Preliminary animal studies on observation of injured spinal cord with intraoperative ultrasound backscatter microscopy

Many studies have shown that strategies of nerve regeneration and cell-based transplantation are valid based on animal models of spinal cord injury (SCI). To apply these strategies and bridge spinal cord defects, the identification and precise localization of lesions during spinal cord surgery is necessary. The aim of the present experiment was to evaluate the capabilities of ultrasound backscatter microscopy (UBM) in identifying morphologic changes after SCI. After laminectomy, high-resolution ultrasound images of the spinal cord were obtained in one normal and seven spinal cord-injured adult Wistar rats using a UBM system with a 55-MHz center frequency scanner. Comparison between histoanatomic and UBM images was also performed. The results showed that UBM can identify cysts after the experimental SCI is removed in adult rats. In addition, the glial scar formed in secondary injury showed obvious hyperechoic speckle in the UBM image and correlated with the histoanatomic image. UBM has obvious clinical value in nerve regeneration and cell-based transplantation strategies in injured spinal cords.