Pediatric Bronchiolitis Obliterans Etiology: bronchiolar inflammation with submucosal peribronchial fibrosis, often seen post-viralCXR: bronchial dilation, hyperinflation, reticulonodular infiltrates Radiology Cases of Bronchiolitis Obliterans CXR (above) shows chronic interstitial infiltrates in both lungs. Bronchograms of both lungs (below) shows airway dilation, left greater than right.