Ordering Recommendation
Not recommended for routine thyroid screening.
Mnemonic
T7
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 |
||||||||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
T3 Uptake | 28-41% uptake | |||||||||||||||||||
Thyroxine |
|
|||||||||||||||||||
Free Thyroxine Index Calculation | FTI 1.7-4.2 |
Interpretive Data
Thyroxine, Free (FT4) (0070138) is the preferred test alternative for T3 uptake and Free Thyroxine Index tests.
Compliance Category
FDA
Note
FTI = Free Thyroxine Index
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
N/A
CPT Codes
84479; 84436
Components
Component Test Code* | Component Chart Name | LOINC |
---|---|---|
0070135 | T3 Uptake | 3050-2 |
0070140 | Thyroxine | 3026-2 |
0070196 | Free Thyroxine Index Calculation | 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
- T3 uptake
- T7
- thyroxine
- Thyroxine Index
Thyroid Panel