A B C D E F G H I J K L M N O P Q R S T U V W X Y Z #

T4 Free, Direct Dialysis and T4 Total

Test Code
36725


CPT Codes
84436, 84439

Preferred Specimen
2 mL serum


Patient Preparation

Fasting is preferred



Minimum Volume
1 mL


Instructions
Please specify the patient's age on the request form


Transport Temperature
Room temperature


Specimen Stability
Room temperature: 4 days
Refrigerated: 7 days
Frozen: 28 days


Reject Criteria (Eg, hemolysis? Lipemia? Thaw/Other?)
Lipemia • Heparin plasma • EDTA plasma


Methodology
Equilibrium Dialysis • Chromatography/Mass Spectrometry • Chemiluminescence (CL)

FDA Status
This test was developed and its analytical performance characteristics have been determined by Quest Diagnostics. It has not been cleared or approved by FDA. This assay has been validated pursuant to the CLIA regulations and is used for clinical purposes.

Setup Schedule
Set up: Mon-Sat; Report available: 3-4 days


Clinical Significance
For the differential diagnosis of euthyroid hyperthyroxinemia from hyperthyroidism or for the differential diagnosis of euthyroid hypothyroxinemia from hypothyroidism.




The CPT Codes provided in this document are based on AMA guidelines and are for informational purposes only. CPT coding is the sole responsibility of the billing party. Please direct any questions regarding coding to the payor being billed. Any Profile/panel component may be ordered separately. Reflex tests are performed at an additional charge.