Fig. 5.

Iron-laden microglia/macrophages at edges of WM lesions of the first sample. a Establishment of a post-mortem threshold (dashed line) for manually counted iron-laden microglia/macrophages to induce a dark rim signal in SWI, based on four multiple sclerosis cases and four WM lesions with available post-mortem scans. Each data point represents one ROI. Numbers in brackets indicate numbers of ROIs. b Application of the threshold (dashed line) for the edges of all 183 WM lesions indicates that 2/10 active/inactive, 11/24 slowly expanding, 6/49 inactive lesions, and 1/74 shadow plaques exceeded this threshold. *P value of Chi-square test between slowly expanding and inactive lesion edges which were either below or above the threshold. Each data point represents the value of one lesion edge. Numbers in brackets indicate numbers of data points and individual lesions