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Free Thyroxine Index (FT4I) 

 

METHODOLOGY

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This is not a test per-se.  It is a calculated ratio of two tests: Total T4 / THBR

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PERFORMED  

 

Tuesday & Friday

 

REPORTED  

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2 days

 

REMARKS

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FT4-Index Components: Thyroxine (T4), Thyroid Hormone Binding Ratio (THBR)

 

REFERENCE RANGE

 

4.5 – 12.5 (no units)

CPT CODES

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84436 (T4), 84479 (THBR)

USC ENDOCRINE SERVICES LABORATORY
126 W. Del Mar Blvd 
Pasadena, CA 91105-2508
Phone: (855) 224-7111
Fax: (855) 224-7123

Email: endolab@usc.edu

The USC Endocrine Services Laboratory is licensed by the State of California, Department of Health Services, and accredited by the College of American Pathologists, and certified by Medicare according to the provisions of the U.S. Department of Health and Human Services Clinical Laboratory Improvement Act of 1988.

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1975 - 2021. All Rights Reserved.

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