Can Ferumoxytol be Used as a Contrast Agent to Differentiate Between Acute and Chronic Inflammatory Kidney Disease?: Feasibility Study in a Rat Model.
OBJECTIVE
Ferumoxytol, an intravenous iron supplement, can be used in off-label mode as a contrast agent in magnetic resonance imaging. The aim of this study was to assess whether ferumoxytol can be used as a marker of inflammation in animal models of acute and chronic inflammatory kidney diseases.


METHODS
The institutional animal care committee approved this study. A total of 18 rats were examined: 6 healthy Sprague Dawley rats as a control group; 6 rats with polycystic kidney disease (PKD) as a model for chronic inflammatory disease; Thy-1, an antibody triggering glomerulonephritis, was injected in 6 rats as a model for acute inflammation. Each rat was examined directly before and 24 hours after intravenous administration of ferumoxytol at a dose of 30 mg Fe/kg body weight. T2* times of renal tissue were approximated using a multiecho sequence. Changes in relative T2* times and T2 signal intensity after ferumoxytol injection were calculated.


RESULTS
Statistically significant differences between the 3 groups were found: the T2* times of both, Thy-1 and PKD rats were statistically significant different compared with the control group (T2* time ratio after/before: Thy-1, 0.21; PKD, 0.19, control, 0.28; P = 0.002). The highest T2 signal loss in the renal cortex was observed in the Thy-1 rats (T2 signal intensity ratio after/before: Thy-1, 0.49; PKD, 0.79; control, 0.78; P = 0.0005).


CONCLUSIONS
Ferumoxytol-enhanced magnetic resonance imaging allows detection and differentiation of acute and chronic inflammatory kidney disease based on different patterns of parenchymal ferumoxytol depositions. Ferumoxytol thus might help to differentiate between different types of inflammation in various kidney diseases.
From the *Department of Clinical Radiology and Nuclear Medicine, and †Medical Research Center, University Medical Center Mannheim, Medical Faculty Mannheim-Heidelberg University, Mannheim, Germany.
Johannes
J
Budjan
Sabine
S
Neudecker
Daniel
D
Schock-Kusch
Bettina
B
Kraenzlin
Stefan O
SO
Schoenberg
Henrik J
HJ
Michaely
Ulrike I
UI
Attenberger
D000208:Acute Disease; D000818:Animals; D002908:Chronic Disease; D003287:Contrast Media / Q000008:administration & dosage; D003937:Diagnosis, Differential; D005240:Feasibility Studies; D005260:Female; D052203:Ferrosoferric Oxide / Q000008:administration & dosage*; D007089:Image Enhancement / Q000379:methods*; D007275:Injections, Intravenous; D008297:Male; D009393:Nephritis / Q000473:pathology*; D015588:Observer Variation; D051381:Rats; D017207:Rats, Sprague-Dawley; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
D003287:Contrast Media; D052203:Ferrosoferric Oxide