Lung inflammation is categorized into lobar pneumonia, lobular pneumonia and interstitial pneumonia, and the CT manifestations of different pneumonias are different, with lobar pneumonia manifesting as ground-glass-like density shadow, lobular pneumonia manifesting as patchy shadow, and interstitial pneumonia manifesting as thickening of tracheal vascular bundles. 1. Lobar pneumonia: in the congestive stage, the lesion area shows a slightly high-density image of ground glass, with fuzzy edges, and the blood vessels in the lesion area are still vaguely visible. In the solid phase, there is a dense solid shadow with uniform density, which is distributed in the lobes or lung segments, and the bronchial air image can be seen in it. In the dissipation stage, there are scattered patchy hyperdense shadows of different sizes with unclear edges. 2. Lobular pneumonia: scattered patchy shadows in the middle and lower lobes of both lungs along the bronchial line, with fuzzy edges, which can be fused to form flaky or flocculent hyperdense shadows with non-uniform density. 3. Interstitial pneumonia: in early stage or mild cases, the bronchial vascular bundles on both sides can be thickened, accompanied by ground glass-like shadow, and in more severe cases, small patchy shadow and nodular shadow can be seen, and thickening of the interlobular septum can be seen, and honeycomb changes and fibrosis can be seen in the lungs. CT manifestations of lung inflammation, specific should consult the clinician.