The differential diagnosis of dyspnea in Emergency Department (ED) patients is broad and atelectasis is one of the differentials among these. We present a 29-year-old women presented to our ED for evaluation of shortness of breath. On her chest examination, air entry and breath sounds were diminished on the left side but normal on the right. A posteroanterior chest radiograph showed radioluscent area in the upper zone of the left lung, around the aortic arch and also hyperdens area neighbouring this, like covered by a veil. Luftsichel sign together with this hiperdensity were consistent with the diagnose of left lung upper lobe collapse. The Luftsichel sign represents the hyperexpanded superior segment of the left lower lobe interposed between the atelectatic left upper lobe and aortic arch. Patient was discharged to home with chest physiotherapy and breathing exercises together with analgesic prescreption.
Keywords: Atelectasis; emergency; luftsichel sign.