Do not eat or drink for four hours before or two hours after your thyroid test.
- Do not eat or drink for four hours before or two hours after your thyroid test. You may drink water.
- If you have any other test today where you are told not to eat or drink for a longer amount of time, please follow those instructions.
Please be sure not to eat or drink anything 2 hours prior to your first appointment (you will also need to refrain from eating or drinking for 2 hours following your appointment—see below for further exam preparation details). You will then return to the department at the same time on the following day for imaging.
Actual scanning time for a thyroid scan is 30 minutes or less . You will be given radioactive iodine (I-123 or I-131) in liquid or capsule form to swallow. The thyroid uptake will begin several hours to 24 hours later.
How do you prepare for the test? You may need to stop eating for several hours before the test . If the test is being done to check for thyroid cancer, you may have to eat a low-iodine diet for several days before the test. Your doctor may have you stop taking thyroid medicines for some time before this test.
Before your thyroid ultrasound, you may eat normally. No special preparation is required . During your ultrasound, pictures of your thyroid will appear on a video screen and several images and measurements will be recorded. A thyroid ultrasound takes approximately 30 minutes to complete.
The tracer you swallow for the uptake will collect in your thyroid gland. with your doctor before you stop taking this medicine. Do not take any oral iodides (such as Lugol's solution or SSKI) for 5 days before your exam . Remain off them until tests are completed.
After your thyroid scan, you must contact your physician for instructions on how to resume taking your thyroid medication. The radioactive iodine in your body is passed when you urinate. You may be advised to drink extra fluids and empty your bladder often to flush out the radionuclide .