Figures & data
Figure 1. Example of chronic active lesion visualization using different neuroimaging modalities. (A) On 3D axial fluid-attenuated inversion recovery sequence, two hyperintense white matter lesions are visible. Both lesions (orange arrows) show a hypointense rim on phase image derived from a multi echo gradient-echo T2* sequence, thus they represent ‘iron rim lesions.’ (B) White matter lesions showing a linear expansion on serial MRI scans (i.e. ‘slowly expanding lesions’ [SELs]) can be identified by linearly fitting the Jacobian of the non-linear deformation field between timepoints obtained using merged T1- and T2-weighted images scans. In particular, T2-hyperintense lesions containing one cluster showing a linear annual increase ≥12.5% and embedding neighboring voxels with an annual increase of at least 4% are classified as SELs. (C) Demonstration of a chronic active lesion showing a peripheral rim on quantitative susceptibility mapping (QSM) (red circle) and 11C-PK11195 uptake, a marker of activated microglia/macrophages, on positron emission tomography (red circle). Figure 1(c) adapted from [Citation11] by permission of Oxford University Press on behalf of the Guarantors of Brain
![Figure 1. Example of chronic active lesion visualization using different neuroimaging modalities. (A) On 3D axial fluid-attenuated inversion recovery sequence, two hyperintense white matter lesions are visible. Both lesions (orange arrows) show a hypointense rim on phase image derived from a multi echo gradient-echo T2* sequence, thus they represent ‘iron rim lesions.’ (B) White matter lesions showing a linear expansion on serial MRI scans (i.e. ‘slowly expanding lesions’ [SELs]) can be identified by linearly fitting the Jacobian of the non-linear deformation field between timepoints obtained using merged T1- and T2-weighted images scans. In particular, T2-hyperintense lesions containing one cluster showing a linear annual increase ≥12.5% and embedding neighboring voxels with an annual increase of at least 4% are classified as SELs. (C) Demonstration of a chronic active lesion showing a peripheral rim on quantitative susceptibility mapping (QSM) (red circle) and 11C-PK11195 uptake, a marker of activated microglia/macrophages, on positron emission tomography (red circle). Figure 1(c) adapted from [Citation11] by permission of Oxford University Press on behalf of the Guarantors of Brain](/cms/asset/4f5b9618-49ef-48ad-97da-3afabe5c750d/iern_a_1953983_f0001_oc.jpg)