Combined pulmonary fibrosis and emphysema (CPFE): what radiologist should know.

Combined pulmonary fibrosis and emphysema is a relatively newly defined entity, which has been deeply studied in the recent years. Despite the wide numbers of papers on this topic, there are still several open questions about pathogenesis, epidemiology, natural history and prognosis. The diagnosis could be assessed only after HRCT scan as functional tests often result in an underestimation of this syndrome. What radiologists need to know about this syndrome consists in the heterogeneity of appearances: emphysema is mainly paraseptal and fibrotic pattern could be variable, including the variant of airspace enlargement with fibrosis which needs to be differentiated from honeycombing. A special attention must be paid on complications which could worsen the prognosis, such as pulmonary hypertension and lung cancer. Further studies are needed to address if the type of fibrotic pattern as well as fibrosis CT index could be considered as prognostic factors. Thus, the role of radiologists in the management of these patients is crucial as it involves diagnosis, detection of complications and could possible concerns the identification of patients at higher risk.