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Test Code TT3 T3 Total

Important Note

Medicare frequency limitations exist for this test in addition to diagnosis requirements. Click on link for list of medically necessary diagnoses: http://www.munsonhealthcare.org/medical-necessity. Click on link for Advance Beneficiary Notice of Noncoverage form: Advance Beneficiary Notice of Noncoverage

EHR Test Codes

  Test Code Test Name
Atlas TT3 T3(Triiodothyronine) Total, Serum
Cerner   T3 Total

Specimen Requirements

Preparation of Patient: 

None

 

Container Type: 

Green Top 5mL Lithium Heparin Separator Tube

Or

 

Gold Top 6mL SST Gel & Clot Activator Tube

Specimen Type:

Plasma or Serum

 

Specimen Volume: 

2.5 mL Plasma or Serum minimum .5 mL

 

Specimen Handling/Transport:

Separate plasma or serum from cells within 2 hours of collection.

Transport ambient, refrigerated or frozen.

 

Specimen Stability/Storage:

8 hours ambient room temperature

2 days refrigerated 2-8°C

>2 days frozen -20°C

Performing Laboratory

Munson Medical Center Laboratories

Chemistry Department

Priority, Frequency, & Turnaround

Priority:

Non-Emergent

 

Frequency:

24 hours 7 days a week

 

Turnaround:

0 - 1 days

Methodology

Chemiluminescence Immunoassay

Reporting

Reference Range:

87 - 170 ng/dL

 

Interpretive Data:
Biotin supplements may falsely increase this analyte.

 

Critical Decision:

None

Clinical Significance

The clinical importance of total serum T3 determination is in the diagnosis of thyroid disorders. Elevated concentrations of T3 can be found in Grave's disease, and most other classical causes of hyperthyroidism. Decreased concentrations occur in primary hypothyroid diseases such as Hashimoto's thyroiditis and neonatal hypothyroidism or secondary hypothyroidism due to defects at the hypothalamo-hypophyseal level.

CPT Code(s)

84480