More on Pseudohypocalcemia and Gadolinium-Enhanced MRI
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《新英格兰医药杂志》
To the Editor: In their letter to the editor, Doorenbos et al. (Aug. 21 issue)1 describe seven cases of severe pseudohypocalcemia after gadolinium-enhanced magnetic resonance angiography with the use of gadodiamide. Their report represents an important warning to all physicians, especially since such laboratory interference can occur after any gadodiamide-enhanced magnetic resonance imaging (MRI) examination. Gadodiamide and gadoversetamide are the two gadolinium chelates known to interfere with the colorimetric methods of measuring serum calcium used in most hospitals.2,3,4,5 However, five other gadolinium contrast agents do not show this interference: gadopentetate dimeglumine (Magnevist) and gadoteridol (ProHance), which are widely used in the United States, and gadobenate dimeglumine (MultiHance), gadobutrol (Gadovist), and gadoterate meglumine (Dotarem), which are available in Europe and selected countries elsewhere.
The reported interference with calcium measurements is due not to the gadolinium but rather to these two chelators. The interference can be completely avoided by requesting only those gadolinium contrast agents that are free of this interference. Alternatively, the interference can be eliminated by avoiding colorimetric methods of measuring serum calcium.
Editor's note: Dr. Prince reports having received honorariums and research support from Amersham, Berlex, Schering, Mallinckrodt, and Bracco and patent revenue from Mallinckrodt and Bracco. Dr. Knopp reports having received honorariums and research support from Amersham, Berlex, Schering, Mallinckrodt, and Bracco and patent revenue from Amersham.
Martin R. Prince, M.D., Ph.D.
Weill Medical College of Cornell University
New York, NY 10021
map2008@med.cornell.edu
Peter L. Choyke, M.D.
National Institutes of Health
Bethesda, MD 20892
Michael V. Knopp, M.D., Ph.D.
Ohio State University
Columbus, OH 43215
References
Doorenbos CJ, Ozyilmaz A, van Wijnen M. Severe pseudohypocalcemia after gadolinum-enhanced magnetic resonance angiography. N Engl J Med 2003;349:817-818.
Prince MR, Erel HE, Lent RW, et al. Gadodiamide administration causes spurious hypocalcemia. Radiology 2003;227:639-646.
Choyke PL, Knopp MV. Pseudohypocalcemia with MR imaging contrast agents: a cautionary tale. Radiology 2003;227:627-628.
Normann PT, Froysa A, Svaland M. Interference of gadodiamide injection (OMNISCAN) on the colorimetric determination of serum calcium. Scand J Clin Lab Invest 1995;55:421-426.
Lin J, Idee JM, Port M, et al. Interference of magnetic resonance imaging contrast agents with the serum calcium measurement technique using colorimetric reagents. J Pharm Biomed Anal 1999;21:931-943.
The authors and a colleague reply: We appreciate the comments of Prince and colleagues. Many clinicians may make mistakes with pseudohypocalcemia because of the interaction between the gadolinium chelate and the colorimetric method used to measure calcium, as Prince and colleagues have described,1 and as we reported in our letter. This problem may be avoided by increasing clinicians' awareness of it; by postponing blood sampling for calcium measurement after the administration of gadolinium, especially in patients with renal failure; by not using the colorimetric method for measuring calcium; or by using a gadolinium preparation that causes no interference.2 The first two solutions are difficult to guarantee, and the third is hard to justify because of the rarity of this problem. Furthermore, measurements of calcium by means of an ion-selective electrode or inductively coupled plasma-atomic emission spectroscopy are not available in most hospitals. Therefore, we prefer the fourth solution: use of a gadolinium preparation that is free from interference,3 as suggested by Prince and colleagues.
Cornelius J. Doorenbos, M.D., Ph.D.
Kenneth Koster, M.D.
Merel van Wijnen, Ph.D.
Deventer Hospital
NL-7415 CM Deventer, the Netherlands
doorenbc@dz.nl
References
Prince MR, Erel HE, Lent RW, et al. Gadodiamide administration causes spurious hypocalcemia. Radiology 2003;227:639-646.
Normann PT, Froysa A, Svaland M. Interference of gadodiamide injection (OMNISCAN) on the colorimetric determination of serum calcium. Scand J Clin Lab Invest 1995;55:421-426.
Lin J, Idee JM, Port M, et al. Interference of magnetic resonance imaging contrast agents with the serum calcium measurement technique using colorimetric reagents. J Pharm Biomed Anal 1999;21:931-943.
Related Letters:
Severe Pseudohypocalcemia after Gadolinium-Enhanced Magnetic Resonance Angiography
Doorenbos C. J., Ozyilmaz A., van Wijnen M.
The reported interference with calcium measurements is due not to the gadolinium but rather to these two chelators. The interference can be completely avoided by requesting only those gadolinium contrast agents that are free of this interference. Alternatively, the interference can be eliminated by avoiding colorimetric methods of measuring serum calcium.
Editor's note: Dr. Prince reports having received honorariums and research support from Amersham, Berlex, Schering, Mallinckrodt, and Bracco and patent revenue from Mallinckrodt and Bracco. Dr. Knopp reports having received honorariums and research support from Amersham, Berlex, Schering, Mallinckrodt, and Bracco and patent revenue from Amersham.
Martin R. Prince, M.D., Ph.D.
Weill Medical College of Cornell University
New York, NY 10021
map2008@med.cornell.edu
Peter L. Choyke, M.D.
National Institutes of Health
Bethesda, MD 20892
Michael V. Knopp, M.D., Ph.D.
Ohio State University
Columbus, OH 43215
References
Doorenbos CJ, Ozyilmaz A, van Wijnen M. Severe pseudohypocalcemia after gadolinum-enhanced magnetic resonance angiography. N Engl J Med 2003;349:817-818.
Prince MR, Erel HE, Lent RW, et al. Gadodiamide administration causes spurious hypocalcemia. Radiology 2003;227:639-646.
Choyke PL, Knopp MV. Pseudohypocalcemia with MR imaging contrast agents: a cautionary tale. Radiology 2003;227:627-628.
Normann PT, Froysa A, Svaland M. Interference of gadodiamide injection (OMNISCAN) on the colorimetric determination of serum calcium. Scand J Clin Lab Invest 1995;55:421-426.
Lin J, Idee JM, Port M, et al. Interference of magnetic resonance imaging contrast agents with the serum calcium measurement technique using colorimetric reagents. J Pharm Biomed Anal 1999;21:931-943.
The authors and a colleague reply: We appreciate the comments of Prince and colleagues. Many clinicians may make mistakes with pseudohypocalcemia because of the interaction between the gadolinium chelate and the colorimetric method used to measure calcium, as Prince and colleagues have described,1 and as we reported in our letter. This problem may be avoided by increasing clinicians' awareness of it; by postponing blood sampling for calcium measurement after the administration of gadolinium, especially in patients with renal failure; by not using the colorimetric method for measuring calcium; or by using a gadolinium preparation that causes no interference.2 The first two solutions are difficult to guarantee, and the third is hard to justify because of the rarity of this problem. Furthermore, measurements of calcium by means of an ion-selective electrode or inductively coupled plasma-atomic emission spectroscopy are not available in most hospitals. Therefore, we prefer the fourth solution: use of a gadolinium preparation that is free from interference,3 as suggested by Prince and colleagues.
Cornelius J. Doorenbos, M.D., Ph.D.
Kenneth Koster, M.D.
Merel van Wijnen, Ph.D.
Deventer Hospital
NL-7415 CM Deventer, the Netherlands
doorenbc@dz.nl
References
Prince MR, Erel HE, Lent RW, et al. Gadodiamide administration causes spurious hypocalcemia. Radiology 2003;227:639-646.
Normann PT, Froysa A, Svaland M. Interference of gadodiamide injection (OMNISCAN) on the colorimetric determination of serum calcium. Scand J Clin Lab Invest 1995;55:421-426.
Lin J, Idee JM, Port M, et al. Interference of magnetic resonance imaging contrast agents with the serum calcium measurement technique using colorimetric reagents. J Pharm Biomed Anal 1999;21:931-943.
Related Letters:
Severe Pseudohypocalcemia after Gadolinium-Enhanced Magnetic Resonance Angiography
Doorenbos C. J., Ozyilmaz A., van Wijnen M.