BACKGROUND: To study the risk predictors of intracranial asymptomatic small aneurysm rupture by electrocardiographic (ECG)-gated 4D-CT angiography (4D-CTA).

MATERIAL AND METHODS: A total of 168 patients with intracranial aneurysms <7 mm who underwent 4D-CTA examinations were retrospectively analyzed and divided into a ruptured group and an unruptured group. The original scanning data of all cases were reconstructed to obtain 20 groups of data in 5% time intervals in the cardiac cycle. After processing with 3D workstation software, 20 sets of images and dynamic images were achieved. The morphological characteristics and clinical features of the 2 groups of aneurysms were analyzed through univariate analysis, then logistic regression analysis was performed for the meaningful indicators. Finally, the optimum diagnostic cut-off point was calculated by ROC curve analysis.

RESULTS: Univariate analysis showed that sex, smoking history, vascular bifurcation point, pulsation point appearance, aneurysm height, aspect ratio (AR), and size ratio (SR) were significantly different (P<0.05) between the ruptured group and unruptured group. Multivariate regression analysis indicated that the pulsation points (OR=8.188, 95% CI: 3.984–17.198) and high SR values (OR=5.325, 95% CI: 1.503–18.867) were independent predictors of asymptomatic small aneurysm rupture. When the SR value was higher than 1.65, the area below the ROC curve was 0.723, the diagnostic sensitivity was 75%, and the specificity was 80%.

CONCLUSIONS: The occurrence of pulsation points and SR values >1.65 were independent predictors for the rupture of asymptomatic small intracranial aneurysms <7 mm in diameter.

Keywords: Angiography, intracranial aneurysm, Rupture, Aneurysm, Ruptured, computed tomography angiography, Electrocardiography, Four-Dimensional Computed Tomography, Image Processing, Computer-Assisted, Logistic Models, Multivariate Analysis, Risk Factors