Correlation of the relationships of brain-tumor interfaces, magnetic resonance imaging, and angiographic findings to predict cleavage of meningiomas

Object. The authors examined the relationships of brain-tumor interfaces, s pecific magnetic resonance (MR) imaging features, and angiographic findings in meningiomas to predict tumor cleavage and difficulty of resection. Methods. Magnetic resonance imaging studies, angiographic data, operative r eports, clinical data, and histopathological findings were examined retrosp ectively in this series, which included 126 patients with intracranial meni ngiomas who underwent operations in which microsurgical techniques were use d. The authors have identified three kinds of brain-tumor interfaces charac terized by various difficulties in microsurgical dissection: smooth type, i ntermediate type, and invasive type. The signal intensity on T-1-weighted M R images was very similar regardless of the type of brain-tumor interface ( p > 0.1). However, on T-2-weighted images the different interfaces seemed t o correlate very precisely with the signal intensity and the amount of peri tumoral edema (p < 0.01), allowing the prediction of microsurgical effort r equired during surgery. On angiographic studies, the pial-cortical arterial supply was seen to participate almost equally with the meningeal-dural art erial supply in vascularizing the tumor in 57.9% of patients. Meningiomas d emonstrating hypervascularization on angiography, particularly those fed by the pial-cortical arteries, exhibited significantly more severe edema comp ared with those supplied only from meningeal arteries (p < 0.01). Indeed, a positive correlation was found between the vascular supply from pial-corti cal arteries and the type of cleavage (p < 0.05). Conclusions. In this analysis the authors proved that there is a strong cor relation between the amount of peritumoral edema, hyperintensity of the tum or on T-2-weighted images, cortical penetration, vascular supply from pial- cortical arteries, and cleavage of the meningioma. Therefore, the consequen t difficulty of microsurgical dissection can be predicted preoperatively by analyzing MR imaging and angiographic studies.