A.颅脑CT增强扫描分直接增强扫描和平扫后增强扫描
B.疑有动脉瘤者采用注射对比剂50ml时开始扫描
C.脑膜瘤者采用注射对比剂60s后开始扫描
D.转移瘤者可在注射对比剂6min后开始扫描
E.颅内感染者可在注射对比剂6min后开始扫描