For BA-MSCTA, 10ml of 45% contrast was injected into BA (1~2ml/s), and scan was started 5s after injection, ranging from low cervix to the bottom of lung ( pitch 5mm, no overlap reconstruction ).

• BA-MSCTA方法是以1~2ml/s的速度注入45%25的造影剂10ml，注入5秒时自下颈部（颈5~6椎体水平）向肺底扫描，准值5mm，无重叠连续重建。