Serum thyroid stimulating hormone (TSH), free triiodothyronine (FT3) and free tetraiodothyronine (FT4) levels were detected after operation or 2, 3 and 4 weeks after drug withdrawl.
The levels of serum free Triiodothyronine (FT3) and free Thyroxine (FT4) with thyroid-stimulating hormone (TSH) were measured by CLIA and RIA methods respectively.