Findings and Prognostic Value of Contrast-Enhanced Early Magnetic Resonance Imaging After Coil Embolization of Cerebral Aneurysms

BACKGROUND: Recent studies imply an association between aneurysm wall enhancement (AWE) on contrast-enhanced magnetic resonance imaging and aneurysm rupture. We investigated the prevalence and clinical significance of AWE and enhancement within the aneurysm (inner enhancement [IE]) in coiled aneurysms. METHODS: We assessed the frequency of AWE and IE after coil embolization on postinterventional magnetic resonance imaging (<6 weeks) in 30 consecutive patients with 33 aneurysms and elucidated the association between enhancement and subsequent aneurysm recurrence or hemorrhage. RESULTS: AWE and IE occurred in 97% and 36% of cases, respectively. There was no rehemorrhage, and there was no significant association between subsequent reperfusion and AWE (P = 0.200) or IE (P = 0.148) during a median follow-up period of 19 months. The greatest share of IE (8 of 12 aneurysms) was found in incompletely coiled aneurysms with small remnants (P = 0.001). CONCLUSIONS: AWE after coil embolization cannot be used for recurrence risk stratification owing to its high prevalence. IE is likely to represent contrast inflow in the coiled aneurysm.