Feasibility and Safety of Intraoperative BOLD MRI Cerebrovascular Reactivity to Evaluate Extracranial-to-Intracranial Bypass Efficacy

Aims: Blood oxygenation-level dependent magnetic resonance imaging (BOLD MRI) sequences help to investigate cerebrovascular reactivity (CVR) to predict stroke risk in patients affected from chronic cerebrovascular steno-occlusive diseases.

We aimed to conduct a preliminary study to investigate the feasibility and safety of intraoperative BOLD MRI to assess CVR in extracranial-to-intracranial bypass (EC-IC) procedures.

Methods: Eight patients operated with EC-IC bypass underwent an additional intraoperative MR scan with BOLD sequences to assess CVR with breath-holding based techniques after the anastomosis.

Results: None of the patients showed postoperative complications or radiological alterations related to prolonged anesthesia time. One patient presented with a hyperperfusion syndrome postoperatively unrelated to the intraoperative MRI. CVR maps were obtained in all subjects showing qualitative variations.

Conclusion: Intraoperative BOLD MRI sequence acquisition is a safe option for patients undergoing surgery for EC-IC bypass. This technique might offer important and immediate information on the success and efficacy of a bypass.