FUNCTIONAL IMPAIRMENT IN FIBROSING ALVEOLITIS - RELATIONSHIP TO REVERSIBLE DISEASE ON THIN-SECTION COMPUTED-TOMOGRAPHY

Thin-section computed tomography (CT) provides a reproducible method o f quantifying global disease extent and can also discriminate between fibrotic disease, with predominance of reticular abnormalities, and re versible inflammatory cell infiltration, shown as ground-glass attenua tion. The aim of this study was to determine whether functional impair ment varied according to the presence of ground-glass attenuation on C T, independently of extent of disease on CT, demographic factors, smok ing history, therapeutic status, and the type of fibrosing alveolitis Gone cryptogenic fibrosing alveolitis (CFA) versus fibrosing alveoliti s associated with systemic sclerosis (FASSc)).Patients with concurrent emphysema on CT (n=16) and FASSc patients with end-stage pulmonary hy pertension (n=5) were excluded. One hundred and eleven patients were s tudied (CFA, n=54; FASSc, n=57). The severity of functional impairment did not vary independently with the presence of predominant ground-gl ass attenuation, mixed appearance and predominant reticulation on CT. In 34 treated patients undergoing serial CT scanning, the severity of functional impairment did not differ independently between patients wi th and without regression of ground-glass attenuation at follow-up. We conclude that the severity of functional impairment does not discrimi nate between inflammatory and fibrotic disease in fibrosing alveolitis , as judged by initial and serial computed tomographic scanning, after adjustment for the morphological extent of disease on computed tomogr aphy.