Using q-space Diffusion MRI for Structural Studies of a Biological Phantom at a 3T Clinical Scanner

Abstract: "Diffusion magnetic resonance imaging (MRI) is today a well-established method in clinics around the world. For example it is a leading method or diagnosing ischaemic stroke at an early stage. Trough research it is a continuously growing field applicable to many different tasks. Alternatively, the diffusion MRI can be used for morphologic studies by the use of q-space analysis. q-space imaging is an established method in NMR spectroscopy for retrieving structural information from biological materials. Structural q-space imaging at a clinical scanner is more difficult to achieve due to limited gradient performance, however apparent mean displacement data has been presented in vivo. The aim of this study was to investigate the possibility for absolute quantification of fiber structure sizes in a biological phantom, using the full width at half maximum (FWHM) of the diffusion propagator and microscopy images were obtained as a “golden standard reference”. The results from the analysis made on Asparagus officinalis show, as expected, that water molecules diffuse like free water along the fibres, while the water diffusion perpendicular to the fibers is restricted. The sizes of these structures were obtained and agreed very well with the microscopy images."