Altered MLV imaging overlaps with skull bone erosion in a patient with GSD. (A) 3D reconstruction of a computed tomography scan in superior view showing the large erosion of the right parietal bone (white circle). (B–F) Meningeal vascular 3D mapping by MRI. (B) Superior view showing a large area of gadobutrol slow-flow (yellow) in the region of the vanished bone (white circle) and extending to the perisinusal area of the SSS. (C) Posterior view showing the extension of the perisinusal gadobutrol enhancement (yellow) all along the SSS. (D) Lateral view showing that MLV hypertrophy involved MLVs of the SSS, StS, LS, SS, and CAV. This MLV hypertrophy was associated with a malformation of the StS that was replaced by a large venous plexus (asterisk) encompassing the StS and an abnormally persistent embryonic falcine sinus (FaS). (E) Lateral view reconstruction highlighting the close relationships between the MMA (red arrow) and its related MLVs (black arrows). (F) Anterior view allowing the visualization of the CAV, ica, and vertebral arteries (VA). MLV hypertrophy allowed to visualize the continuity of MMA-related MLVs toward the skull base. Note that, instead of lining the MMA toward the spinosum foramen, MLVs followed the middle meningeal vein toward the sphenoparietal sinus (SPPS) toward the CAV. Scale bar: 1 cm (A–F).