[A study on the efficiency of the serial radiography of the distal esophagus].
D000368:Aged; D004938:Esophageal Neoplasms / Q000000981:diagnostic imaging; D004947:Esophagus / Q000000981:diagnostic imaging*; D006801:Humans; D008297:Male; D011859:Radiography; D013679:Technology, Radiologic