磁共振辅助的近红外扩散光学断层成像

MRI-aided diffuse optical tomography

将大脑磁共振T1加权像分割为头皮、头骨、脑脊液、灰质和白质,并生成分层体网格.利用具有大脑解剖结构信息的分层体网格建立近红外扩散光学断层成像前向光学模型和实现功能重建,可以避免目前所使用的半球头模或图谱头模空间定位不准的问题,解决图像重建过程中所解方程的欠定性和病态性.在棋盘格旋转视觉刺激及扩张视觉刺激实验中,基于磁共振图像的扩散光学断层成像重建的含氧血红蛋白图像具有更高的空间分辨率及定位精度.

T1 weighted magnetic resonance imaging of the brain was segmented into scalp, skull, cerebrospinal fluid, gray matter and white matter, and then meshed in volume with different tissues. The volumetric mesh based on subject specific anatomy was used to build forward optical model and reconstruct image in the diffuse optical tomography for solving low position-accuracy, ill-condition and under-determined problems caused by hemisphere model or brain atlas. In the visual experiments of counter-clockwise wedge stimulus and expanding ring stimulus, the diffuse optical tomography guided by magnetic resonance imaging can obtain higher space resolution and more accurate position for activated oxy- genated haemoglobin signals.