Faces of Density of the Lung Parts Size Subtle Decrease in Density CXR Spontaneous Pneumothorax CXR Spontaneous Pneumothorax20-year-old female presents with acute left sided chest pain. She has asthenic build which raises the suspicion for a spontaneous pneumothorax. Frontal CXR shows a small subtle pneumothorax characterised by a thin pleural line (b, white arrowhead) and relative lucency of the left apex compared to the right (b, ringed)Ashley Davidoff MD TheCommonVein.net 117246c02 Shape Position Character Time Infection Inflammation Malignancy Mechanical Atelectasis Trauma Metabolic Circulatory- Hemorrhage Immune Infiltrative Idiopathic Iatrogenic