Iodixanol 320 results in better renal tolerance and radiodensity than do gadolinium-based contrast media: Arteriography in ischemic porcine kidneys

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.