Chest ImagingUsual interstitial pneumonia
(UIP), the most common type of chronic
interstitial pneumonia described by Liebow. In its early stages, UIP is characterized histologically by alveolitis and increased cellularity of the alveolar wall. As this process progresses,
pulmonary fibrosis and
honeycombing develop. Clinically, the term UIP is often used synonymously with
idiopathic pulmonary fibrosis, but identical findings of UIP can be seen in patients with other diseases, particularly collagen
vascular diseases such as
rheumatoid arthritis and
progressive systemic sclerosis. The 5-year mortality for UIP is 45% and only 10% of patients respond to treatment.
The HRCT appearances of UIP are characterized by a predominance of reticular opacities, which correspond to areas of irregular fibrosis, lung destruction, honeycombing and traction bronchiectasis; these findings are visible in virtually all patients with UIP, and frequently show a peripheral, subpleural and basal predominance (Fig.1). Ground glass opacities are seen in less than half of patients with UIP, usually related to the presence of alveolitis, alveolar wall thickening or early fibrosis.
RW
To view high resolution images,
please register first.
Click
here
to register.
Already registered? Enter your e-mail in the window below.Re-registerFig.1
HRCT in a patient with UIP showing typical subpleural honeycombing.
 | |
Usual interstitial pneumonia, Fig.1 | |