Gadolinium contrast media are more nephrotoxic than a low osmolar iodine medium employing doses with equal X-ray attenuation in renal arteriography: an experimental study in pigs.
OBJECTIVE
To investigate in a unilaterally nephrectomized porcine model whether gadolinium contrast media (Gd-CM) are less nephrotoxic than iodine media (I-CM) in x-ray arteriography of a kidney made temporarily ischemic by arterial balloon occlusion.


METHODS
In a noncrossover design, 3 mL of each test solution were injected in eight pigs (mean weight 19 kg) at a rate of 20 mL/min into the right renal artery at the start of a 10-minute period of ischemia. In group 1 (40 pigs) we injected 0.5 M gadopentetate, 0.5 M gadodiamide, 0.5 M iohexol (190 mg I/mL), 0.18 M iohexol (70 mg I/mL; with an x-ray attenuation equal to that of 0.5 M Gd-CM at 80 kV), and saline. In group 2 (24 pigs), we tested 0.18 M iohexol with ischemia and saline with and without ischemia. Gd- and iodine contrast media functioned as markers of glomerular filtration rate (GFR). When saline was tested, a low dose of iohexol (3 mL per pig; 300 mg I/mL) was injected as GFR marker intravenously in group 1 and into the renal artery in group 2. The plasma half-life elimination times of the CM 1-3 hours after injection were used to compare the effects of the different test solutions on GFR. Longer half-life means lower GFR.


RESULTS
Group 1: median plasma half-life elimination time of the GFR marker was 3 340 minutes after injection of 0.5 M gadopentetate, 256 after 0.5 M gadodiamide, 179 after 0.5 M iohexol, 143 after 0.18 M iohexol, and 133 minutes after saline. All differences except that between 0.18 M iohexol and saline were statistically significant (P < .01). Group 2: median plasma half-life was 174 minutes after 0.18 M iohexol with ischemia, 196 minutes after saline with ischemia, and 195 minutes after saline without ischemia. There were no significant differences between the test solutions in group 2 (P > .05).


CONCLUSIONS
In pigs, 0.5 M Gd-CM were more nephrotoxic than both equal-attenuating (70 mg I/mL) and equimolar (190 mg I/mL) concentrations of the I-CM iohexol. These results do not support the "off-label" use of Gd-CM for renal x-ray arteriography in man instead of commercially available concentrations of iodine contrast media at 140, 150 and 180 mg I/mL or diluted to 70 mg I/mL.
Elmståhl
Barbara
B
Department of Diagnostic Radiology, Malmö University Hospital, Lund University, SE-205 02 Malmö, Sweden. barbara.elmstahl@rontgen.mas.lu.se
Nyman
Ulf
U
Leander
Peter
P
Chai
Chun-Ming
CM
Frennby
Bo
B
Almén
Torsten
T
D000792:Angiography / Q000379:methods*; D000818:Animals; D003287:Contrast Media / Q000008:administration & dosage / Q000009:adverse effects* / Q000378:metabolism; D004195:Disease Models, Animal; D004305:Dose-Response Relationship, Drug; D005682:Gadolinium / Q000008:administration & dosage / Q000009:adverse effects* / Q000097:blood; D006207:Half-Life; D007091:Image Processing, Computer-Assisted; D007269:Injections, Intra-Arterial; D007455:Iodine / Q000008:administration & dosage / Q000009:adverse effects* / Q000097:blood; D007668:Kidney / Q000000981:diagnostic imaging / Q000187:drug effects* / Q000378:metabolism; D007674:Kidney Diseases / Q000209:etiology; D008297:Male; D009994:Osmolar Concentration; D013552:Swine; D013997:Time Factors
D003287:Contrast Media; D007455:Iodine; D005682:Gadolinium