lung and airway disorders
Chest Imaging
Nuclear Lung Scanning
 Radionuclide Scanning can be useful in detecting A nuclear lung ventilation/perfusion scan is noninvasive and fairly accurate but takes longer than CT angiography. A ventilation/perfusion scan is actually two scans, one that measures breathing (ventilation) and one that measures blood flow (perfusion). The tests are usually done together but can also be done separately. For a lungperfusionscan, a tiny amount of radioactive substance is injected into a vein and travels through the pulmonary arteries to the lungs, where it outlines the blood supply of the lung. In a lungventilationscan, the person inhales a harmless gas containing a trace amount of radioactive material, which is distributed throughout the small air sacs of the lungs (alveoli). The areas where carbon dioxide is being released and oxygen is taken up can then be seen on a scanner. By comparing the ventilation scan to the pattern of blood supply shown on the perfusion scan, doctors can usually determine whether a person has pulmonary emboli. 