Combined Pulmonary Fibrosis and Emphysema (CPFE): A distinct Clinico- Radiological entity

Combined pulmonary fibrosis and emphysema (CPFE) is a common yet under diagnosed entity with imaging findings of both pulmonary emphysema and fibrosis.Many have challenged the definition of CPFE and there still exists a lot ofcontroversy over various aspects of this syndrome. Initially considered to represent a chance coexistence of two separateentities, CPFE is now being increasingly recognized as a distinct syndrome. The recognition of this syndromeis important, as it is associated with a worse prognosis when compared to pulmonary emphysema or fibrosis alone. Its diagnosis is mainly based on HRCT findings and is clinically characterized by relatively preserved spirometric values with disproportionate impairment of gas exchange. Since radiology plays a key role in making this diagnosis, it is important for radiologists to be familiar with the existence and appearance of this syndrome. We review this unique clinic-radiological entity with special emphasis on its CT appearances.