ABSTRACT
Two groups of radiopharmaceuticals are used to assess lung ventilation. Xenon133, the prototype for the radioactive noble gases, has been widely available for many years. More recently, a wide range of " mTc-labeled aerosols have replaced 133Xe in many facilities. Despite differences in physiology and technical procedure, overall diagnostic accuracy is similar with these agents. Alternative ventilation imaging techniques, which are less widely available include 127Xe, 81mKr, 99mTc-Technegas and 99mTc-Pertechnegas.
