PET/CT scans are offered at select Sentara advanced imaging centers and hospitals. Sentara offers the latest equipment, and a staff that is dedicated to patients’ understanding and comfort while undergoing the procedure. Your PET/CT scan will be performed by a nuclear medicine technologist. A radiologist who has specialized training in nuclear medicine and PET/CT will interpret the images and forward a report to your referring physician.
About PET/CT Scans
PET/CT scans are a type of nuclear medicine imaging. A PET and a CT scan are performed at the same time with the same machine, providing a more comprehensive image than each could produce alone.
PET scans takes pictures of the function of the organs and tissues using nuclear medicine technology, while CTs create a 3D physical image using X-rays.
A PET/CT scan is used often to image the heart, brain, liver or other organs. It is is one of the most effective ways to study cancer.
Oral contrast medium may be used to outline or highlight organs of the body so that they can be seen more easily.
What is a PET/CT scan?
PET/CT stands for Positron Emission Tomography/Computed Tomography and is a type of nuclear medicine imaging. An integrated PET/CT scan combines the images from a PET scan and a CT scan, performed at the same time on the same machine.
PET captures functional images of very small changes in your body’s metabolism caused by the growth of abnormal cells. CT images simultaneously allow physicians to measure the physical size, shape and precise location of the diseased tissue or tumor. When the results of the scans are fused together they provide more complete information than either test alone.
During the CT scan, a thin beam of X-rays is focused on a specific part of your body. The X-ray tube moves rapidly around this site, enabling multiple images to be made from different angles to create cross-sectional picture. During a PET scan, a ring of detectors picks up radiation signals from the patient’s body coming from previously injected radiopharmaceuticals. The computer analyzes the information and constructs an image.
During some PET/CT scans, a contrast medium may be used to outline blood vessels or highlight organs to be more visible.
What can a PET/CT scan tell my doctor?
PET/CT is used to help diagnose a number of different diseases, including:
Brain abnormalities, such as tumors, memory disorders, seizures and other central nervous system disorders.
Cancer: Diagnosing, staging, evaluating of current therapies and monitoring of reoccurrence of the disease.
Coronary heart disease: heart attacks and their effects on the heart, and to identify areas of the heart muscle that would benefit from angioplasty or coronary artery bypass surgery.
Bone imaging for cancer metastases.
Map normal human brain and heart function.
The Sentara Cancer Network's mobile PET/CT in Hampton Roads can now perform a full body scan of the skeleton to discover and stage cancers that may have spread to the bones.
The FDA has approved the use of 18F-Sodium Fluoride as an injection. The fluoride is absorbed into the bone tissue and shows bone reaction and blood flow during the PET scan, revealing areas of cancer in the bones.
The CT scan is simultaneously performed to mark the exact position of any cancer that shows up on the PET scan. The new application can be used for staging and evaluating the response of bone cancers to chemotherapy and radiation.
How do I prepare for my exam?
Depending on the type of radiopharmaceutical used during your PET/CT scan, your doctor will probably ask you not to eat or drink anything, except for plain water, for six hours before the exam. In addition, you may be asked not to take certain medications for a time period prior to your exam.
PET/CT Scheduling and Info
Patients should inform the doctor about medicine they are currently taking, drug allergies (especially iodine allergies) and whether they are breastfeeding or pregnant.
Please arrive 15-30 minutes early for your scan to fill out paperwork. The tracer that you will be injected with is ordered just for you. Since it is radioactive it will decay away. If you are more than 30 minutes late for your scan, you will have to be rescheduled.
If you have any anxiety or a history of claustrophobia, it might be wise to ask your referring physician to prescribe a sedative or muscle relaxer for you. Please remember to fill the prescription and take it prior to coming to your appointment.
If you must cancel for any reason, please do so by 3 p.m. the day before your scan by calling (757) 507-0427. This is important as we order an expensive radioactive material specifically for you. If you are unable to make your exam and do not cancel with central scheduling, we cannot reschedule you after the third missed appointment.
How is the test performed?
Patients may be asked to drink a cup of CT contrast at the PET/CT scan. A tech will obtain a small blood sample to check your blood sugar (glucose) level. Elevated glucose levels (over 200) will necessitate canceling the scan, as it can provide false results.
The tech will then start an IV line. The patient will be given an injection of a small amount of radioactive sugar (FDG) through the IV line. Diabetic patients need not worry; it would take one million doses of FDG to equal the glucose in one teaspoon of sugar. Patients will be asked to rest quietly for about one hour as the tracer is distributed throughout your body. The IV line will be removed.
A staff member will escort you to the restroom to empty your bladder and ask you to remove any metal or possibly change into a hospital gown. The tech will position you on the scanning bed as comfortably as possible. The CT will be done first and then you will be moved into the machine very slowly as the PET portion is acquired.
It is important that you lie still during this process. The scan takes approximately 30 to 45 minutes, but you should plan on being at the PET/CT center for approximately two to three hours.
Are there risks?
Because the doses of radiotracer administered are small, diagnostic nuclear medicine procedures result in low radiation exposure, acceptable for diagnostic exams. As a result, the radiation risk is very low compared with the potential benefits. Nuclear medicine has been used for more than five decades, and there are no known long-term adverse effects from such low-dose exposure.
To be on the safe side, talk to your doctor about how long you should wait before getting too close to an infant, or anyone who's pregnant.
How will I find out the results?
If your physician has ordered a diagnostic CT, a radiologist with specialized training in interpreting CT exams will report the findings of the CT and forward a report to your referring physician.