Laboratory Services

  1. Laboratory Services
  2. Test Directory

T3 (Triiodothyronine), Reverse, Serum

Print this page

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)
Minimum Sample Volume

0.4 mL
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
Reference Range

10-24 ng/dL
Performing Lab

Mayo
LOINC Code(s)

3052-8
Additional Information