Geisinger Proven Diagnostics Test Catalog

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TSH W/FT4 IF TSH IS ABNORMAL

SPECIMEN COLLECTION
Test code:
TSHR
Specimen type:
Plasma or serum
Collection container:
Specimen Required:
2 mL plasma or serum; minimum 0.5 mL

SPECIMEN PROCESSING
Specimen Processing Instructions:
Plasma: Centrifuge at 1100-2000 g for a minimum of 10 minutes.
Serum: Allow to clot. Centrifuge at 1100-2000 g for a minimum of 10 minutes. 
Transport temperature:
Refrigerated (preferred) or frozen.
Specimen stability:
Refrigerated: 7 days. Frozen: 1 month.
Rejection criteria:
Stability limits exceeded.

TEST DETAILS
Reference range:
TSH: 0.27-4.2 uIU/mL
Free T4: 0.7 - 1.7 ng/dL
Additional information:
Specimens containing human anti-mouse antibodies may affect results.
CPT code(s):
84443
Note: The billing party has sole responsibility for CPT coding.  Any questions regarding coding should be directed to the payer being billed.  The CPT codes provided by GML are based on AMA guidelines and are for informational purposes only.
Test includes:
Thyroid stimulating hormone (TSH) with an add-on of “Free T4” if the TSH is abnormal.
Methodology:
Electrochemiluminescence
Synonyms:
Thyroid Stimulating Hormone w/Free thyroxine if Thyroid Stimulating Hormone is abnormal
Clinical Significance:
Typically, a small change in free T4 is accompanied by a big change in TSH. Thus, abnormal TSH levels often occur before free T4 abnormalities are detectable. This makes the “TSH w/FT4 if TSH is abnormal” test most suitable for screening for primary thyroid dysfunction and evaluation of thyroid nodule.
Doctoral Director Review:
Hoi-Ying Elsie Yu Ph.D.     Review Date: 09/10/2014

Performing Locations

Geisinger Medical Center

Performing laboratory: Automated Chemistry
Technical Lead: Larry Quinton
Frequency: Daily, all shifts
Performed stat? N

Geisinger Wyoming Valley Medical Center

Performing laboratory: ATL+
Technical Lead: Melissa Whetstone    
Frequency: Daily, all shifts    
Performed stat? N