Laser Speckle Contrast Imaging for Intraoperative Monitoring of Cerebral Blood Flow

Intraoperative monitoring of cerebral blood flow provides an important information required for clinicians to select optimal tactics during the neurosurgery procedures, including clipping cerebral vessel aneurysms, bypass, and arteriovenous malformation surgery. Presently, robust cost-effective non-invasive optical imaging techniques suitable to assess cerebral blood flow in the operating room do not exist. In current study we report a development of prototype of the Laser Speckle Contrast Imaging (LSCI) system as a complementary tool for non-invasive real-time visualization and quantitative assessment of cerebral blood flow during neurovascular surgery. The LSCI is based on the scattering of coherent laser light within dynamic turbid medium, such as biological tissues, including brain. The speckle patterns appeared due to interference of partial components of the dynamically scattered light are recorded by digital camera. To observe blood flow in large and small vessels as well as in the microcirculatory bed of the cerebral cortex the recorded images are quantitatively analyzed utilizing low-order statistical moment, known as imaging contrast or enhancement of visibility. The purpose of current pilot study is to assess general feasibility of the LSCI approach in terms technical abilities of image acquisition, its quality evaluation and further implication to day-to-day clinical practice.