Nuclear Imaging FAQs

Will I be allergic to the radioactive dose? If so, who should I call if I develop a reaction?

Allergy to radioactivity does not exist. In very rare cases there can be an allergic reaction to the chemical to which the radioactive isotope is attached to. If you should have an allergic reaction the Nuclear Medicine Physician will treat you. Be sure to notify the staff of any allergies or allergic reactions you have had in the past.

How long will the radioactivity stay in my system?

With most of the tracers used, the radioactivity will be almost completely gone by the following day.

Is it dangerous to be around others, especially around children or pregnant women?

Except for patients being treated with radioactive isotopes (most commonly thyroid cancer) there is no risk in exposing others to dangerous amounts of radioactivity.

What precautions should I take after receiving a radioactive dose?

You do not need to take any precautions.

What does the radioactive dose do?

The radioactive dose is attached to a molecule which goes to the organ system that needs to be imaged. A special camera (gamma camera) records the radioactivity coming out of the body and from the organ. A computer then creates an image which will be read by the Nuclear Medicine Physician.

Why do I have to wait so long between injection and scan?

The amount of time needed to complete a nuclear medicine procedure depends on the type of test. Nuclear medicine exams are performed in three steps, administering the pharmaceutical compound, taking the pictures and analyzing the results. The amount of time needed for the compound to accumulate in the body part to be scanned can vary from a few hours to days.

What are the risks when having a Nuclear Medicine stress test?

Cardiac stress testing (either with a treadmill or by using a medication called Adenosine or Dobutamine) has been proven to be effective and safe in hundreds of thousands of tests. The risks associated with cardiac stress testing are minimal. During and after the test you will be continuously monitored by a physician who will immediately stop the stress test should there be any indication of complications.

How is the radioactive dose administered?

The test that has been ordered by your physician will determine how the radioactive dose will be administered. Usually the dose is injected into an arm vein. For some tests the dose needs to be given by mouth.

Is this like contrast?

The tracers we inject are different from iodine and contrast used with CAT scanning. Therefore injection of a radioactive tracer will not cause any problems for a patient with an allergy to iodine or contrast.

For Thyroid patients: If I'm allergic to iodine, will I react to the I-131 or I-123?

Since the dose is given as a pill to be taken by mouth (and not injected into a vein) and since the actual amount of iodine given is very small the occurrence of an allergic reaction is highly unlikely.

Is there a limit as to the amount of radiation I should receive in a given period of time?

The amount of radiation received from nuclear medicine procedures is usually very low. For example it usually falls far below what the government sets as a yearly limit for people working with radioactivity (which is 5000mrem/year).

When can I or my physician expect to receive the results of my exam?

Images are usually read the same day and the results should be available to your physician within 36 hours.
The Technologist is not authorized to give your results to you.

Do I have to wear a gown?

Depending on what test you have, you might be asked to wear a gown.

Can I wear jewelry?

Please remove all jewelry before the test. Jewelry can potentially cause artifacts on the images.

Can I have the exam if I have a pacemaker or some other medical device/implant?

A pacemaker or other implanted medical devices do not pose a problem. However please let the staff know if you have any implanted medical devices or prosthesis.

Is the radioactivity I'm receiving dangerous?

The dose of radioactivity you will receive is very small (for most Nuclear Medicine tests usually in the range of the dose you receive from a chest X-ray) and will not cause any problems.

What is the difference among nuclear medicine tests with other diagnostic modalities such as CT scan, MRI, Sonography? Which one is better, Cardiac scan or Angiography?; Kidney scan or Sonography?

In total, the nuclear medicine tests are complementary to other diagnostic techniques and don’t substitute them. In other words, radiological tests emphasize on anatomical characters while nuclear medicine tests address on functional properties. For example, Cardiac angiography shows the coronary vessels while Cardiac scan demonstrates cardiac walls.

We may need to verify your name and date of birth more than once during your visit. This ensures your safety and we appreciate your cooperation.

Please come at your appointed time and if you cannot attend your appointment, please call us as soon as possible.

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