The possibility of distinguishing fibrosing from non-fibrosing lung diseases on high resolution computed tomography (HRCT) is very important in order to be able to establish the appropriate therapy early in the course of the disease and, in some pathologies, to avoid the evolution towards a fibrosing irreversible pattern. For this reason, this article will deal with non-fibrosing pulmonary parenchymal diseases, with an acute or subacute course, which occur on HRCT with a prevalent pattern of diffuse density increase (ground glass opacities and consolidations).
Since these alterations, especially ground glass opacities, are often the early sign of the onset of diseases that evolve towards fibrosis, it is important to be able to recognize them and to propose a correct differential diagnosis.
