Positron Emission Tomography (PET) and Computerized Tomography (CT) are both standard imaging tools that allow physicians to pinpoint the location of cancer within the body before making treatment recommendations. Alone, each imaging test has particular benefits and limitations, but when the results of PET and CT scans are put togehter, the combined image provides complete information on cancer location and metabolism.
In one continuous full-body scan, PET captures images of miniscule changes in the body's metabolism caused by the growth of abnormal cells, while CT images simultaneously allow doctors to pinpoint the exact location, size, and shape of the diseased tissue or tumor.
Because a PET scan shows cancerous activity in the body and the CT scan reveals the exact locations of the organs, doctors can use the two images together to determine the precise location of abnormal or cancerous cells.
Both PET and CT use very small amounts of radiation.
How should I prepare for my PET/CT?
•iiiDo not exercise for 48 hours prior to the study.
•iiiDo not eat for six hours prior to the study.
•iiiDrink 8 ounces of water prior to arriving for the PET scan.
•iiiTake all non-diabetic medications the day of the test.
•iiiWear loose and comfortable clothing.
What happens during the exam?
•ii A temporary intravenous (IV) will be placed in a vein in your arm so that the radiotracer can be administered. You will sit quietly for one hour.
•iiiYou will lie on your back for your scan.
•iiiThe PET/CT machine performs both scans during the same exam.
•iiiThe scan will take approximately 30 minutes.
•iiiThe entire test will take approximately 2 hours.
Additional preparations for diabetic patients:
Type I Diabetic
Take your normal insulin the day prior. On the morning of the study, check your blood sugar. If it’s in the normal range, come in for the study, but bring all of your insulin and what you use as a “travel breakfast.” If your blood sugar is too low and you must eat something, please call to reschedule your appointment. Eating and taking insulin just prior to the study can result in the radiotracer being taken up preferentially by your muscle, leaving little for any cancerous cells.
Type II Diabetic
If your morning blood sugar is >130 mg/dL, please avoid all carbohydrates for 24 hours prior to the test (i.e. no cereal, potatoes, rice, sugar or sweets, pasta, etc.). You can eat as much meat and vegetables as you like. Please do not take your diabetes medications on the day of the test, but instead, bring them with you along with a snack (with carbohydrates). You will be allowed to eat and take your medications one hour after the radiotracer injection.
