ISMRM 24th Annual Meeting & Exhibition 07-13 May 2016 Singapore

Sunrise Educational Session: Controversies in Diffusion & Functional MRI

Skill Level: Intermediate to Advanced

Organizers: Daniel C. Alexander, Ph.D., Jay J. Pillai, M.D. & Jonathan R. Polimeni, Ph.D.

Tuesday 10 May 2016

This session will survey several current controversial topics in diffusion and functional MRI, including those affecting assessment of tissue microstructure, applications to presurgical mapping, and new approaches to measuring and analyzing functional MRI signals.

Target Audience
Cognitive neuroscientists, neuroradiologists and other clinicians as well as imaging scientists who currently utilize functional or diffusion MRI for basic science or for presurgical planning. This course assumes basic knowledge of functional and diffusion MRI and a working knowledge of basic analysis methods.

Educational Objectives
Upon completion of this course, participants should be able to:

  • Explain the limits of diffusion MRI sensitivity and potential benefits of combining with other modalities;
  • Understand the difficulties of multimodal acquisition and modelling and why the benefits of multimodality are unclear for microstructure imaging;
  • Recognize the advantages and limitations of different diffusion tractography approaches for presurgical mapping;
  • Understand the promise as well as the limitations of resting state BOLD with respect to presurgical mapping;
  • Implement a model-free analysis of task-driven fMRI data and evaluate the suitability of a canonical hemodynamic response model; and
  • Evaluate the many techniques available for measuring neuronal activity without utilizing the hemodynamic response, including neuronal current imaging.

Moderator: Daniel Alexander
      Diffusion: A One Stop Shop for Microstructure?  
Microstructural Features Accessible from Diffusion MRI
Sune Jespersen

Diffusing spins probe length scales on the order of 210 m during typical diffusion weighted MRI experiments, and their trajectories are therefore shaped by the tissue structure on this scale. The exciting prospect is that diffusion MRI can provide detailed quantitative information of microstructural properties, surpassing the nominal image resolution by orders of magnitude. Achieving this goal depends on biophysical modelling and subsequent validation. The purpose of this lecture is to give the audience an understanding of the principles underlying the quantification of microstructural tissue features from diffusion MRI, as well as the potential and the pitfalls.

Benefits of a Multimodal Approach
Nikola Stikov1
1Ecole Polytechnique/University of Montreal
Typical diffusion MRI acquisitions are blind to myelin, due to its short T2 time.  Given that myelin comprises about 50% of the fiber volume, it is necessary to add a complementary myelin measure to better characterize white matter microstructure.   Combining diffusion and myelin imaging sensitizes the MR measurement to the myelin g-ratio (a measure of myelin thickness), helping scientists gain novel insights into brain microstructure during development, aging, and disease.

Adjournment & Meet the Teachers

The International Society for Magnetic Resonance in Medicine is accredited by the Accreditation Council for
Continuing Medical Education to provide continuing medical education for physicians.