NEW YORK --  We don’t think about it much, but medications used during common laboratory studies can lead to problems and patients as well as their doctors need to be aware. 

Medicines used in M.R.I.s may pose a risk...medications known as contrast agents, which help better visualize certain structures in the body when an M.R.I. scan is done. According to the F.D.A., this may cause serious injury or death in cases. 

Agents using a material called Gadolinium are the issue. Gadolinium is a rare earth element that is bound to another material called EDTA to make it safe in the body.

In people with kidney failure, that binding can disconnect and you get free Gadolinium. Your body is in trouble if this happens. Free Gadolinium is toxic and this toxicity appears to result in a disease called Nephrogenic Cystic Fibrosis, which causes thickening of the skin like Scleroderma, and can be fatal. 

The vast majority of people who need to receive Gadolinium-based contrast agents as part of an M.R.I. scan are perfectly safe but it’s a perfect example of why we need to be careful about all tests.