Thyroid Uptake and Scan
Care Before the Procedure
- Preparation:
- Fasting: Avoid food and drinks for 2–4 hours before tracer administration (check facility guidelines).
- Medication Hold: Stop thyroid medications (e.g., levothyroxine, methimazole) as directed—usually 1–4 weeks prior.
- Iodine Restrictions: Avoid iodine-rich foods (e.g., seafood, iodized salt), supplements, and contrast media for 2–6 weeks.
- Health Disclosure: Inform staff if you are pregnant, breastfeeding, or taking lithium, amiodarone, or thyroid hormones.
- Tracer Administration: Swallow a tasteless capsule or liquid containing the radioactive tracer.
Care During the Procedure
- Uptake Measurement (6–24 hours post-tracer):
- A painless gamma probe is placed near the neck for 1–5 minutes to measure radioactivity.
- Scan (after uptake or separately):
- You lie still on a table while a gamma camera rotates around your neck, capturing images for 20–30 minutes.
- Patient Experience:
- No pain or discomfort; you must remain still during imaging.
- Radiation exposure is low and considered safe for non-pregnant adults.
Care After the Procedure
- Radiation Safety:
- Drink plenty of fluids to flush out the tracer.
Avoid close contact with pregnant women and infants for 24–48 hours.
- Drink plenty of fluids to flush out the tracer.
- Results:
- Uptake Value: High uptake suggests hyperthyroidism (e.g., Graves’ disease); low uptake indicates hypothyroidism or thyroiditis.
- Scan Findings:
- “Hot” nodules (high tracer uptake) are rarely cancerous.
- “Cold” nodules (low uptake) may require further evaluation (e.g., biopsy).
- Results are interpreted by a nuclear medicine physician and shared by your referring doctor.
- Follow-Up:
- Abnormal results may lead to:
Medication adjustments. - Radioactive iodine therapy for hyperthyroidism.
- Ultrasound or biopsy for suspicious nodules.
- Abnormal results may lead to:
- Resume Normal Activities:
- Restart thyroid medications as advised.
- No dietary restrictions after the test.
- Note: This test requires careful preparation to avoid false results. Always follow your facility’s instructions precisely. While radiation exposure is minimal, it is not suitable for pregnant or breastfeeding patients. Alternative tests (e.g., thyroid ultrasound) may be used if contraindicated.
Eligibility
- This test is typically ordered for patients with:
Abnormal thyroid hormone levels (e.g., high TSH, low T4/T3) or symptoms of thyroid dysfunction. - Thyroid nodules found on physical exam or ultrasound.
- Suspected Graves’ disease, toxic nodules, or thyroiditis.
- History of thyroid cancer requiring evaluation.
- Preparation:
- Fasting: Avoid food and drinks for 2–4 hours before tracer administration (check facility guidelines).
- Medication Hold: Stop thyroid medications (e.g., levothyroxine, methimazole) as directed—usually 1–4 weeks prior.
- Iodine Restrictions: Avoid iodine-rich foods (e.g., seafood, iodized salt), supplements, and contrast media for 2–6 weeks.
- Health Disclosure: Inform staff if you are pregnant, breastfeeding, or taking lithium, amiodarone, or thyroid hormones.
- Tracer Administration: Swallow a tasteless capsule or liquid containing the radioactive tracer.
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