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- Elmståhl, Barbara, et al.
(författare)
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Gadolinium contrast media are more nephrotoxic than iodine media. The importance of osmolality in direct renal artery injections
- 2006
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Ingår i: European Radiology. - : Springer Science and Business Media LLC. - 0938-7994 .- 1432-1084. ; 16:12, s. 2712-2720
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Tidskriftsartikel (refereegranskat)abstract
- A study was undertaken of the role of osmotoxicity in gadolinium (Gd) and iodine contrast media (CM) nephrotoxicity in ischemic porcine kidneys. Test solutions: mannitol iso-osmotic to 0.5 M: gadopentetate (1.96 Osm/kg H2O), 0.5 M: gadodiamide (0.78 Osm/kg H2O) and 0.5 M: iohexol (190 mg I/ml, 0.42 Osm/kg H2O). Each solution was injected [3 ml/kg body weight (BW)] into the balloon-occluded (10 min) renal artery of eight left-sided nephrectomized pigs. The plasma half-life of a glomerular filtration rate (GFR) marker was used to compare their effects on GFR 1-3 h post-injection. The median half-lives of the GFR marker after injection of gadopentetate (1,730 min) and mannitol 1.96 Osm/kg H2O (2,782 min) did not differ statistically (P = 0.28), but were significantly longer than after all other solutions (P < 0.001). There was no significant difference (P = 0.06) between gadodiamide (218 min) and mannitol 0.82 Osm/kg H2O (169 min), while there was (P = 0.03) between iohexol (181 min) and mannitol 0.43 Osm/kg H2O (148 min). The difference between gadodiamide and iohexol was significant (P = 0.01). Reduction in GFR, as a marker of nephrotoxicity, induced by gadopentetate correlated with its high osmolality, while the effect of gadodiamide and iohexol may include chemotoxicity. Iohexol molecules were less nephrotoxic than the Gd-CM molecules and contain three-times the number of attenuating atoms per molecule.
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- Elmståhl, Barbara, et al.
(författare)
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Iodixanol 320 results in better renal tolerance and radiodensity than do gadolinium-based contrast media: Arteriography in ischemic porcine kidneys
- 2008
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Ingår i: Radiology. - : Radiological Society of North America (RSNA). - 1527-1315 .- 0033-8419. ; 247:1, s. 88-97
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Tidskriftsartikel (refereegranskat)abstract
- Purpose: To prospectively compare nephrotoxicity and radiodensity of plasma hyperosmotic gadolinium chelates (attenuation-osmotic ratio of 1: 1) with those of plasma iso-osmotic iodine-based contrast media (attenuation-osmotic ratio of 3: 1 or 6: 1) after renal arteriography in ischemic porcine kidneys. Materials and Methods: The local animal care committee approved this study. The following contrast media were used: (a) iodixanol (150 mg of iodine per milliliter and 320 mg I/mL, 0.29 osm/kg H2O), (b) iopromide (150 mg I/mL, 0.34 osm/kg), (c) 0.5 mol/L gadodiamide (0.78 osm/kg), and (d) 1.0 mol/L gadobutrol (1.6 osm/kg). After left-sided nephrectomy, contrast media (3 mL per kilogram of body weight) were injected (20 mL/min) in a noncrossover design into the right renal artery of pigs during a 10-minute ischemic period. There were eight pigs in each group and one group for each contrast medium. We compared histomorphology, radiographic contrast medium excretion, subjective radiodensity of nephrograms (70 kVp) at the end of injection, and contrast medium plasma half-life elimination times 1-3 hours after injection. Longer elimination times resulted in lower glomerular filtration rates. Results: Gadobutrol caused extensive tubular necrosis and moderate glomerular necrosis; gadodiamide and iopromide, minimal to mild tubular necrosis; and iodixanol, no necrosis. Gadobutrol was the only contrast medium to show no sign of excretion, and its plasma half-life elimination time (median, 1103 minutes; P = .001) was significantly longer than that of other contrast agents. Gadodiamide had a significantly longer plasma half-life elimination time (median, 209 minutes; P = .01) than did iodine-based contrast media (median, 136-142 minutes). The 320 mg I/mL dose of iodixanol had the highest radiodensity, whereas gadodiamide had the lowest radiodensity. The radiodensity of the 320 mg I/mL dose of iodixanol was greater than that of the 150 mg I/mL dose of iodixanol, which was equal to the radiodensities of the 150 mg I/mL dose of iopromide and 1.0 mol/L gadobutrol, which in turn were greater than that of 0.5 mol/L gadodiamide. Conclusion: Plasma iso-osmotic iodine-based contrast media used at commercially available concentrations have superior attenuation and nephrotoxic profiles compared with equal volumes of hyperosmotic nonionic 0.5-1.0 mol/L gadolinium-based contrast media when performing renal arteriographic procedures. (c) RSNA, 2008.
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| 4. |
- Golman, Klaes, et al.
(författare)
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13C-angiography.
- 2002
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Ingår i: Academic Radiology. - 1878-4046. ; 9:Suppl 2, s. 507-510
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Tidskriftsartikel (refereegranskat)
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| 5. |
- Golman, Klaes, et al.
(författare)
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Cardiac metabolism measured noninvasively by hyperpolarized (13)C MRI.
- 2008
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Ingår i: Magnetic Resonance in Medicine. - : Wiley. - 1522-2594 .- 0740-3194. ; 59:5, s. 1005-1013
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Tidskriftsartikel (refereegranskat)abstract
- Pyruvate is included in the energy production of the heart muscle and is metabolized into lactate, alanine, and CO(2) in equilibrium with HCO(3) (-). The aim of this study was to evaluate the feasibility of using (13)C hyperpolarization enhanced MRI to monitor pyruvate metabolism in the heart during an ischemic episode. The left circumflex artery of pigs (4 months, male, 29-34 kg) was occluded for 15 or 45 min followed by 2 hr of reperfusion. Pigs were examined by (13)C chemical shift imaging following intravenous injection of 1-(13)C pyruvate. (13)C chemical shift MR imaging was used in order to visualize the local concentrations of the metabolites. After a 15-min occlusion (no infarct) the bicarbonate signal level in the affected area was reduced (25-44%) compared with the normal myocardium. Alanine signal level was normal. After a 45-min occlusion (infarction) the bicarbonate signal was almost absent (0.2-11%) and the alanine signal was reduced (27-51%). Due to image-folding artifacts the data obtained for lactate were inconclusive. These studies demonstrate that cardiac metabolic imaging with hyperpolarized 1-(13)C-pyruvate is feasible. The changes in concentrations of the metabolites within a minute after injection can be detected and metabolic maps constructed. Magn Reson Med 59:1005-1013, 2008. (c) 2008 Wiley-Liss, Inc.
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| 7. |
- Golman, Klaes, et al.
(författare)
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Molecular imaging with endogenous substances
- 2003
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Ingår i: Proceedings of the National Academy of Sciences. - : Proceedings of the National Academy of Sciences. - 1091-6490 .- 0027-8424. ; 100:18, s. 10435-10439
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Tidskriftsartikel (refereegranskat)abstract
- Dynamic nuclear polarization has enabled hyperpolarization of nuclei such as C-13 and N-15 in endogenous substances. The resulting high nuclear polarization makes it possible to perform subsecond C-13 MRI. By using the dynamic nuclear polarization hyperpolarization technique, 10% polarization was obtained in an aqueous solution of 100 mM C-13-labeled urea, ready for injection. The in vivo T, relaxation time of C-13 in the urea solution was determined to 20 +/- 2 s. Due to the long relaxation time, it is possible to use the hyperpolarized substance for medical imaging. A series of high-resolution (approximate to1-mm) magnetic resonance images were acquired, each with a scan time of 240 ms, 0-5 s after an i.v. injection of the hyperpolarized aqueous [C-13]urea solution in a rat. The results show that it is possible to perform C-13 angiography with a signal-to-noise ratio of approximate to275 in approximate to0.25 s. Perfusion studies with endogenous substances may allow higher spatial and/or temporal resolution than is possible with current proton imaging techniques.
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| 8. |
- Golman, Klaes, et al.
(författare)
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Overhauser-enhanced MRI.
- 2002
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Ingår i: Academic Radiology. - 1878-4046. ; 9 Suppl 1, s. 104-108
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Tidskriftsartikel (refereegranskat)
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| 9. |
- Leander, Peter, et al.
(författare)
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Early effect of gadopentetate and iodinated contrast media on rabbit kidneys
- 1992
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Ingår i: Investigative Radiology. - 0020-9996. ; 27:11, s. 922-926
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Tidskriftsartikel (refereegranskat)abstract
- RATIONALE AND OBJECTIVES. The authors compared the physiologic and nephrotoxic effects of the magnetic resonance imaging contrast medium gadopentetate with two conventional radiographic contrast media. METHODS. Rabbits were injected intravenously with one of the following solutions: 1) gadopentetate (0.1 M); 2) iohexol (300 mg I/mL); 3) metrizoate (300 mg I/mL); and 4) NaCl (0.9%). Blood samples were taken before and 5, 15, 45, 90, and 180 minutes after injection of the solutions and were analyzed for creatinine, aldosterone, and contrast media levels. Urine was sampled before and 1, 2.5, and 5 hours after injection of the solutions, and creatinine, leucine amino peptidase (LAP), alkaline phosphatase (ALP), gamma glutaryl transferase (GGT), and N-acetyl beta-D-glucosaminidase (NAG) activities were quantified. RESULTS. Contrast media clearance was similar for gadopentetate, iohexol, and metrizoate. Plasma aldosterone was significantly higher in the two groups injected with iodinated contrast agents compared with the gadopentetate and saline groups in the 3-hour samples. During the 5 hours after injection, the excretion of brushborder enzymes LAP, ALP, and gamma GT was significantly higher for all contrast media compared with pre-contrast values and 0.9% NaCl controls. NAG, a lysosomal enzyme from tubular cells, showed a significant increase compared with pre-contrast values for all contrast media. CONCLUSIONS. Intravenous injection of gadopentetate in rabbits showed nephrotoxicity of the same order as that of conventional iodinated contrast media.
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