, or carbamoyl wherein the substituents contain from 1 to about 6 carbon atoms, p and q can be the same or different and represent integers between 1 and 6, and wherein z of the R 1 ' groups are -O" and the
- ⁇ , R Also disclosed is a method of performing an NMR diagnostic procedure which involves administering to a warm-blooded animal an effective amount of one of the above-described complexes and then exposing the warm- blooded animal to an NMR imaging procedure, thereby imaging at least a portion of the body of the warm ⁇ blooded animal.
- the complexing agents employed in this invention are derivatives of well-known polyaminocarboxylic acid chelating agents, such as DTPA and ethylenediamine- tetraacetic acid (“EDTA”) and cyclic polyaminocarboxylic acid chelating agents such as 1,4,7,10-tetraazacyclododecane N,N',N",N"'-tetra acetic acid (“DOTA").
- DTPA ethylenediamine- tetraacetic acid
- EDTA ethylenediamine- tetraacetic acid
- DOTA 1,4,7,10-tetraazacyclododecane N,N',N",N"'-tetra acetic acid
- free carboxylic acid groups of the chelating agent (those not involved in bond formation with the paramagnetic ion) are converted to aminoalkylamide groups of the formula:
- the polyaminocarboxylic acid chelating agent is DTPA
- the paramagnetic ion is trivalent
- two of the carboxylic acid groups will be derivatized to the aminoalkylamide form.
- the paramagnetic ion is divalent
- three of the carboxylic acid groups of DTPA or two of the carboxylic acid groups of EDTA will be derivatized to the aminoalkylamide form.
- aminoalkylamide derivatives useful as complexes include those wherein the aminoalkylamide group is
- the aminoalkylamide group is a orpholinoalklylamide.
- An alternative class of compounds encompassed by this invention includes cyclic polyamino carboxylic acid chelating agents, such as DOTA and TRITA and represented by the general formula:
- free carboxylic acid groups are 0 R :
- Examples of types of derivatives useful as complexes include those wherein the amino alkylamide group is:
- the aminoalkylamide group is morpholinoalkylamide.
- the aminoalkylamide derivatives of the chelating agents may be prepared by conventional amide-forming reactions. In general, they are prepared by reacting a stoichiometric amount of an aminoalkylamine with a reactive derivative of the polyaminocarboxylic acid chelating agent or cyclic polyaminocarboxylic acid chelating agent under amide-forming conditions.
- reactive derivatives include, for example, anhydrides, mixed anhydrides and acid chlorides.
- the aminoalkylamine has the general formula: R 5
- the aminoalkylamide has the general formula: R 5 ' CH,CH 2 0) p -R 3
- the reactions are conducted in an organic solvent at an elevated temperature.
- Suitable solvents include those in which the reactants are sufficiently soluble and which are substantially unreactive with the reactants and products.
- Lower aliphatic ketones, ethers, esters, chlorinated hydrocarbons, benzene, toluene, xylene, lower aliphatic hydrocarbons, some lower aliphatic alcohols and the like may advantageously be used as reaction solvents.
- solvents examples include isopropanol, acetone, methylethyl ketone, diethylketone, methyl acetate, ethyl acetate, chloroform, methylene chloride, dichloroethane, hexane, heptane, octane, decane, and the like.
- the reaction solvent advantageously is one which does not contain reactive functional groups, such as hydroxyl groups, as these solvents can react with the acid chlorides, thus producing unwanted by ⁇ products.
- the reaction temperature may vary widely, depending upon the starting materials employed, the nature of the reaction solvent and other reaction conditions. Such reaction temperatures may range, for example, from about 25° C to about 80° C, preferably from about 25 ° C to about 50°C.
- any remaining anhydride or acid chloride groups can be hydrolyzed to the carboxylate groups by adding a stoichiometric excess of water to the reaction mixture and heating for a short time.
- the resulting aminoalkylamide compound is recovered from the reaction mixture by conventional procedures.
- the product may be precipitated by adding a precipitating solvent to the reaction mixture, and recovered by filtration or centrifugation.
- the paramagnetic ion is combined with the aminoalkylamide compound under complex-forming conditions.
- any of the paramagnetic ions referred to above can be employed in making the complexes of this invention.
- the complexes can conveniently be prepared by mixing a suitable oxide or salt of the paramagnetic ion with the complexing agent in aqueous solution. To assure complete complex formation, a slight stoichiometric excess of the complexing agent may be used.
- an elevated temperature e.g., ranging from about 20°C to about 100°C, preferably from about 40°C to about 80°C, may be employed to insure complete complex formation.
- complex formation will occur within a period from a few minutes to a few hours after mixing.
- the complex may be recovered by precipitation using a precipitating solvent such as acetone, and further purified by crystallization or chromatography, if desired.
- novel complexes of this invention can be formulated into diagnostic compositions for enteral or parenteral administration.
- These compositions contain an effective amount of the paramagnetic ion complex along with conventional pharmaceutical carriers and excipients appropriate for the type of administration contemplated.
- parenteral formulations advantageously contain a sterile aqueous solution or suspension of from about 0.05 to l.OM of a paramagnetic ion complex according to this invention.
- Preferred parenteral formulations have a concentration of paramagnetic ion complex of 0.1M to 0.5M.
- Such solutions also may contain pharmaceutically acceptable buffers and, optionally, electrolytes such as sodium chloride.
- compositions advantageously can contain one or more physiologically acceptable, non-toxic cations in the form of a gluconate, chloride or other suitable organic or inorganic salt, including suitable soluble complexes with a chelant/ligand, to enhance safety.
- the chelant/ligand desirably is derived from DTPA or EDTA.
- Such ligands include the ligands set forth above used to complex the paramagnetic and or heavy metals to provide the complex formulations of this invention.
- the cation-ligand complex is provided in amounts ranging from about 0.1 mole % to about 15 mole % of the ligand- etal complex.
- a typical single dosage formulation for parenteral administration has the following composition: Gadolinium DTPA-di(morpholinoethylamide) 330mg/ml Calcium DTPA-tri(morpholinoethylamide) 14mg/ml Distilled Water q.s. to 1 ml pH 7.3 ⁇ 0.1
- Parenteral compositions can be injected directly or mixed with a large volume parenteral composition for systemic administration.
- Formulations for enteral administration may vary widely, as is well-known in the art. In general, such formulations are liquids which include an effective amount of the paramagnetic ion complex in aqueous solution or suspension. Such enteral compositions may optionally include buffers, surfactants, thixotropic agents, and the like. Compositions for oral administration may also contain flavoring agents and other ingredients for enhancing their organoleptic qualities.
- the diagnostic compositions are administered in doses effective to achieve the desired enhancement of the NMR image.
- doses may vary widely, depending upon the particular paramagnetic ion complex employed, the organs or tissues which are the subject of the imaging procedure, the NMR imaging equipment being used, etc.
- parenteral dosages will range from about 0.01 to about 1.0 mmol of paramagnetic ion complex per kg of patient body weight.
- Preferred parenteral dosages range from about 0.05 to about 0.5 mmol of paramagnetic ion complex per kg of patient body weight.
- Enteral dosages generally range from about 0.5 to about 100 mmol, preferably from about 1.0 to about 20 mmol of paramagnetic ion complex per kg of patient body weight.
- the novel NMR image contrasting agents of this invention possess a unique combination of desirable features.
- the paramagnetic ion complexes exhibit an unexpectedly high solubility in physiological fluids, notwithstanding their substantially non-ionic character. This high solubility allows the preparation of concentrated solutions, thus minimizing the amount of fluid required to be administered.
- the non-ionic character of the complexes also reduces the osmolality of the diagnostic compositions, thus preventing undesired edema and other side effects.
- the compositions of this invention have very low toxicities, as reflected by their high LD 50 values. The low toxicity of these complexes is thought to result, in part, from the high stability constant of the complexes.
- aminoalkyl moieties provide additional sites for the formation of coordination bonds with the paramagnetic metal ion, thus strengthening the coordination complex. Therefore, the aminoalkyl groups not only neutralize the free carboxylic acid groups of the complexing agent, but they also participate in the formation of the complexes.
- compositions of this invention are used in the conventional manner.
- the compositions may be administered to a warm-blooded animal either systemically or locally to the organ or tissue to be imaged, and the animal then subjected to the NMR imaging procedure.
- the compositions have been found to enhance the magnetic resonance images obtained by these procedures.
- the complexing agents of this invention may also be employed for delivery of radiopharmaceuticals or heavy metals for x-ray contrast into the body.
- the invention is further illustrated by the following examples, which are not intended to be limiting.
- a DTPA morpholinoethylamide Gd complex was prepared in two steps a ⁇ shown below:
- the acute intravenous toxicity of the compound of Example 1 was determined as follows: ICR mice, at 1 to 4 per dose level, received single intravenous injections of the test substance via a lateral tail vein at the rate of approximately 1 ml/minute. The test sub ⁇ tances were at concentrations chosen to result in dose volumes of 5 to 75 ml/kg body weight. Dosing began at a volume of 10 ml/kg. Dose adjustments up or down were made to closely bracket the estimated LD 50 with 4 animals per group (2 males and 2 females).
- mice were recorded at times 0, 0.5, 1, 2, 4 and 24 hours and once daily thereafter for up to 7 days post injection. On the 7th day post injection, the mice were euthanized, weighed and necropsied. Abnormal tissues were noted. At this time a decision was made as to whether any histopathology was to be performed and whether or not the tissues should be retained. Necropsies were also performed on mice expiring after 24 hours post-injection, except for dead mice found on the weekends. The LD so values, along with 95% Cl were calculated using a modified Behrens- Reed-Meunch method. The results for the complex of Example 1 are reported below:
- LD 50 10.0 m ol/kg (no exces ⁇ ligand, 0.5M solution)
- LD 50 17.3 mmol/lkg (5% exce ⁇ ligand as calcium salt, 0.5M solution)
- Tj_ or longitudinal relaxation times were measured at 90MHz for the complex in 25%D 2 0/75%H 2 0 mixture at 20mM down to 0.65mM.
- the T_ is obtained using the spin- echo sequence on the JEOL FX90Q FT-NMR spectrometer.
- the relaxivities were determined by applying linear least-squares fit to the 1/T_ versus concentration data.
- the target correlation coefficient (r 2 ) is about 0.9990. All 13 C NMR spectra were taken on a JEOL FX90QQ FT-
- NMR Spectrometer and all ⁇ NMR Spectra were taken on a Varian Gemini 300 FT-NMR Spectrometer at room temperature.
- the IR spectrum was done on a Perkin- Elmer IR Spectrophotometer 727. Elemental analyses were performed by Galbraith Laboratories of Knoxville, TN, and Atlantic Microlab of Norcros, GA. pH measurements were made on a Corning Ion Analyzer 250 meter using a Corning combination electrode. All spectrophotometric measurements were made on a Varian CARY 2215 uv/vis spectrophotometer at room temperature. All computer calculations were done on an IBM Personal System 2 or an IBM-compatible PC Kaypro.
- the relaxation rate for the complex of Example 1 was 5.13 ⁇ 0.07 M ⁇ sec "1 at 90 MHz and 25°C.
- the correlation coefficient (r 2 ) was 0.9993.
- the title ligand is ⁇ ynthesized from DOTA and CH 3 0CH 2 CH 2 NHCH 3 by following the general method reported by Krejearek and Tucker (Biochem. Biophys. Res. Commun. 72581 (1977)) .
- Example 10 A mixture of the ligand from Example 8 (10 gr. 0.021 mol. and Gd 2 0 3 (3.6 gr, 0.01 mol) in deionized water (50 ml) i ⁇ heated at 100°C until most of the solid is dissolved. The mixture is cooled and filtered through a 0.2 micron filter to remove insolubles present. The filtrate is passed through an ion exchange column and the fractions containing the product are concentrated. The product may be further purified, if necessary, in accordance with conventional procedures. The procedure produces the title compound in good yield.
- Example 10 A mixture of the ligand from Example 8 (10 gr. 0.021 mol. and Gd 2 0 3 (3.6 gr, 0.01 mol) in deionized water (50 ml) i ⁇ heated at 100°C until most of the solid is dissolved. The mixture is cooled and filtered through a 0.2 micron filter to remove insolubles present. The filtrate is passed through an ion exchange column and the fractions containing the product are concentrated
- Example 9 The procedure of Example 9 is repeated in all essential details except that the ligand used here is the mono 4-morpholinoethylamide of DOTA, synthe ⁇ ized in Example 10. The procedure produces the title compound in good yield.
Abstract
Description
Claims
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US07/402,623 US5011925A (en) | 1989-03-09 | 1989-09-05 | Morpholinoamido EDTA derivatives |
US402,623 | 1989-09-05 |
Publications (1)
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WO1991003261A1 true WO1991003261A1 (en) | 1991-03-21 |
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PCT/US1990/001196 WO1991003261A1 (en) | 1989-09-05 | 1990-03-05 | Novel magnetic resonance imaging agents |
Country Status (5)
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EP (1) | EP0490897A1 (en) |
JP (1) | JPH04507401A (en) |
AU (1) | AU646393B2 (en) |
CA (1) | CA2065415A1 (en) |
WO (1) | WO1991003261A1 (en) |
Cited By (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO1992002259A1 (en) * | 1990-08-03 | 1992-02-20 | Mallinckrodt Medical, Inc. | Novel compositions for magnetic resonance imaging |
WO1992004919A1 (en) * | 1990-09-13 | 1992-04-02 | Mallinckrodt Medical, Inc. | Novel magnetic resonance imaging agents |
EP0660925A4 (en) * | 1990-11-21 | 1994-02-02 | Mallinckrodt Medical Inc | Alkoxyamide derivatized chelates for mri. |
EP0594640A1 (en) * | 1991-05-23 | 1994-05-04 | ImaRx Pharmaceutical Corp. | Liposoluble compounds for magnetic resonance imaging |
EP0692977A1 (en) * | 1993-03-15 | 1996-01-24 | Mallinckrodt Medical, Inc. | Novel heterocycle based nitrogen-sulfur ligands useful in radiographic imaging agents |
DE19507819A1 (en) * | 1995-02-21 | 1996-08-22 | Schering Ag | New di:ethylene-tri:amine penta:acetic acid amide complexes |
DE19507822A1 (en) * | 1995-02-21 | 1996-08-22 | Schering Ag | New di:ethylene-tri:amine penta:acetic acid amide derivs. and complexes |
Families Citing this family (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5384108A (en) * | 1989-04-24 | 1995-01-24 | Mallinckrodt Medical, Inc. | Magnetic resonance imaging agents |
Citations (4)
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FR2590484A1 (en) * | 1983-01-21 | 1987-05-29 | Schering Ag | PHYSIOLOGICALLY ACCEPTABLE METAL COMPLEX SALTS USEFUL FOR NMR DIAGNOSIS |
EP0130934B1 (en) * | 1983-07-01 | 1987-08-05 | Schering Aktiengesellschaft | Complexing agents, complexes and complex salts |
US4822594A (en) * | 1987-01-27 | 1989-04-18 | Gibby Wendell A | Contrast enhancing agents for magnetic resonance images |
WO1990001024A1 (en) * | 1988-07-19 | 1990-02-08 | Mallinckrodt, Inc. | Novel magnetic resonance imaging agents |
-
1990
- 1990-03-05 AU AU55351/90A patent/AU646393B2/en not_active Ceased
- 1990-03-05 EP EP19900907932 patent/EP0490897A1/en not_active Ceased
- 1990-03-05 CA CA002065415A patent/CA2065415A1/en not_active Abandoned
- 1990-03-05 JP JP50674790A patent/JPH04507401A/en active Pending
- 1990-03-05 WO PCT/US1990/001196 patent/WO1991003261A1/en not_active Application Discontinuation
Patent Citations (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
FR2590484A1 (en) * | 1983-01-21 | 1987-05-29 | Schering Ag | PHYSIOLOGICALLY ACCEPTABLE METAL COMPLEX SALTS USEFUL FOR NMR DIAGNOSIS |
EP0130934B1 (en) * | 1983-07-01 | 1987-08-05 | Schering Aktiengesellschaft | Complexing agents, complexes and complex salts |
US4822594A (en) * | 1987-01-27 | 1989-04-18 | Gibby Wendell A | Contrast enhancing agents for magnetic resonance images |
WO1990001024A1 (en) * | 1988-07-19 | 1990-02-08 | Mallinckrodt, Inc. | Novel magnetic resonance imaging agents |
Non-Patent Citations (1)
Title |
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Nuclear Medicine and Biology, Vol. 16, No. 6, 1989, International Journal of Radiation Applications and Instrumentation, Part B, (Oxford, GB), V.M. RUNGE et al.: "Experimental Trials with Gd(DO3A) - a Nonionic Magnetic Resonance Contrast Agent", pages 561 - 567 * |
Cited By (10)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO1992002259A1 (en) * | 1990-08-03 | 1992-02-20 | Mallinckrodt Medical, Inc. | Novel compositions for magnetic resonance imaging |
WO1992004919A1 (en) * | 1990-09-13 | 1992-04-02 | Mallinckrodt Medical, Inc. | Novel magnetic resonance imaging agents |
EP0660925A4 (en) * | 1990-11-21 | 1994-02-02 | Mallinckrodt Medical Inc | Alkoxyamide derivatized chelates for mri. |
EP0594640A1 (en) * | 1991-05-23 | 1994-05-04 | ImaRx Pharmaceutical Corp. | Liposoluble compounds for magnetic resonance imaging |
EP0594640A4 (en) * | 1991-05-23 | 1998-06-03 | Evan C Unger | Liposoluble compounds for magnetic resonance imaging |
EP0692977A1 (en) * | 1993-03-15 | 1996-01-24 | Mallinckrodt Medical, Inc. | Novel heterocycle based nitrogen-sulfur ligands useful in radiographic imaging agents |
EP0692977A4 (en) * | 1993-03-15 | 1996-04-10 | Mallinckrodt Medical Inc | Novel heterocycle based nitrogen-sulfur ligands useful in radiographic imaging agents |
DE19507819A1 (en) * | 1995-02-21 | 1996-08-22 | Schering Ag | New di:ethylene-tri:amine penta:acetic acid amide complexes |
DE19507822A1 (en) * | 1995-02-21 | 1996-08-22 | Schering Ag | New di:ethylene-tri:amine penta:acetic acid amide derivs. and complexes |
DE19507822B4 (en) * | 1995-02-21 | 2006-07-20 | Schering Ag | Substituted DTPA monoamides of the central carboxylic acid and its metal complexes, pharmaceutical compositions containing these complexes, their use in diagnostics and therapy, and methods for the preparation of the complexes and agents |
Also Published As
Publication number | Publication date |
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EP0490897A1 (en) | 1992-06-24 |
JPH04507401A (en) | 1992-12-24 |
AU5535190A (en) | 1991-04-08 |
CA2065415A1 (en) | 1991-03-06 |
AU646393B2 (en) | 1994-02-24 |
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