Anomalous Diffusion and Non-Monoexponential b-decay
Mackay C, Robson M, Barrick T, Hall M
University of Oxford
We present an alternative interpretation of the non-monoexponential signal attenuation with b-value observed in diffusion imaging of the brain in terms of the theory of anomalous diffusion. We derive a scaling relation and analyse the results of an experiment that reproduces non-monoexponential decay in terms of this relation. We show that the assumption of anomalous diffusion leads to a simpler fitting problem than is the case for the biexponential model typically assumed. Results indicate that diffusion in cortical grey and white matter is consistant with a sub-diffusion hypothesis.