title: The ventilation study: before or after the perfusion lung scan?
mesh_terms: D006801:Humans; D008168:Lung / Q000000981:diagnostic imaging*; D008173:Lung Diseases, Obstructive / Q000000981:diagnostic imaging; D011655:Pulmonary Embolism / Q000000981:diagnostic imaging*; D011877:Radionuclide Imaging; D013997:Time Factors; D014692:Ventilation-Perfusion Ratio; D014980:Xenon Radioisotopes
chemical_list: D014980:Xenon Radioisotopes