Laboratory Services

T3 (Triiodothyronine), Reverse, Serum

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Updated Test Information:

Test Description
T3 (Triiodothyronine), Reverse, Serum
Test ID
RT3
General Information

Useful for diagnosis of Sick-euthyroid syndrome

Specimen Type

Serum

Specimen Requirements

  • Preferred: Red Top

  • Acceptable: Serum Gel (SST)

Stability

  • Refrigerated (preferred): 28 days

  • Ambient: 28 days

  • Frozen: 28 days

Unacceptable Specimen Conditions

Gross hemolysis

Limitations

Generally, reverse triiodothyronine tests are not necessary since triiodothyronine should not be ordered in hospitalized or sick patients

Methodology

Liquid Chromatography-Tandem Mass Spectrometry (LC-MS/MS)

Estimated TAT

2-6 days

Testing Schedule

Monday - Friday

Retention

14 days

CPT Code(s)

84482

Additional Information
Minimum Sample Volume

0.4 mL

Reference Range

10-24 ng/dL

Performing Lab

Mayo

LOINC Code(s)

3052-8