Teaching NeuroImages: Delayed nonischemic cerebral enhancing lesions post endovascular coil embolization

Abstract

A 50-year-old woman underwent embolization of an anterior communicating artery aneurysm, via the left internal carotid artery, using the penumbra SMART coil system. Follow-up CT angiography at 16 months revealed a 2-mm hyperdense lesion in the left parietal lobe (figure 1). MRI confirmed multiple punctate enhancing foci with surrounding edema favored to represent nonischemic cerebral enhancing (NICE) lesions (figure 2). NICE lesions are rare complications of coil embolization putatively associated with nickel allergy or coil emboli,1 although the SMART coil system is platinum based. The patient remained asymptomatic and further workup was withheld. Follow-up MRI at 1.5 months showed resolution.