About Nuclear Medicine and Molecular Imaging
Positron Emission Tomography (PET) Scan
What is a PET Scan?
While other imaging techniques—such as X-rays or CT scans—provide anatomical information about the way organs or tissues look, a PET scan shows what the cells in those organs or tissues are doing. That functional information is then used for diagnosis, evaluation and treatment of disease.
How Does a PET Scan Work?
Because a PET scan is noninvasive and does not involve the risks of surgery, it can be performed repeatedly, if necessary, with minimal risk.
Most individuals undergo PET scans as outpatients. During the scan, the patient is asked to lie still while the PET camera images the distribution of radiotracer in his or her body. The very small amount of tracer administered usually remains in the body for only a short period of time; there are no known adverse effects from such low doses.
During the imaging process, patients are cared for by nuclear medicine technologists. Technologists and other specialists work with sophisticated imaging devices, computers and assessment techniques.
After the PET scan, a nuclear medicine physician reviews the images, prepares a written report and may discuss the results with the patient's doctor.
Why Is a PET Scan Important?
PET scans often reveal disease before it can be seen with other tests. Often, in addition to imaging the disease, it can provide information used to determine the most promising treatment methods. PET scans are also used to evaluate how well treatments are working and can often show significant changes far sooner than other tests.
PET and Cancer
A PET scan is considered to be the most accurate diagnostic procedure for assessing whether many types of cancer have recurred after treatment. It is also effective in evaluating the potential success of specific therapies.
PET and Heart Disease
PET and Alzheimer's and other Brain Disorders
PET and the Future
PET is now being combined with other imaging techniques—such as computed tomography (CT)—to create "fusion" images that provide an anatomical context to the functional information.
In 2005, an estimated 1,129,900 clinical PET scan patient studies were performed using PET or PET/CT scanners or nuclear medicine cameras in 1,725 hospital and non-hospital sites in the United States. According to a report by IMV Medical Information Division, the number of patient studies increased more than 60 percent since 2003, for an average annual growth rate of 26.5 percent over the two-year period.
The PET scan—alone and in combination with other techniques—will continue to provide a unique look into the body and yield valuable information for therapy and preventive health measures.
SNM and PET