Thyroid Uptake and Scan

The thyroid scan is used to determine the size, shape and position of the thyroid gland.
The thyroid uptake is performed to evaluate the function of the gland.

A physician may order these tests to:

determine if the gland is working properly.

help diagnose problems with the thyroid gland, such as an overactive thyroid gland, a condition called hyperthyroidism, cancer or other growths.

determine whether nodules are present in the gland.

detect areas of abnormality, such as lumps or inflammation.

determine whether thyroid cancer has spread beyond the thyroid gland.

to see if an existing condition has changed following surgery, radiotherapy or chemotherapy.

A whole-body thyroid scan is typically performed on people who have had thyroid cancer.

What to expect with your procedure

You should tell your physician if you:

• have had any tests, surgeries or treatments using radioactive materials or x-rays using iodine contrast materail within the last five years.
• are taking medications or ingesting other substances that contain iodine, including kelp, seaweed, cough syrups, multivitamins or heart medications.
• if you have any allergies to iodine, medications and anesthetics.
• if you are or might be pregnant.
• if you are breastfeeding.

In the days prior to your examination, blood tests may be performed to measure the level of thyroid hormones in your blood. You may be told not to eat for several hours before your exam.

Prior to the exam, you will be asked to remove jewelry, dentures and anything else metallic that could interfere with the imaging.

Preparing for your procedure

The patient will be given a radioactive iodine (I-123 or I-131) capsule to swallow. The patient is then scheduled to have the thyroid uptake measured at 6 hours and again at 24 hours. This allows the dose to circulate throughout the body and gives the gland enough time to absorb the iodine.

When the patient returns for the 24 hour uptake, a complete thyroid scan is performed. The patient will lie down on an examination table with the head tipped backward and the neck extended. The gamma camera will then take a series of images, capturing images of the thyroid gland from three different angles. The patient will need to remain still for brief periods of time while the camera is taking pictures.

This procedure lasts approximately 30 minutes.