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.

Thursday 12 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: Jonathan Polimeni
      New Approaches to fMRI: Is it Time to Think Outside of the Box?  
Uncovering Hidden Activation Using Model-Free Analysis
Javier Gonzalez Castillo1 and Peter A Bandettini1
1Section on Functional Imaging Methods, NIMH, NIH, Bethesda, MD, United States
Many functional MRI studies provide a limited view of brain function due to high noise and the use of overly strict predicted response models that do not properly account for inter-regional hemodynamic response variability. As such limitations are reduced, a richer picture of brain function emerges, and the highly distributed nature of brain activity can be observed with fMRI. Here we discuss a series of experiments and analytical approaches that highlight the exquisite detail that can be observed in fMRI signals beyond what it is normally examined.

Prospects for "bloodless fMRI"
Mukund Balasubramanian1,2
1Department of Radiology, Boston Children's Hospital, Boston, MA, United States, 2Harvard Medical School, Boston, MA, United States
It may surprise many to learn that attempts to record fMRI signals in the human brain that are nonvascular in origin are almost as old as those utilizing the hemodynamic response to neuronal activity. But whereas hemodynamic fMRI (especially BOLD-fMRI) has gone on to achieve fame and fortune, “bloodless fMRI” has floundered in the shadows of its more illustrious (“bloody”) counterpart. Here we will review several contrast mechanisms that have been proposed for bloodless fMRI and discuss the possibility that substantive progress in this area might have been impeded, in part, by our collective failure to ask the right questions.

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.