As the first community hospital in Los Angeles County to introduce PET
imaging, Torrance Memorial Medical Center has been and remains a leader
in the use of this innovative and important technology here in our South
Bay area. We currently perform and interpret more than 1300 PET/CT scans
What is PET/CT?
Positron emission tomography (PET) is a type of imaging that uses nuclear
medicine to detect problems at the molecular level. This sophisticated
technology can identify abnormalities in cellular activity at a very early
stage, generally before anatomic changes are visible. When combined with
computed tomography (CT), which provides a detailed picture of the body's
internal anatomy, PET/CT combines the strength of these two well-established
modalities into a single state-of-the-art scan that provides important
information to help guide potentially life-saving treatments.
- PET/CT is used in oncology to determine the extent (stage) of many types
of cancers, to monitor treatment effectiveness and to check for recurrence.
- In cardiology, PET/CT can assess coronary artery disease. After a heart
attack, PET/CT can determine if the heart muscle would benefit from bypass surgery.
- In neurology, PET/CT can help in the diagnosis of dementia and Alzheimer's disease.
What to Expect During a PET/CT Scan
A PET/CT scan is typically done on an outpatient basis. The appointment
lasts between one-and-a-half to two hours. Generally, you'll be asked
not to eat anything for several hours, since digestion may alter the distribution
of the PET tracer in the body. You will be encouraged to drink water but
to avoid other liquids, since any ingested sugar may alter the reliability
of the study. Diabetic patients may be given specific instructions.
PET/CT involves injecting a small amount of a radioactive tracer into a
vein in the arm or hand. You will feel a small pin prick sensation when
the needle is inserted. When the radiotracer is injected, some patients
feel a cool sensation in the arm, but generally there are no other side
effects. The radiotracer typically needs to circulate for approximately
one hour, so you will sit comfortably in a reclining chair during this
The PET/CT scanner is a large machine with a doughnut-shaped hole in the
middle. The actual time spent in the scanner is usually 30 minutes or
less. As you pass through it, the scanner's multiple detectors pick
up the radiotracer emission and highlight areas of increased uptake in
your body. Sophisticated computer software is used to process the information
so that it can be displayed in three dimensional planes on a computer
workstation. A radiologist will interpret the images and send a report
to the referring physician. The report is typically available within 48
hours and will be discussed with you by your physician.
PET/CT and Radiation
Because the dose of radiotracer administered during a PET/CT is small,
there is relatively low radiation exposure. The radiation risk is very
low and typically outweighed by the potential benefits of the study. Through
the natural process of decay, the small amount of injected radiotracer
will lose its radioactivity over time. It will also pass out of your body
through the urine. Therefore, it is important to drink plenty of water
to help flush the radioactive material from your body.
How Will You Learn About Your Results?
The technologist will not give you the test results directly, as the images
still need to be reviewed by a radiologist. After reviewing the study,
the radiologist will send an official report to your physician, who can
then discuss the results with you.
For More Information
For more information on these types of exams please visit
Schedule an Appointment
We make it easy to schedule an imaging appointment.