PET-CT scan

A PET-CT scan combines two types of imaging to gather very precise information about how parts of your body look and function. It’s a type of nuclear medicine scan. PET-CT scan stands for positron emission tomography-computed tomography.

Why do I need a PET-CT scan?
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Your physician might ask you to get a PET-CT exam to help detect, diagnose or guide treatment of:

  • Brain and nervous system disorders
  • Cancer
  • Heart problems
Preparing for PET-CT
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Follow your care team’s instructions to make sure you get clear, accurate results.

What to eat

Your doctor will ask you to follow a special low-carbohydrate diet for 24 to 48 hours before your test, depending on the reason for your exam. Drink plenty of water during this time.

Foods that are ok

Suggested foods include:

  • Beverages: Black coffee or tea (OK to add artificial sweetener and half-and-half) diet soda, sugar-free Crystal Light, water (plain and zero-calorie flavored water)
  • Condiments: Dill pickles; hot sauce; mayonnaise, salad dressing; oil; olives; tartar sauce; vinegar
  • Dairy: Butter, cheese, half-and-half, sour cream
  • Proteins: Eggs; hot dogs; lunch meat; nonbreaded poultry, meat or seafood
  • Vegetables: asparagus, broccoli, cabbage, cauliflower, celery, cucumber, green beans, lettuce, mushrooms, radishes, spinach, zucchini
Foods to avoid

When following your pre-PET-CT scan diet, do not consume:

  • Beverages: Alcohol, juice, nondiet soda
  • Bread, chips, crackers, pasta, rice and other grains (including those labeled “low carb”)
  • Condiments: Jam and jelly, ketchup, sauces and gravies, syrup
  • Fruits
  • Sugar or foods containing sugar, including gum and breath mints
  • Vegetables: Carrots, corn, legumes/beans, peas, potatoes, squash, tomatoes, veggie burgers
When to stop eating

6 to 18 hours before your exam depending on the indication, stop eating, chewing gum or drinking anything other than water


Ask your care team if it’s OK to take your regular medications the day of your exam. If you have diabetes, you will need to stop taking insulin the day of your exam. Talk to your doctor about other ways to control your glucose.

Physical activity

The day before your exam, avoid strenuous physical activity, such as jogging or heavy lifting.

What if I need to reschedule?
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If you need to reschedule, please give us at least 24 hours’ notice. Reschedule by calling 616.267.2626.

What to bring
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When you come to Spectrum Health for your PET-CT scan:

  • Wear comfortable, loose-fitting clothes with no or little metal
  • Leave jewelry at home
  • Bring a list of current medications
  • Bring a book, if desired
What to expect
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Plan to spend about three hours at Spectrum Health for your PET-CT scan.

You’ll relax in a private room while you receive a small, safe amount of a radioactive material through an IV. Your room has a recliner and a television with a DVD player, so you can watch TV or a movie while you wait for the material to travel through your body.

During your imaging test, you’ll lie on a narrow table that slides into a donut-shaped machine with a wide, spacious opening. We’ll help you feel as comfortable as possible by providing pillows and blankets, and tuning our satellite radio to music you enjoy.

The scanning bed will move back and forth several times during your test. Most scans take 15 to 45 minutes.

For some tests, your care team may ask you to take another medication or some contrast material to make parts of your body show up better on the images.

After your PET-CT
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After your test, you can return to your usual activities, unless your doctor gives you other instructions. Drink plenty of water to help the radioactive material pass through your body.

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Your test results will be available in 24 to 48 hours. We’ll share your results with the doctor who ordered your test and add them to your MyChart account. Your doctor will explain the results and help you decide next steps.

Contact Us

Schedule an Appointment or Find a Radiology Location Near You.