Fig. 4

Illustration of the sensitivity analysis. The patient has a right-sided ICA occlusion. All simulation results are calculated under normo-tension (120/80 mmHg). In the current state (a), the patient has no changes in hemodynamics. Adding a 90% stenosis of the ICA on the other side (b, red arrow) leads to only a little drop in perfusion pressure in both MCA supply areas (yellow supply areas). This can be attributed to a very marked posterior communicating artery on the left side. Adding a 50% stenosis of the left Pcom leads to high vulnerability of the anterior circulation system (red supply areas) of both sides (c, orange arrow). The color changes within each segment are graphical features indicating the natural flow direction of the blood and are not related to simulation parameters