[The assessment of the activity of idiopathic pulmonary fibrosis by high-resolution computed tomography].

The authors report the results of the study performed with high resolution CT (HRCT) in a group of 29 patients affected with idiopathic pulmonary fibrosis (IPF). Each patient underwent HRCT at the beginning of the study and after one year. A complete clinico-functional assessment was available in 20 cases and functional CT correlation was made in these patients; 15/20 subjects underwent immunosuppressive therapy with corticosteroids and cyclophosphamide. Disease severity was assessed with chest radiography and HRCT. On the basis of CT findings the patients were classified into three groups, according to Wells classification: predominant ground-glass pattern, mixed pattern and predominant reticular disease with honeycombing. Furthermore, a visual score was assigned to total disease extent and a different score to ground-glass and reticular opacities. Our data confirm the poor accuracy of chest radiography in assessing disease type and overall severity, versus the outstanding diagnostic accuracy of HRCT. We also found a high incidence of mediastinal adenopathies (37.9% of the patients) and signs of pulmonary arterial hypertension (62%), together with low extent of pulmonary emphysema (65.5% of the patients; mean extent: 5.4%). Ground-glass attenuation is an early sign of IPF and might suggest alveolitis activity. In our series, however, the patients with grade I disease were rare (6.8%), but likely to benefit from therapy. Different from Wells, we found no significant difference in the evolution of the patients with grade II versus grade III disease. Wells grading was useful in early disease assessment, but the visual score of total disease extent and the score of ground-glass and reticular opacities were much more useful in the follow-up because they can assess disease progression. Furthermore, in the few patients with predominant alveolitis, who improve after therapy, the relative prevalence of the reticular pattern might allocate the patient in a higher Wells group with a "paradoxical" worsening, if the visual score of the extent of the primary lesion is not used.