3005976
print

Free Thyroxine Index Panel

FTIP
Example Reports
Abnormal
Normal

Ordering Recommendation

Not recommended for routine thyroid disorder screening; for initial screening, refer to Thyroid Stimulating Hormone (0070145). 
Test includes Thyroxine, Total (T4) (3005978) and T Uptake (3005977). The preferred alternative to this test is Thyroxine, Free (Free T4) (0070138).

Methodology

Quantitative Electrochemiluminescent Immunoassay

Performed

Sun-Sat

Reported

Within 24 hours

New York DOH Approval Status

This test is New York DOH approved.

Specimen Required

Patient Preparation
Collect

Serum separator tube. Also acceptable: Lavender (K2EDTA or K3EDTA), pink (K2EDTA), or green (lithium heparin).

Specimen Preparation

Allow specimen to clot completely at room temperature. Separate serum or plasma from cells ASAP or within 2 hours of collection. Transfer 1 mL serum or plasma to an ARUP Standard Transport Tube. (Min: 0.5 mL)

Storage/Transport Temperature

Refrigerated.

Unacceptable Conditions

Grossly hemolyzed specimens.

Remarks
Stability

After separation of cells: Ambient: 4 days; Refrigerated: 8 days; Frozen: 1 year

Reference Interval

Test Number
 Components
 Reference Interval
  T Uptake 0.8-1.3 TBI
  Thyroxine, Total T4
Cord Blood 6.60-17.50 ug/dL
0-3 days 5.37-22.40 ug/dL
4-30 days 5.24-23.20 ug/dL
1-23 months 5.37-16.00 ug/dL
2-6 years 5.26-14.80 ug/dL
7-11 years 5.70-14.10 ug/dL
12-19 years 4.74-14.60 ug/dL
20 years and older 4.50-11.70 ug/dL

  Free Thyroxine Index Calc 4.8-12.7 ug/dL

Interpretive Data

Thyroxine, Free (FT4) (0070138) is the preferred test alternative for T Uptake and Free Thyroxine Index tests.

Compliance Category

FDA

Note

FTI = Free Thyroxine Index

Hotline History

View Hotline History

 

Hotline History

Date of Change
Test Name Change
Methodology
Performance/Reported Schedule
Specimen Requirements
Reference Interval
Interpretive Data
Note
CPT Code
Component Change
Other Interface Change
New Test
Inactive
02/21/2023
X
N/A

CPT Codes

84479; 84436

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Components

Component Test Code* Component Chart Name LOINC
3005979 T Uptake 74795-6
3005980 Thyroxine, Total T4 3026-2
3005981 Free Thyroxine Index Calc 32215-6
* Component test codes cannot be used to order tests. The information provided here is not sufficient for interface builds; for a complete test mix, please click the sidebar link to access the Interface Map.

Aliases

  • Free thyroxine index
  • FT4 index
  • FTI
  • T4 uptake
  • T7
  • Thyroxine index
Free Thyroxine Index Panel