Diffusion MRI is used to non-invasively characterize the microstructure of the brain. However, the accuracy of the characterization is difficult to verify because no other non-invasive imaging modality provides the same information. This thesis presents a novel 3D printed axon-mimetic (3AM) diffusion MRI phantom, a synthetic object designed to mimic the brain\u27s microstructure.
The phantoms were characterized using microscopy, synchrotron micro-computed tomography, and diffusion MRI, and found to have sufficiently axon-mimetic properties to be useful as diffusion MRI phantoms. A set of phantoms designed to have anatomically realistic and complex fibre structures was used to test the response of diffusion MRI models of white matter to fibre orientation dispersion. All tested models were found to respond to orientation dispersion, but some robust metrics were identified. The studies in this thesis demonstrate that 3AM phantoms are a novel, flexible, and inexpensive tool for validating diffusion MRI models of white matter
