Background: Quantitative imaging surrogates of myelin and axonal integrity using magnetization transfer and diffusion tensor imaging may provide beneficial prognostic details on long-term post-surgical recovery in dogs with spinal cord injury (SCI) secondary to intervertebral disc herniation (IVDH).
Hypothesis: Magnetization transfer ratio (MTR), mean diffusivity (MD), axial diffusivity (AD), radial diffusivity (RD), and fractional anisotropy (FA) will be significantly different in patients with a successful outcome compared to patients with an unsuccessful outcome.
Animals: 61 dogs with SCI secondary to IVDH were included in the final analysis. All dogs had to undergo surgical correction for SCI secondary to IVDH and be followed out for 12 weeks.
Methods: Prospective cohort study. MTR, MD, AD, RD, and FA were calculated in dogs with SCI secondary to IVDH. A Wilcoxon signed-rank test was used to compare MTR, MD, AD, RD, and FA values between patients with a successful outcome and patients with an unsuccessful outcome. Statistical significance was set at p<0.05. For quantitative imaging surrogates with a significant relationship with outcome, a receiver operator characteristic (ROC) curve analysis was performed and the sensitivity and specificity for predicting successful outcome.
Results: MTR (p=0.0013) was significantly lower in patients with a successful outcome compared to patients with an unsuccessful outcome. FA (p=0.435) was not significantly between groups. MD (p=0.0006), AD (p=0.0008) and RD (p=0.0002) were significantly higher in patients with a successful outcome compared to patients with an unsuccessful outcome. ROC curves were performed for MTR, AD and RD. If MTR was ≤ 53, AD ≥ 1.7 × 10-3mm2/s or RD ≥ 0.37 × 10-3 mm2/s, this resulted in a sensitivity of 96.3% and specificity of 100 in predicting a successful outcome.
Conclusion and clinical relevance: MTR, MD, AD, and RD were helpful in predicting successful outcome in canine patients with surgically treated SCI secondary to IVDH. A larger cohort is needed for further evaluation. / Master of Science / Background: Certain magnetic resonance imaging (MRI) techniques can provide information about the severity of spinal cord injury. The information obtained from these MRI techniques can be helpful in predicting prognosis in dogs with intervertebral disc disease (IVDD).
Hypothesis: We hypothesized that the measurements obtained from these MRI techniques would be able to predict the patients who would be able to walk following surgery (good long-term outcome), versus the patients who did not regain the ability to walk following surgery (poor long-term outcome).
Animals: 62 MRIs were performed on dogs with IVDD in our study and were followed out for 12 weeks following surgery to assess long-term outcome.
Results: Of the 5 MRI techniques investigated, 4 of the techniques were found to be helpful in predicted long-term outcome. When these techniques were combined, the ability to predict long-term outcome improved. Using the combined technique, all 53 patients predicted to have a good long-term had a good long-term outcome. For patients with a poor long-term outcome, 9 were predicted to have a poor long-term outcome, but only 7 patients had a poor long-term outcome.
Conclusion and clinical relevance: MRI can be helpful in predicting long-term outcome in dogs with IVDD following surgery. A larger population of dogs is needed for further evaluation.
| Identifer | oai:union.ndltd.org:VTETD/oai:vtechworks.lib.vt.edu:10919/107416 |
| Date | 14 July 2020 |
| Creators | Shinn, Richard Levon |
| Contributors | Biomedical and Veterinary Sciences, Pancotto, Theresa Elizabeth, Rossmeisl, John H., Stadler, Krystina L. |
| Publisher | Virginia Tech |
| Source Sets | Virginia Tech Theses and Dissertation |
| Detected Language | English |
| Type | Thesis |
| Format | ETD, application/pdf, application/pdf |
| Rights | In Copyright, http://rightsstatements.org/vocab/InC/1.0/ |
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