Test Code TSHR TSH REFLEX CASCADE to FT4, FT3
Performing Location
Specimen Required/Volume
1.0 mL
Specimen Type
Plasma or serum
Collection Container
Light Green (lithium heparin), Gold top, or Marble Red top vacutainer
Collection Instructions
Reference Values
TSH: 0..47– 4.68 uIU/mL
Free T4: 0.8- 2.2 ng/dL
T3 Free 2.3 – 4.2 pg/mL
To review the Thyroid Cascade testing algorithm, refer to the Reflex Testing section of this manual.
Turn-Around Guidelines
Upon arrival
Method
Electrochemiluminescence immunoassay - Roche cobas
LOINC
3016-3 - TSH
(3024-7 - T4 Free reflex)
(3051-0 - T3 Free reflex)
CPT
84443 - TSH
+ reflex Free T4 - 84439 as appropriate
+ reflex T3 Free - 84481 as appropriate