Imaging Procedures - Patient Information
 


Thyroid Uptake and Scan

Why would my physician order this procedure

This procedure helps your physician determine function and morphology (size and shape) of the thyroid gland.


Exam preparation
  This is a functional test.  Your cooperation with the preparation is very important.
 

You must be off the following interfering medications for the defined periods:

  1. PTU or Tapazol:  1 week
  2. Seaweed tablets (kelp) or multiple vitamins that contain iodine:  2 weeks
  3. Cytomel or Amiodarone (cardiac medication):  2 weeks
  4. Synthroid or Levothroid:  3 weeks
  5. Desiccated thyroid or  L-thyroxine:  6 weeks
 

You must not have an exam with contrast in the time intervals below:

  1. IVP, gallbladder, angiogram, arteriogram or CT:  2 weeks
  2. Myelogram with Metrizamide:  2 weeks
  3. Myelogram with Pantopaque:  2 years
  4. Bronchogram:  1 year
  You are allowed clear liquids only on the morning of your first day.  You can have a normal diet 2 hours after you get your radioactive capsule.
 

To perform this exam, we must give you a small amount of radioactive materials. 

Tell your doctor if you might be pregnant, if you are pregnant, or if you are a nursing mother.

What to expect

A technologist will explain the entire process to you prior to starting the exam.  He/she will also ask you some health history questions, which will help our radiologist interpret your exam.

For the first day a technologist will give you a capsule containing a tracer amount of radioactive iodine.  You will be instructed not to eat for about another 2 hours.

On the second day we will have you sitting in a chair while we measure how much of the radioactive iodine your thyroid has taken up (uptake portion of exam).  If your thyroid measurement is too low, we will not be able to proceed with the scan portion. 

For the scan portion, a technologist will give you an intravenous (IV) injection of another radioactive material to help us visualize your thyroid gland. We will wait about 30 minutes before we can start imaging. 

For the images, you will be lying flat on our scanning bed while the camera is rotated to different positions around your neck area.  These images will take about another 30 minutes.

If you have any technical questions specific to this procedure, please don’t hesitate to ask the technologist at scan time.  All clinical questions should be directed to your physician.

A report will be sent to your ordering physician.

How long will it take

An uptake and scan is a 2 consecutive day procedure.  For the first day you will probably be in our department for about 15 minutes.

(If your physician had requested a multiple uptake, you will need to return 3 hours after you swallow the capsule for about another 15 minutes.)

The second day you will be with us for about 90 minutes. These tests can be scheduled individually.  The appointment desk will give special instructions as needed.

Possible complications or side effects

No complications are expected from this procedure.

Radiation risk statement

Studies of the health effects of radiation have shown that high doses of radiation can cause cancer.  However, this hospital procedure requires that we inject you with a very low level of radioactive material. 

The risk from lower doses of radiation, such as you will receive during this exam, is uncertain.  Most scientists believe that the risk is very small.  Certainly, the benefits received from the exam far outweigh the small risk associated with this procedure