Ordering Recommendation

Generally not recommended for routine evaluation of thyroid disorders, although may be considered in pregnant women.

Mnemonic

RT3 TMS

Methodology

Quantitative Liquid Chromatography-Tandem Mass Spectrometry

Performed

Sun-Sat

Reported

1-4 days

New York DOH Approval Status

This test is New York DOH approved.

Specimen Required

Patient Preparation
Collect

Plain red or serum separator tube. Also acceptable: Lavender (EDTA) or pink (K2EDTA).

Specimen Preparation

Allow serum specimen to clot completely at room temperature. Separate serum or plasma from cells ASAP or within two hours of collection. Transfer 2 mL serum or plasma to an ARUP Standard Transport Tube. (Min: 1 mL)

Storage/Transport Temperature

Frozen.

Unacceptable Conditions

Grossly hemolyzed specimens

Remarks
Stability

Ambient: 24 hours; Refrigerated: 1 week; Frozen: 3 months

Reference Interval

Age
Reference Interval
0 -17 years Not established
18 years and older 9.0 - 27.0 ng/dl

Interpretive Data

This test was developed and its performance characteristics determined by ARUP Laboratories. It has not been cleared or approved by the US Food and Drug Administration. This test was performed in a CLIA certified laboratory and is intended for clinical purposes.

Compliance Category

Laboratory Developed Test (LDT)

Note

Hotline History

N/A

CPT Codes

84482

Components

Component Test Code* Component Chart Name LOINC
2007919 Triiodothyronine, Reverse - LC-MS/MS 3052-8
* Component test codes cannot be used to order tests. The information provided here is not sufficient for interface builds; for a complete test mix, please click the sidebar link to access the Interface Map.

Aliases

  • Reverse T3
  • Reverse T3, Serum
  • Reverse Triiodothyronine
  • RT3
  • T3
Triiodothyronine, Reverse by Tandem Mass Spectrometry