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 ?
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%.