Evaluation of hyperbaric oxygen therapy for spinal cord injury in rats with different treatment course using diffusion tensor imaging

Study design Animal study. Objectives To evaluate the efficacy of hyperbaric oxygen (HBO) therapy for spinal cord injury (SCI) in rats with different treatment course using diffusion tensor imaging (DTI). Setting Hospital in Fuzhou, China. Methods Fifty adult Sprague-Dawley rats were grouped as: (A) sham-operated group (n = 10); (B) SCI without HBO therapy group (n = 10); (C) SCI with HBO therapy for 2 weeks (SCI+HBO2W) group (n = 10); (D) SCI with HBO therapy for 4 weeks (SCI+HBO4W) group (n = 10); (E) SCI with HBO therapy for 6 weeks (SCI+HBO6W) group (n = 10). Basso Beattie Bresnahan (BBB) scores and diffusion tensor imaging parameters including fractional anisotropy (FA), mean diffusivity (MD), radial diffusion (RD), and axial diffusion (AD) values in the injury epicenter, as well as 2 mm rostral and caudal to the injury epicenter were collected and analyzed 6 weeks post-injury. Results Higher BBB score and FA values were found in the SCI+HBO4W group than in the SCI and SCI+HBO2W groups (all P < 0.05), whereas no significant differences of these metrics were observed between the SCI+HBO4W and SCI+HBO6W groups. MD and RD values of the SCI+HBO4W group were significantly lower than those of the SCI group (all P < 0.01). FA values were positively correlated with BBB scores. MD and RD values were negatively correlated with BBB scores. Conclusion DTI parameters, especially FA, could non-invasively and quantifiably evaluate the efficacy of HBO treatment for rats with SCI and 4 weeks may be the more appropriate treatment course.