Free Thyroxine Index Range. The free thyroxine index (fti) is determined by the following calculation: The free triiodothyronine (t3) index.
Interassay precision (cv) is <5%. May also include abnormal ranges. Thyroxine binding capacity (units are in thyroxine binding index:
Reference ranges for the free thyroxine index:
Patients with hypothyroidism require a higher level of serum free thyroxine to achieve a normal tsh value in comparison with euthyroid control subjects. Thyroxine binding capacity (units are in thyroxine binding index: The free triiodothyronine (t3) index. A free t4 measures what is not bound and able to enter and affect the body tissues.