Show pageBacklinksCite current pageExport to PDFFold/unfold allBack to top This page is read only. You can view the source, but not change it. Ask your administrator if you think this is wrong. ====== Extra axial ====== Extra-[[axial]] is a descriptive term to denote lesions external to the [[brain parenchyma]], in contrast to [[intra-axial]] which describes lesions within the brain substance. ===== Radiographic features ===== Often it is trivially easy to distinguish an intra-axial from an extra-axial mass. In many cases, especially when the mass is large and associated with parenchymal changes, such as oedema, localisation can be more difficult. A number of features are helpful in suggesting that a mass or lesion is extra-axial, including: subarachnoid space CSF cleft sign widening of adjacent subarachnoid space/cistern intervening pial arteries or veins brain parenchyma absence of a claw sign intervening cortex between mass and white matter white matter buckling sign bone and meninges dural tail sign erosion or invasion/destruction of bone hyperostosis ((https://radiopaedia.org/articles/extra-axial-1)). extraaxial.txt Last modified: 2025/04/29 20:26by 127.0.0.1