On the left a patient with ground glass pattern in a mosaic distribution. Some lobules are involved and others are not. The differential diagnosis is hypersensitivity pneumonitis, bronchiolitis or thromboembolic disease. The history was typical for hypersensitivity pneumonitis. Hypersensitivity pneumonitis usually presents with centrilobular nodules of ground glass density (acinar nodules). When they are confluent, HRCT shows diffuse ground glass. #Clinical #Radiology #CTChest #GGO #MosaicAttenuation #Mosaic #HypersenstitivityPneumonitis #RadiologyAssistant
