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. Avoid wearing jewelry or clothes with metal zippers, snaps or fasteners.

  • 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.

  • Refrain from strenuous physical activity for 24 hours prior to your exam, such as working out, jogging, heavy lifting, etc.

  • Bring copies of your most recent CT, X-ray, or MRI films with you on the day of your PET/CT scan.

Be prepared to stay at the imaging facility for approximately two 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

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

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.

You will receive an intravenous injection of a radioactive glucose, and then you will be asked to rest quietly for approximately 60 minutes, allowing the glucose to circulate throughout the body. A nurse may check your blood sugar level before injecting the radioactive glucose, particularly if you are diabetic.

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. The procedure is painless and has no side effects.

How Long Will the Scan Take?

You should plan on spending at least two to three hours at the imaging facility. There is a 60 minute resting period before imaging, and your actual scan will take approximately 15-35 minutes, depending on the type of scan you are having and the type of scanner being used. The results are interpreted by a trained nuclear medicine physician or radiologist and your physician will receive a written report approximately 24 to 48 hours after completion of the study.

Diabetic Patients

Make sure you inform the imaging facility staff ahead of time if you are diabetic, and follow their specific instructions or the instructions given to you by your physician.

A nurse may check your blood sugar level before injecting the radioactive glucose. Your blood sugar level should be between 100-200 mg/dL before your PET/CT scan.


PET imaging is a nuclear imaging procedure. All molecular and nuclear imaging procedures are very safe. Unlike surgery, they are noninvasive, which eliminates an entire set of risks.

The amount of radiopharmaceutical used is extremely small, so radiation exposure is minimal. The amount of radiation in most nuclear medicine procedures is comparable to that received during a CT scan.

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 these procedures are generally free of known side effects. While exposure to radiation does involve risk, naturally occurring background radiation and modern activities such as watching television and flying in an airplane all contribute to a lifetime exposure that is only slightly increased by medical imaging. The benefits of early and accurate diagnosis outweigh the risk of exposure to this small quantity of radioactive material.

Molecular Imaging Safety Fact Sheet

After Your PET/CT 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.

Results of Your PET/CT Scan

Your PET/CT scan results will be reported to your referring physician. Please contact your physician to discuss the results.