title: Reproducibility of ventilation studies.
abstract: Differences in ventilation patterns were observed in several instances in two consecutive ventilation studies with 127 Xe and 133Xe gas involving a group of 20 patients with COPD and other pulmonary disorders. Included were differences in the distribution of a tracer gas bolus during the initial inspiration, the distribution of gas tracer after equilibration and during gas washout, artifacts external to the lung, and variations in the half-time for gas washout. The observed discrepancies are clinically significant and could lead to erroneous or ambiguous diagnoses.
mesh_terms: D000368:Aged; D003951:Diagnostic Errors; D004646:Emphysema / Q000000981:diagnostic imaging; D006801:Humans; D008176:Lung Volume Measurements; D008297:Male; D008722:Methods; D008875:Middle Aged; D011658:Pulmonary Fibrosis / Q000000981:diagnostic imaging; D011877:Radionuclide Imaging; D012140:Respiratory Tract Diseases / Q000000981:diagnostic imaging*; D014980:Xenon Radioisotopes
chemical_list: D014980:Xenon Radioisotopes