Clinical Significance of Circumferential Aneurysmal Wall Enhancement in Symptomatic Patients with Unruptured Intracranial Aneurysms: aHigh-resolution MRI Study

Background and Purpose The estimates on the risk of rupture of intracranial aneurysms remain acontroversial topic. Circumferential aneurysmal wall enhancement (CAWE) on vessel wall magnetic resonance imaging (MRI) has been described in unstable aneurysms. Sentinel headaches and third nerve palsy are possible symptoms prior to the rupture of intracranial aneurysms. In this study, we aimed to demonstrate that CAWE could be associated with these symptoms. Methods We performed aretrospective analysis of consecutive symptomatic or asymptomatic patients with unruptured intracranial aneurysms who were examined by high-resolution MRI from October 2014 to November 2016. Two experienced neurovascular radiologists read the images independently and determined whether there was CAWE of the unruptured intracranial aneurysms. Then, we compared variable factors between patients with and without symptoms through univariate comparison and multivariable logistic regression analyses. Results A total of 45 unruptured intracranial aneurysms were detected in 37 patients. The agreement between 2 experienced readers for CAWE was good (kappa=0.82; 95% confidence interval 0.66-0.99). CAWE of unruptured intracranial aneurysm was more frequently observed in symptomatic than in asymptomatic patients (16/23, 69.6% versus 6/22, 27.3%, respectively, P < 0.05). The CAWE was the only independent factor associated with symptoms in the multivariable logistic regression analysis (odds ratio 5.17; 95% confidence interval 1.30-20.52; P = 0.02). Conclusions Our study demonstrates that CAWE correlated with sentinel headaches and third nerve palsy caused by unruptured aneurysms, and this may be an additional clue to distinguish the cause of these symptoms.