A fast imaging method to calculate Fe3+ diffusion coefficient in Fricke-infused gels

A fast imaging method was employed for the calculation of ferric ion diffusion coefficient in Fricke-infused agarose gels. It allows MR data acquisition to be completed in minutes instead of hours as in conventional methods. Smearing of steep dose distributions due to ferric ion diffusion over such a short period of time can be ignored. The diffusion coefficient is calculated for a typical Fricke-agarose gel containing 1 mM ammonium ferrous sulfate, 1% agarose, 1 mM sodium chloride and 50 mM sulfuric acid; its ferric ion diffusion coefficient is 1.31×10^-2 cm² h^-1. This value falls within the 1∼2×10^-2 cm² h^-1 range reported by previous studies under varying concentrations of gel ingredients.