Internal Gradients Affect the γ Value Arising from Anomalous Diffusion Stretched Exponential Model

Marco Palombo¹, Silvia De Santis¹, Silvia Capuani¹,²

γ parameter arising from Anomalous diffusion stretched-exponential method has been used to investigate tissues, showing the ability of γ maps to discriminate between different brain structures on the basis of their microstructural complexity. Here, we measure γ in controlled phantoms comprised of monodispersed and polydispersed micro beads in water solution to tested the influence of the internal gradient (due to the magnetic susceptibility difference between diffusing water and obstacles) with respect to the capability of γ to discriminate between structures characterized by different geometrical dimensions. Experimental data showed that the higher the internal gradient, the lower the γ value.