Brainmap: Special seminar: Microstructure imaging with diffusion MRI

Daniel Alexander, Ph.D.
Professor of Imaging Science
University College London
 
My talk will give an overview of the research in my group in developing microstructure imaging techniques using MRI and other activities.  The aim of microstructure imaging is to estimate and map histological features of tissue non-invasively. Diffusion MRI sensitizes the MR signal to the dispersion of water arising from diffusion.  It is a cornerstone of microstructure imaging, because it gives unique sensitivity to the cellular architecture of tissue, which determines the pattern of water dispersion.  Other MR modalities, such as relaxometry, magnetization transfer, and susceptibility imaging can also contribute.  I will talk about the work we have done towards development of the biophysical models that underpin parameter estimation (Panagiotaki et al Neuroimage 2012; Ferizi et al MRM 2014); the design of imaging sequences and protocols that provide and maximize sensitivity (Alexander MRM 2008; Drobnjak et al JMR 2010); specific techniques that emerge such as ActiveAx (Alexander et al Neuroimage 2010; Zhang et al Neuroimage 2011) and NODDI (Zhang et al Neuroimage 2012) for neuroimaging, and VERDICT (Panagiotaki et al Cancer Research 2014) for cancer imaging; and their validation and application.  If time permits, I will also mention more recent work on the development of computational models for disease progression with application in Alzheimer's disease and other neurological conditions; see (Fonteijn et al Neuroimage 2012).