PET (Positron Emission Tomography) and CT
(Computed Tomography) studies are both standard
imaging tools that physicians use to pinpoint
disease states in the body. A PET scan demonstrates
biological function of the body while the CT scan
provides information about the body’s anatomy.
Alone, each imaging test has particular benefits and limitations but when both scans—PET and CT—are performed on the same scanner and at the same time, the combined image provides complementary information which enables physicians to more accurately diagnose and identify cancer, heart disease and brain disorders.
When disease occurs, the biochemistry of the body’s tissue and cells change. In some diseases, like cancer, the metabolic activity of the malignant cells increases, thus requiring higher glucose uptake and utilization.When the small amount of FDG (radioactive glucose analog) is injected into the patient, it travels through the body and accumulates in cells which then emit signals that are captured by the PET/CT scanner and then transformed into images of biological function.
A radiopharmaceutical is a radioactive drug. The most commonly used PET/CT radiopharmaceutical is FDG (fluorodeoxyglucose), which is a radioactive form of glucose (sugar).
To begin the PET/CT procedure, a small amount of the glucose is injected into your bloodstream. There is no danger to you from this injection. FDG has a half-life of approximately 110 minutes, so it is quickly expelled from your body. FDG must pass multiple quality control measures before it is used for any patient injection.
PET/CT is used to diagnose and stage patients with cancer, as well as patients with certain brain and heart disorders.
In cancer, PET/CT can: distinguish benign from malignant tumors, stage cancer by showing metastases anywhere in your body, prove whether or not treatment therapies are working (chemotherapy/ radiation).
In the brain, PET/CT can: diagnose Alzheimer’s disease for early intervention, locate tumors in the brain and distinguish tumor from scar tissue, locate the focus of seizures for some patients with epilepsy, more accurately assess tumors and other sites in the brain for delicate surgery.
The risks associated with a PET/CT scan are very minimal. The quantity of radiation is kept to a minimum and the FDG degrades quickly so that no detectable radioactivity is present after several hours. In addition to the radioactive decomposition, the remaining FDG is eliminated from the body through urine. Family members are not at risk for exposure since greater than 90% of the radioactivity has left the body or decomposed before the patient has left the center.
You should fast for at least 6 hours prior to your appointment. Please limit your exercise on the day of the exam ie/ do not use a treadmill, no exerted walking etc. It is important that you arrive on time for your study. Please bring the following to your appointment: insurance information, written order from your physician, films and reports from any previous PET, CT or MRI studies not previously performed at WRA.
Remember to wear warm, comfortable clothing. Plan to spend about two to three hours at the Nuclear Medicine PET/CT Center. Exam times and procedures vary with each patient.
The nurse will take a medical history and any prior PET/CT exams will be reviewed. Your blood sugar level will be checked. The technologist will then administer the imaging tracer (FDG) using an injection. A one-hour resting period will be required before the scanning begins. This resting period is necessary for the FDG to be distributed throughout the body.
You will be positioned on the scan table. The table will be moved into a large opening in the PET/CT scanner. You will be asked to lie still while the scanner acquires the images. The time of the scan varies but typically ranges from 20–30 minutes.
No, there are no side effects to having a PET/CT scan performed. It is a completely painless and non-invasive study. At WRA, our radiologists have extensive experience performing PET/CT studies every day. If any questions should arise after your procedure, you should contact your referring physician or the radiologist who oversaw the procedure.
After the radioactive tracer is processed by the organ being studied and the scanner records the information, the images are interpreted by a WRA board-certified radiologist with special training in PET/CT. Your scan results will be sent to your physician generally within 24-48 hours of your study.
Nuclear Medicine – PET/CT Center
2021 K Street,NW
Suite T-120
Washington, DC 20006
202-466-2033
Four Seasons Three
3022 Williams Drive, Suites 104, 200 & 204
Fairfax,Virginia 22031
703-698-8800
Lakeside At Loudoun Tech Center I
21351 Ridgetop Circle, Suites 100 & 150
Sterling,Virginia 20166
571-434-0140
Chase Tower
4445 Willard Avenue, Suite 200
Chevy Chase,Maryland 20815
301-654-4242
Camalier Building
10215 Fernwood Road, Suites 50 & 103
Bethesda,Maryland 20817
301-564-1053
Washington Radiology provides imaging services for patients upon referral from a physician. Patients are seen by appointment. However, emergencies do occur and we make every attempt to accommodate these cases. To schedule your PET/CT at Washington Radiology, please have your physician order and insurance card, and call: (202) 466-2033