Sune Jespersen, PhD
Professor at Aarhus University, Department of Clinical Medicine - Center of Functionally Integrative Neuroscience
Department of Physics and Astronomy
Título: Quantifying brain microstructure with diffusion MRI
Resumen: Being sensitive to tissue structural features on the micrometer level (microstructure), diffusion MRI combined with biophysical modeling has the potential to map relevant biological properties on scales far below the nominal voxel resolution. In the brain and spinal cord, much work in this direction has been based on a relatively simple biophysical model of diffusion, recently dubbed “the standard model”. This model characterizes the diffusion signal in terms of a handful of relevant parameters: neurite volume fraction, intra-neurite and extra-neurite diffusivity, and the neurite or fiber orientation distribution. In this talk, I will give some background for the standard model and an overview of our work with it, covering efforts to validate the model in animal model systems including comparisons to histology. I will also outline some current problems with the model, ongoing attempts to overcome them and extend the modeling to gray matter. I will also discuss our work on kurtosis as well as double diffusion encoding, and its connections to the standard model. Throughout, I will give examples of applications in health and disease.