Effects of gadopentetate dimeglumine and gadodiamide on serum calcium, magnesium, and creatinine measurements

Purpose To investigate the in vivo effects of gadodiamide (Gd‐DTPA‐BMA) and gadopentetate dimeglumine (Gd‐DTPA) on the laboratory measurements of serum calcium, magnesium, and creatinine. Materials and Methods Medical records from 1993 to 2004 were reviewed to identify inpatients for whom laboratory data were available regarding serum calcium, creatinine, and magnesium levels before and within one day after gadodiamide and gadopentetate dimeglumine enhanced MRI. Patients who underwent both gadolinium (Gd)‐enhanced MRI and iodinated contrast‐enhanced examinations on separate days within a six‐month period were also identified to compare changes in serum creatinine. Results Serum creatinine did not increase in 2788 cases following gadopentetate dimeglumine and gadodiamide injection. By comparison, serum creatinine increased from 1.21 to 1.28 mg/dL following iodinated contrast, and there were 20 cases (2.6%) of contrast‐induced nephrotoxicity (P < 0.01). Gadopentetate dimeglumine did not affect serum calcium or magnesium measurements. Following 1157 gadodiamide‐enhanced examinations, measured serum calcium spuriously dropped from 8.65 to 8.33 mg/dL (P < 0.0001) and 34 patients had spurious critical hypocalcemia (