A parathyroid scan is a nuclear medicine exam to determine the function and health of the parathyroid gland which regulates calcium uptake in the body.
This type of scan is called a sestamibi scan, after the tiny protein molecule that attaches to active parathyroid tissue in this test and that is injected into the bloodstream as the first step in the test. A sestamibi parathyroid scan is a procedure which is performed to localize parathyroid adenoma, which causes hyperparathyroidism (when your parathyroid glands create too much parathyroid hormone in the bloodstream).
When would I get Parathyroid Imaging?
Your doctor may consider an I-131 whole body scan to be appropriate in the evaluation of:
- localization of parathyroid adenomas (a benign tumor on one of your parathyroid glands)
- localization of persisting parathyroid tissue in patients with persistent or recurrent disease.
By knowing which of the four parathyroid glands is hyperfunctioning, a surgeon is able to remove only the one parathyroid gland that is producing excessive amounts of parathyroid hormone and no longer under the biochemical control of the body. The other three normal parathyroid glands are left in place.
What Will I Experience?
There are two parts to this test. When you first arrive, you will take two radioactive iodine capsules. There are no known side effects to these capsules. The capsules will be absorbed by your thyroid and will allow your doctor to see how your thyroid is functioning. After you take these capsules, you may leave and return three to four hours later.
You will lie on an examination table. A technologist will insert an intravenous (IV) catheter into a vein in your hand or arm.
When it is time for the imaging to begin, the camera or scanner will take a series of images. The camera may rotate around you or it may stay in one position and you may be asked to change positions in between images. While the camera is taking pictures, you will need to remain still for brief periods of time. In some cases, the camera may move very close to your body. This is necessary to obtain the best quality images. If you are claustrophobic, you should inform the technologist before your exam begins.
Typically, parathyroid imaging will take approximately 30 minutes to complete.