What is a PET Scan?
PET is an imaging test that introduces a radioactive substance into the
body known as a “tracer.” A special camera is used to detect
signals emitted within the body by this compound. Those signals allow
the camera to create three-dimensional images of the corresponding organ
or system. PET-CT machines combine PET scans with CT imaging (a specialized
x-ray scan) to create single, highly detailed, superimposed images.
Why is it used?
Unlike other imaging techniques, PET scans reveal bodily tissues at the
cellular level, allowing doctors to observe and measure the actual function
of the organ or system. PET scans are especially advantageous for detecting
and measuring cancer metastasis. These scans can also:
- Detect heart problems, cancer, and disorders of the brain and central nervous system
- Provide a more in-depth view of coronary artery disease, brain tumors,
memory disorders, seizures and other complex illnesses
- Diagnose Alzheimer’s disease and other types of dementia
- Allow doctors to determine exact areas of the brain impacted by diseases
such as epilepsy, which in turn allows more effective treatment
- Gauge how well a specific cancer treatment is working
- Measure and observe blood flow to specific bodily organs and systems
- Gauge metabolism and oxygen intake
What happens during the test?
The tracer is delivered intravenously. The patient must wait between 45
and 60 minutes for the compound to reach the designated area. To begin
imaging, the patient lies on a table that slides into the donut-like machine.
The scan lasts between 15-30 minutes during which time the patient must
remain still. PET scans are painless and do not require a hospital stay.