Using diffusion-relaxation MRI to estimate the inner radius of co-electrospun axon-mimicking fibres

A new approach for estimating inner axon radii from intra-axonal T2 relaxation times was recently proposed. However, further validations are required before this technique can be used widely. The main aim of this study is to validate this T2-based pore size estimation technique in phantoms comprising co-electrospun hollow axon-mimicking fibres designed to have non-circular cross-sections and different radii distributions. For this purpose, a diffusion-relaxation MRI dataset was acquired with a 7T preclinical scanner, from which the intra-fibre T2 times and pore sizes were estimated. The resulting pore sizes were compared to those measured from Scanning Electron Microscope images.