PET (positron emission tomography)
A PET scan is a special kind of imaging test which allows doctors to see how certain tissues and organs within the body are functioning.
The most significant difference between a PET scan and other imaging tests such as MRI or CT scans is the ability to detect changes in the body at the cellular level rather than after a disease has progressed enough to actually affect the surrounding tissue or organs.
A PET scan is a complementary test. This means that it is usually used with other tests, such as X-rays or MRI scans.
The scan is performed by injecting a small amount of radioactive chemical into a vein. As the chemical travels through the body, it is absorbed by the organs and tissues. During the test, a scanner records the energy produced by the cells. A computer converts the recording into three-dimensional pictures of an area of the body and any cells that are changing show up at a brighter contrast to any surrounding, normal cells.
There is very little preparation involved prior to a PET scan and it is usually done on an outpatient basis. In general, most patients are simply given restrictions on food or drink for 6 to 12 hours prior to the test, which takes approximately 2 hours to complete. A PET scan is painless and side effects are unlikely.Back to previous page