Hemodynamic Failure Staging With Blood Oxygenation Level–Dependent Cerebrovascular Reactivity and Acetazolamide‐Challenged ( 15 O‐)H 2 O‐Positron Emission Tomography Across Individual Cerebrovascular Territories

Staging of hemodynamic failure (HF) in symptomatic patients with cerebrovascular steno-occlusive disease is required to assess the risk of ischemic stroke. Since the gold standard positron emission tomography-based perfusion reserve is unsuitable as a routine clinical imaging tool, blood oxygenation level-dependent cerebrovascular reactivity (BOLD-CVR) with CO