Prof Tom Barrick: Quasi-Diffusion Imaging

Upcoming Webinar: Friday 15th May 06:00 AM Brisbane. Register online

Quasi-Diffusion Imaging

Quasi-Diffusion Magnetic Resonance Imaging (QDI) is a new diffusion imaging technique that provides a probe of subvoxel tissue complexity using short acquisition times (1-4 ​min). QDI is a quantitative technique that is based on a special case of the Continuous Time Random Walk model of diffusion dynamics and assumes the presence of non-Gaussian diffusion properties within tissue microstructure. The diffusion signal attenuation is parameterised according to the rate of decay (i.e. diffusion coefficient, D in mm² s^-1) and the shape of the power law tail (i.e. the fractional exponent, α). QDI also provides analogous tissue contrast to Diffusional Kurtosis Imaging (DKI) by calculation of normalised entropy of the parameterised diffusion signal decay curve, H_n, but does so without the limitations of a maximum b-value. We show that QDI generates images with superior tissue contrast to conventional diffusion imaging within clinically acceptable acquisition times of between 84 and 228 ​s. We show that QDI provides clinically meaningful images in cerebral small vessel disease and brain tumour case studies. Our initial findings suggest that QDI may be added to routine conventional dMRI acquisitions allowing simple application in clinical trials and translation to the clinical arena.

Tom currently works as at St George’s, University of London and is developing Quasi-Diffusion Imaging, an advanced diffusion MRI technique based on fractional diffusion models that can be rapidly acquired in clinically feasible time.