Annotated image - Chest radiographs (annotated)
Frontal (figure 1) and lateral chest (figure 2) radiographs demonstrate increased opacity in the left mid and upper zone with associated lucency surrounding the aortic arch/knuckle: Luftsichel sign (dotted red line). The lateral projection shows the anterior displacement of the oblique fissure (red arrows). The left hilum and hemidiaphragm are elevated compatible with volume loss. There is also an additional density in the left hilum with a convex and well-defined lateral margin (yellow star). Overall imaging appearance is classic for left upper lobe collapse secondary to left hilar mass concerning for central lung malignancy.