A gas ventilation scintigraphy is a diagnostic imaging test of lung ventilation with radioactive noble gases during breathing maneuvers, e.g. with krypton (81mKr) or xenon (133Xe).
The radioactive gas is administered by a mask and requires a special delivery and trapping system (gas trap). The radioactivity in the lungs is measured with a gamma camera and is subsequently evaluated.
The use of krypton or xenon gases involves problems like the relatively short half-lives (about 15-30 seconds) and relatively high costs of xenon and krypton. The short half-life requires that the scan is performed directly after administration of the gas. In addition, the gaseous radiopharmaceutical is expelled from the body almost quantitatively within a few minutes of completing the study.
A ventilation scintigraphy combined with a pulmonary perfusion scintigraphy is highly sensitive for the detection of pulmonary embolism.
Radioactive noble gases are widely used as a ventilation agent to diagnose pulmonary embolism. However, 81mKr and 133Xe are rare and expensive, which limits their continuous availability. Tc99m-Technegas can be an alternative ventilation agent with the advantage of being less expensive and available daily.

See also Inhalation Scintigraphy.

A mismatch describes an activity loss in lung perfusion scintigraphy combined with normal ventilation scintigraphy, e.g. in case of pulmonary embolism.

A perfusion scintigraphy records the organ blood circulation usually directly or during the first two minutes after the injection of a radioactive tracer.
Different types of radiopharmaceuticals are used, depending on the target organ.

Typical perfusion scans include:
See also First Pass Scintigraphy, Myocardial Scintigraphy, Heart Scintigraphy, Whole Body Scintigraphy, and Flare Phenomenon.

An aerosol ventilation scintigraphy is a nuclear medical imaging procedure that records the distribution of an inhaled radioactive aerosol within the bronchopulmonary system.
Aerosol ventilation in the gamma camera section does not constitute a significant radiation hazard to personnel. Patient compliance is an important factor to minimizing the dose. Clear instructions and practice are a vital part of the diagnostic imaging procedure.

See also Lung Scintigraphy, Aerosol Method, Gas Ventilation Scintigraphy and Inhalation Scintigraphy.