Imaging in Moyamoya Disease - Study to Investigate Different Imaging Technologies for a Better Understanding of Various Imaging Techniques to Evaluate Cerebral Hemodynamics, Disease-activity and Possibly the Etiology in Moyamoya Patients

Aim of this study is to improve patient care in Moyamoya Patients by improving Imaging technologies and aiming to identify factors involved in disease progression. Main tasks are: * Analysis of CO2-triggered BOLD fMRI for analysis of cerebral hemodynamics in comparison to H2 15O PET/CT * Analysis of longitudinal changes of contrast enhancement in vessel-wall imaging and correlation of disease activity with biosampling * Definition of a standardized recommendation for pre- and postoperative imaging of Moyamoya patients