The CT imaging diagnosis of emphysema is as follows: 1. In the early stage of emphysema, the main manifestation is the limited increase of lung translucency or the increase of translucency of the whole lung lobe, and then it can also manifest the thinning and straightening of lung texture, often accompanied by the appearance of pulmonary blisters; 2. In the late stage of emphysema, there can be barrel-shaped changes of the thorax, the anterior and posterior diameter of the thorax is obviously enlarged, and at the same time, the vascular texture of the peripheral lung becomes thin or even disappears; 3.