What Is Positron Emission Tomography (PET) Scan?
Positron emission tomography, also called PET imaging or a PET scan,
is a type of nuclear medicine imaging. A PET scan measures important
body functions, such as blood flow, oxygen use, and sugar (glucose)
metabolism, to help doctors evaluate how well organs and tissues are functioning.
PET is a powerful diagnostic test that is having a major impact on
the diagnosis and treatment of disease. A PET scan (positron emission
tomography scan) monitors the biochemical functioning of cells by
detecting how they process certain compounds, such as glucose (sugar).
PET can detect extremely small cancerous tumors, subtle changes of the
brain and heart, and give doctors important early information about
heart disease and many neurological disorders, like Alzheimer's.
Most common medical tests, like CT and MRI scans, only
show details about the structure of your body. PET scans give doctors
images of function throughout the entire body, uncovering
abnormalities that might otherwise go undetected. This allows doctors
to treat these diseases earlier and more accurately. A PET scan puts
time on your side. The earlier the diagnosis, the better the chance
for treatment.
For example, a PET scan is the most accurate, non-invasive way to
tell whether or not a tumor is benign or malignant, sparing patients
expensive, often painful diagnostic surgeries and suggesting treatment
options earlier in the course of the disease. Although cancer spreads
silently in the body, PET can inspect all organs of the body for
cancer in a single examination.
Today, most PET scans are performed on instruments that are combined
PET and CT scanners. The combined PET/CT
scans provide images that pinpoint the location of abnormal
metabolic activity within the body. The combined scans have been shown
to provide more accurate diagnoses than the two scans performed separately.
About nuclear medicine
Nuclear medicine is a branch of medical imaging that uses small
amounts of radioactive material to diagnose or treat a variety of
diseases, including many types of cancers, heart disease, and certain
other abnormalities within the body. Depending on the type of nuclear
medicine exam you are undergoing, the radiotracer is either injected
into a vein, swallowed or inhaled as a gas and eventually accumulates
in the organ or area of your body being examined, where it gives off
energy in the form of gamma rays. This energy is detected by a device
called a gamma camera, a PET scanner and/or probe.
Learn more about other nuclear
imaging tests.