Positron
Emission Tomography (P.E.T. Scan)
What
is Positron
Emission Tomography (P.E.T. Scan)
PET (positron emission tomography) is a medical imaging
scan which creates functional pictures of the human body.
Unlike x-rays, ultrasound, CT or MRI scans, which create
images of your body structure (anatomy), PET provides
data in the form of images which reveal the functional
processes (physiology or metabolism) of the body. Here
are some of the most frequently asked questions about
PET imaging:
What does PET stand for?
PET is short for positron emission tomography. The name
refers to the type of radioactive isotopes that are used
in the injectable radiopharmaceuticals, which are positron
emitters. Tomography is the way the computer makes the
picture into two and three dimensions.
What
is going to happen to me today?
The staff at Pinnacle Imaging Center will collect
a basic medical history from you and explain the scanning
process. Next, the technologist will start a small temporary
IV (intravenous) access in one of your arms, through which
a radiopharmaceutical will be injected. The technologist
will then remove the IV and you will be asked to rest
in a recliner for thirty minutes to an hour while the
radiopharmaceutical circulates through your body. After
the waiting period, you will be taken to the restroom
so that you can empty your bladder prior to the imaging
process. Finally, you will lie down on the scanner table.
The technologist will make you as comfortable as possible.
Just try to lie quietly and breathe normally.
Is
this going to hurt?
The only part of the PET scan that you will feel is when
the technologist establishes an IV (intravenous) access
in your arm with a small needle. This IV access port will
be used to give you the radiopharmaceutical injection.
What
is in the injection that I get for the scan?
The radiopharmaceutical injected into you for your PET
scan is called FDG, which stands for “fluoro-deoxy-glucose”.
This is a very low concentration solution of glucose in
water. The glucose, or sugar molecules, have a radioactive
isotope of fluorine attached to them which allows the
scanner to “see” where the sugar is being
used (metabolized) in your body.
Will
I have any reactions or effects from the injection?
You will not have any side effects or adverse reactions
to the injection.
I
am a diabetic. Will this injection of sugar upset my diabetes?
No. The amount of sugar injected into your bloodstream
will not upset your sugar balance.
How
long does the PET process take?
You will be here for approximately two hours, depending
on the type of study your doctor has requested.
Do
I have to get undressed to have my scan taken?
No. The camera can collect all of the necessary data with
you being fully clothed. We suggest that you NOT wear
any jewelry (other than wedding bands) on your scan day.
You will be asked to remove necklaces, earrings, any metal
objects in your pockets, etc. before the scanning begins.
Why
can’t I eat before this test?
The injection given for the PET study uses sugar (glucose)
as a transport molecule. If your blood sugar level is
too high at the time of the injection, the scan will be
invalid.
Can
I have water before I come for my test?
Yes. Water is the only substance you may have prior to
your test. Diabetic patients should check with their personal
physicians to discuss dietary restrictions in relation
to this test.
Should
I take my medicines as I normally do?
Yes. Most medications do not interfere with this test.
Check with your personal physician to be sure you know
what to do about your medications.