Application and evaluation of NODDI in the cervical spinal cord of multiple sclerosis patients

Samantha By; Junzhong Xu; Bailey A Box; Francesca R Bagnato; Seth A Smith

doi:10.1016/j.nicl.2017.05.010

Application and evaluation of NODDI in the cervical spinal cord of multiple sclerosis patients

Neuroimage Clin. 2017 May 17:15:333-342. doi: 10.1016/j.nicl.2017.05.010. eCollection 2017.

Authors

Samantha By¹, Junzhong Xu², Bailey A Box³, Francesca R Bagnato⁴, Seth A Smith⁵

Affiliations

¹ Department of Biomedical Engineering, Vanderbilt University, Nashville, TN, USA; Vanderbilt University Institute of Imaging Science, Vanderbilt University Medical Center, Nashville, TN, USA.
² Department of Biomedical Engineering, Vanderbilt University, Nashville, TN, USA; Vanderbilt University Institute of Imaging Science, Vanderbilt University Medical Center, Nashville, TN, USA; Department of Radiology and Radiological Sciences, Vanderbilt University Medical Center, Nashville, TN, USA.
³ Vanderbilt University Institute of Imaging Science, Vanderbilt University Medical Center, Nashville, TN, USA.
⁴ Department of Neurology, Vanderbilt University Medical Center, Nashville, TN, USA.
⁵ Department of Biomedical Engineering, Vanderbilt University, Nashville, TN, USA; Vanderbilt University Institute of Imaging Science, Vanderbilt University Medical Center, Nashville, TN, USA; Department of Radiology and Radiological Sciences, Vanderbilt University Medical Center, Nashville, TN, USA. Electronic address: seth.smith@vanderbilt.edu.

Abstract

Introduction: There is a need to develop imaging methods sensitive to axonal injury in multiple sclerosis (MS), given the prominent impact of axonal pathology on disability and outcome. Advanced multi-compartmental diffusion models offer novel indices sensitive to white matter microstructure. One such model, neurite orientation dispersion and density imaging (NODDI), is sensitive to neurite morphology, providing indices of apparent volume fractions of axons (v_in), isotropic water (v_iso) and the dispersion of fibers about a central axis (orientation dispersion index, ODI). NODDI has yet to be studied for its sensitivity to spinal cord pathology. Here, we investigate the feasibility and utility of NODDI in the cervical spinal cord of MS patients.

Methods: NODDI was applied in the cervical spinal cord in a cohort of 8 controls and 6 MS patients. Statistical analyses were performed to test the sensitivity of NODDI-derived indices to pathology in MS (both lesion and normal appearing white matter NAWM). Diffusion kurtosis imaging (DKI) and diffusion tensor imaging (DTI) analysis were also performed to compare with NODDI.

Results: A decrease in NODDI-derived v_in was observed at the site of the lesion (p < 0.01), whereas a global increase in ODI was seen throughout white matter (p < 0.001). DKI-derived mean kurtosis (MK) and radial kurtosis (RK) and DTI-derived fractional anisotropy (FA) and radial diffusivity (RD) were all significantly different in MS patients (p < 0.02), however NODDI provided higher contrast between NAWM and lesion in all MS patients.

Conclusion: NODDI provides unique contrast that is not available with DKI or DTI, enabling improved characterization of the spinal cord in MS.

Keywords: Axon; Diffusion; Multiple sclerosis; NODDI; Spinal cord; Volume fraction.

Publication types

Evaluation Study

MeSH terms

Adult
Cervical Cord / diagnostic imaging*
Diffusion Magnetic Resonance Imaging / methods*
Diffusion Magnetic Resonance Imaging / standards
Feasibility Studies
Female
Humans
Image Interpretation, Computer-Assisted / methods*
Image Interpretation, Computer-Assisted / standards
Middle Aged
Multiple Sclerosis, Relapsing-Remitting / diagnostic imaging*
Neurites*
Reproducibility of Results

Abstract

Publication types

MeSH terms

Grants and funding