Obliterative bronchiolitis

Differential diagnosis: obliterative bronchiolitis This is a CT scan of a patient with chronic post-viral obliterative bronchiolitis. This patient's lungs have dark and light patches. The darker areas suggest air-trapping, with grey areas showing less severely affected regions of the lung. The pattern of patchy narrowing of the small airways is known as a 'mosaic attenuation pattern'. Obliterative bronchiolitis has many causes (including viral infection) and is defined as scarred or narrowed small airways in the lung periphery. Patients usually present with chronic or subacute onset of dyspnoea, cough and episodic wheezing.