Depth-adaptive voxel size reconstruction for diffuse reflective optical tomography

We study diffuse reflective optical tomography (DROT), aiming at the real-time imaging of the redox state change of the human cerebral cortex with the brain activity. In the uniform voxel size and simple regularization scheme we studied so far, the spatial resolution in the shallow region is unnecessarily good, whereas the noise and the sensitivity in the shallow region are too large to recover the signal in the depth. In this report, we present the result of the depth-adaptive voxel size reconstruction. By assigning wider lateral voxel size in the shallow range, the noise and the sensitivity in the shallow range is suppressed so that the signal in the deep range would be less masked by the presence of the unwanted target in the shallow range. We demonstrate the improvement of the 3-dimensional reconstructed image using the proposed depth-adaptive voxel size reconstruction.