ABSTRACT
Multiple sclerosis (MS) is one of the most, if not the most, thoroughly studied neurological disease processes in the 20-year history of magnetic resonance imaging (MRI). Countless imaging sequences and analysis methods have been developed to study MS. Typically, the focus of MRI studies has been on whole-brain anatomical assessment of lesion burden. These methods have provided only a very rough guide to disease severity and progression. A strong argument can be made that developing a complete understanding of the effect of inflammatory lesions and subsequent or ongoing neurodegenerative changes will require new imaging techniques. Specifically, techniques which can directly assess pathway integrity and function will be required to understand thoroughly both the inflammatory and neurodegenerative components that result in clinical disease progression and disability. This chapter outlines the drawbacks of the current standard approaches for imaging, develops particular arguments for adopting a pathway-specific approach to
MS imaging and discusses the pathway-specific imaging techniques available for studying MS. Three techniques are discussed in detail: diffusion tensor imaging (DTI), functional MRI (fMRI) and functional connectivity. These techniques have the potential to assess the integrity and function of individual pathways. The direct assessment of pathways offers a new window for improved understanding of the interaction between inflammatory and neurodegenerative components of MS. The ultimate goal would be to develop accurate techniques to test future therapies directed at not only inflammation but also neuroprotection and neural restoration.
