Cerebrovascular reserve in moyamoya disease: relation to cerebral blood flow, capillary dysfunction, oxygenation, and energy metabolism

BACKGROUND: Cerebral hemodynamics in moyamoya disease (MMD) is complex and needs further elucidation. The primary aim of the study was to determine the association of the cerebrovascular reserve (CVR) with cerebral blood flow (CBF) disturbances, oxygen extraction fraction (OEF(max)), and energy metabolism ([Formula: see text]) in MMD, using arterial spin label magnetic resonance imaging (ASL-MRI) before and after acetazolamide administration. METHODS: Thirty-nine ASL-MRI scans with a concurrent acetazolamide challenge from 16 MMD patients at the Uppsala University Hospital, Sweden, 2016–2021, were retrospectively analyzed. CBF was assessed before and 5, 15, and 25 min after acetazolamide administration, and the maximal response CVR(max) was used for further analyses. Dynamic susceptibility contrast (DSC) MRI was performed 30 min after acetazolamide injection, and the data were analyzed using the Cercare Medical Neurosuite to assess capillary transit time heterogeneity (CTTH; indicating microvascular function), OEF(max), and [Formula: see text]. RESULTS: In the ACA territory, a lower CVR(max) was associated with lower baseline CBF, higher CTTH, and higher OEF(max) but not with [Formula: see text] in generalized estimating equation models. In the MCA territory, lower CVR(max) was associated with lower baseline CBF and higher [Formula: see text] but not with CTTH and OEF(max.). CONCLUSION: Altogether, a compromised CVR in MMD patients reflected disturbances in macro-/microvascular blood flow, oxygenation, and CMRO(2). ASL-MRI with acetazolamide challenge is a feasible and radiation-free alternative to positron emission tomography (PET) imaging in MMD.