You may be asked to wear a gown during the exam or you may be allowed to wear your own clothing.

Women should always inform their physician or technologist if there is any possibility that they are pregnant or if they are breastfeeding.

You should inform your physician and the technologist performing your exam of any medications you are taking, including vitamins and herbal supplements. You should also inform them if you have any allergies and about recent illnesses or other medical conditions.

You will receive specific instructions based on the type of PET scan you are undergoing. Diabetic patients will receive special instructions to prepare for this exam.

If you are breastfeeding at the time of the exam, you should ask your radiologist or the doctor ordering the exam how to proceed. It may help to pump breast milk ahead of time and keep it on hand for use after the PET radiopharmaceutical and CT contrast material are no longer in your body.

Metal objects including jewelry, eyeglasses, dentures and hairpins may affect the CT images and should be left at home or removed prior to your exam. You may also be asked to remove hearing aids and removable dental work.

Generally, you will be asked not to eat anything for several hours before a whole body PET/CT scan since eating may alter the distribution of the PET tracer in your body and can lead to a suboptimal scan. This could require the scan to be repeated on another day, so following instructions regarding eating is very important. You should not drink any liquids containing sugars or calories for several hours before the scan. Instead, you are encouraged to drink water. If you are diabetic, you may be given special instructions. You should inform your physician of any medications you are taking and if you have any allergies, especially to contrast materials, iodine, or seafood.

You will be asked and checked for any conditions that you may have that may increase the risk of using intravenous contrast material.

Additional Guidelines to consider for studies that involve radiopharmaceutical administration:

  • If you are pregnant, tell your doctor because radioiodine should not be given during pregnancy.
  • If you plan to become pregnant, ask your doctor how long you should wait after the treatment.
  • If you have been breastfeeding your baby, you must stop because radioiodine is secreted in breast milk. Talk to your doctor to find out when you can resume breastfeeding.
DIS PET-CT Patient Brochure