Sinus pericranii (SP) is a cranial venous anomaly in which there is an abnormal communication between intracranial dural sinuses and extracranial venous structures, usually via an emissary transosseous vein.
It is considered a type of low flow vascular malformation. It occurs in close communication with the cranial vault and most frequently involves the superior sagittal sinus.
When suspected on radiological basis, a simple clinical test can be performed. Unless thrombosed, the sinus pericranii will appear more prominent on supine position than when sitting, because of variable venous pressure with gravity. The lesions are not classically associated with discoloration of the overlying skin.
They are comprised of non-muscular venous blood vessels which tightly adhere to the outer calvarium and directly communicate with an intracranial venous sinus through diploic veins 1,4.
Colour Doppler may show communication with superficial veins and dural venous sinuses 2.
- non contrast
- slightly increased attenuation compared with brain parenchyma
- may show an associated cranial vault defect
- post contrast
- unless thrombosed, the abnormal communication between dural sinuses and the cranial vault will tend to enhance to the same degree as cerebral venous structures
Signal may vary due to slow flow 2. An abnormal communication between dural sinuses and the cranial vault is usually seen.
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- 4. Bigot JL, Iacona C, Lepreux A et-al. Sinus pericranii: advantages of MR imaging. Pediatr Radiol. 2000;30 (10): 710-2. - Pubmed citation