Bronchiolitis obliterans with organizing pneumonia versus chronic eosinophilic pneumonia: High-resolution CT findings in 81 patients

OBJECTIVE, The objective of this research was to compare high-resolution CT findings of bronchiolitis obliterans with organizing pneumonia (BOOP) with those of chronic eosinophilic pneumonia (CEP) and to determine whether high-resolution CT can differentiate the two. MATERIALS AND METHODS, We retrospectively reviewed high-resolution CT scans of 38 patients with BOOP and 43 patients with CEP. Without knowledge of the diagnosis, two radiologists evaluated the frequency and distribution of high-resolution CT findings in both groups of patients and made a diagnosis using a three-point scale of confidence. RESULTS. Nodules, nonseptal linear or reticular opacities. and bronchial dilatation were significantly more common in BOOP than in CEP (31.6% vs. 4.7%, p < 0.005: 44.7% vs. 9.3%. p < 0.001, and 57.9% vs. 25.6%, p < 0.005, respectively). Septal line thickening was more frequent in CEP than in BOOP (72.1% vs, 39.5%. p < 0.005). Peribronchial distribution consolidation was more frequent in BOOP than in CEP (28.9% vs, 9.3%. p < 0.05). A correct diagnosis was made in 69.7% of cases. and the diagnostician was confident in 21.7%. Interobserver agreement was good (<kappa> = 0.6). CONCLUSION. Although several of the high-resolution CT findings of BOOP and CEP are different, these diseases are: differentiated with confidence in only a small percentage of cases.