I'm not familiar with this. Have you talked this over with your doctors? Once you get more info, perhaps you'll let this group know. If this hasn't come up in the past, it may in the future and what you learn could benefit someone else. Good luck with this.
I haven't read any information about gadolinium affecting thyroid hormone levels. There is a black box warning for all gadolinium contrast agents (Omniscan, Magnevist, OptiMARK, ProHance, Multihance) stating that patients with kidney disease or renal failure are at risk of developing Nephrogenic Systemic Fibrosis (NSF).
An eGFR of less than 30 mL/min is considered to be at a high risk of NSF and gadolinium should be avoided. Excerpt from "Duke Radiology Gadolinium Use" for advanced stage 3 kidney disease (eGRF 30 - 45): "if contract is deemed necessary by the appropriate radiologist, then the smallest effective dose of gadobenate dimeglumine (Multihance, Brasco Diagnostics Inc), should be administered."
I meant contrast not contract. :)
I have got Gadolinium a few times during thyroid medication. I have not noticed any affect.
A GFR has not been determined for me, only creatinine.