PET/CT Scan

For any questions or concerns about a PET/CT scan, please call Community Imaging Center South at 317-497-2878.

To schedule an exam, please call 317-355-4680.

What is a PET/CT Scan?

A PET/CT scan combines two scans to help provide a more accurate diagnosis then the two scans done separately. This also helps to cut down scan time, avoid additional imaging and invasive procedures.

PET stands for positron emission tomography. The PET scan allows doctors to see how organs and tissues inside your body are functioning. To do this they inject a radioactive tracer called FDG into a vein in your arm. FDG stands for fluorodeoxyglucose. FDG acts like glucose in the body. All cells use glucose as an energy source. However, cancer cells grow faster than normal cells. Organs and tissue using the most energy will absorb the FDG. The PET scan detects where the radioactive tracer has been absorbed to produce images of inside the body.

CT stands for computed tomography. The CT scan creates a 3D picture of the inside of the body. It gives detailed pictures of bone, blood vessels and soft tissue all at once. The PET and CT images are then combined allowing doctors to locate an area for biopsy, detect cancer, find out the cancer’s stage, develop a radiation treatment plan or evaluate the effectiveness of cancer treatments.

What to Expect

Your PET/CT will take around 90 minutes. During this time, the person having the scan is monitored within the PET/CT Department. Any accompanying persons will be asked to wait in our main waiting area.

After you check in with our registration staff you will be taken to a private room in the PET/CT area where a technologist will review your medical history with you. The technologist will check your blood sugar level. You must have a blood sugar level below 200 to have the test done. If blood sugar levels are within acceptable range the technologist will then start an IV and give an intravenous injection of FDG. After the injection you will be seated in a quiet and dimly lit room for about 1 hour. This allows time for the material to diffuse through the body. You may bring reading material with you.

After the waiting period, you will be moved to the scanner. The scanning portion is usually between 20-30 minutes. The PET/ CT scanner resembles a large donut. The technologist will help position you on a padded exam table. You will be positioned on your back with your arms above your head. You will be asked to remain still during the exam because motion can interfere with the results. You may have straps or pillows to hold you place. 

If this is being performed as part of radiation therapy treatment planning, you may have masks or body casts to keep your body in the same position that will be used for your radiation treatment. During the first scans the table will move quickly through the scanner. This helps the technologist confirm you are positioned properly. For the remainder of the scan, the table will move slowly. You may hear some soft machine noise but you will not feel anything unusual. 

During the scan, a technologist will monitor you through a large window in the control area. You will be able to see the technologist and communicate with them through an intercom system.

*If you have difficulty with claustrophobia or feel the PET/CT may cause anxiety, please contact the ordering physician. You will need to obtain a prescription for something to relax you from the ordering physician prior to your appointment.

How to Prepare

Day Before Your PET/CT

  • AVOID strenuous exercise for 24 hours prior to your PET/CT.
  • AVOID caffeine, alcohol and nicotine.
  • AVOID all food with sugars and more than 6 grams of carbohydrates per serving. Example: Avoid all dairy (except for cheese), yogurt, bread, pasta, potatoes, fruits, cereal, oatmeal, snack chips, (pretzels, corn, popcorn), sodas and fruit juices.
  • DO eat high protein, low carbohydrate meals. Example: you may have all meats, fish, eggs, and cheese, non-starchy vegetables like green beans, broccoli, spinach, zucchini, and lettuce. Meal suggestions include scrambled eggs, omelets with veggies or meat, chicken or tuna salad, wrapped in lettuce leaves, chicken with broccoli and cheese, steak with mushrooms.

Day of Your PET/CT

  • DO NOT eat at least 6 hours prior to study. (This includes coffee, gum, candy, breathe mints, cough drops or anything containing sugar.)
  • DO drink as much water as possible prior to your scan.
  • DO take all your medications like normal EXCEPT diabetic medication and water pills.
    • *Oral or injection diabetic medication may be taken to ensure a glucose level under 200 mg/dl only if taken 4 hours prior to appointment time. These medications can interfere with the exam. If taken within 4 hours of appointment time this may result in cancellation of exam.
    • *Claustrophobic patients need to wait until arrival at the hospital to take anxiety medication prescribed by your ordering doctor.
    • You will also need to arrange for a friend or family member to drive you home after any sedative.
  • Metal objects including jewelry and hairpins may affect the images and should be left home or removed prior to your scan.
  • Wear warm, loose fitting clothing that is free of metal. Avoid clothing with metal snaps, fasteners, zippers, and bras with underwire. If all clothing is metal free you will not be required to wear an exam gown.

After the Scan

You have been injected with a small amount of radioactive tracer so we ask that you avoid close, prolonged contact with small children or pregnant women for approximately 6 hours after your injection.

Drink plenty of water (an extra 64 ounces of water). The extra water will cause you to urinate frequently (this is desired) which will aid in eliminating the radioactive material from your body. You can otherwise return to your normal activities immediately after your PET/CT scan, including driving.

We do not have results immediately after your scan. The ordering physician should receive results within 24-48 hours of your PET/CT scan. Please contact the ordering physician for results.