Technological advances are providing physicians with a better understanding of cell metabolism than ever before. At the forefront of these advances is the PET/CT scan, which provides diagnostic information unavailable from other imaging tests, such as computed tomography (CT) or magnetic resonance imaging (MR) as well as PET (only) Scans.
Unlike the MR and CT, which provide anatomic imaging of the physical structure of the body, a PET/CT scan provides metabolic imaging that show how the body’s organ systems function and how cells grow. The PET/CT is able to show whether tissue is normal or abnormal based on cellular metabolism. This information can allow the physician to assess chemical and physiological changes related to metabolism. PET/CT images can therefore demonstrate pathological changes long before they would be revealed in a CT or MR.
PET/CT can help physicians with early diagnosis of a disease and provide additional information that can help predict a patient’s prognosis for surgery. PET can also help physicians monitor a patient’s response to treatment as well as identify distant metastases that can affect treatment, helping curtail ineffective treatments and reduce unnecessary invasive procedures.
What is PET/CT?
The Positron Emission Tomography (PET) portion of your scan produces images of molecular-level physiological functioning, which can help physicians identify normal and abnormal states. As in traditional nuclear medicine, PET uses radiopharmaceuticals or “tracers,” which are labeled with isotopes such as carbon, oxygen, nitrogen and fluorine. These isotopes mimic sugars, water, proteins and oxygen. As a result, PET can often reveal more about the cellular-level metabolic status of a disease than the CT or MR. PET can help diagnose a disease often before it shows up on other tests. PET can also show the progress of a disease as well as how the body is responding to treatment. When a CT is done at the same time on the PET/CT system, the CT images produced are fused together with the PET images into one set of images that display the area of metabolic activity more accurately.
The three areas in which PET/CT is making critical contributions are:
- Oncology: lung cancer, breast cancer, testicular and ovarian cancer, recurrent colorectal cancer, lymphoma, melanoma, recurrent brain tumors, tumor-therapy monitoring, and assessing effectiveness of treatments such as chemotherapy.
- Cardiology: coronary artery disease and myocardial viability.
- Neurology and Psychiatry: Diagnosis of Parkinson’s, Alzheimer’s, Huntington’s, epilepsy, and stroke victims.
How PET/CT Works
PET/CT procedures may vary, but in general, a PET/CT technologist administers the radioisotope by injection to the patient, who lies still for about 60 minutes, and then is scanned in the CT portion of the machine followed by the PET portion of the machine. The entire time in the PET/CT system is approximately 45 minutes.
Will my insurance cover PET/CT?
Many insurance companies are reimbursing for PET procedures. Medicare has approved the following exams: lung cancer, recurrent colorectal, melanoma and lymphoma. Contact your insurer directly to learn about payment reimbursement.
Positron Emission Tomography (PET) and Computed Tomography (CT) when done together is a sophisticated imaging technique that assists in the diagnoses and management of many diseases. Using PET/CT, physicians can identify disease, particularly cancer, often before it is visible in other imaging procedures. PET/CT can change the way your physician cares for you.
Your PET/CT Scan
Your physician has referred you for a PET/CT scan because he or she believes it may help determine whether you have a disease, the extent of the disease, and the best course of treatment.
A PET/CT scan is a painless study that will take about two hours. You will be able to resume normal activities after the test.
Preparation For Your Test
Preparation for your PET/CT Scan – Downloadable Information Sheet (Click to open and print in Word Document .docx format)
On the day of your test, please bring to following with you to the PET/CT Center:
- Insurance information
- Previous CT/MRI films and reports
- Chemotherapy/Radiation Therapy history
- Please refrain from strenuous exercise for 2 days prior to the exam
- No eating or drinking (other than water) 6 hours prior to the exam
- Drinking plenty of water is encouraged prior to the exam
- Diabetic patients will require special preparation and should call the PET Center for instructions.
If you have any questions about your pre-test preparation, please contact the PET/CT Center.
Upon arrival at the PET/CT center, you will be escorted to a quiet preparation room. The PET/CT scan procedure begins with a small finger stick to measure your Blood Glucose Level. The technologist will then insert a small intravenous catheter and inject FDG (flourodeoxyglucose), a radioactive tracer that resembles glucose (sugar).
You will be asked to rest quietly as the FDG circulates throughout your body. You will then be positioned on the camera and scanned. It is important to remain still as the images of your body are obtained. The imaging time varies, but generally takes about 30 minutes.
A physician specially trained in reading PET/CT scans interprets the images acquired during the procedure. Your referring physician will receive the results within 48 hours.
Frequently Asked Questions
Who should have a PET/CT scan?
Your primary care physician or specialist will determine if a PET/CT scan is appropriate for you. PET/CT scans have been particularly useful in diagnosing many types of cancer, including: lung cancer, breast cancer, colorectal cancer, ovarian cancer, esophageal cancer, head and neck cancer, lymphoma and melanoma.
PET/CT can detect an abnormality and determine if it is benign or malignant. It can also evaluate your response to chemotherapy or radiation therapy. PET/CT is useful in diagnosing many types of neurological disorders, such as Alzheimer’s disease and epilepsy, and to identify certain types of heart disease.
Pregnant or nursing women should not have a PET/CT scan unless their doctor believes it is essential to their care.
How does a PET/CT scan work?
A person having a PET/CT scan is injected with a radioactive tracer, such as FDG, about an hour before the scan. The FDG, which is a form of radioactive glucose (sugar), is absorbed by the body’s tissue. The PET/CT scanner produces both PET and CT pictures of this tissue and surrounding anatomy, which reveals important information and will assist your physician in your treatment.
What’s the difference between a PET/CT scan and other imaging tests, such as CT and MRI?
PET/CT is a way of imaging how the body is functioning and accurately showing the location of those functions. CT and MRI, which are used to visualize the structure of the body, do not provide images of metabolic activity. In some cases, PET/CT can identify abnormal activity before it is visible on CT or MRI. When used in conjunction with these other imaging modalities, PET/CT can provide an even more comprehensive picture of the body function.
How much radiation is a patient exposed to during the procedure?
The amount of radiation received from a PET/CT scan is similar to that of other diagnostic imaging exams.
Will My Insurance Cover My PET/CT Scans?
Most insurance companies reimburse for PET procedures. It is important to contact your insurer regarding coverage. Your referring physician may be able to assist with referrals, pre-authorizations, or other specific insurance company requirements
Is PET/CT painless?
Yes. You will not experience any discomfort and can relax while the scan is being performed.
How do I get a PET/CT scan scheduled?
You or someone from your referring physician’s office will contact the PET/CT Center to schedule the procedure. You will be contacted by the PET/CT Center to confirm your appointment.
PET/CT (Positron Emission Tomography with simultaneous CT) is a recognized clinical certainty with proven uses in three major areas: Oncology, Neurology and Cardiology. PET/CT can accurately determine whether most tumors are benign or malignant, show the progression of disease and accurately track the effectiveness of cancer treatment. PET/CT can reveal dysfunctional cognitive patterns, making it a valuable tool for assessing patients with various forms of dementia. PET/CT is an imaging modality that has helped advance the treatment of refractory seizures as a pre-surgical diagnostic tool to guide treatment options. A PET/CT scan provides one of the highest levels of accuracy of any non-invasive test for the diagnosis of coronary artery disease and the assessment of myocardial viability. PET/CT technology also has a potentially larger and valuable role in early diagnosis and tailoring therapies.