Days Set Up
Monday, Wednesday, Friday
Analytic Time

4 - 6 days

MiChart Code
T3, Reverse
Soft Order Code
RT3

Test Updated:

Synonyms

Triiodothyronine, Reverse
Reverse T3 (Triiodothyronine)
T3 (Triiodothyronine), Reverse
RET3
RT3
Reverse T3, S

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Find a Requisition

All specimens should be accompanied by a requisition.

Submitting Specimens

Learn about how to properly label and where to ship specimens.

Order Kits and Supplies

MLabs provides all the supplies necessary for the collection of specimens.

Test FAQ

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Test Overview

Test Methodology

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

Test Usage

In hospitalized or sick patients with low triiodothyronine (T3) values, elevated reverse triiodothyronine (rT3) values are consistent with "sick euthyroid" syndrome. Also, the finding on an elevated rT3 level in a critically ill patient helps exclude a diagnosis of hypothyroidism.

Reference Range

9 - 27.0 ng/dL

* Reference ranges may change over time. Please refer to the original patient report when evaluating results.

Specimen Requirements

Collection Offsite

Collect specimen in a red top tube. Centrifuge, aliquot serum into a plastic vial within 2 hours of collection, and refrigerate.

Yellow Top Tube
Normal Volume
1.0 mL
Minimum Volume
0.5 mL

Billing Information

CPT Code
84482
Pro Fee Code
 
LOINC
3052-8

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Our High Standard

Quality that sets us apart

As the reference laboratory division of Michigan Medicine's Department of Pathology, MLabs shares the institution's commitment to applying established quality principles to clinical laboratory testing. Like other large organizations in complex, consequential fields, we rely on an established approach to monitor quality throughout the testing process.