Mystery Case: Rim enhancement in cerebral aneurysm An atypical feature

초록

A 54-year-old man experienced sudden onset of severe headache 3 days prior to admission. Evidence of infection or trauma was absent. Brain MRI revealed a mass-like lesion with rim enhancement and surrounding edema in the right sylvian fissure (figure, A-C). A 0.7-cm aneurysm at the right middle cerebral artery bifurcation was revealed through additional magnetic resonance angiography (figure, D) and aneurysm rupture was confirmed under microscopy during emergent surgery. Rim enhancement could be related to the presence of vasa vasorum in the aneurysm wall or neovascularization in granulation tissue within the intraluminal thrombus.(1) A round lesion with rim enhancement may be an atypical imaging feature of cerebral aneurysm.