Atretic parietal cephalocele. [Neuroradiology] [MR]
Atretic parietal cephalocele. [Neuroradiology] [MR]
Photo: 8 year old with a mass at the top of his head since birth.
Top left: Sagittal T1 shows a pedunculated mass protruding through the midline calvarium.
Top & bottom mid: Sagittal postcontrast T1 SPGR shows the relation of the hairpin-shaped vessel and the superior sagittal sinus to the scalp mass. There is a fenestration (hole) in the superior sagittal sinus through which the fibrous stalk courses.
Top right: Sagittal T2 shows a hairpin-shaped vessel directed towards the lesion.
Bottom right: 3D MR venogram shows the hairpin-shaped vessel pointing towards the lesion.
Atretic parietal cephalocele is a congenital abnormal herniation of the brain covering +/- brain through a midline defect of the parietal bones. It is atretic because this herniation then atrophies until only a fibrous stalk connects it to the rest of the intracranial compartment. It is associated with a persistent falcine sinus, an embryonic vertical positioning of the straight sinus.