A B C D E F G H I J K L M N O P Q R S T U V W X Y Z #

Thyroxine, Free

Message
Performed in the Chemistry Laboratory, x5820
10.2018


Test Code
FT4


Preferred Specimen
Plasma from a green top (PST) tube


Minimum Volume
1mL


Transport Container
Green Top (PST) tube


Transport Temperature
Room temperature


Specimen Stability
2 - 8 oC: 24 hours


Methodology
Chemiluminescent microparticle immunoassay (Abbott Architect)

Setup Schedule
This assay is performed 24 hours per day, 7 days per week


Limitations
Performance not established on neonatal specimens.


Reference Range
0.7 - 1.48  ng/dL


Clinical Significance
This test is generally used to follow up on TSH changes.  The free thyroxine value, combined with the TSH value, gives a more accurate picture of the thyroid status in patients with abnormal thyroid-binding globulin levels such as pregnant  women or patients who are receiving treatment with estrogens, phenytoin, or salicylates.




The CPT Codes provided in this document are based on AMA guidelines and are for informational purposes only. CPT coding is the sole responsibility of the billing party. Please direct any questions regarding coding to the payor being billed. Any Profile/panel component may be ordered separately. Reflex tests are performed at an additional charge.