Analysis of risk factors for the rupture of small intracranial aneurysms by four?dimensional CT angiography / 中华放射学杂志

ABSTRACT

Objective Electrocardiographic (ECG) gated 4?dimensional CT angiography (4D?CTA) was performed to analyze the morphological characteristic differences between ruptured and unruptured intracranial aneurysms less than 5 mm to predict the rupture risk of small intracranial aneurysms. Methods A total of 118 patients with intracranial aneurysms less than 5 mm who underwent 4D?CTA examinations in our hospital from May 2014 to May 2017 were retrospectively analyzed. The whole study population was divided into ruptured group and unruptured group. Seventy?two patients were in the ruptured group and 46 patients were in the unruptured group. Original scanning data were reconstructed to produce 20 data sets of cardiac cycles with 5% time intervals. In addition, 20 groups of images and dynamic graphs were generated using three?dimensional software. We concluded the convex was point of impulse if small bubble or small pointed convex could be found in continuous three or more images at the same location. The morphological characteristics and clinical features of the two groups of aneurysms were firstly analyzed by univariate analysis, and then the meaningful indicators were analyzed by logistic regression, and the optimal diagnostic cutoff values were calculated using ROC curves. Results Univariate analysis showed that women, smoking history, location of aneurysm at the bifurcation, pulsation point, aspect ratio (AR) and size ratio (SR) were statistically significant different between the two groups of small aneurysms (P<0.05), but age, hypertension, type 2 diabetes, family history, history of multiple aneurysms, history of drinking, location, size, neck and tumor height had no significant differences between the two groups (P>0.05). Multivariate regression analysis showed that pulsation point (odds ratio=8.843, 95% confidence interval 2.800—27.925) and large SR value (odds ratio=4.484, 95% confidence interval 1.094—18.385) were independent risk factors for the aneurismal rupture. when the SR value was greater than 1.65, the area under the ROC curve was 0.832, the sensitivity to diagnose the risk of small aneurysm rupture was 76%, and the specificity is 70%. Conclusion The occurrence of pulsation point and SR value greater than 1.65 are independent predictors of the risk of intracranial aneurysm rupture less than 5 mm.