A PET scan uses radioactive tracers injected into the body to produce 3D images showing functional processes. A short-lived radioactive tracer, FDG, is injected and detected as it breaks down, showing glucose metabolism levels in tissues. Different metabolism levels appear as different colors, allowing the computer to generate images of functional abnormalities like cancers or brain disorders. PET scans can detect diseases earlier than other scans and help avoid unnecessary surgery by precisely identifying areas needing treatment.

1. PROJECT
Positron Emission Tomography
PET SCAN
DATE
NOV.1ST 2013
CLIENT
THERESA YIP & MICHELLE MA

2. What is a PET Scan?
Full name: Positron Emission Tomography
A nuclear medical imaging technique which produces a
three dimensional image of functional processes in the
body.
Especially valuable in imaging the brain
Detects the metabolism level of injected substances
(glucose), made radioactive to show the most active parts
of the brain.

3. How does a PET scan
work?
A short lived radioactive tracer isotope (a simple sugar and a
small amount of radioactive fluorine), called F-fluorodeoxyglucose
(FDG), is injected into the patient. The tracer is chemically
incorporated in to a biologically active molecule(usually glucose).
PET detects the gamma rays emitted by positively-charged
particles (positrons) when the radiotracer is broken down inside
the body
Different concentrations of positrons that represent different levels
of tissue function then show up as areas of different colours and
brightness
These are then processed by the computer to generate images.

4. PET Scan images
IMAGES ON HOW THE BRAIN SCAN LOOKS
DURING DIFFERENT SITUATIONS

5. Strengths
Early PET scan can diagnose any abnormalities in activity level e.g. Can help
detect cancer, brain disorders, heart conditions and other diseases
By identifying changes in the body at the cellular level, PET imaging may detect
the early onset of disease before it is evident on other imaging tests such as CT
or MRI.
PET scan can avoid unnecessary surgery
For many diseases, nuclear medicine scans yield the most useful information
needed to make a diagnosis or to determine appropriate treatment, if any.
Nuclear medicine is less expensive and may yield more precise information than
exploratory surgery.
The information provided by nuclear medicine examinations is unique and
often unattainable using other imaging procedures.

6. Limitations
Time-consuming
Not as precise as fMRI scan
PET scan might be dangerous depending on each individual’s
heart conditions
PET scan can sometimes show up areas of high activity which my
be mistake for cancers
The radioactive substance has a very short decay and therefore
appointments must run on schedule.
PET scans are a very expensive form of imaging, and are not
readily available all the time.

7. Bibliography
•
Brain Positron Emission Tomography. (n.d.). In
Wikipedia. Retrieved from
http://en.wikipedia.org/wiki/Brain_positron_emission_tom
ography
•
Raichle. M. (n.d.). Retrieved from
http://www.alz.org/living_with_alzheimers_your_brain.asp
•
Silverman D. (Doctor) (2011, July 18). What is a PET
Sc an? Podcast retrieved from
http://www.youtube.com/watch?v=scoOTHl879A
•
(n.d.) Retrieved from http://www.snm.org/index.cfm?
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