[MRI features of 13 cases of intracranial ependymoma].

OBJECTIVE: To improve the accuracy of qualitative diagnosis of intracranial ependymomas by analyzing their magnetic resonance (MR) images. METHODS: The MR images of 13 cases of intracranial ependymomas confirmed by pathological examinations were investigated retrospectively. RESULTS: In the 10 cases of ventricle ependymomas, the tumors were identified in the fourth ventricle in 3 cases and in the lateral ventricle in 7 cases. The T(1)-weighted MR images presented isointense or hypointense signals and T(2)-weighted images showed inhomogeneous hyperintense ones. No edema occurred around these tumors, and the contrast-enhanced scans presented inhomogeneous enhancement. In the other 3 cases of ependymomas in the brain parenchyma, including 2 cases of supratentorial and 1 subtentorial ependymomas. The tumor parenchyma presented hypointense signals in T(1)-weighted MR images as compared to the signals of the brain parenchyma, and in T(2)-weighted images, the signals intensities were similar to or higher than those of the gray matter. Mild edema could be seen around the tumors. Enhanced scans of the tumor parenchyma showed mild to moderate enhancement. CONCLUSION: MR examination may help in the preoperative detection of intracranial ependymomas.