So why am I talking about an iceberg on the Gadolinium Toxicity website?  Let me explain.

Not long after I started researching NSF and Gadolinium in early 2010, I saw a reference to an editorial by Dr. Henrik Thomsen of Denmark that had been published in 2008.  The title was, Is NSF Only the Tip of the “Gadolinium Toxicity” Iceberg?  The title caught my attention and really made me think.  It took me a while, but I finally managed to find the editorial.  After reading it, I had more questions than answers.

It seems that in the early 1990s, there was already concern about the stability of the nonionic linear GBCAs, and the macrocyclic agents were found to be significantly more stable in serum.  It was known that transmetallation with other metal ions in the body was more apt to occur with the DTPA-based chelates, and when transmetallation occurs it results in the toxic Gadolinium ion remaining in the body.  Dr. Thomsen asked, “Why were nonionic linear chelates chosen instead of macrocyclic chelate?”  That is a very good question.

For those of us in the U.S., a better question might be, why did it take the FDA longer to react than the European Medicines Agency (EMEA) and the Japanese authorities?  (more…)