关于CT多方位和三维图像的叙述,正确的是 ["A.可直接用于影像诊断而不再需要横断面图像","B.需通过横断面图像的重组才能获得","C.一般都直接从原始扫描数据重建而成","D.尚无任何诊断的参考价值","E.其重组所需时间太长,无实用意义"]
为显示肝内高密度转移灶,窗宽的设置是 ["A.约在100~250HU ","B.约在0~350HU ","C.约在250~450HU ","D.约在-50~150HU ","E.约在200~500HU"]
永久硬度
水的总硬度
下列哪项不引起吸气性呼吸困难() ["气管异物","喉癌","急性喉炎","气管肿瘤","支气管哮喘"]
暂时硬度