title: Gastric xenon trapping mimicking COPD: recognition using an effervescent agent.
abstract: Trapping of xenon 133 in the stomach due to gas swallowing can mimic xenon 133 retention in the left lower lobe due to obstructive lung disease on pulmonary ventilation/perfusion studies. In such cases, ingestion of sodium citrate-bicarbonate-simethicone crystals, which form CO2 gas on contact with water, can distend the xenon-containing stomach and allow clear delineation of its gastric location. This approach is useful in selected cases and may help avoid false-positive diagnoses of obstructive airways disease.
mesh_terms: D000328:Adult; D000863:Antacids; D001639:Bicarbonates; D002951:Citrates; D019343:Citric Acid; D003937:Diagnosis, Differential; D004338:Drug Combinations; D005740:Gases; D006801:Humans; D008168:Lung / Q000000981:diagnostic imaging; D008173:Lung Diseases, Obstructive / Q000000981:diagnostic imaging*; D008297:Male; D011877:Radionuclide Imaging; D017693:Sodium Bicarbonate; D013270:Stomach / Q000000981:diagnostic imaging*; D014980:Xenon Radioisotopes
chemical_list: D000863:Antacids; D001639:Bicarbonates; D002951:Citrates; D004338:Drug Combinations; D005740:Gases; D014980:Xenon Radioisotopes; C031210:citric acid, sodium bicarbonate drug combination; D019343:Citric Acid; D017693:Sodium Bicarbonate