A gas-filled space, seen as lucency or low-attenuation area, within a nodule, mass or area of parenchymal consolidations. It has a clearly defined wall over 4 mm thick.
Comment:
A cavity has been defined in the radiology literature as (pathologically) a gas-filled space within a zone of pulmonary consolidation or within a mass or nodule, produced by the expulsion of a necrotic part of the lesion via the bronchial tree and (radiographically) a lucency within a zone of pulmonary consolidation, a mass, or a nodule; hence, a lucent area within the lung that may or may not contain a fluid level and that is surrounded by a wall, usually of varied thickness. A pulmonary cavity can be caused by microorganisms (bacteria including mycobacteria, funghi, viruses, parasites), malignant processes or autoimmune disorders.