Pneumonia

This radiograph demonstrates a lingular consolidation concerning for pneumonia. The location of the consolidation can be localized to the lingula even without a lateral radiograph using silhouette sign. There is a loss of sharpness and definition, or “silhouetting,” of the left heart border at the location of the consolidation, indicating that the consolidated lung makes direct contact with the left heart. Anatomically the pulmonary lobe that has the greatest area of contact with the left heart is the left upper lobe, specifically the inferior left upper lobe (the lingula), making the silhouette sign a reliable method of localization. The lingula is a relatively common location for pneumonia.

This radiograph demonstrates a poorly defined focal opacity in the left inferior lung field consistent with pneumonia. The opacity silhouettes the left heart border, which localizes it to the lingular segment. There is a high degree of soft tissue attenuation consistent with obesity. The exam is otherwise unremarkable.