Bronchiolitis: Classification and Radiologic Approach

The terms and classification of bronchiolitis has been confusing and evolving. Histopathologic groups of bronchiolitis include cellular bronchiolitis(distinctive subtypes: diffuse panbronchiolitis, follicular bronchiolitis), respiratory bronchiolitis, bronchiolitis obliterans with intraluminal polyps/BOOP, constrictive bronchiolitis, mineral dust airway disease.

The introduction of thin-section CT has improved the diagnosis of bronchiolitis. Thin- section CT in deep inspiration and expiration can be very helpful for detection and characterization of bronchiolitis. Normal bronchiole cannot be recognized radiologically. In order for bronchiolar disease to be visible on CT, they must cause dilatation, wall thickening and often mucus plugging. Various bronchiolitis can be readily identified and may lead to characteristic findings on thin-section CT. Various bronchiolitis result in one or a combination of three main patterns in thin-section CT: centrilobular nodules and branching densities, ground-glass attenuation and consolidation, and low attenuation and mosaic perfusion pattern.

The terms, classification, CT features, and radiologic approach of bronchiolitis will be discussed.

Lernziele:

• Various bronchiolitis can be readily identified and may lead to characteristic findings on thin-section CT.

• Bronchiolitis results in one or combination of three main patterns in thin-section CT: centrilobular nodules and branching densities, ground-glass attenuation and consolidation, and low attenuation and mosaic perfusion pattern.

• Knowledge of CT features of bronchiolitis would help the proper radiologic approach to various bronchiolitis.

Korrespondierender Autor: Kang EY

College of Medicine, Korea University, Department of Radiology, 80 Guro-dong, Guro-ku, 152–050, Seoul

E-Mail: [e-mail]