PET/CT
What is a PET/CT scan?
A PET/CT scan is one of the most advanced diagnostic imaging procedures
available in the world. It combines two different imaging technologies that
image two different aspects of disease. CT (computerized tomography) is
primarily an anatomic imaging technique while PET (Positron emission tomography)
is a functional imaging modality that images the metabolic function of various
organs/systems in the body.
Why do a PET/CT scan
Historically, CT has been the imaging modality of choice for the diagnosis and staging of malignant disease and monitoring the response to therapy. More recently, PET has been shown to be more accurate than CT in staging and assessment of response to therapy in malignant diseases. A PET study is generally read in conjunction with the corresponding CT scan, side-by-side. The new PET CT Scanner at Science Park provides clinical PET and clinical CT capability within a single, integrated scanner. This permits simultaneous visualization of the anatomy and the function with precision. However, both PET and CT have their limitations and complement each other to improve the diagnostic accuracy. Therefore, these images or ‘slices' provide thin cross sectional views, allowing the radiologist to make an accurate diagnosis and determine the extent or spread of disease.
Uses for PET/CT include the detection of cancer, monitoring the effects of cancer therapy, evaluation of coronary artery disease, determination of blood flow to the heart muscle, determination of the viability of heart muscle tissue after a heart attack, evaluation of memory disorders, evaluation of suspected or proven brain tumors and the evaluation of seizure disorders that are not responsive to medical therapy and are candidates for surgery.
How do I prepare for my PET/CT Scan?
On the day of your exam wear comfortable loose fitting clothes. Do not eat or drink anything other than water 6 hours before the scan. Consult with your doctor regarding the use of medications before the exam. For more detailed instructions, please CAREFULLY read the list below.
- Do not eat for 6 hours before your test.
- Drink at least 2 glasses of water in that time.
- Call us as soon as possible if you are Diabetic, pregnant or nursing, or if you take medications for Diabetes.
- All other medications may be taken with water. If you must take your medication with food, please call us for instructions.
- Maintain a low-carbohydrate diet starting the day before your test. Limit the amount of pasta, breads, potatoes, cereals, rice deserts, candy and sugar.
- Avoid strenuous activity and do not exercise for 12 hours.
- No caffeine or tobacco in any form for 24 hours before the test.
- If you are claustrophobic, please obtain a light sedative from your doctor. If a sedative is used, you will need to arrange transportation to and from your examination.
Diabetic patients should ask for any specific diet guidelines to control glucose levels during the day of the test.
How is a PET/CT performed?
Because PET/CT utilizes two different imaging technologies, it is conducted in two stages which occur rapidly and seamlessly. Often, to improve the quality of the images and to enhance the appearance of various organs in your body, it is necessary to administer contrast agents, either by mouth or intravenously via injection. The oral contrast is given to you to drink prior to your scan – it takes 30 minutes to one hour for the oral contrast to fill your stomach and intestines. After this time interval, your scan can be performed. If it is determined that intravenous contrast may be necessary, this will be fully explained to you, describing the important benefits and minimal risks associated with the injection. You will be asked to sign a consent form. At Borg Imaging, we use non-ionic contrast, which is extremely safe and has been used in daily routine scanning for many years.
The PET portion of the scan requires you receiving an injection of a very short-lived radiotracer that is metabolized by the body part to be studied. The PET scans the metabolic distribution of the injected radiotracer in the body. Computerized software fuses or superimposes the CT scan with the PET scan, providing an extremely accurate simultaneous image of anatomy and metabolic function of the organs.
Once the examination begins, you will lie down on the scanning table, which will position the part of your body to be scanned inside the scanner which contains a rotating x-ray tube and a PET scanner. The examination table then moves short distances through the scanner (or as images are obtained). You will then hear mechanical sounds from the machine and possible clicking sounds from the table movement. PET/CT scanning is completely painless.
During the procedure, you are never alone. The technologists/nurses can always see and hear you. We will try to make you as comfortable as possible and it is very important that you lie as still as possible during your exam. Any motion, however slight, may cause the images to distort and blur, requiring rescanning. If pain makes it difficult for you to lie still, you may want to ask your physician for pain medication beforehand.
How will I learn about the results of my scan ?
After your scan is completed, your study is interpreted by our radiologist and a full report of your findings is forwarded to your referring doctor. Often, the report is sent out via mail or fax on the same day as your scan, usually within 24 hours.
If you have any question or concerns prior to the examination, please call us at (585) 271-0401.