TSH Rfx on Abnormal to Free T4
Thyroid Stimulating Hormone with Reflex
TSH with Reflex to Free T4
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.
Serum Separator Tube (SST®)
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.
Room temperature: 7 days
Refrigerated: 7 days
Frozen: 28 days
plasma specimen; improper labeling