COPD最常见的病因为() ["A.空气污染","B.吸烟","C.呼吸系统反复感染","D.营养不良","E.遗传因素"]
左前斜位主动脉窗内不能见到下述哪一项() ["A.肺动脉","B.降主动脉","C.气管分杈","D.左肺动脉","E.左支气管"]
诊断COPD最重要的检查是() ["A.胸部X线检查","B.B超检查","C.胸部CT检查","D.肺功能试验","E.血气分析"]
颅咽管瘤的临床表现、诊断和治疗原则是什么?
关于X线的发生,下列哪项不对() ["A.X线管阳极材料多为钨或钼 ","B.只有极少的电能转化为X线 ","C.管电压与人体吸收量成反比 ","D.旋转阳极可延长球管寿命 ","E.管电压与产生的X线穿透力成反比"]
中枢神经系统的放射治疗原则是什么?其主要放射治疗技术有哪些?