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



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