第1题: [单项选择]为了获得高质量的断层图像,作SPECT采集时要采用() A. 尽可能小的旋转半径,以提高图像的分辨率 B. 尽可能小的采集矩阵,以加快图像重建速度 C. 尽可能少的投影数,以减少患者运动的影响 D. 尽可能短的采集时间,以减少核素在体内的代谢的影响 E. 尽可能延长采集时间,以减少患者运动的影响 参考答案:A 答案解析:采集时旋转半径越小,重建图像误差越小,图像分辨率越高。
A. By treating sea water. B. By getting it from the surrounding islands. C. By building a small lake of fresh water inside the city. D. By transporting it from the mainland. 参考答案:A 答案解析:[解析]由文章第二段最后一句“On one of the islands would be a speciai factory to take the salt out of sea water an