mesh_terms: D001926:Brain Death / Q000000981:diagnostic imaging*; D002533:Cerebral Angiography / Q000592:standards*; D000072226:Computed Tomography Angiography / Q000592:standards*; D019317:Evidence-Based Medicine; D005858:Germany; D006801:Humans; D017410:Practice Guidelines as Topic; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity