Large right extra-axial posterior parafalcine mass is heterogeneous, but of similar signal intensity to brain parenchyma on T1 and T2-weighted imaging. Slightly increased signal on FLAIR. Diffuse homogeneous bright enhancement with central nonenhancing T2 hyperintense component. There is markedly lobulated surface contour.
The mass compresses the trigone of the right lateral ventricle, displaces and compresses the splenium of the corpus callosum, and compresses the medial right occipital lobe. There is abnormal T2 hyperintensity in the white matter of the right parietal, posterior right frontal, and right occipital lobes. There are large vessels along the surface of the mass.
Markedly elevated relative cerebral blood volume. MR spectroscopy demonstrates marked elevation of choline, depletion of creatine and NAA. No alanine peak (if present, would favour meningioma).
Conclusion: Large right parafalcine extra-axial mass likely to represent a haemangiopericytoma with the obvious differential of a meningioma.