free thyroxine test

free thyroxine (FT4) test

a blood test used to determine thyroid function, especially when the patient has concurrent clinical situations that may alter protein blood levels. Abnormal levels indicate either hyper- or hypothyroid states.
References in periodicals archive ?
antibody to thyroglobulin test 200 antibodies to thyroid peroxidase test 200 free triiodothyronine test 400 free thyroxine test 400 thyroglobulin test 100 thyrotropin test 800 estradiol e2 test 100 follicle-stimulating hormone test 200 intact human chorionic gonadotropin test 500 luteinizing hormone test 200 progesterone test 200 prolactin ii test 200 testosterone test 400 cross-test 100 test 100 test 500 test cancer antigen 125 test 2600 cancer antigen 15.
A free thyroxine test should be done when the TSH is undetectable or 10 mU/L and higher.
Results ranged between 96% and 109% of untreated values for all analytes, including the blood coagulation indicators, except the free thyroxine test on the AxSYM, which showed an increase to 122%.