PET/CT: Frequently Asked Questions

The registered nuclear medicine technologist will explain the procedure to you, ask you to complete a questionnaire and answer any questions that you might have. The technologist will take all prior studies including CT and MR that you have brought for comparison and then give you a small amount of a radioactive tracer, which is injected into your bloodstream. The radiation exposure associated with PET is similar to that associated with a conventional CT scan. Following this injection you must wait approximately 1 hour before your PET scan begins. This must be a time of complete rest and relaxation with no physical activity what so ever. No activity is essential in order for the dose to absorbed properly by the body. When the rest period is completed, you will be positioned on an imaging table and moved through the scanner at set intervals until the scan is completed. You may not move during this time.

In most cases you will be on the scanner table for less than an hour. The scan itself causes no pain. Because the GEMINi GXL system gantry is open in the middle, you will be able to see and speak with your exam technologist. An IV line could be started in your hand or arm in order to infuse a radiopharmaceutical. Occasionally, a urinary catheter may need to be inserted for the scan.

For PET scans, a very small amount of a radiopharmaceutical is infused into the bloodstream. The substance contains molecules that provide imaging information when absorbed, or concentrated in tissue. Areas with rapid cell activity will show much higher concentrations of the dose than normal healthy tissue. A computer records this information and converts it into pictures for diagnostic purposes. For a PET/CT scan, you may also receive a contrast agent by mouth or intravenous (IV) injection. The amount of radiation you will receive is about the same as any other radiology procedure, such as an X-ray. You should not feel any side effects from the material.

It is important that you drink as much water as possible for the rest of the day and empty your bladder as often as possible. This will result in a more rapid clearance of the radiopharmaceutical and/or contrast agent from your body. You can drive and resume normal activities immediately afterward unless you have received sedation.

Insurance companies, including Medicare and Medicaid, reimburse many, but not all PET procedures. Contact your insurance company or Lenox Hill Radiology for the most current information on which PET procedures are covered.