title: [Regional ventilation-perfusion ratio in chronic lung diseases measured with krypton-81m].
mesh_terms: D000368:Aged; D005260:Female; D006801:Humans; D007726:Krypton; D008173:Lung Diseases, Obstructive / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D011868:Radioisotopes; D014692:Ventilation-Perfusion Ratio
chemical_list: D011868:Radioisotopes; D007726:Krypton