Imaging was performed on a GE Healthcare Discovery MR750 3.0T system. For voxel placement, an axial dual-echo Fast Spin Echo (FSE) MRI (field of view = 24cm, frequency encodes = 256, TE1/TE2/TR = 17/102/7500ms, phase encodes = 192, echo-train length = 8, slice thickness = 2.5mm, spacing = 0mm) was collected.