Frequently Asked Questions (FAQ)
» What is Nuclear Medicine?
» How does a PET (Positron Emission Tomography) procedure work?
» How do I make an appointment for a PET/CT exam?
» How should I prepare for the procedure?
» What will I experience during the procedure?
» How long will the exam take?
» Are there any after effects to the exam?
» When and how will I received my test results?
Nuclear Medicine is a specialized area of radiology that uses radioactive materials or radiopharmaceuticals to provide diagnosis, management, treatment and prevention of diseases.
For conventional X-ray or CT examinations, the radiation comes out of the machine and then passes through the patient to create the image. For Nuclear Medicine examinations, the radioactive material is introduced into the patient’s body (usually by injection into a vein), and is then detected by a machine called a gamma camera. There is usually a specific waiting time for the radioactive material to be distributed in the body or the organ of interest.
Some patients may think this type of exam is dangerous. However, approximately 90% of the radiopharmaceuticals used in Nuclear Medicine have very short half-life spans, meaning they decay rapidly and are inside the patient’s body for a short time. Also, the total radiation dose is relatively small, similar to (or sometimes even less than) the dose used for CT and X-ray examinations.
PET is a nuclear medicine procedure that produces pictures of the body’s metabolic functions. You will receive a CT scan as part of your PET study. The CT scan improves the accuracy of the PET scan by providing excellent localization to any abnormalities seen on PET. The CT may detect abnormalities not seen by PET, and vice-versa. The radiation exposure associated with PET is safe and lower than most conventional radiology examinations.
- Patients need to be scheduled at least 24 hours in advance of an exam.
- For “same day” PET/CT scans, the Nuclear Medicine department must approve the exam first.
- Written physician’s order can be faxed to the Scheduling department at 713-394-6010 or the Nuclear Medicine Department at 713-441-4080.
- The hospital can suggest parking garages closest to the Nuclear Medicine department.
What you are asked to do before your exam will depend on the type of study ordered by your physician. However, most exams require the following:
- Avoid drinking or eating anything 4 hours prior to your exam.
- Inform your doctor of any prescribed medications you are taking. Most medications can be taken the day of the exam unless instructed differently by your physician.
- Inform your physician if you are diabetic.
- Avoid strenuous activity 12 hours in advance of your study and engage in only minimal physical activity on the day of the exam.
- Please dress warmly and in comfortable clothes, making sure to leave all valuables at home.
- Plan to arrive 15 minutes before your scheduled exam.
- Before your exam begins, you will be injected with a radioactive tracer. This tracer is a compound of complex sugars labeled with a shorted-lived radioisotope.
- You will be asked to rest for approximately 45 to 60 minutes while the radioactive tracer travels throughout your body. During this time you will asked to refrain from talking, walking, or chewing gum.
- The technologist will then ask you to lie on the scanner table. The table slowly passes through the scanner. The PET scanner detects and records the signals the tracer emits. The signals are reassembled into actual images through the use of a computer and will then be processed for interpretation by the reading physician.
The exam will usually take at least 2 hours. The type of study being performed will determine the exact length of the exam.
There are no known side effects resulting from the injected tracer so you should feel fine after your exam.
Your PET scan results will not immediately be available. Your physician will be contacted when the results are ready and he or she will inform you of all pertinent information ascertained from the scan.