[On sources of error in examination of the esophagus for evaluation of enlargement of the left atrium].
D006332:Cardiomegaly / Q000000981:diagnostic imaging*; D004947:Esophagus / Q000000981:diagnostic imaging*; D006325:Heart Atria; D006801:Humans; D006984:Hypertrophy; D011859:Radiography
ESOPHAGUS/radiography; HEART ENLARGEMENT/radiography