Intraoperative Laser Speckle Contrast Imaging of Cerebral Blood Flow

The purpose of this research study is to evaluate the ability of laser speckle contrast imaging to visualize blood flow in real time during neurosurgery. Real-time blood flow visualization during surgery could help neurosurgeons better understand the consequences of vascular occlusion events during surgery, recognize potential adverse complications, and thus prompt timely intervention to reduce the risk of stroke. The current standard for visualizing cerebral blood flow during surgery is indocyanine green angiography (ICGA), which involves administering a bolus of fluorescent dye intravenously and imaging the wash-in of the dye to determine which vessels are perfused. Unfortunately, ICGA can only be used a few times during a surgery due to the need to inject a fluorescent dye, and provides only an instantaneous view of perfusion rather than a continuous view. Laser speckle contrast imaging does not require any dyes or tissue contact and has the potential to provide complementary information to ICGA. In this study we plant to collect blood flow images with laser speckle contrast imaging and to compare the images with ICGA that is performed as part of routine care during neurovascular surgical procedures such as aneurysm clipping.