Figure 1.
Definition of morphological parameters used in the analysis.
Maximum aneurysm height (Hmax) is measured between the center of the aneurysm neck and the greatest distance to the aneurysm dome. Maximal perpendicular height (H) is the largest perpendicular distance from the neck of the aneurysm to the dome of the aneurysm. Aspect ratio is calculated as the ratio of the H and neck diameter of the aneurysm. Size ratio is the ratio between Hmax and the mean vessel diameter of all branches associated with the aneurysm (L_A1v, L_A2v, R_A1v, R_A2v). Aneurysm angle is the angle formed between the neck of the aneurysm and the maximum height of the aneurysm (Hmax). Vessel angle is the angle between the parent vessel and the plane of the aneurysm neck. Flow angle is the angle between the maximum height of the aneurysm and the parent vessel.
Figure 2.
Computed Tomography Angiogram (CTA) and three-dimensional models of anterior communicating aneurysms with a dominant A1 or with co-dominant A1’s.
Coronal MIP images are shown for an ruptured AcoA aneurysm with a dominant left A1 (A) and an unruptured AcoA aneurysm with co-dominant A1’s (C). The corresponding 3-D reconstructed images from Slicer are shown in B and D with definitions of morphological parameters. Solid line (B and D) indicates aneurysm neck.
Table 1.
Demographic information and clinical risk factors for patients with ruptured and unruptured anterior communicating artery (ACoA) aneurysms.
Table 2.
Univariate analyses for the morphological parameters measured for ruptured and unruptured ACoA aneurysms.
Table 3.
Multivariate analysis after adjustment for clinical and morphological risk factors.
Figure 3.
Scatter plots depicting the interaction between size ratio and other morphological parameters.
Linear regression analysis for scatter plot of size ratio and aspect ratio yielded an R2 value of 0.75 for the ruptured group and 0.74 for the unruptured group (A), suggesting inter-dependency of the two variables. No clear dependency was observed between size ratio and aneurysm angle (B), flow angle (C), or parent-daughter angle (D).
Figure 4.
Scatter plots depicting the interaction between flow angle and other morphological parameters.
Linear regression analysis for scatter plot of aneurysm angle and flow angle yielded an R2 value of 0.76 and 0.56 for the ruptured and unruptured groups, respectively (Figure A). No apparent relationship was found between flow angle and size ratio (B), aspect ratio (C), or parent-daughter angle (D).
Table 4.
Morphological and hemodynamic parameters evaluated in the literature.