下列关于窗位的概念,错误的是() ["A、窗位相当于显示灰阶的中心 ","B、窗位规定所显示CT值的范围 ","C、不同机器的窗位值相同 ","D、窗位的选择与所显示的组织CT值有关 ","E、增强后CT窗位选择应高于CT平扫"]
眼球钙化见于() ["A、视网膜脱离 ","B、脉络膜血管瘤 ","C、眼球内转移瘤 ","D、视网膜母细胞瘤 ","E、黑色素瘤"]
患者体内高密度结构或异物形成的CT伪影常表现为() ["A、影像边缘模糊 ","B、双边影像 ","C、平行的条纹状影 ","D、放射状条纹状影 ","E、局部影像消失"]
腮腺混合瘤CT常见增强表现是() ["A、明显增强 ","B、均匀增强 ","C、不均匀增强 ","D、延迟增强 ","E、不增强"]
当窗宽为80、窗位为40时,其CT值(Hu)显示范围为() ["A、40~80 ","B、0~80 ","C、0~40 ","D、40~120 ","E、80~120"]
过流保护的手段通常有三种,即()()和热继电器