Fig. 2. The image of an aneurysm is classified as a deviated neck type (Type D). The image illustrates the method of dimension measurements: neck width, depth (the longest diameter between the neck and dome), width (the maximum distance vertical to height) and maximum size (Dmax, the largest measurement in terms of maximum dome diameter or width). Aspect ratio (AR) is calculated as depth divided by neck width, depth-to-width ratio (DW) is calculated as depth divided by width, and the bottleneck factor (BF) is calculated as width divided by neck width.