A positron emission tomography scan, also known as a PET scan, uses a radiotracer to show activity within the body on a cellular level. Combined with a CT, a PET scan can produce multidimensional, color images of the inside workings of the human body. It shows not only what an organ looks like, but how it is functioning.
A PET scan is used to diagnose certain health conditions, to plan treatment, to find out how an existing condition is developing, and to see how effective a treatment is. To do this a radioactive tracer is injected into a vein in your arm. The PET scan detects where the radioactive tracer has been absorbed to produce images of inside the body. 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.
To schedule an exam, please call 317-355-4680. For questions or concerns about a PET/CT scan, please call Community Imaging Center South at 317-497-2878.
What to Expect
*Please note the following instructions are specific to FDG oncology PET/CT scans. If your doctor has scheduled you for a NETSPOT or Axumin PET/CT scan the instructions will vary. The PET/CT department will contact you prior to your appointment with specific instructions for the day of your scan.
Your PET/CT will take around 90 minutes and any accompanying persons will be asked to wait in our main waiting area.
Your blood sugar level must be below 200 mg/dl to have the test done. The technologist will start an IV, test your blood sugar and give an intravenous injection of FDG. After the injection you will remain in the injection room for about 1 hour. The room has a recliner and a television. This allows time for the radiotracer to metabolize through the body. Please do not speak on your cellphone during this time period as this will increase uptake in the head and neck area. You may bring reading material with you.
After the uptake period, you will be asked to empty your bladder and remove any metal clothing/accessories. The PET/CT scanner resembles a large donut, but is deeper than a CT scanner because the PET scanner is connected to the back side. The technologist will help position you on the scan table. You will be positioned on your back with your arms above your head (if possible). You will be asked to remain still during the exam because motion can interfere with the results. We can provide a cushion under your knees for comfort.
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. Your scan may take approximately 25 to 35 minutes. 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 your ordering physician. You will need to obtain a prescription for something to relax you from your ordering physician prior to your appointment.
How to Prepare
*If your doctor is scheduling you for a PET scan and you are breastfeeding please notify the PET department. You will receive special instructions.
Day Before Your PET/CT
- AVOID strenuous exercise for 24 hours prior to your PET/CT.
It is highly recommended that you follow a high-protein, low-carbohydrate diet for 24 hours prior to your test to increase the quality of your PET/CT images. Below are diet suggestions:
- AVOID caffeine, alcohol and nicotine.
- AVOID food with sugars and more than 6 grams of carbohydrates per serving. Example: Avoid 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, 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, and steak with mushrooms.
Day of Your PET/CT
- DO NOT eat at least 6 hours prior to study. (This includes coffee, clear liquids, gum, candy, breath mints, cough drops or anything containing sugar.)
- DO drink as much plain, unflavored water as possible prior to your scan; 32 oz. is recommended unless on fluid restriction. Do not use thickener.
- DO take all your medications as normal EXCEPT diabetic medications.
- *Oral or injection diabetic medication may be taken at least 4 hours prior to appointment time to ensure a glucose level under 200 mg/dl. These medications can interfere with the exam if taken within 4 hours of appointment time and this may result in cancelation of exam.
- *Claustrophobic patients need to wait until arrival at the center to take prescription medication prescribed by your ordering doctor.
- You will also need to arrange for transportation home after taking any sedative.
- 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
There is a small amount of radioactivity present in the urine and bodily fluids for up to 24 hours. Double flush the toilet after using the restroom and practice good hand hygiene by washing with soap and water. Also, drink plenty of fluids as this will help flush the tracer through your system (unless you are on fluid restrictions).
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.