Performing
an actual PET scan involves having the patient recline on a table that
slides into the middle of an "open-air" scanner. Within the
scanner are rings of detectors containing special crystals that produce
light when struck by radiation. The patient is injected with a fluid called
radiopharmaceutical approximately 45 minutes before the PET scan. The
scanner's electronics record detected gamma rays and maps an image of the
area where the radiopharmaceutical is concentrated. Since the
radiopharmaceutical is comprised of a chemical commonly used by the body,
PET enables the physician to detect the location of the metabolic process.
As an example, a post therapy or surgery PET study, using fluro-deoxyglucose
(FDG) as the radioisotope, will demonstrate where glucose uptake
is occurring differentiating necrotic tissue from new and recurrent tumor
growth.
PET
Examination preparation requirements:
- Avoid strenuous
activities on the day before the PET examination. Excessive muscular
activity may interfere with interpretation of your scan
- Cancer patients
need to fast after midnight or at least six hours prior to their
examination with the exception of water, and you should be well hydrated
- Cardiac patients
must eat a light breakfast the morning of the PET examination
- If you are
diabetic, please bring your medication and a light snack with you. Make
sure that our staff is aware of your condition ahead of time
- Please be
prepared to stay with us for approximately three to four hours
