Differentiation of typical from atypical and malignant meningiomas using diffusion weighted magnetic resonance imaging

• Published in: Journal of Clinical and Scientific Research Vol. 6; no. 2; pp. 80 - 88
• Main Authors: VS, Khaja Naseruddin, B, Vijaya lakshmi Devi, BCM, Prasad, N, Rukmangada, AY, Lakshmi
• Format: Journal Article
• Language: English
• Published: Wolters Kluwer Medknow Publications 01.04.2017
• Subjects: apparent diffusion coefficients; differentiation; diffusion magnetic resonance imaging; meningioma; normalized apparent diffusion coefficients
• ISSN: 2277-5706; 2277-8357
• DOI: 10.15380/2277-5706.JCSR.16.02.002

Background: Atypical and malignant meningiomas are associated with less favourable clinical outcome as they are more prone to recurrence and aggressive growth. Conventional magnetic resonance imaging (MRI) can reliably differentiate meningiomas from other extra-axial neoplasms, but grading of meningiomas as typical or atypical/malignant is not possible. Diffusion weighted MRI (DWMRI) has been used reliably for grading of gliomas. There are only few studies to investigate utility of DWMRI in grading of meningiomas. So we have planned in this study to investigate the utility of DWMRI parameters such as apparent diffusion coefficients (ADC) and normalized ADC (NADC) ratios in the preoperative characterization of meningiomas. Methods: Thirty patients with pathologically proven meningiomas [typical (n=25) atypical/malignant (n=5)] underwent MRI at 1.5 T. The signal intensity of lesions on DWI was evaluated. ADC values of lesion and NADC ratios from lesion and contralateral normal white matter were calculated. Results: The mean apparent diffusion constant (ADC) values (χ 10-3 mm2/ s) were 0.92±0.2 and 0.66±0.08 in typical and atypical/malignant meningiomas respectively. The mean NADC ratios were 1.24±0.28 and 0.86±0.08 for typical and atypical/malignant meningiomas respectively. Conclusions: Atypical and malignant meningiomas have significantly lower ADC and NADC ratios compared to typical meningiomas.