A PET scan of the chest shows how well the lungs are functioning and checks for lung cancer and other problems with the lungs, reports MedlinePlus. PET stands for positron-emission tomography.
During a PET scan, a radioactive substance is injected into the bloodstream, explains MedlinePlus. This substance accumulates in the tissues of the body, making it easier to see certain areas. The test produces 3-D images that aid in the diagnosis of respiratory problems and the monitoring of patients who have already been diagnosed with lung cancer. PET scans are also used to detect the spread of lung cancer in other areas of the body. A PET scan of the chest takes approximately 90 minutes to complete.