There is an expansile lesion centered in the right parietal bone, infiltrating and expanding the diploic space. The lesion is heterogeneously T1 and T2 hypointense and has areas of abnormally restricted diffusion.
The lesion measures 8 cm in maximal diameter and extends laterally into the adjacent soft tissues and medially into the epidural space. There is mild local mass effect with mild effacement of adjacent sulci, without associated increased T2/FLAIR hyperintensity in the brain parenchyma.
This may represent an intraosseous meningioma or fibrous dysplasia with other etiologies also possible. Head CT is recommended to further characterize the lesion.