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Positron Emission Tomography or PET Scan

PET scans can help doctors diagnose a wide variety of conditions. Read about this imaging test here:

PET Scan

PET Scan

PET Scan

What is a PET Scan?

Positron Emission Tomography, or PET, scans are a diagnostic tool used to create images that allow doctors to observe how tissue and organs are functioning. This is accomplished through the use of a a small, controlled amount of radioactive substance called a tracer.

Who needs a PET Scans?

Your doctor may order a PET scan to help diagnose vascular diseases, cancer, neurological disorders, or other conditions that affect the tissue or organs in the body. PET scans may also be used in addition to other imaging tests to learn more about a particular condition. PET scans are used to reveal changes in organ or tissue function, structure, or chemistry that may not be seen with other scans like magnetic resonance imaging, or MRI, or computed tomography, or CT.

What are the steps in a PET Scan?

Preparing for a PET Scan

To obtain the most accurate images, your doctor may tell you to fast for a set time period prior to the PET scan. About an hour before the PET scan, you will be given a small amount of radioactive chemical called a tracer. The tracer is used to improve the amount of detail revealed in the scan. The tracer may be administered using different methods depending on the purpose of the test. Often the tracer is injected into a vein in the arm, but it may also be inhaled or taken orally. The patient is given 30 minutes to an hour to allow the tracer to absorb into the organs or tissues being studied.

The Procedure

After enough time has passed, the patient is positioned on a padded table. Once patient is placed in the correct position, which may require pillows or straps, the scanning process is started. Once the machine is activated, the table will slowly move into the tunnel-shaped scanning device. The time it takes for a PET scan may vary, but the procedure usually lasts 30 minutes to an hour. If the patient moves during the procedure, it may be necessary to stop and restart the process.

Monitoring the Procedure

During the PET scan procedure, a technician in the next room observes the procedure and the imagery provided during the scanning process. The patient and the technician communicate by a microphone and speaker during the procedure.


After the scan is completed, a radiologist reviews the PET images and sends a report to the referring physician. The patient and physician will discuss the results of the test to determine a course of treatment.