Guideline 14. Clinical Utility of Serum Free T3 Estimate Tests Serum T3 measurement has little specificity or sensitivity for diagnosing hypothyroidism, since enhanced T4 to T3 conversion ...

Traditionally, the free thyroxine index, sometimes called a "T7" is derived from the product of a T3-uptake test and a TT4 measurement, often expressed as a % uptake (adsorbent bound counts ...