MRIs are a common medical procedure. However, there is one potentially dangerous element in them and everyone needs to know about it. It’s called gadolinium. It’s a metallic substance used in contrast dyes and patients ingest it to make the results easier to read. It’s also potentially toxic. Gadolinium can stay in your system, causing symptoms like pain in the joints, hair loss, skin lesions, tinnitus, muscle weakness, balance problems and cognitive issues.