Accessory Skull Suture

Etiology: congenital
Imaging: zigzag pattern, not diastatic, merges with adjacent suture, no associated soft tissue swelling
DDX: skull fracture has straight lucency which widens as it approaches suture, can cross adjacent suture, associated with soft tissue swelling

Radiology Cases of Accessory Skull Suture

3D CT of accessory skull suture — 3D reconstruction of a CT without contrast of the brain shows a lucency arising from the left lambdoid suture inferiorly and curving to the left that has a zig zag pattern and seems to interdigitate within the skull. Soft tissue windows showed no associated soft tissue swelling.

3D CT of intraparietal accessory skull suture — 3D reconstruction of a CT without contrast of the brain shows a lucency arising from the left lambdoid suture anteriorly and curving anteriorly that has a zig zag course through the parietal bone.