title: Taking gas from a pearl.
mesh_terms: D003937:Diagnosis, Differential; D004931:Esophageal Achalasia / Q000000981:diagnostic imaging*; D004940:Esophageal Stenosis / Q000000981:diagnostic imaging*; D005740:Gases; D006801:Humans; D011859:Radiography; D013270:Stomach / Q000000981:diagnostic imaging*
chemical_list: D005740:Gases