常规的X线胸部摄影是让患者深吸气屏气时曝光,所得胸片称典型吸气相片。此种胸片对比清晰,肺野显露大,心、膈、肋骨边缘锐利,层次分明,诊断率高。小儿、聋哑人及重症患者不会或不能与投照者合作,常规法胸部摄影的曝光时间可以落在呼吸周期的任何位相上,因而无法保证其胸片为典型吸气相片。如果曝光于呼吸运动速度位相上(尤其小儿啼哭时),就会导致胸片模糊,质量下降,甚至出现废片。 Conventional X-ray chest photography is to allow patients to take a deep inspiration breath-hold, the resulting chest film called a typical inhalation photos. This contrast is clear chest, lung field revealed large, heart, diaphragm, rib edge sharp, structured, high diagnostic rate. Children, deaf-mutes and critically ill patients do not or can not cooperate with the shooter. Conventional chest photography can be exposed at any phase of the respiratory cycle, and therefore can not be guaranteed to have a chest X-ray typical of inspiration. If exposure to the phase of respiratory movement speed (especially when children cry), it will lead to blurred chest, quality decline, and even scrap pieces.