Basic Signs in Chest Radiology: Silhouette, Hilar Overlay, and Hilar Convergence Signs

Abstract

The basic “signs” in chest radiology are each formed by a combination of imaging findings that are known to be characteristic for a specific observation, often leading the radiologist to a more precise conclusion. Many of these signs were developed in the earliest decades of chest radiographic interpretation; others have been recognized in more recent years in the era of chest CT. Radiologists who are familiar with imaging signs facilitate the rapid recognition of complex imaging patterns, enabling the suggestion of a specific diagnosis, or a narrowed differential of diagnostic possibilities to be considered.