PET and PET/CT Preps

There are two types of PET scans: 

  • Cardiac exams (Myocardial Perfusion PET, which is also called Adenosine or Rubidium PET)
  • FDG-PET, which is used to study tumors, brain disorders, or infections, although it can also be used to study the heart

The required preparations for the two types of PET are very different; please see below.

If you are unsure which exam you are receiving, please call our scheduling department at: 310.423.8000 (option 1).

Why Choose the S. Mark Taper Foundation Imaging Center for PET scans?

Myocardial Perfusion PET (also known as Rubidium or Adenosine PET)

Exam time: approximately 3-4 hours.

  1. Consult with your physician about going off beta blockers for 48 hours and calcium channel blockers for 24 hours before the test.
  2. Do not eat or drink 6 hours prior to your exam (Diabetics: please consult your physician about the preparation for this exam.)
  3. No caffeine for 24 hours (i.e. chocolate, sodas, teas, coffee, or Excedrin) prior to the exam. Please note: decaffeinated products contain caffeine.
  4. Please wear a comfortable 2-piece outfit and walking shoes.
  5. Please bring all of your medications with you.


Exam time: approximately 3-4 hours.

This is the preparation for an FDG PET. This exam is used for such things as tumor detection, brain disorders, or infection--it is also used for a study of the heart called myocardial viability. There is a different PET scan available, which is used to perform an exam called Myocardial Perfusion PET or Rubidium PET--the preparation for Rubidium PET is very different than for an FDG PET. This exam requires the following of a particular (no-carbohydrate) diet* beginning 24 hours before your exam.

FDG PET scans require careful preparation, so please follow instructions carefully.

Diabetics should discuss the preparation with their physician before making any alteration to their diet.

PET/CT (approx. visit time: 3½ hours)

  • 48 hours before exam: Do not do any strenuous exercise or deep tissue massage.
  • 24 hours before exam: Stay on a VERY LOW-carbohydrate, NO-sugar diet. You may NOT eat: sweet foods or drinks; desserts or candy; fruits or fruit juices; starchy foods like cereal, potatoes, rice, pasta; milk, yogurt, nutritional shakes, or smoothies. Do NOT use chewing gum or mints. You may eat a HIGH PROTEIN diet to include meat and poultry, eggs, nuts, and green vegetables. You may drink water and zero calorie drinks. (See below for guide).
  • 6 hours before exam: Please do not eat or drink anything, with the exception of water.  Drinking water is encouraged to assure hydration for best test results.
    Continue to take medications as prescribed. If you are diabetic, ask your doctor about diet and medication. Carefully monitor and control your blood sugar the 48hrs before the scan.  Call (310) 423-8738 for more information.

PET Brain (approx. visit time: 3 hours)

  • Follow above preps for PET/CT. In addition, no caffeine for 24 hours before exam.
  • Low-Carbohydrate Diet Guide:

Foods allowed:

  • All meats
  • Hard cheeses
  • Unsweetened peanut butter
  • Diet soda ( be careful to avoid caffeinated and decaffeinated sodas.)
  • Tofu
  • Eggs
  • Oil, margarine, butter
  • Non-strachy vegetables (such as: broccoli, spinach, grean beans.)

Foods NOT allowed:

  • Cereals
  • Pasta
  • Dry beans
  • Fruit and fruit juices
  • Sugar and candy
  • Starchy vegetables (such as: peas, corn, potatoes)
  • Alcohol
  • Breads
  • Rice
  • Gravies
  • Jams and jellies
  • Honey
  • Milk (including non-dairy milk)
  • Coffee or Tea

If you are unsure if this is the correct preparation for your exam, please call our scheduling department at: 310.423.8000 (option 1).

The S. Mark Taper Foundation Imaging Center provides a full range of advanced imaging, both radiology and cardiology, as well as interventional radiology and interventional tumor (oncology) treatments to the greater Los Angeles area, including Beverly Hills, Encino, Mid-Cities, Sherman Oaks, Silver Lake, Studio City, Toluca Lake, and West Hollywood.