title: Value of measurement of alveolo-arterial gradient of PCO2 compared to pulmonary scan in diagnosis of thromboembolic pulmonary disease.
mesh_terms: D000368:Aged; D000792:Angiography; D002245:Carbon Dioxide / Q000097:blood*; D005260:Female; D006801:Humans; D007457:Iodine Radioisotopes; D008722:Methods; D008875:Middle Aged; D011650:Pulmonary Alveoli / Q000098:blood supply*; D011655:Pulmonary Embolism / Q000175:diagnosis*; D011877:Radionuclide Imaging; D013667:Technetium; D014692:Ventilation-Perfusion Ratio
chemical_list: D007457:Iodine Radioisotopes; D002245:Carbon Dioxide; D013667:Technetium