> No, it's not at all a weak justification, and it is the primary reason you shouldn't get these scans done.

Yes, it is weak. The so-called downside is that you might need to do intrusive procedures as a followup.

But guess what? You don't HAVE to do that.

> The cost of a false positive imaging flag is far worse

Now think about the costs of not detecting a true reading. Most cancers start having visible symptoms only when they are far too advanced to be cured.

So the status quo is: you wait until you get an incurable disease, and then use MRI to solemnly confirm that. And then use it to give you estimates on how soon you'll die.

> Rather: you'll pay the price in follow-up imaging, which won't be as benign as the MRI, or worse, in unnecessary intrusive diagnostics.

Or you can just wait for a bit and do another MRI to check if there's any worsening. If you can afford an MRI, you likely can afford a second one.