Stages | CT appearance |
Early cerebritis | May be invisible. Poorly marginated cortical or subcortical hypodensity with mass effect with little or absence of enhancement. An ill-defined area of low density on plain CT corresponds to developing necrotic center in the cerebritis stage. |
Late cerebritis | Irregular ring-enhancing lesion with a hypodense center, better defined than early cerebritis. |
Early capsule | Well-defined rim-enhancing mass, an outer hypodense and inner hyperdense rim (double rim sign) is seen in most cases. A slightly hyperdense, faint ring is seen surrounding a necrotic hypodense center [44] . |
Late capsule | Rim-enhancing lesion with thickened capsule and diminished hypodense central cavity. The capsule is seen as a ring in plain CT. |