Evaluation of the Effect of Hyperbaric Oxygen Preconditioning in Spinal Cord Injury Rats Using Diffusion Tensor Imaging.

INTRODUCTION

UTo investigate the potential value of diffusion tensor imaging (DTI) in spinal cord injury (SCI) rats undergoing hyperbaric oxygen preconditioning (HBO-PC) at different time points.

METHODS

Seventy-two rats were randomly allocated into three groups: sham-operated group (laminectomy only); SCI group (the spinal cord weight dropping model); HBO-PC group (HBO-PC for five consecutive days before SCI). Each group was further randomized into four time-point subgroups (6 hours, 24 hours, three days, seven days). Basso, Beattie, Bresnahan (BBB) scores and DTI parameters, including fractional anisotropy (FA), axial diffusivity (AD), radial diffusivity (RD), and mean diffusivity (MD), were collected and analyzed. Spinal cord tissues were processed for hematoxylin, eosin, and Nissl staining.

RESULTS

HBO-PC groups exhibited higher FA values than SCI groups at different time points (all p < 0.05). RD and MD values were higher in SCI groups than in HBO-PC groups from 24 hours to 7 days (all p < 0.05). The SCI group showed more pronounced inflammatory cell infiltration and neuronal atrophy than the HBO-PC group. The number of surviving neurons in the injured spinal cord in the HBO-PC group was higher than that in the SCI group at each time point (all p < 0.05). FA values were negatively correlated with BBB scores, while RD and MD values were positively correlated with BBB scores.

DISCUSSION: HBO-PC can reduce neuronal cell death and promote nerve function recovery. DTI can quantitatively evaluate HBO-PC's protective effect in rats with SCI.