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24789 Thyroid Index Panel (T7, T4, T3 Uptake for OB)

Thyroid Index Panel (T7, T4, T3 Uptake for OB)
Test Code: T7
Synonyms/Keywords
T7, Free Thyroxine Index, FTI​
Test Components
​T4, T3 Uptake
Specimen Requirements
Fasting Required Specimen Type Preferred Container/Tube Acceptable Container/Tube Specimen Volume Specimen Minimum Volume
(allows for 1 repeat)		 Pediatric Minimum Volume
(no repeat)
No​ Serum​ Red Top Tube (RTT)​ Serum Separator Tube (SST)​ 1.0 mL​ 0.5 mL​ ​
Collection Processing Instructions
​Samples collected in RTT must be removed from the cells within 1 hour for storage or transport. Samples collected in SST tubes must be aliquotted from the primary tube before transport. Do not send the primary collection tube.
Specimen Stability Information
Specimen Type Temperature Time
Serum​ Refrigerated​ <48 hours​
Serum​ Frozen​ >48 hours​
Interference
​In patients receiving murine-based agents for chemotherapy or tumor imaging studies, Human Anti-Murine Antibodies (HAMA) may develop leading to test interference.
Performing Laboratory Information
Performing Location Day(s) Test Performed Analytical Time Methodology/Instrumentation
​Marshfield Monday through Sunday​ Less than 2 hours​ Chemiluminescent Immunoassay / Calculation​
Test Information
​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.
Reference Range Information
Performing Location Reference Range
Marshfield​ T4: 5.2 - 13.0 ug/dL
T3-Uptake: 33 - 46 %
T7: 1.9 - 4.2 ​
Outreach CPTs
CPT Modifier
(if needed)		 Quantity Description Comments
84436​ ​ ​ T4​ ​
84479 ​ ​ ​ T3 Uptake​ ​
Synonyms/Keywords
T7, Free Thyroxine Index, FTI​
Test Components
​T4, T3 Uptake
Ordering Applications
Ordering Application Description
​Centricity ​Thyroid Index (T7 for OB)
​Cerner Thyroid Panel​
If the ordering application you are looking for is not listed, contact your local laboratory for assistance.
Specimen Requirements
Fasting Required Specimen Type Preferred Container/Tube Acceptable Container/Tube Specimen Volume Specimen Minimum Volume
(allows for 1 repeat)		 Pediatric Minimum Volume
(no repeat)
No​ Serum​ Red Top Tube (RTT)​ Serum Separator Tube (SST)​ 1.0 mL​ 0.5 mL​ ​
Collection Processing
​Samples collected in RTT must be removed from the cells within 1 hour for storage or transport. Samples collected in SST tubes must be aliquotted from the primary tube before transport. Do not send the primary collection tube.
Specimen Stability Information
Specimen Type Temperature Time
Serum​ Refrigerated​ <48 hours​
Serum​ Frozen​ >48 hours​
Interference
​In patients receiving murine-based agents for chemotherapy or tumor imaging studies, Human Anti-Murine Antibodies (HAMA) may develop leading to test interference.
Test Components
​T4, T3 Uptake
Reference Range Information
Performing Location Reference Range
Marshfield​ T4: 5.2 - 13.0 ug/dL
T3-Uptake: 33 - 46 %
T7: 1.9 - 4.2 ​
For more information visit:
Performing Laboratory Information
Performing Location Day(s) Test Performed Analytical Time Methodology/Instrumentation
​Marshfield Monday through Sunday​ Less than 2 hours​ Chemiluminescent Immunoassay / Calculation​
For billing questions, see Contacts
Outreach CPTs
CPT Modifier
(if needed)		 Quantity Description Comments
84436​ ​ ​ T4​ ​
84479 ​ ​ ​ T3 Uptake​ ​
For most current information refer to the Marshfield Laboratory online reference manual.