【名词&注释】
室间隔缺损(ventricular septal defect)、肺栓塞(pulmonary embolism)、肺动脉瓣(pulmonary valve)、肺动脉主干(pulmonary artery trunk)
[单选题]CT诊断肺栓塞的直接征象是
A. 患侧肺透亮度增高
B. CT增强扫描示肺动脉主干(pulmonary artery trunk)内充盈缺损区
C. CT增强扫描示尖端指向肺门的楔状明显强化区
D. 患侧肺透亮度减低
E. 患侧肺血管影减少