## 3 Results and Discussion
In addition, for the Without-stent case, the distal neck edges on the parent artery wall and aneurysm distal wall have high wall shear stress values, while for the stented cases, the peak WSS occurs on the stent wall, which is safer in terms of aneurysm rupture reduction risk [32].The exact regions of high wall shear stress are evident by navigation in the 3D virtual space and by observing the inside space of the sac from viewpoint 1. It is obvious from screenshots of Figure 18 that the regions of high WSS are located on the stent wires (Figure 18b,c) contrary to the untreated case for which this location is on the distal sac wall (Figure 18a). Some locations of high WSS are shown with black circles in Figure 18. The navigation through viewpoints 1 and 2 can provide extremely informative insight about the flow behavior and WSS distribution inside the aneurysm. The Videos S3 and S4 in Supplementary Materials show the animation of velocity vectors for Without-stent and With-stent1 with the focus on the wall-stent gap. Figure 15: Velocity vectors, colored by velocity magnitude (m/s), displayed in VR environment, \(t=t2\). Figure 16: Streamlines, colored by velocity magnitude (m/s), displayed in VR environment, \(t=\) t2: (**a**) Without-stent; (**b**) With-stent1 (bottom: from Viewpoint 1); (**c**) With-stent2 (bottom: Viewpoint 1). Figure 17: Wall shear stress magnitude (Pa) contours, \(t=t2\): (**a**) Without-stent; (**b**) With-stent1; (**c**) With-stent2. Figure 18: _Cont._  
The changes in flow behavior and high WSS regions due to stenting can be explained by displaying velocity contours on Slice 7. Figure 19 shows the velocity magnitude contours and streaking patterns on Slice 7. The streak pattern shows that the flow enters the untreated aneurysm and then impinges on the distal sac wall with high speed (white arrow in Figure 19) that is the reason behind the higher wall shear stress and pressure values in this region. The inflow flows in both upward and lateral directions and leads to the creation of two small recirculating zones around the impingement point (red arrows Figure 19). In addition, this figure shows the higher flow rate into the sac for the untreated aneurysm, in comparison to the stented cases, and the With-stent2 case has the lowest inflow. It is obvious that the presence of the wall-stent gap influences the inflow rate into the aneurysm. Figure 19: Velocity magnitude (m/s) on Slice 7, \(t=\)t2: (**a**) Without-stent; (**b**) With-stentI; (**c**) With-stent2. Figure 18: Velocity vectors, colored by velocity magnitude inside the vessel wall colored by WSS, displayed in VR environment, \(t=\)t2: (**a**) Without-stent; (**b**) With-stentI; (**c**) With-stent2. To show the time variation of parameters, it is required to use several slices in routine postprocessing methods. An example is presented in Figure 20 that shows the velocity magnitude contours and streak patterns on Slice 4 at four points in time. It is evident that the highest inflow rate into the aneurysm is associated with the Without-stent case at all times. For stented cases, the high velocity is limited to the near neck regions, especially for Stent2. As the flow enters the aneurysm sac, a slow speed zone adjacent to the parent artery opposite to the neck is generated and results in the creation of a vortex pair at the entrance. Similar behaviors can be seen in the inflow region of stented cases. The lower the flow rate into the aneurysm, the smaller the slow-speed zone, and the larger the vortex pair size. The streak patterns in Figure 20 illustrate this flow behavior. Furthermore, Zone 2, introduced in Figure 14, can be seen in Figure 20 for both stented cases, while that of With-stent2 is smaller due to the lower inflow rate. More detailed spatial CFD results and their changes versus time are represented by VR visualization, as shown in Figure 21. This figure shows some screenshots of velocity magnitude contours on Slices 1 to 6.The disadvantages of traditional postprocessing methods are obvious from previous section figures.