Automated segmentation and quantitative analysis of vascular curvature features in unruptured intracranial aneurysms...

Arterial tortuosity is closely related to the formation, progression, and rupture of unruptured intracranial aneurysms (UIAs). This study aimed to assess the relationship between 3-dimensional (3D) centerline curvatures and the UIA formation risk, at the level of the entire cerebral arterial trunks and the parent arteries of UIAs in different hemodynamic locations.

This retrospective study evaluated the association between 3D centerline curvatures and the risk of UIAs in a cohort of 101 patients (114 aneurysms) and 145 healthy controls (HC) enrolled between March 2020 and February 2023. Tortuosity index (TI) and 3D centerline curvatures of 9 major cerebral arteries were automatically extracted from magnetic resonance angiography (MRA). Curvature parameters of cerebral arterial trunks were compared between UIA patients and HC and analyzed for their association with UIA formation. Additionally, curvature parameters of the parent arteries were compared with their contralateral counterparts in both sidewall and bifurcation aneurysms.

Compared to HC, UIA patients exhibited significantly higher curvature parameters (P<0.001), whereas TI showed no significant difference. Increased curvature parameters are strongly correlated with a higher UIA risk [odds ratio (OR) ranging from 2.69 to 10.62]. In parent artery analysis, sidewall aneurysms demonstrated elevated curvature parameters versus contralateral arteries, including total absolute curvature (P=0.049), average absolute curvature (P=0.023), root-mean-square curvature (P =0.014), standard deviation of curvature (P=0.014), and 90% maximum absolute curvature (P=0.008), whereas bifurcation aneurysms showed no differences.

Increased 3D centerline curvatures of cerebral arteries significantly correlate with higher UIA risk, particularly in sidewall aneurysms. Assessing 3D centerline curvatures provides valuable insights into aneurysm hemodynamics and supports a comprehensive assessment of aneurysm risk.