Idiopathic pulmonary fibrosis: progression of honeycombing at thin-section CT.

PURPOSE: To evaluate the progression of honeycombing at computed tomography (CT) and to determine serial changes in the pattern of disease. MATERIALS AND METHODS: CT scans, obtained in 29 patients with idiopathic pulmonary fibrosis who had undergone at least two serial CT examinations 1-52 months apart, were reviewed. Twelve patients had received no treatment, and 17 patients had received corticosteroids. Initial and follow-up CT scans were evaluated independently and then directly compared with each other. RESULTS: Twenty-six of the 29 patients showed progression of honeycombing, which was variable at CT (median, 0.4% [range, 0%-11%] per month) but not significantly different between untreated and treated patients. Areas of ground-glass attenuation on CT scans preceded and were predictive of the development of honeycombing in that location. Corticosteroid treatment reduced areas of ground-glass attenuation, but honeycombing on CT scans was irreversible. CONCLUSION: Low-dose therapy with corticosteroids does not suppress alveolitis sufficiently to prevent continued deterioration of the alveolar structures.