中文说明：基于MRI的脑组织分割。首先从给定的MRI图像中得到脑区域，而后计算脑容积；再得到脑白质灰质区域，并计算百分比。
English Description：
Brain tissue segmentation based on MRI. Firstly, the brain area is obtained from the given MRI image, and then the brain volume is calculated; then the white matter gray matter area is obtained, and the percentage is calculated.