title: [Reduction in transparency of the airway tracheogram, a sign of upper mediastinal pathology].
abstract: Some cases of mediastinal pathology in which the only pathological pattern was a "dimness" of the tracheal transparency are described. This sign is not described in previous reports and is described as a short break in the aerial tracheogram as seen on the frontal roentgenograph. This sign is produced by an increase in the structures outside the trachea or by a decrease in the air column inside the trachea. Conventional and CT anatomic findings which account for the sign are discussed. A short review of the "normal" causes of tracheal dimness is presented. This sign may be useful especially in emergency radiology, since it provides additional information to a simple routine chest roentgenograph.
mesh_terms: D004630:Emergencies; D006801:Humans; D008477:Mediastinal Diseases / Q000000981:diagnostic imaging*; D008482:Mediastinum / Q000000981:diagnostic imaging; D011859:Radiography; D014132:Trachea / Q000000981:diagnostic imaging*
vernacular_title: La riduzione di trasparenza del tracheogramma aereo, segno di patologia mediastinica superiore.