MRI Imaging Features of Meningioma

ABSTRACT

Meningiomas are the most common non glial extra axial primary brain tumors of the central nervous system (CNS), accounting for between 16 to 20% of all intracranial tumors. Aim: In this study we tried to describe typical and atypical locations and findings of intracranial meningiomas on MRI and also MRI features of meningiomas that differentiate from other extra axial lesions. Methods: Studied population was advised to undergo MRI investigations for confirmation of meningiomas and to differentiate from other extra axial tumors and CT suggested in few cases for confirmation of calcification and boney changes. All MR imaging were performed with 1.5T bravo MR imaging unit with standard protocol. In operated cases, MRI findings were correlated with intraoperative findings and histopathological diagnosis. Results: Majority of meningioma patients were observed in the age group of 51-70 years i.e., 24 (80%) out of 30 cases. The most common site of occurrence are the cerebral convexities, parasaggital location/falx, posterior fossa, sphenoid ridge, olfactory groove and others accounting for 33.3%, 20%. 20%, 10%, 6.7% and 10% respectively. 67% of meningiomas showed homogenous enhancement, 56% cases had dural tail sign, 40% meningioma cases observed with CSF cleft, 37% of cases showed mass effect on surrounding arteries, cranial nerves, ventricular system and brainstem noted in twelve cases. 33% of cases noticed with perilesional edema, 30% had calcifications, 20% hyperostosis, 13% sinus invasion and 10% were others such as haemorrhages, cystic or non enhancement areas. Conclusions: As Meningiomas are not an uncommon tumors, radiologists should be aware of different MRI characteristics and locations of meningiomal tumors, this will help to arrive at accurate diagnosis especially in atypical and misleading meningioma features.