Type I | T1: hyperintense core | Subacute hemorrhage, surrounded by a rim of hemosiderin-stained macrophages and gliotic brain |
T2: hyper- or hypointense core with surrounding hypointense rim |
Type II | T1: reticulated mixed-signal core | Loculated areas of hemorrhage and thrombosis of varying ages, surrounded by gliotic, hemosiderin-stained brain; in large lesions, areas of calcification may be seen |
T2: reticulated mixed-signal core with surrounding hypointense rim |
Type III | T1: iso- or hypointense core | Chronic resolved hemorrhage, with hemosiderin staining within and around the lesion |
T2: hypointense with a hypointense rim that magnifies the size of the lesion |
GE: hypointense with greater magnification than T2 | |
Type IV | T1: poorly seen or not visualized at all | Two lesions in the category were pathologically documented as telangiectasias |
T2: poorly seen or not visualized at all |
GE: punctate hypointense lesions | |