Thin-section CT findings in rheumatoid arthritis-associated lung disease: CT patterns and their courses

Purpose: The purpose of this study was to describe the long-term follow-up CT evaluation in rheumatoid arthritis (RA)-associated lung disease. Method: Thin-section CT scans from 29 patients with RA and suspected associated lung disease were reviewed. Twenty-two, patients underwent sequential CT evaluation during 3 to 108 months of follow-up (mean 28 months). Histologic confirmation of pulmonary involvement was available in 19 patients. Results: Three major patterns were identified: reticulation with or without honeycombing (n = 19), centrilobular branching lines with or without bronchial dilatation (n = 5), and consolidation (n = 5). Reticulation and centrilobular branching lines corresponded to usual interstitial pneumonia (n = 14) and bronchiolitis obliterans (n = 1), respectively. Consolidation corresponded to bronchiolitis obliterans organizing pneumonia (BOOP; n = 3) and coexistent chronic eosinophilic pneumonia (CEP) and POOP (n = 1). Patients with reticulation had rapid deterioration when there was new appearance of multifocal areas of ground-glass attenuation. Centrilobular branching lines progressed to bronchiectasis in one case. There was mild progression of existing bronchiectasis associated with centrilobular branching lines in one case. Area of consolidation in two patients with BOOP and one with coexistent CEP and BOOP evolved into honeycombing at serial CT. Conclusion: Thin-section CT is a noninvasive technique for monitoring disease morphology in RA-associated lung disease. Initial CT findings and their evolution on sequential examinations may be useful in evaluating prognosis.