Localization of intrathoracic lesions by means of the postero-anterior roentgenogram; the silhouette sign.

Abstract

With the rapid advances in thoracic surgery, segmental localization of pulmonary disease has assumed greater importance. This has required that the roentgenologist use any method which may serve to localize disease processes within the thorax. The earliest method of localization was by means of stereoscopic films. Later, combined postero-anterior and lateral roentgenograms were employed. More recent refinements in this direction have included oblique views, laminagraphy, bronchography, etc. It is often helpful, if possible, to determine the exact location of a pulmonary density from the postero-anterior film alone. The following criteria, currently utilized, are of distinct value in such localization. An area of radiopacity involving the extreme apex of a lung is almost invariably situated in an upper lobe. One which involves a pulmonary costophrenic angle usually lies in a lower lobe. An abnormality in the right upper lung field, the lower border of which is delineated by the minor fissure, lies in the r...