TSH Rfx on Abnormal to Free T4

Test ID:


CPT code:



Thyroid Stimulating Hormone with Reflex

TSH with Reflex to Free T4

Clinical Use:

For differential diagnosis of primary, secondary, and tertiary hypothyroidism. Also useful in screening for hyperthyroidism. This assay allows adjustment of exogenous thyroxine dosage in hypothyroid patients and in patients on suppressive thyroxine therapy for thyroid neoplasia.

Specimen Type:


Requested Volume: 

1 mL

Minimum Volume: 


Container Type: 

Serum Separator Tube (SST®)

Patient Preparation: 

Specimen collection after fluorescein dye angiography should be delayed for at least 3 days. For patients on hemodialysis, specimen collection should be delayed for 2 weeks.


should only be ordered on patients 1 year of age or older. Orders on patients younger than 1 year will have a TSH only performed.

Storage Instructions:

Room temperature

Stability Requirements:

Room temperature: 7 days
Refrigerated: 7 days
Frozen: 28 days

Expected Turnaround Time:

1 to 2 Days

Rejection Criteria

plasma specimen; improper labeling

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MCI Diagnostic

Providing top patient care with fast results. 

7018 South Utica Avenue

Tulsa, Oklahoma 74136

Hours of Operation

Mon – Sat: 7AM-11PM

Sun: 7AM-3PM

Government Contract

Mon – Sat: 7AM-11PM

Sun: 7AM-3PM


Mon – Sat: 7AM-11PM

Sun: 7AM-3PM

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