That would have been frightening. Did it require treatment beyond antihistamine? I’ve given MR contrast to patients a lot of times (probably tens of thousands)

That would have been frightening. Did it require treatment beyond antihistamine? I’ve given MR contrast to patients a lot of times (probably tens of thousands) and have seen hives and rashes a handful of times but vastly more often with iodinated contrast in X-ray procedures (usually CT).