The diagnostic value of conventional and diffusion-weighted magnetic resonance imaging in predicting the histological grade of meningioma

Abstract

Introduction: Meningiomas are the most frequent primary tumours of the central nervous system. Sufficient grading of meningiomas is important, as the clinical treatment and prognosis differ between distinct grades of tumor.
Objective: To highlight conventional and diffusion-weighted magnetic resonance imaging characteristics in distinguishing benign from high-grade meningiomas (World Health Organization [WHO] grade II and III) preoperatively.
Methods: A descriptive cross-sectional study, total of 92 patients with meningioma were assessed by conventional MRI and DWI. The correlation between imaging findings, histopathological grading was analyzed via univariate and multivariate logistic regression analysis. The optimal cutoff for the absolute apparent diffusion coefficient (ADC) to differentiate between the groups was determined by using receiver operating characteristic (ROC) analysis.
Result: The presence of irregular tumor margins, adjacent bone invasion are predictors of higher grade meningiomas, OR = 9,0 and OR = 4,1 respectively. Conventional MRI shows 66,7% sensitivity, 90,4% specificity. ROC analysis showed that ADC thresholds of 0,721 x10^-3 mm2/s had the best accuracy, sensitivity of 90,5%, specificity of 72,2% for grading meningiomas.
Conclusion: Diffusion-weighted MRI was found to have high sensitivity and accuracy to conventional MRI in distinguishing benign from high-grade meningiomas.