Figure 15c. Sinus pericranii. (a) Lateral radiograph shows diffuse as well as more discrete areas (arrows) of cortical thinning. (b) Sagittal contrast-enhanced T1-weighted MR image demonstrates a serpiginous scalp mass with avid enhancement. (c) Sagittal venous phase brain angiogram obtained after the injection of contrast material into the internal carotid artery demonstrates multiple small, transosseous vessels that supply the scalp venous malformation.