结果与二维采集相比，三维采集条件下重建图像的本底和高频噪音较多，且对颅顶、颅底结构的显示较差，但对大脑中间结构的显示与二维采集基本一致。
Results Compared with 2D mode , much higher background and noise were observed on the reconstruction images of 3D mode , and the bottoms of the brain structure were not well displayed .
本底噪音