Marieke van Rosmalen

General introduction and thesis outline 19 1 The value of electrophysiology and nerve ultrasound as biomarkers have been studied previously. These efforts did not result in the identification of quantitative measures that correlate to clinical outcomes or prognosis (unpublished data from our center). 41–43 Quantitative MRI techniques, such as DTI, are a potentially powerful tool to monitor tissues. DTI has been explored in several studies of the central nervous system. These studies showed differences in diffusion parameters over time and sometimes showed correlations with clinical parameters. 44–49 However, there is only a very limited number of studies of the peripheral nervous system. It is therefore unknown if quantitative MRI captures relevant differences in the peripheral nervous system, for example early treatment effects. THESIS OUTLINE The aim of this thesis is to explore the feasibility and value of qualitative and quantitative MRI techniques in diagnosis, pathophysiology, disease course, and treatment response in chronic inflammatory neuropathies. Chapter 2 contains a description of the natural history of MMN and an analysis of the correlates of a progressive disease course. Chapter 3 evaluates the interrater variability of current practice, i.e. a qualitative assessment of nerve thickening on brachial plexus MRI. In Chapter 4 we explore feasibility and diagnostic performance of a quantitative assessment of nerve thickening. In chapter 5 we study involvement of intraspinal roots in CIDP and MMN. In chapter 6 we assess the use of quantitative MRI techniques (i.e. DTI, T2 mapping, and fat fraction analysis) and attempts to study nerve architecture in CIDP and MMN in vivo . In chapter 7 we present data of quantitative MRI after one year of follow-up. Chapter 8 contains a summary and discussion of the main findings of this thesis and provides recommendations for clinical practice.