PET/CT Preparation FAQs

Growing cells use glucose, a form of sugar, as a major source of energy. In preparation for a PET/CT scan, patients are given a small amount of a glucose that emits tiny particles called positrons. More active cells, such as cancer cells, use more glucose than normal cells and will have higher concentrations of positrons during the test. The PET/CT scan detects the positrons and creates highly detailed images that show the precise location of the abnormal cells and whether there is increased activity in the surrounding tissue. PET/CT scans provide remark­ably clear pictures of what is happening in the body, often eliminating the need for additional tests and/or exploratory surgeries. 

A PET/CT scan will enable your doctor to identify a potential health problem faster and more accurately than other diagnostic procedures will. If a disease is detected, the PET/CT scan helps your physician stage it, identify the best treatment approach and/or monitor your progress. If you are not responding to treatment as well as expected, you can be switched to a more effective therapy immediately. Just ask your physician what he or she hopes to learn from your PET/CT exam. 

• You should not eat or drink anything (including candy and gum) for four to six hours before your test; however, we highly recommend you drink plenty of water
• If you are not on any dietary restrictions, you should eat a low carbohydrate diet during the 18 to 20 hours prior to your exam
• Avoid any physical exertion 24 hours prior to your exam; this includes strenuous physical activities such as yoga, walking, running or weight lifting
• You should continue to take any medications pre­scribed by your physician; if you need to take your medications with food, take them with a few soda crackers four to eight hours before your exam
• If you are diabetic, please let us know ahead of time so we can work with your physician to determine the best way for you to prepare for the scan
• If you are or think you may be pregnant, discuss this with your physician; generally, PET/CT scans are not performed during pregnancy

• Shields PET/CT scheduling department will confirm your arrival time within 72 hours of your appointment
• If you need to cancel or reschedule, please do so at least 24 hours before your appointment

• Your insurance card(s)
• Previous CT scans, PET scans and X-rays
• A copy of your medical history and a list of your medications
• A copy of any previous pathology reports
• Personal reading materials or music

• The scanner room is cool, so you will want to wear warm, comfortable clothing
• We recommend sweatpants and sweatshirts so you will not need to change for the exam
• Please wear metal-free clothing and remove all jewelry prior to your appointment (if you wear pants with buttons or zippers, you will be required to change into scrub pants for the scan)

After you register, you will go to an area to prepare for the exam. A small IV line will be put in your arm to give you the glucose needed for the test. You will be asked to rest without talking for 50 to 60 minutes as the glucose is absorbed into your body. You may also need to take an oral contrast agent, depending on the type of PET/CT scan you are having. The actual scan will take about 20 to 30 minutes. 

• You can leave immediately after the exam
• You may drive if you wish and resume all your normal activities; there are no restrictions on your diet or exercise
• Take your prescribed medications
• We recommend you drink extra fluids to help eliminate the injection from your body quickly
• As a precaution, we recommend that you remain at least a 6-foot distance from children (anyone under 18) or anyone who is pregnant for eight hours after your scan
• Your PET/CT scan will be reviewed by a physician, who will send a report to your doctor
• Your doctor will contact you to discuss the results of the exam

There are three ways to ask further questions:

• Call 866-258-4738
• Visit www.shields.com
• Consult your physician