Dynamic Volume Change Rate and Aspect Ratio Are Correlated to the Formation of an Irregular Morphology of Unruptured Intracranial Aneurysm.

Objective: The aim of this research was to study the factors influencing the formation of intracranial aneurysms with irregular morphology by observing the dynamic volume change rate of intracranial unruptured aneurysms and other aneurysm characteristics.

Method: Sixty-five unruptured intracranial aneurysms of 51 consecutive patients from 1 center were included in this study. All patients underwent a dual-source computed tomography electrocardiogram-gated 4-dimensional computed tomography angiography examination. The original data at the end of the scan were reconstructed, and 20 sets of data packages through a cardiac cycle with 5% interval were obtained. Data packages were processed by a 3-dimensional software workstation to obtain 20 sets of images and dynamic diagrams. The volume of each aneurysm in the 20 sets of images was measured, and the volume change was calculated by a specific formula. The other data features of the aneurysm such as aneurysm neck, aneurysm height, aspect ratio (AR), location at bifurcation, and clinical features such as age, sex, hypertension history, type 2 diabetes history, smoking history, family history, multiple aneurysm history, and subarachnoid hemorrhage history, were documented in detail. After single factor analysis data, logistic regression analysis of the meaningful indicator was conducted to study the predictive factors of irregular aneurysms.

Results: Of the 65 aneurysms, 25 possessed an irregular shape and 40 were of regular shape; 51 were anterior circulatory aneurysms and 14 were posterior circulatory aneurysms. Single factor analysis showed that AR (P = 0.001), volume change rate (P = 0.002), and location of aneurysm at the bifurcation (P = 0.038) of the vessel were significantly correlated with irregular aneurysms, but not correlated with age, sex, hypertension history, type 2 diabetes history, smoking history, family history, multiple aneurysm history, and subarachnoid hemorrhage history. Multifactor analysis showed that volume change rate greater than 30% (P = 0.008; odds ratio, 6.934) and AR greater than 1.4 (P = 0.004; odds ratio, 8.258) were independent correlative factors of the formation of intracranial aneurysm with irregular shape.

Conclusion: The volume change rate and AR are independent correlative factors of the formation of intracranial aneurysm with irregular shape.