Objective: Aneurysm wall enhancement on high-resolution magnetic resonance imaging (HR-MRI) is seen in ruptured aneurysms. However, site, size and other morphology features also contribute to aneurysm rupture. We introduce a model combining aneurysm wall enhancement and these factors to predict rupture status of aneurysm.
Methods: We prospectively collected data of patients with intracranial aneurysms who received HR-MRI scan before surgical treatment. Aneurysms were divided into ruptured group (n=25) and unruptured group (n=116). Clinical features, imaging features including size, site, width of neck, aspect ratio(AR), daughter sac, and aneurysm wall enhancement scale(AWES) in both groups were analyzed. AWES was categorized on HR-MRI contrast-enhanced T1WI images: grade 0, no enhancement; grade 1, enhancement greater than grade 0 but less than that of the pituitary infundibulum or choroidal plexus; grade 2, enhancement greater than or equal to that of the pituitary infundibulum or choroidal plexus. Univariate and multivariate logistic regression were performed to evaluate the risk factors of aneurysm rupture status.
Results: AWES(P<0.001),AR(P=0.0001),daughter sac(P=0.001) and non-ICA location(P=0.002) were higher in ruptured aneurysms. Multivariate logistic regression showed that AWES(OR 5.99,95%CI 2.51-14.29,P<0.001),daughter sac(OR6.22,95%CI 1.68-23.16,P=0.006),and non-ICA location(OR6.25,95%CI 1.35-28.30,P=0.019) were associated with aneurysm rupture status. A simplified predicting model (SAD model) using site(non-ICA,1; ICA,0), AWES(2,1,0), daughter sac(yes,1; no,0) predicted 0, 2%, 12%, 44% and 100% of ruptured aneurysms from scale 0 to 4(Area under curve 0.8920, 95%CI 0.8241-0.9404).
Conclusion: SAD model is helpful to predict rupture stutus of aneurysm and may provide a new tool to screen high-risk aneurysms.