How to Prepare for Your PET/CT Scan - General Directions

  • If you are, or there is a chance you are, pregnant or if you start breastfeeding, please call the PET/CT department in advance of your scan day: 401-444-7777.
  • If at all possible, avoid unnecessary or prolonged contact with young children and pregnant women for eight hours after your scan has been completed.
  • Because this test relies on the measurement of metabolic activity of your heart, it is very important that you follow these instructions carefully.

The Day Before Your PET/CT Scan

Please avoid all forms of strenuous exercise and/or physical activity for 24 hours prior to your appointment.

Avoid all caffeine and de-caffeinated beverages for 24 hours prior to exam.

It is important that you stay well hydrated. Unless you are on fluid restriction, please drink at least eight glasses of plain water.

The quality of your scan may be improved if you follow a high protein, low carbohydrate, low sugar diet during the 24 hours prior to your scan.

For 12 hours prior to your appointment, do not use nicotine products, including nicotine patches and cigarettes.

On the Day of Your PET/CT Scan

For six hours before your appointment, do not eat or drink anything other than plain water.

If the patient is a child who is having sedation during the appointment, stop all liquids two hours before the appointment.

Do not use, or ingest, chewing gum of any kind (including sugarless), no hard candies or throat lozenges of any kind (including sugarless), no tube feedings, no flavored water, and no medication that is flavored or chewable (e.g., cherry Tylenol).

Any non-diabetic medications may be taken the day of your scan. See diabetic medication instructions below.

Try to stay warm on the day of your scan. If possible, do not wear clothing with belts, zippers, snaps or metal of any kind to your appointment. Women should try to wear a bra without underwire or clips (sports bra).

If you have favorite music, please bring it with you to listen to while your scan is going on.

Diabetic Medications on the Day of your PET/CT Scan

If your PET/CT scan is scheduled before 12 noon, do not take any insulin or oral diabetic medications on the day of your appointment.

If your PET/CT Scan is scheduled after 12 noon, do not use long acting or mixed (70/30) insulin after midnight the night before your scan.

At least six hours before your appointment, take your usual oral diabetic medications with a light breakfast of a high protein, low carbohydrate, low sugar meal.

Do not have caffeine or de-caffeinated coffee or tea.

If insulin dependent, inject one-half of your normal short acting insulin six hours prior to your appointment.

What to Expect the Day of Your PET/CT Scan

The technologist will escort you to the injection room and go over your detailed history.

The team will test your blood glucose level. We are looking for your blood glucose level to be between 70mg/dL and 200mg/dL. If your blood glucose falls within those limits and you have followed the prior instructions the technologist will proceed.

The technologist will start an intravenous line and administer the radiopharmaceutical injection.

After the injection you may be given one cup of an oral barium contrast to drink. You will rest quietly in a reclining chair for 75 minutes. Twenty minutes prior to the start of your scan you may be given another cup of the oral barium contrast to drink.

You will be asked to empty your bladder just before your PET/CT Scan.

Most PET/CT scans take between 15 and 35 minutes.

Please Note: If your blood glucose level is outside of the recommended levels, or you have not followed the specific instructions prior to your test (special diet, medications, fasting, etc.), your scan will need to be rescheduled.

After Your PET/CT Scan

For several hours following your scan, continue to hydrate to help the radiopharmaceutical and oral barium contrast pass out of your body.

How PET CT works