MR assessment of iodinated contrast-medium-induced nephropathy in rats using ultrasmall particles of iron oxide.
The purpose of this study was to determine the diagnostic value of ultrasmall particles of iron oxide (USPIO)-enhanced MR imaging at different concentrations to evaluate experimental nephropathy. This study was conducted in 23 uninephrectomized rats using a model of iodinated contrast media-induced renal failure. Eleven rats received selective intra-arterial renal administration of diatrizoate (370 mg I/ml) and were compared to two control groups, including five animals injected with isotonic saline and seven noninjected animals. MR imaging was performed 28 hours after the procedure, including T1- and T2-weighted images before and after intravenous administration of successively 5 mumol Fe/kg and 60 mumol/kg of USPIO. Results were interpreted qualitatively and quantitatively with respect to pathologic data, and differences were studied statistically. The maximal signal intensity decrease was noted in normal kidneys in cortex (-65 +/- 4%) and medulla (-84 +/- 5%) on T2-weighted images after injection of 60 mumol/kg of USPIO. At this dose, diseased kidneys displayed less signal intensity decrease than normal kidneys on T2-weighted images (p = .05). Moreover, qualitative analysis showed that the highest sensitivity and specificity to diagnose kidney involvement were obtained with T2-weighted MR images (75% and 91%, respectively) when 60 mumol/kg of USPIO were used (p < .01). USPIO should be useful for in vivo evaluation of the severity of experimentally induced iodinated contrast media renal impairment in animals.
Laissy
J P
JP
Department of Radiology, Hôpital Bichat, Paris, France.
Benderbous
S
S
Idée
J M
JM
Chillon
S
S
Beaufils
H
H
Schouman-Claeys
E
E
D000818:Animals; D003287:Contrast Media; D004195:Disease Models, Animal; D004305:Dose-Response Relationship, Drug; D005290:Ferric Compounds / Q000008:administration & dosage / Q000009:adverse effects; D007089:Image Enhancement / Q000379:methods*; D007275:Injections, Intravenous; D007668:Kidney / Q000187:drug effects / Q000473:pathology; D008279:Magnetic Resonance Imaging; D008297:Male; D010316:Particle Size; D051381:Rats; D017207:Rats, Sprague-Dawley; D051437:Renal Insufficiency / Q000139:chemically induced / Q000175:diagnosis*
D003287:Contrast Media; D005290:Ferric Compounds; C000499:ferric oxide