Fig. 5

Variable degrees of honeycombing appearance. HRCT images in three different UIP patients, with variable degrees of honeycombing representation. Image A shows a subpleural reticular pattern and small honeycombing area. The diagnosis of UIP was also successfully confirmed by histological biopsy. Patient DLCO was 89 % at the time of diagnosis. In a second patient (B), with respiratory insufficiency and severe reduction of DLCO (39 %), the UIP pattern was again diagnosed by CT examination. C and D show diffuse honeycombing, which massively involves the basal regions of lower lobes. The patient in C and D, at the time of clinical examination, was a smoker of 40 pack/years, with progressive dyspnoea and productive cough for 2 years. Pulmonary function tests showed lung failure and severe DLCO reduction (30 %) with obstructive spirometric pattern