The safety of gadolinium in patients with stage 3 and 4 renal failure.

BACKGROUND Although there is a well-documented risk of acute renal failure (ARF) with the iodinated contrast agents, intravenous gadolinium-based contrast agents are considered non-nephrotoxic and have been widely used for magnetic resonance imaging (MRI). However, debate continues regarding the safety issue of gadolinium, especially in patients with kidney failure. Therefore, we aimed to evaluate the safety of gadolinium in patients with stage 3 and 4 renal failure as well as risk factors for nephrotoxicity. METHOD We retrospectively analysed 473 patients with chronic renal failure who underwent angiographic MRI procedures in our centre from February 1999 to March 2005 in whom gadolinium was used as the sole contrast agent at a dose of 0.2 ml/kg. Among them, 91 patients with stage 3 or 4 renal failure according to K/DOQI definition, who had available data in their files, were enrolled in the study. The ARF was defined as an increase of at least 0.5 mg/dl in serum creatinine level over baseline after using gadolinium. RESULTS Eleven of 91 (52 males, 39 females; median age 59 years; median estimated glomerular filtration rate (eGFR) 33 ml/min/1.73 m2) patients developed ARF (12.1%). The median eGFR was lower in patients with ARF than in those who did not develop ARF. The risk factors for ARF were baseline eGFR, older age, diabetic nephropathy and low baseline haemoglobin and albumin levels. Baseline eGFR and diabetic nephropathy were determined as the independent risk factors in regression analysis. CONCLUSIONS An ARF can occur after gadolinium-based contrast agents in patients with moderate to severe chronic renal failure. Risk factors for ARF after gadolinium toxicity include diabetic nephropathy and low GFR.