PET/CT Scanning for Patients

Patient Preparations

Because PET imaging depends on visualizing the distributions of the glucose based radiopharmaceutical throughout your body, correct preparation for your PET study is more critical than for other commonly performed imaging studies.

Dress in warm, comfortable clothing, as some scanner rooms may be cool. Avoid wearing jewelry or clothes with metal fasteners and zippers.

Food and Drink
Please call the imaging facility for specific instructions. Generally, the day before your scan you'll need to be on a low carbohydrate/high protein diet and limit the amount of sugar and caffeine you consume. On the day of the scan do not eat or drink anything except plain water for four to six hours before your scan. Drink several glasses of water before your scan to ensure hydration.

Take your regularly scheduled medication with water prior to arriving for your scan, unless instructed otherwise.

Diabetic Patients
Inform the imaging department ahead of time if you are diabetic to discuss specific instructions. A technologist will test your blood sugar level before the scan, it should be approximately 75-150mg/dL. A maximum of 200 mg/dl is acceptable for performing this exam. If higher on the day of scanning we may need to reschedule the exam for another day.

For 24 hours prior to your exam, refrain from physical activity such as working out, jogging, heavy lifting, and long walks.

How Long Will the Scan Take?
You should plan on spending at least two hours at the imaging facility. There is a 60-minute resting period before imaging. Your actual scan will take approximately 15-35 minutes, depending on the type of scan you are having.

What to Expect

The following information will help you prepare for your appointment at the imaging facility.

The scanner rooms can sometimes be cool, so we suggest that you wear warm comfortable clothing. You should avoid wearing jewelry or clothes with metal fasteners or zippers.

You will be given specific preparation instructions regarding food and drink, but generally you will be instructed not to eat or have any liquids, except water, for at least four to six hours before your scan. In addition, refrain from strenuous physical activity for 24 hours prior to your exam, such as working out, jogging, heavy lifting, etc.

If possible, bring copies of your most recent CT, X-ray, or magnetic resonance imaging (MRI) films with you on the day of your PET/CT scan.

Be prepared to stay at the imaging facility for approximately two to three hours. You will be asked to lie quietly for approximately 60 minutes before the scan, and to lie still for approximately 30 minutes while the scan is being performed.


Before arriving at the imaging facility you should carefully follow the patient preparation instructions. Correct preparation for your PET/CT study is very important.

Once at the imaging center, you will be asked to complete the necessary paperwork to begin the procedure. Be sure to bring your insurance cards with you to ensure accurate billing. It may also be helpful to bring a list of any medications you are currently taking.

A technologist will test your blood sugar level before the scan, it should be approximately 75-150mg/dL. A maximum of 200 mg/dl is acceptable for performing this exam. If higher on the day of scanning we may need to reschedule the exam for another day.

You will receive an intravenous injection and then you will be asked to rest quietly for approximately 60 minutes. After this resting period you will empty your bladder and the technologist will escort you into the scanning room where you will lie down on the scanner table. It is important to be comfortable and lie as still as possible for 15-35 minutes as the table passes slowly through the scanner acquiring several sets of images. A PET or PET/CT scan is fast straight forward and painless.

Following the Scan

Once the PET/CT scan is complete, you will be able to leave the imaging facility. Make sure you drink plenty of water or other fluids throughout the day.

The results of your scan will be interpreted by a radiologist and your physician will receive a written report approximately 24 to 48 hours after completion of the study.

Please contact your physician to discuss the results.

Indications & Safety Information

PET/CT imaging is a safe, noninvasive nuclear medicine or molecular imaging procedure.

Radiopharmaceuticals are approved by the Food and Drug Administration and prepared with great care. They are tested carefully prior to general use. Nuclear imaging has been used for more than five decades and side effects are rare. While exposure to radiation does involve risk, naturally occurring background radiation and activities such as watching television and flying in an airplane all contribute to a lifetime exposure that is only slightly increased by medical imaging. Your physician has determined that the benefits of early and accurate diagnosis outweigh the risk of exposure to this small quantity of radioactive material.

Indications and Important Safety Information

For Intravenous Use

Fludeoxyglucose F 18 Injection is indicated for positron emission tomography (PET) imaging in the following settings:

Oncology: For assessment of abnormal glucose metabolism to assist in the evaluation of malignancy in patients with known or suspected abnormalities found by other testing modalities, or in patients with an existing diagnosis of cancer.

Radiation Risk:
Radiation-emitting products, including Fludeoxyglucose F 18 Injection, may increase the risk for cancer, especially in pediatric patients. Use the smallest dose necessary for imaging and ensure safe handling to protect the patient and health care worker.

Blood Glucose Levels: In the oncology and neurology setting, suboptimal imaging may occur in patients with inadequately regulated blood glucose levels. In these patients, consider medical therapy and laboratory testing to assure at least two days of normoglycemia prior to administration.

Hypersensitivity reactions with pruritis, edema and rash have occurred; have emergency resuscitation equipment and personnel immediately available.

PETNET Solutions, 810 Innovation DRive, Knoxville, TN 37777