A Prospective Follow-up Study on Risk Factors to Predict the Progression of Unruptured Intracranial Aneurysms on Enhanced HR-MRI

Abstract

Rationale and objectives: To prospectively investigate the potential correlation between qualitative and quantitative assessment of aneurysm wall enhancement (AWE) on initial enhanced high-resolution magnetic resonance imaging (HR-MRI) and aneurysm progression during follow-up.

Materials and methods: From June 2016 to January 2021, we prospectively recruited patients with unruptured intracranial aneurysms (UIAs) for enhanced HR-MRI examination. The patients' demographic and clinical data and aneurysm characteristics, including AWE features, were collected and analyzed. Follow-up images were compared to evaluate IA progression. Univariate and multivariate Cox proportional hazards regression analyses were performed to identify the risk factors associated with aneurysm progression.

Results: Seventy-seven patients with 95 UIAs met our research criteria, and the median follow-up time was 15.7 months. Progression was observed in 18 aneurysms; the remaining 77 remained stable. Progressive UIAs were larger in size, more frequently displayed obvious AWE and showed a higher enhancement ratio (ER) than nonprogressive UIAs. Multivariate Cox regression analysis showed that both ER (hazard ratio, 6.304, p < 0.001) and aneurysm size (hazard ratio, 1.343, p = 0.014) were independent risk factors for aneurysm progression. The combination of ER and aneurysm size had an area under the curve of 0.920 for the prediction of aneurysm progression, with a sensitivity of 88.9% and specificity of 87.0%.

Conclusion: A higher ER value of the aneurysm wall and a larger aneurysm size on initial HR-MRI may predict an increased risk of aneurysm progression, which suggests that closer monitoring by imaging or preventive intervention may be required for the clinical management of these aneurysms.

Keywords: Aneurysm progression; Aneurysm size; Aneurysm wall enhancement; Follow-up; High-resolution magnetic resonance imaging; Risk factors; Unruptured intracranial aneurysm.