First, I would enlist the doc as your advocate against the facility (radiologist) that performed the MRI. Your doc is only relating what he was told. Most never see the actual images of CT or MRI's. Everything is in terms of what the radiologist says (because medicine is so highly compartmentalized - the docs we see rarely 'read' anything in the radiologists pervue...they just report the findings).

I would approach it 'innocently' - like I'm confused...... or here's what I don't get.....
could there be a mistake?..... That (ridiculous) approach will probably get your doc most inclined to become your champion.

Re. contrast - - that was up to your doc to specify on the 'order'. If he did not say with and without contrast - they would not use contrast. (you, the patient, always have the right to refuse contrast - but never the right to add it!)

Re: the change in direction on the thymectomy, my first suspicion would be what your insurance requires for 'proof' the procedure is necessary. Believe it or not, some doctor's recommendations on course of treatment are increasingly influenced by insurance companies.

Call me cynical - but medicine is more big business than patient care in many instances. So important for us to be our own advocates.

Good luck with this - pls. let us know how it all goes.