Search our extensive Laboratory Test Directory to find test codes, ordering recommendations, specimen stability information, Test Fact Sheets, and more.
Recommendations when to order or not order the test. May include related or preferred tests.
New York DOH Approval Status
Indicates test has been approved by the New York State Department of Health.
This test is New York state approved.
Specimen Required
Patient PreparationInstructions patient must follow before/during specimen collection.
CollectSpecimen type to collect. May include collection media, tubes, kits, etc.
Serum separator tube or plain red. Also acceptable: Lavender (EDTA) or pink (K2EDTA).
Specimen PreparationInstructions for specimen prep before/after collection and prior to transport.
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 TemperaturePreferred temperatures for storage prior to and during shipping to ARUP. See Stability for additional info.
Frozen.
Unacceptable ConditionsCommon conditions under which a specimen will be rejected.
Grossly hemolyzed specimens.
RemarksAdditional specimen collection, transport, or test submission information.
StabilityAcceptable times/temperatures for specimens. Times include storage and transport time to ARUP.
After separation from cells: Ambient: 24 hours; Refrigerated: 1 week; Frozen: 3 months
Methodology
Process(es) used to perform the test.
Quantitative Liquid Chromatography-Tandem Mass Spectrometry
Performed
Days of the week the test is performed.
Sun-Sat
Reported
Expected turnaround time for a result, beginning when ARUP has received the specimen.
1-5 days
Reference Interval
Normal range/expected value(s) for a specific disease state. May also include abnormal ranges.
Test Number
Components
Reference Interval
Triiodothyronine, Reverse - LC-MS/MS
Age
ng/dL
0-17 years
Not Applicable
18 years and older
9.0-27.0
Triiodothyronine, Total - LC-MS/MS
Age
ng/dL
Cord Blood
14-86
0-3 days
96-292
4-30 days
62-243
1-23 months
81-281
2-6 years
83-252
7-11 years
92-219
12-19 years
83-215
20 years and older
80-200
Triiodothyronine, Ratio (T3:RT3)
Age
Ratio
0-17 years
Not Applicable
18 years and older
4.2-11.0
Interpretive Data
May include disease information, patient result explanation, recommendations, or details of testing.
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.
The American Medical Association Current Procedural Terminology (CPT) codes published in ARUP's Laboratory Test Directory are provided for informational purposes only. The codes reflect our interpretation of CPT coding requirements based upon AMA guidelines published annually. CPT codes are provided only as guidance to assist clients with billing. ARUP strongly recommends that clients confirm CPT codes with their Medicare administrative contractor, as requirements may differ. CPT coding is the sole responsibility of the billing party. ARUP Laboratories assumes no responsibility for billing errors due to reliance on the CPT codes published.
* 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
Other names that describe the test. Synonyms.
T3 total and reverse
Total and reversed Triiodothyronine T3 total and reverse
Triiodothyronine, Total and Triiodothyronine, Reverse with Ratio Calculation by Tandem Mass Spectrometry
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