Nuclear Medicine Preparation and Exams

What should I expect during this exam?

Although imaging time can vary, the exam generally takes 20 to 45 minutes.

  • A radio-pharmaceutical, known as a tracer, is usually administered either intravenously or by mouth. What radio-pharmaceutical is used and when the imaging will be done - immediately, a few hours later, or even several days after the injection, is dependent upon the type of exam you're having.
  • For most nuclear scans, you will lie down on a table and a nuclear imaging camera will be used to capture the image of the area being examined. The camera is either suspended over or below the exam table or in a large donut-shaped machine similar to a CT scanner. While the images are being obtained, you must remain as still as possible.
  • Most of the radioactivity is expelled out of your body in urine or stool. The rest simply disappears through over time.

What will I experience during the procedure?

Although usually done with a small needle, some patients experience some minor discomfort from the intravenous injection, or IV. Also, lying still on the examining table may be uncomfortable for some patients. You will hear low-level clicking or buzzing noises from the machine.

Typical Nuclear Medicine Exams 

  • Hepatobiliary Scan 
  • Lymphoscintigraphy 
  • Heart Scan 
  • Nuclear Stress Test 
  • Thyroid Scan 
  • SPECT Scan 
  • Gastric Emptying 
  • Bone Scan

Prep Instructions

Nuclear medicine scans are noninvasive procedures. Most exams, except for thyroid studies, involve an injection of the isotope through a vein with a needle that is much smaller than those used for taking blood. The injection IS NOT A DYE, and has no side effects or reactions.

The isotopes travel through the body and a special "gamma camera" is used to detect the isotope and produce medical images. The amount of radiation received is less than having back x-rays taken.

Usually, the patient does not even need to change their clothes and just lies quietly on the imaging table during the procedure. Exam times are generally longer than for routine x-ray studies because we are recording body functions, no just anatomy. Some exams may require more than one visit.

Important notes for all Nuclear Medicine exams:

A written referral order rom your physician is absolutely required at the time of service. Please obtain this from your doctor and bring it with you.

We need patients to bring any related prior imaging studies so that our radiologist can make comparisons and provide the best interpretation of the exam.

If there is a chance that the patient could be pregnant, we need you to call and notify our office in advance. A doctor administered pregnancy test may be necessary in order to avoid unnecessary radiation during pregnancy. For women of childbearing age (12-50 years of age), nuclear medicine exams are to be scheduled between day one and day fourteen of the menstrual cycle unless there is no possibility of pregnancy.

Hepatobiliary Scan instructions:

  • Do not eat or drink for 6 hours prior to the exam.

Thyroid Uptake instructions:

Patients having thyroid scans and uptake studies receive a capsule to swallow instead of the injection. There are no side effects or reactions with the capsule, the capsule can even be given to patients who are allergic to iodine as the amount of iodine is miniscule (about the amount found in salt or bread).

  • Do not eat seafood for 72 hours prior to the exam
  • Do not eat or drink anything for 4 hours prior to the exam except for water
  • Do not take thyroid hormones for 2 weeks prior to the exam
  • Do not take thyroid suppressants for 5 days prior to the exam
  • No imaging exams that use CT/x-ray contrast for 4 weeks prior to the exam

Bone Scan:

  • No preparation is required
  • This is not a bone density or DEXA scan

Renal Scan:

  • Drink at least one large glass of water 30 minutes prior to the exam.
  • We need your BUN and Creatinine results from your doctor's office, if available
  • Additional instruction may be provided for exams evaluating high blood pressure