What is a thyroid scan and when is it needed?
A thyroid study is a type of thyroid test that uses nuclear medicine imaging to find out how well your thyroid is functioning and the size, shape, location and function of your thyroid gland. A thyroid uptake test tells your doctor how well your gland works by measuring the amount of radioiodine it uses to produce hormones.
Indications:
- Graves disease
- Hypothyroid
- Hyperthyroid
- Thyroid nodules
What are the risks?
123-I Thyroid Uptake: Unlike radioactive thyroid therapy[1] , thyroid uptake studies use a fraction of the radioactive iodine. It is a much safer dose, with no potential for exposure after the test.
Tc-Thyroid: no iodine is used
Please let the office know if you are pregnant and/or breastfeeding, as the radiotracers maybe harmful to a fetus.
The risk to other people is very low, so these scans are considered safe and effective ways to diagnose disease.
How do you prepare for a thyroid scan?
123-I Thyroid Uptake/Scan - 2 day exam: 1st day - 15 minutes, 2nd day - 30 minutes
- 1st day - NPO x 4 hours after taking the capsules you will need to wait 1 more hour to eat and drink
- 2nd day - No restrictions
- Wear comfortable clothing
- No thyroid meds for 6 weeks
- No CT contrast or IVP dyes for 6 weeks
Tc-Thyroid - 1 day exam - 30 minutes
- No restrictions
- Wear comfortable clothing
- No thyroid meds for 6 weeks
- No CT contrast or IVP dyes for 6 weeks
How does a thyroid scan work?
123-I Thyroid Uptake and Scan
Day 1 - 15 minutes - you swallow 2 capsules
Day 2 - 30 minutes - your neck is placed in front of an uptake probe that will give a percent on how well your thyroid is actually functioning. Then a special camera is used to take 4 images of your thyroid to see if there are any nodules and what those nodules look like
Tc-Thyroid
30 minutes - The technologist will give you an injection into a vein in your arm. A special camera is then used to take 4 images of your thyroid, each image takes 5 minutes
What should I expect after my thyroid scan?
It usually take 24-48 hours for your doctor to receive a report. Drink plenty of fluids to help flush the radiotracer out of your body, what does not get flushed out of your body will decay out. There are no other restrictions.