单项选择题
A.10-120s B.20-180s C.30-300s D.40-360s
A.US B.CEUS C.CT D.MRI
A.与病灶的关注时相有关 B.造影剂呈现快进快出现象 C.病灶均呈现低或无增强区域 D.病灶出现局部增强区域