We used near-infrared spectroscopy technology to monitor and assess the treatment effect of dehydrating agent in injured rat brain in real time style. We employed the brain edema model in rats resulting from Feeney's freefall damage, then treated with different doses of mannitol, and collected reduced scattering coefficient (μ's) and intracranial pressure (ICP) values after the injury and during the treatment. The results showed that brain edema happened 1 h after the injury in rats' brain tissue, peaked around 72 h after injury, and then began to decrease gradually. The reduced scattering coefficient and ICP values of the treatment group injected with mannitol all decreased after administration. Compared with the effect of low-dose mannitol treatment, that of high-dose mannitol treatment was much better. The duration of the plateau was longer and most experiments results declined significantly. From this we conclude that the reduced scattering coefficient and ICP are consistent with the trend changes, and the reduced scattering coefficient could be used as an indicator for monitoring cerebral edema.
Accurate placement of pedicle screws is a key factor of spinal surgery. Investigation of a new real-time intra-operative monitoring method is an important area of clinical application research which makes a contribution to planting pedicle screw accurately. Porcine spines were chosen as experimental objects.The changes of reduced scattering coefficient (μ's) along normal puncture path, medial perforation path and lateral perforation path were measured and studied. A conclusion is drawn that there are two distinct peaks throughout the puncture process, appearing at the junction of cancellous bone and cortical bone, at the beginning and at the end, respectively. The reduced scattering coefficient is proved to be a good monitoring factor which can identify whether the screw is about to reach the critical position of the spine puncture. Moreover, the variation provides an important reference for spinal surgical navigation process.