Initial chest radiograph showed the luftsichel sign (i.e., complete atelectasis of the left upper lobe) and trace left pleural effusion (Figure 1).
Interestingly, left upper lobe atelectasis, which is present in this case, seen on chest radiographs in the form of the luftsichel sign, is not a common imaging description in PPL.
Caption: Figure 1: PA chest radiograph demonstrates complete left upper lobe atelectasis and the luftsichel sign.