Fig 1.

Schematic drawings show measurement of aneurysmal diameters in aneurysms with simple and complex shapes.

A, An aneurysm with simple shape (oval with a small bleb). Neck size (a) used in this study is the largest axial diameter of the orifice of the aneurysm. Dome size used for the dome-to-neck ratio is a short axial diameter of the dome (b). Estimation of the maximum diameter of the sac is shown (c). The small bleb is not included when estimating the maximal diameter of the sac.

B, Aneurysm with complex shape (multilobular). Dome size used for the dome-to-neck ratio in this type is the short axial diameter of the proximal dome (b).