Optical tomographic imaging of activation of the infant auditory cortex using perturbation Monte Carlo with anatomical a priori information

We have developed a perturbation Monte Carlo method for calculating forward and inverse solutions to the optical tomography imaging problem in the presence of anatomical a priori information. The method uses frequency domain data. In the present work, we consider the problem of imaging hemodynamic changes due to brain activation in the infant brain. We test finite element method and Monte Carlo based implementations using a homogeneous model with the exterior of the domain warped to match digitized points on the skin. With the perturbation Monte Carlo model, we also test a heterogeneous model based on anatomical a priori information derived from a previously recorded infant T1 magnetic resonance (MR) image. Our simulations show that the anatomical information improves the accuracy of reconstructions quite significantly even if the anatomical MR images are based on another infant. This suggests that significant benefits can be obtained by the use of generic infant brain atlas information in near-infrared spectroscopy and optical tomography studies.