Pathology.—Paraseptal emphysema is characterized by predominant involvement of the distal alveoli and their ducts and sacs. It is characteristically bounded by any pleural surface and the interlobular septa (42,43).
CT scans.—This emphysema is characterized by subpleural and peribronchovascular regions of low attenuation separated by intact interlobular septa (Fig 47), sometimes associated with bullae. The term distal acinar emphysema is synonymous. (See also emphysema.) [Fleischner Society]