What Is a Brain PET Scan?
positron emission tomography (PET) scan is an imaging test that allows doctors
to see how your brain is functioning.
captures images of the activity of the brain after radioactive “tracers” have
been absorbed into the bloodstream. These tracers are “attached” to compounds
like glucose (sugar). Glucose is the principal fuel of the brain.
of the brain will be utilizing glucose at a higher rate than inactive areas.
When highlighted under a PET scanner, it allows doctors to see how the brain is
working and helps them detect any abnormalities.
an outpatient procedure. This means you’ll be able to go about your day after
the test is complete.
Why Is a Brain PET Scan Performed?
accurately details the size, shape, and function of the brain.
scans, a brain PET scan allows doctors a view of not only the structure of the
brain, but how it is functioning as well.
if cancer has spread to the brain
dementias, including Alzheimer’s disease
between Parkinson’s disease and other conditions
for epilepsy surgery
may have you undergo a brain PET scan regularly if you’re undergoing treatment
for brain disorders. This can help them monitor the success of your treatment.
How to Prepare for a Brain PET Scan
will provide you with complete instructions to help you prepare for your brain
PET scan. Alert your doctor to any medications you may be taking, whether they
are prescription, over the counter, or even nutritional supplements.
You may be
instructed not to eat anything for up to eight hours before your procedure. You
will be able to drink water.
doctor if you’re pregnant or believe you could be pregnant. The test might be
unsafe for your fetus. You should also tell your doctor about any medical
conditions you may have. For example, people with diabetes will likely be given
special instructions for the test. Fasting beforehand could negatively affect
their blood sugar levels.
before the test, you may be asked to change into a hospital gown and remove all
of your jewelry.
Of course, you
want to plan your day around your appointment as well.
How a Brain PET Scan Is Performed
brought into the procedure room and seated in a chair. A technician will insert
an intravenous catheter (IV) into your arm. A special dye with radioactive
tracers will be injected into your veins through this IV. Your body needs time
to absorb the tracers as blood flows through the brain, so you will wait before
the scan begins. This typically takes about an hour.
Next, you will
undergo the scan. This involves lying on a narrow table attached to the PET
machine, which looks like a giant toilet paper roll. The table glides slowly
and smoothly into the machine so the scan can be completed.
You will have
to lie still during the scans. The technician will tell you when you need to
remain motionless. The scans record brain activity as it’s happening. These can
be recorded as video or as still images. The tracers are concentrated in areas
of increased blood flow.
desired images are stored in the computer, you’ll exit the machine. The test is
Following up After a Brain PET Scan
It’s a good
idea to drink plenty of fluids after the test to help flush the tracers out of
your system. Generally all tracers are out of your body after two days.
Other than that,
you’re free to go about your life unless your doctor gives you other
specialist trained in reading PET scans will interpret the images and share the
information with your doctor. Your doctor will then go over the results at a
Interpreting the Results of a Brain PET Scan
The images of
brain PET scans appear as multicolored images of the brain, ranging from dark
blue to deep red. Areas of active brain activity come up in warmer colors, such
as yellow and red. Your doctor will look at these scans and check for
For example, a
brain tumor will show up as darker spots on the PET scan. A person with
Alzheimer’s and other forms of dementia will have larger-than-normal portions
of their brain appear darker on the scan. In both of these cases, the dark
areas signify areas of the brain that are impaired.
will go over your personal scan to explain what the results mean and what will
be the next course of action.
The Risks of a Brain PET Scan
While the scan
does use radioactive tracers, the exposure is minimal. It’s too low to affect
the normal processes of the body.
The risks of
the test are minimal compared with how beneficial the results can be.
radiation is believed to be unsafe for fetuses, so women who are pregnant,
think they may be pregnant, or are nursing should not undergo a brain PET scan
or any other kind of PET scan.
include uncomfortable feelings, if you are claustrophobic or anxious about