What are the ct manifestations of emphysema

CT manifestations of emphysema can be divided into the following types: 1. centrilobular emphysema, typical change is alveolar dilation, CT manifestations are scattered small holes in the lungs, small circular low density areas, diameter of 2~4 mm, located in the middle of the pulmonary lobules, pulmonary blood vessels are normal, 2. panlobular emphysema, typical change is the expansion of the whole pulmonary lobules, CT manifestations are diffuse low density areas in both lungs, irregular size and shape. 3. Paraseptal emphysema, involving the lobular ends, presenting on CT as subpleural bullae. Bullae present as localized air sacs in the lungs, with loss of parenchymal structure. 4. Scarring emphysema, surrounding scar areas. CT findings are areas of low density scar in the parenchyma.