MR imaging appearances of meningiomas

The magnetic resonance (MR) appearances of 40 biopsy-proved meningiomas were correlated with their predominant histologic pattern: fibroblastic, transitional, syncytial, angioblastic, or mixed. Signal intensity and features on T2-weighted images strongly correlated with histophatologic findings in over 75% of cases. Meningiomas that were markedly hypointense to cortex on T2-weighted images were composed predominantly of fibroblastic or transitional elements. Markedly hyperintense meningiomas were composed primarily of syncytial or angioblastic elements. Consideration of secondary features visible on MR images (degree of edema, cyst formation, calcium aggregates) led to a more specific histologic prediction in over half of the remaining isointense tumors. The varied MR appearance of meningiomas has a clear histologic basis, and crude prediction of pathologic subtype is possible in over three-fourths of cases