A thyroid scan evaluates the size, shape and location of your thyroid gland. When you arrive for your appointment, a small amount of radioactive tracer will be injected into a vein in your arm. Then, several images are taken over your neck. A thyroid scan takes about 60 to 90 minutes.

Preparation

• You should be off all thyroid hormones for six weeks prior to your appointment unless specifically instructed by your physician.
• You should not have any exams where X-ray dye was injected, such as a CT scan, IVP X-rays, etc., for at least four weeks before your appointment.
• Kelp (seaweed) or sushi wrapped in kelp should not be eaten four to six weeks before the scan.
• You may eat and drink as usual the day of your appointment.
• You may take your medications as directed by your physician.
• Remember to bring the written order (prescription), for this test, given to you by your doctor