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

Abstract

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+HBO 2W ) group (n = 10); (D) SCI with HBO therapy for 4 weeks (SCI+HBO 4W ) group (n = 10); (E) SCI with HBO therapy for 6 weeks (SCI+HBO 6W ) 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+HBO 4W group than in the SCI and SCI+HBO 2W groups (all P < 0.05), whereas no significant differences of these metrics were observed between the SCI+HBO 4W and SCI+HBO 6W groups. MD and RD values of the SCI+HBO 4W 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.