Feasibility of postoperative 3-tesla diffusion tensor imaging in cervical spondylotic myelopathy: A comparison of single-shot EPI and multi-shot EPI

Utility of Diffusion Tensor Imaging for Prognosis and Management of Cervical Spondylotic Myelopathy: A PRISMA Review

OBJECTIVE

As advances are made in quantitative magnetic resonance imaging, specifically diffusion tensor imaging, researchers have investigated its potential to serve as a biomarker of disease or prognosticator for postoperative recovery in the management of cervical spondylotic myelopathy. Here, we narratively review the current state of the emerging literature, describing areas of consensus and disagreement.

METHODS

In accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses, we queried 2 large databases for original manuscripts published in English and systematically produced a narrative review of the use of diffusion tensor imaging in the management of cervical spondylotic myelopathy.

RESULTS

Of the 437 manuscripts initially returned in our query, 29 met the final inclusion criteria, and data were extracted regarding diffusion tensor imaging indices and their relationships with clinical outcomes following surgery. Preoperative fractional anisotropy was most commonly found to correlate closely with postsurgical clinical outcomes, though results were mixed.

CONCLUSIONS

Preoperative fractional anisotropy most frequently and best correlates with functional outcomes following surgery for cervical spondylotic myelopathy, according to a review of the current literature. The findings were not universal and at times contradictory, highlighting the need for high-quality future investigations to better define the utility of diffusion tensor imaging in spinal disease.

Multi-shot echo-planar diffusion tensor imaging in cervical spondylotic myelopathy

AIMS

The aim of this study was to use diffusion tensor imaging (DTI) to investigate changes in diffusion metrics in patients with cervical spondylotic myelopathy (CSM) up to five years after decompressive surgery. We correlated these changes with clinical outcomes as scored by the Modified Japanese Orthopedic Association (mJOA) method, Neck Disability Index (NDI), and Visual Analogue Scale (VAS).

METHODS

We used multi-shot, high-resolution, diffusion tensor imaging (ms-DTI) in patients with cervical spondylotic myelopathy (CSM) to investigate the change in diffusion metrics and clinical outcomes up to five years after anterior cervical interbody discectomy and fusion (ACDF). High signal intensity was identified on T2-weighted imaging, along with DTI metrics such as fractional anisotropy (FA). MJOA, NDI, and VAS scores were also collected and compared at each follow-up point. Spearman correlations identified correspondence between FA and clinical outcome scores.

RESULTS

Significant differences in mJOA scores and FA values were found between preoperative and postoperative timepoints up to two years after surgery. FA at the level of maximum cord compression (MCL) preoperatively was significantly correlated with the preoperative mJOA score. FA postoperatively was also significantly correlated with the postoperative mJOA score. There was no statistical relationship between NDI and mJOA or VAS.

CONCLUSION

ms-DTI can detect microstructural changes in affected cord segments and reflect functional improvement. Both FA values and mJOA scores showed maximum recovery two years after surgery. The DTI metrics are significantly associated with pre- and postoperative mJOA scores. DTI metrics are a more sensitive, timely, and quantifiable surrogate for evaluating patients with CSM and a potential quantifiable biomarker for spinal cord dysfunction. Cite this article: Bone Joint J 2020;102-B(9):1210-1218.