title: Effects of gadopentetate dimeglumine and gadodiamide on serum calcium, magnesium, and creatinine measurements.
abstract: OBJECTIVE
  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.
  
  
  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 (<6 mg/dL). Of 60 patients with high-dose gadodiamide injection and renal insufficiency, 36.7% (N = 22) had spurious critical hypocalcemia immediately post MRI. In 216 patients with renal insufficiency, the mean serum magnesium level increased slightly from 1.69 to 1.77 mEq/L following gadodiamide injection (P < 0.0001).
  
  
  CONCLUSIONS
  Gd-based contrast agents are safe for MRI and MR angiography (MRA), and do not induce nephrotoxicity. However, gadodiamide interferes with serum calcium and magnesium measurements-particularly at high doses and/or with renal insufficiency.
authors.affiliation: Department of Radiology, Weill Medical College of Cornell University, 416 East 55th Street, New York, NY 10022, USA.
authors.forename: Hong Lei
authors.initials: HL
authors.lastname: Zhang
authors.forename: Hale
authors.initials: H
authors.lastname: Ersoy
authors.forename: Martin R
authors.initials: MR
authors.lastname: Prince
mesh_terms: D002118:Calcium / Q000097:blood*; D003287:Contrast Media / Q000494:pharmacology*; D003404:Creatinine / Q000097:blood*; D019786:Gadolinium DTPA / Q000494:pharmacology*; D006801:Humans; D008274:Magnesium / Q000097:blood*; D008279:Magnetic Resonance Imaging
chemical_list: D003287:Contrast Media; C064925:gadodiamide; D003404:Creatinine; D008274:Magnesium; D019786:Gadolinium DTPA; D002118:Calcium