Evaluation the effect of acute hyperglycemia on cerebral tissue properties with diffuse optical imaging systems

In this work, we demonstrate the application of two optical imaging systems namely, dual-wavelength laser speckle and integrated spatial frequency domain imaging systems to image the changes in mouse brain tissue properties following acute hyperglycemia. We assume that hyperglycemia alters brain function which in turn can be monitored using these two optical modalities. Hyperglycemia was induced by intraperitoneal injection of an anesthetic ketamine and xylazine combination which is found to increase blood glucose more than threefold relative to normoglycemia. A total of ten mice were used, randomized into two groups of normoglycemia (n = 4) and hyperglycemia (n = 6). Experimental results demonstrated reductions in cerebral blood flow, tissue oxygen saturation, and cerebral metabolic rate of oxygen following acute hyperglycemia. In addition, differences in both cerebral tissue optical properties (absorption and scattering) with increasing glucose level were observed. Overall, experimental result demonstrates the capability of both systems to provide and map various brain tissue metrics following hyperglycemia.