Geisinger Medical Laboratories/Geisinger Proven Diagnostics Test Catalog
TSH WITH FREE T4 IF INDICATED |
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ORDERING INFORMATION: |
Geisinger Epic Procedure Code: LAB3206 Geisinger Epic ID: 41920 | |
SPECIMEN COLLECTION |
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Specimen type: |
Plasma or serum | |
Preferred collection container: |
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Alternate Collection Container: |
3 mL green/black top lithium heparin tube
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Specimen required: |
2 mL plasma or serum; minimum 0.5 mL | |
SPECIMEN PROCESSING |
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Specimen processing instructions: |
Allow serum to clot. Centrifuge to separate serum or plasma within 2 hours of collection. | |
Transport temperature: |
Refrigerated (preferred) or frozen. | |
Specimen stability: |
Refrigerated: 7 days. Frozen: 1 month. | |
Rejection criteria: |
Stability limits exceeded. | |
TEST DETAILS |
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Reference interval: |
TSH: 0.27-4.2 uIU/mL Free T4: 0.9 - 1.7 ng/dL. |
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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 |
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Synonyms: |
Thyroid Stimulating Hormone w/Free thyroxine if Thyroid Stimulating Hormone is abnormal TSHR
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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(s:) |
Hoi-Ying Elsie Yu, PhD, DABCC Sheng-Ying (Margaret) Lo, PhD, DABCC |
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Review Date: | 12/14/2022 |
Performing Locations
Geisinger Wyoming Valley Medical Center