A PET scan uses radioactive tracers to detect disease in the body at a cellular level. It works by injecting a small amount of radioactive sugar molecule called FDG into the bloodstream. Cancer cells absorb more FDG than normal cells, allowing cancers to be seen as hot spots on PET images. PET scans are useful for detecting cancer, epilepsy, Alzheimer's disease, and evaluating treatment response. While exposing patients to radiation, PET scans provide metabolic imaging to detect diseases earlier than other scans.
2. What is a Pet Scan?
• Nuclear 3-D imaging test that
uses a radioactive substance
called a tracer to look for
disease in the body.
• Shows how organs and tissues
are working at a molecular and
cellular level. Scan is non-
invasive, but does involve
exposure to ionizing radiation.
• Best known for its role in
detecting cancer imaging.
3. How Do Pet
Scans work?
• A small amount of a radioactive
sugar molecule, 18 fluoro-2-
deoxyglucose (FDG), is injected
into the bloodstream (can also be
inhaled as gas or swallowed in
pill form).
• A PET Scan is used to detect and
generate images that indicate
areas of high FDG uptake.
• Many cancers require more
energy than normal cells, and the
FDG tracer accumulates in these
cells.
• This allows cancers to be seen on
the Pet images as hot spots.
4.
5. Pet scan of a patient showing wide
spread of cancer metastasis.
A 61-year-old woman with
metastasis of breast cancer to
the left supraclavicular lymph
node
6. Scan of a healthy
child's brain.
Scan of an abused
child’s brain
8. PET SCAN ADVANTAGES
• Unlike CT or MRI scans, PET
scans can measure cellular-
level metabolic changes
occurring in an organ or
tissue (early stage detection).
• CT’s and MRI’s cannot detect
changes until the disease has
already began to cause
changes or damage in the
structure of organs or tissues.
9. PATIENT COST & TIME
$3,000 to
$6,000
per scan
Takes 2
to 4
hours
10. RISK FACTORS
Cause a major allergic reaction, in rare
instances
Expose your unborn baby to radiation if you
are pregnant
Expose your child to radiation if you are
breast-feeding
11. CONSIDERATIONS
It is possible to have
false results on a
PET scan. Blood
sugar or insulin
levels may affect the
test results in people
with diabetes.
Most PET scans are
now performed
along with a CT
scan. This
combination scan is
called a PET/CT.
This helps find the
exact location of the
tumor.
17. REFERENCES
Joseph, U. A. (June 01, 2012). Positron Emission Tomography. Journal
of Nuclear Medicine, 53, 6, 1002-1003.
Kumar, R., Halanaik, D., & Malhotra, A. (January 01, 2010). Clinical
applications of positron emission tomography-computed
tomography in oncology. Indian Journal of Cancer, 47, 2.)
Politis, M., & Piccini, P. (January 01, 2012). Positron emission
tomography imaging in neurological disorders. Journal of
Neurology, 259, 9, 1769-80.
Society of Nuclear Medicine and Molecular Imaging. (2014). Pet
scans: Get the facts. Retrieved from:
http://interactive.snm.org/index.cfm?PageID=7988
Hinweis der Redaktion
A positron emission tomography (PET) scan is used to produce a detailed, three-dimensional picture of the inside of the body. The images clearly show the part of the body that is being investigated and can also highlight how effectively certain functions of the body are working. Pet scans are most commonly used to help diagnose a range of different diseases and/or disorders to work out the best possible course of treatments for a patient.
The scanner contains an array of detectors that receive signals emitted by the radiotracer. Using these signals, the Pet scanner measures metabolic activity while a computer reassembles the signals into images. The Pet scan itself should not be painful, but for some people, being inside the scan tends to cause claustrophobia.
PET scans are occasionally used to help plan complex heart surgery, such as a heart transplant. They are also used to help diagnose a number of conditions that affect the normal workings of the brain (neurological conditions), such as dementia and Alzheimer’s disease. It can accurately assess the location and stage of a malignant condition. It also helps by replacing multiple medical testing procedures with a single exam and reducing or eliminating any ineffective or unnecessary treatment. Pet scans can eliminate the need for surgical biopsy because PET can detect whether lesions are benign or malignant. PET is currently the most effective way to check for cancer recurrence.
PET scanners are expensive (price ranging between $ 2.5 and $ 6.5 million), so they are usually only found at larger hospitals and some specialized research centers such as Moffitt Cancer Research Center in Tampa, Florida. Due to the lack of availability, PET scans are often only recommended for people with complex health problems (ex. Hodgkin's Lymphoma). They are not routinely used to diagnose cancer, but they are often used in confirmed cancer cases to check how far the cancer has spread and whether treatment has been effective. Due to the equipment high cost and limited availability, the cost of having the procedure performed on a patient can be pricey as well.