Meningioma originates from the arachnoid plexus and is connected to the dura mater. It is a typical extracerebral tumor and may occasionally occur in the ventricles of the brain. Meningioma CT manifestations include: 1. Typical manifestations: the tumor is connected to the skull or dura mater with a wide base, often with a uniform slightly high or equal density and clear borders. Most of the tumors have peritumoral edema and intra-tumoral calcification foci are visible, but hemorrhage, necrosis and cystic changes are less common. Enhancement scan shows homogeneous significant enhancement with sharp edges; 2. Atypical presentation: tumor is mainly cystic with uneven density within the tumor; 3. circumferential enhancement; 4. wall nodules; 5. whole tumor with low density and uneven enhancement; 6. high density intra-tumor hemorrhagic foci; 7. complete calcification of tumor; 8. ossifying meningioma; 9. peritumor cerebrospinal fluid-like hypodense area; 10. cool intracerebral tumor; 11. multiple meningioma.