印戒征是胸部CT扫描的一种表现。由一个小的圆形软组织密度影和一个含圆形低密度区的较大的环形软组织密度影相连而成。环形软组织密度影为扩张的支气管壁,其内低密度为扩张支气管含有的空气。环旁圆形软组织密度为肺动脉,紧贴于扩张的支气管。 印戒征是支气管扩张的一种CT表现。支气管扩张的定义是指不可逆的支气管异常扩张,在中级支气管表现最明显。此外,支气管平滑肌萎缩、支气管 Ring sign is a manifestation of chest CT scan. It consists of a small round soft tissue density shadow and a large looped soft tissue density shadow with a circular low density zone. Ring soft tissue density shadow of the expansion of the bronchial wall, which is low-density expansion of the air contained in the bronchus. Circular soft tissue density around the pulmonary artery, close to the expansion of the bronchus. Ring signet sign is a CT manifestation of bronchiectasis. The definition of bronchiectasis refers to the irreversible expansion of bronchial abnormalities, the most obvious in the intermediate bronchus. In addition, bronchial smooth muscle atrophy, bronchus