@Denese - It’s the contrast w/ MRIs that is the trouble. The contrast contains Gadolinium which is a heavy metal which some people have a bad reaction to after the scan & sometimes for a long time later. Many of us have had MRIs with contrast & have had no ill after effects from it, but others have not been so fortunate. It’s just a good idea to be informed.
Here’s a link to a post from @vdm regarding Gadolinium toxicity: