A PET scan is an effective way to examine the chemical activity in certain parts of your body, which may help detect abnormalities in those areas. PET scans are most often used in people who have cancer, heart disease or brain disorders.


Cancer cells show up as brighter spots on PET scans because they have a higher metabolism rate than do normal cells. PET scans may be useful in determining:

  • The extent or spread of certain cancers
  • How well the cancer is responding to treatment
  • If the cancer has recurred

PET scans must be interpreted carefully because noncancerous conditions can resemble cancer, and many types of cancer do not appear on PET scans. The types of cancer most likely to show up on PET scans include:

  • Brain
  • Breast
  • Cervical
  • Colon
  • Esophageal
  • Lung
  • Lymphoma
  • Melanoma
  • Pancreatic
  • Thyroid

Heart disease

Doctors use PET scanning to detect areas of decreased blood flow in the heart. This can help show which areas of the heart might benefit from angioplasty or coronary artery bypass surgery.

Brain disorders

A PET scan can show which areas of the brain have the most activity during various tasks. This technology also can evaluate specific brain abnormalities, such as:

  • Tumors
  • Memory disorders
  • Seizures
May. 07, 2011