Intraoperative cerebral perfusion monitoring with ultrafast power doppler imaging

Brain perfusion monitoring during cerebrovascular surgery is highly desirable; however, this technology is not yet available to surgeons. Our center has developed and implemented a dedicated ultrafast power Doppler imaging (UPDI) sequence along with a novel postprocessing analysis. This method enables intraoperative, real-time (1 Hz) detection of changes in cerebral blood volume (CBV) at high spatial resolution (100 μm). We performed continuous UPDI acquisitions in 10 patients undergoing surgery for intracranial aneurysm clipping, AVM resection, or cerebrovascular bypass surgery. When temporary clipping was required during surgery, we recorded perfusion in the parenchyma within the vascular territory of the affected artery. Recordings began with a 30-second baseline and continued for up to 60 s after clip release. The UPDI sequence successfully demonstrated cerebral perfusion up to the level of the penetrating arterioles. The time-series data captured vascular phenomena such as ischemia, collateral recruitment, and hyperperfusion in both the cortex and white matter following the placement and removal of temporary clips. UPDI shows promise as a tool for continuous CBV monitoring during (cerebrovascular) surgery, as it enables quantitative vascular monitoring of the parenchyma.