CT and MR diagnosis of supratentorial intraparenchymal ependymoma

Purpose: To analyse the CT and MRI features of supratentorial intraparenchymal ependymoma. Materials and methods: Twenty-four cases of supratentorial intraparenchymal ependymoma proved by surgery and pathology had CT and MRI scanning. There were 16 males and 8 females. Nine cases were below 10 years old, 6 11∼20 years old, and 9 over 20 years. Results: Twenty-one cases of supratentorial intraparenchymal ependymoma were partial cystic. The consistency of the tumors was mostly cystic. The cyst fluid was low density on CT scan, slightly greater than intensity of CSF on MR T1-weighted, CSF-like high intensity on T2-weighted. The solid of the tumor was iso- or slightly hyper-dense, slightly hypo-intense on T1-weighted imaging and slightly hyperintense on T2-weighted imaging. The calcification was common in the solid of tumor. The peritumoral edema was absent or minimal. The solid of tumor and wall of cystic part were mild to moderate enhancement after contrast administration. Solid was common in elder adults, frequently involving the bifrontal. On CT scan, the tumor was slightly hyperdense with marked inhomogeneous enhancement after contrast injection. The intratumoral calcification and hemorrhage were common. The peritumoral edema was marked. Conclusion: Supratentorial intraparenchymal ependymoma might be divided into partial cystic and solid. The CT and MR findings of partial cystic are characteristic, and offer accurate diagnosis. The differentiation of solid and glioma is difficult