Photon Migration Tomography

Our approach to reconstruction of the optical properties of a medium from time-resolved Photon Migration Tomography employs two principal tecnical advances.

The first is the use of a Boltzman transport model for simulation of photon migration. Under some circumstances this provides considerably better accuracy than simplified computational strategies, for example treating transport as a simple diffusion process.

The other advance is the use of an adjoint differentiation technique that allows calculation of the derivative of the simulation results with respect to the assumed properties of the medium, in a time comparable to the computation of the transport model itself.  This allows the use of gradient descent techniques to update the medium model efficiently for use in iterative reconstruction schemes.