Free Thyroxine Index (T7)
Order Code: FTI
Test Summary
Thyroid Index (T7), also called Free Thyroxine Index (FTI), is a calculation requiring both a total T4 and a T3-Uptake.
Aliases
- FTI
- T7
- Free Thyroxine Index
Specimen Collection
Special Instructions
N/A
Preferred Specimen
1 mL serum
Minimum Volume
1 mL
Instructions
Barrier tubes (serum separator tubes or plasma separator tubes) are preferred. If non-barrier tubes are utilized, the serum/plasma must be removed immediately after centrifuging and placed in a screw-cap transfer tube.
Collection notes: Avoid hemolysis. Invert tubes at least 8 times. Allow to clot in an upright position for 30 minutes. Within 2 hours, centrifuge tubes 10 minutes. Keep tightly stoppered.
Do NOT re-centrifuge tubes. Do NOT freeze the primary collection tube.
Collection notes: Avoid hemolysis. Invert tubes at least 8 times. Allow to clot in an upright position for 30 minutes. Within 2 hours, centrifuge tubes 10 minutes. Keep tightly stoppered.
Do NOT re-centrifuge tubes. Do NOT freeze the primary collection tube.
Patient Preparation
N/A
Storage
Original tube preferred, may be sent in a screw-top transfer tube.
Transport Temperature
Room Temperature or Refrigerated
Specimen Stability
- Room Temperature: 5 Days
- Refrigerated: 7 Days
- Frozen: 30 days
Limitations
N/A
Other Acceptable Specimens
Plasma from Lithium Heparin (Light Green Top) tube
Unacceptable Specimens
- Hemolysis
- Lipemia
- Incorrect specimen type
- Insufficient sample volume
- Improper storage conditions
- Exceeds specimen stability guidelines
- Contaminated sample
Order Code
FTI
EPIC (Premier) Code
LAB2132
Includes
Thyroxine, Total;
T3 Uptake
T3 Uptake
CPT Code
- 84436
- 84479
Billing Code
- 300389
- 300399
CPT Statement
Methodology
Calculation.
Thyroid Index (T7), also called Free Thyroxine Index (FTI), is a calculation requiring both a total T4 and a T3-Uptake. T7= (T4 x T3-Uptake)/100
Thyroid Index (T7), also called Free Thyroxine Index (FTI), is a calculation requiring both a total T4 and a T3-Uptake. T7= (T4 x T3-Uptake)/100
FDA Status
FDA Approved
Physician Attestation of Informed Consent
N/A
Testing Laboratory
CompuNet Clinical Laboratories, LLC
2308 Sandridge Drive
Moraine OH, 45439
2308 Sandridge Drive
Moraine OH, 45439
Department
Chemistry
Reference Range
See Report
Setup Schedule / Expected Turnaround Time
24/7; Report available: Within 1 day of set up
Specimen Collection
Special Instructions
N/A
Preferred Specimen
1 mL serum
Minimum Volume
1 mL
Instructions
Barrier tubes (serum separator tubes or plasma separator tubes) are preferred. If non-barrier tubes are utilized, the serum/plasma must be removed immediately after centrifuging and placed in a screw-cap transfer tube.
Collection notes: Avoid hemolysis. Invert tubes at least 8 times. Allow to clot in an upright position for 30 minutes. Within 2 hours, centrifuge tubes 10 minutes. Keep tightly stoppered.
Do NOT re-centrifuge tubes. Do NOT freeze the primary collection tube.
Collection notes: Avoid hemolysis. Invert tubes at least 8 times. Allow to clot in an upright position for 30 minutes. Within 2 hours, centrifuge tubes 10 minutes. Keep tightly stoppered.
Do NOT re-centrifuge tubes. Do NOT freeze the primary collection tube.
Patient Preparation
N/A
Storage
Original tube preferred, may be sent in a screw-top transfer tube.
Transport Temperature
Room Temperature or Refrigerated
Specimen Stability
- Room Temperature: 5 Days
- Refrigerated: 7 Days
- Frozen: 30 days
Limitations
N/A
Other Acceptable Specimens
Plasma from Lithium Heparin (Light Green Top) tube
Unacceptable Specimens
- Hemolysis
- Lipemia
- Incorrect specimen type
- Insufficient sample volume
- Improper storage conditions
- Exceeds specimen stability guidelines
- Contaminated sample
Result Information
Methodology
Calculation.
Thyroid Index (T7), also called Free Thyroxine Index (FTI), is a calculation requiring both a total T4 and a T3-Uptake. T7= (T4 x T3-Uptake)/100
Thyroid Index (T7), also called Free Thyroxine Index (FTI), is a calculation requiring both a total T4 and a T3-Uptake. T7= (T4 x T3-Uptake)/100
Testing Laboratory
N/A
Reference Range
See Report
Setup Schedule / Expected Turnaround Time
24/7; Report available: Within 1 day of set up