Spurious hypocalcemia after gadodiamide administration.

Severe hypocalcemia may require prompt intervention to avoid life-threatening consequences. We report a case in which a 78-year-old man had a critically low serum calcium level measured with use of standard colorimetric assay after gadodiamide administration during magnetic resonance angiography. Reanalysis of the same serum specimen using absorption spectroscopy revealed normal calcium values, confirming the diagnosis of spurious hypocalcemia. The increasing use of gadolinium chelates during magnetic resonance imaging and anglography will lead to a marked increase in reports of critically low serum calcium values. Increasing physicians' awareness of gadodiamide-induced spurious hypocalcemia may prevent unnecessary and potentially inappropriate therapeutic interventions.