title: The validity of performing a ventilation study after the perfusion lung scan.
mesh_terms: D006801:Humans; D012129:Respiratory Function Tests / Q000379:methods*; D012542:Scattering, Radiation; D013667:Technetium; D014980:Xenon Radioisotopes
chemical_list: D014980:Xenon Radioisotopes; D013667:Technetium