Magnetic resonance imaging to characterize chronic inflammatory neuropathies

This thesis focuses on the characteristics of chronic inflammatory demyelinating polyneuropathy (CIDP) and multifocal motor neuropathy (MMN) evaluated in multiple MRI-studies. Possible improvements of assessment of brachial plexus MRI in diagnosis of CIDP and MMN has been described, as well as an evaluation of quantitative MRI to study pathophysiology. Finally, quantitative MRI has been studied to serve as a potential biomarker to predict disease course and treatment response. The diagnostic value of brachial plexus MRI for the diagnosis of CIDP can be improved by using a quantitative assessment method. The method described in this thesis is reliable and has an acceptable test characteristics. In particular for patients with CIDP MRI may be of added value, especially when nerve conduction studies do not fulfil the electrodiagnostic criteria for CIDP and nerve ultrasound shows no nerve thickening. Quantitative MRI, such as diffusion tensor imaging, has been evaluated to study differences in quantitative diffusion parameters between CIDP and MMN. The differences found can be related to differences in underlying pathophysiological mechanisms. Finally, diffusion tensor imaging has been explored as a biomarker to predict disease course and treatment response in a longitudinal study. Differences in diffusion parameters have been found in patients with CIDP after one-year follow-up. However, these changes over time do not seem to correlate to clinical data