Thyroxine Free, Direct Dialysis (FT4) - (QUEST DIAGNOSTICS)
Free T4 by equilibrium dialysis is the most accurate measure of Free T4. Results are independent of the concentration of the T4-binding proteins, the presence of molecular variants of these proteins, or circulating autoantibodies. Free T4 is useful in distinguishing euthyroidism from thyroid disease. Thyroxine (T4) is a hormone produced by the thyroid gland. A test of the amount of T4 in the blood is a way to see how well the thyroid gland is working.
A significant deviation from the normal range may require further evaluation by your physician.
Alternative Name(s): FT4; T4 Free
Thyroxine Free, Direct Dialysis (FT4)
Samples should not be collected during or soon after the administration of Heparin.
Estimated turnaround for results is 7 business days. If confirmation testing is required, the estimated time may be extended.
Thyroxine (T4) is a hormone produced by the thyroid gland. A test of the amount of T4 in the blood is a way to see how well the thyroid gland is working. Free thyroxine (free T4) tests are used to help evaluate thyroid function and diagnose thyroid diseases, including hyperthyroidism and hypothyroidism, usually after discovering that the thyroid stimulating hormone (TSH) level is abnormal.
A significant deviation from the normal range may require further evaluation by your physician.
Thyroxine Free, Direct (FT4)
This test may exhibit interference when sample is collected from a person who is consuming a supplement with a high dose of biotin (also termed as vitamin B7 or B8, vitamin H or coenzyme R). It is recommended to stop biotin consumption at least 72 hours prior to the collection of specimen. Samples should not be collected during or soon after the administration of Heparin.
