Ependymal enhancement on magnetic resonance imaging for the identification of high-grade gliomas

BACKGROUND: High-grade gliomas have high infiltrative potential and spread along white matter and blood vessels. Enhancement of ependymal lining on magnetic resonance imaging (MRI) is considered as a marker of parenchymal spread of disease. In this study, we aimed to assess the sensitivity, specificity, and positive and negative predictive values of ependymal enhancement (EE) for identification of high-grade glial tumors. METHODS: We reviewed preoperative MRI scans of 94 consecutive patients surgically treated for space occupying lesions of the brain for EE. Assessment for EE was blind to the final histopathological diagnosis of the patient. An enhancement of more than 2 mm was considered positive. Pathologies of these patients were reviewed and matched to the radiological findings. Percentage and proportion of EE in glial and non-glial pathology groups was then calculated and a sensitivity and specificity analysis was performed. RESULTS: The population included 94 cases (64 males and 30 females) with population mean age 45 ± 15.5 years. Sensitivity of EE in differentiating glioma from total number of cases was 82.61% specificity 35.42% (P value = 0.048). EE had a sensitivity of 67.39% and specificity of 64.58% (P value = 0.002) in identifying high-grade glioma within the glioma group with a positive predictive value of 64.58% (95% CI: 49.46% to 77.83%), negative predictive value of 67.39% (95% CI: 51.98% to 80.46%). CONCLUSION: EE has moderate sensitivity and specificity for high-grade gliomas. However, larger sample studies are required for further validation of this observations.