Findings and prognostic value of contrast enhanced early MRI after coil embolization of cerebral aneurysms.

Abstract Background Recent studies imply an association between aneurysm wall enhancement on contrast enhanced MRI and aneurysm rupture. We investigated the prevalence and clinical significance of aneurysm wall enhancement and enhancement within the aneurysm in coiled aneurysms. Methods We assessed the frequency of aneurysm wall enhancement and enhancement within the aneurysm (inner enhancement) after coil embolization on postinterventional MRI ( Results aneurysm wall enhancement and inner enhancement occurred in 97% and 36% of cases, respectively. There was no re-hemorrhage and there was no significant association between subsequent reperfusion and aneurysm wall enhancement (p=.200) or inner enhancement (p=.148) during a median follow-up period of 19 months. The greatest share of inner enhancement (8/12) was found in incompletely coiled aneurysms with small remnants (p=.001). Conclusions aneurysm wall enhancement after coil embolization cannot serve for recurrence-risk-stratification, due to its high prevalence. Inner enhancement is likely to represent contrast inflow in the coiled aneurysm.