Free Thyroxine Index Normal Range. The fti is a normalized determination that remains relatively constant in healthy individuals and compensates for abnormal levels of binding proteins. In most cases, free thyroxine (also known as free t4) is good indicator of thyroid function, along with tsh and other measures.
Reference ranges for the free thyroxine index: Normal ranges for free t4: 1 the normal range for the free thyroxine index (ft 4 i) is given as 1 to 4 ng per 100 ml,.
Fti = thyroxine (t4) / thyroid binding capacity.
1 the normal range for the free thyroxine index (ft 4 i) is given as 1 to 4 ng per 100 ml,. Free thyroxine (free t4) optimal range: A normal total t4 level in adults ranges from 5.0 to 12.0μg/dl. Fti increases could be caused by hyperthyroidism whilst decreased fti could be attributed to hypothyroidism.
