WASHINGTON, June 25 (UPI) — Repeated use of specific “linear”-type gadolinium-based contrast agents, or GBCAs, for MRIs leads to deposits of the heavy metal gadolinium in the brain, according to a new study. The agents have been widely used in MRIs since their approval in 1988, with roughly 30 million doses given each year. “This important safety issue may lead to certain linear GBCAs not being used in the future,” said Val M. Runge, M.D., of University Hospital Zurich, in a press release. Runge, editor-in-chief of the journal Investigative Radiology, which published the study, first proposed the concept of using gadolinium as a contrast agent in 1982 and demonstrated the effectiveness of the first GBCA developed in 1984. “All of the currently approved GBCAs should be evaluated by the methods used” in this study, he added. {read more here}