Reproducibility of tract‐specific magnetization transfer and diffusion tensor imaging in the cervical spinal cord at 3 tesla

Abstract

Damage to specific white matter tracts within the spinal cord can often result in the particular neurological syndromes that characterize myelopathies such as traumatic spinal cord injury. Noninvasive visualization of these tracts with imaging techniques that are sensitive to microstructural integrity is an important clinical goal. Diffusion tensor imaging (DTI)-and magnetization transfer (MT)-derived quantities have shown promise in assessing tissue health in the central nervous system. In this paper, we demonstrate that DTI of the cervical spinal cord can reliably discriminate sensory (dorsal) and motor (lateral) columns. From data derived from nine healthy volunteers, two raters quantified column-specific parallel (λ || ) and perpendicular (λ ⊥ ) diffusivity, fractional anisotropy (FA), mean diffusivity (MD), and MT-weighted signal intensity relative to cerebrospinal fluid (MTCSF) over two time-points separated by more than 1 week. Cross-sectional means and standard deviations of these measures in the lateral and dorsal columns were as follows: λ || : 2.13 ±0.14 and 2.14 ±0.11 μm 2 /ms; λ ⊥ : 0.67 ±0.16 and 0.61 ±0.09 μm 2 /ms; MD: 1.15 ±0.15 and 1.12 ±0.08 μm 2 / ms; FA: 0.68 ±0.06 and 0.68 ±0.05; MTCSF: 0.52 ±0.05 and 0.50 ±0.05. We examined the variability and interrater and test-retest reliability for each metric. These column-specific MR measurements are expected to enhance understanding of the intimate structure-function relationship in the cervical spinal cord and may be useful for the assessment of disease progression.

Clinically Feasible Microstructural MRI to Quantify Cervical Spinal Cord Tissue Injury Using DTI, MT, and T2*-Weighted Imaging: Assessment of Normative Data and Reliability

“…Image acquisition was successful in all subjects, and automated analysis provided robust readouts from multiple ROIs, with the results validated by acceptable reliability data. Our results establish normative data for CSA, FA, and MTR that are consistent with previous reports at 3T, 12,21,[27][28][29] in addition to our novel T2*WI WM/GM metric. T2*WI WM/GM, FA, and MTR all showed strong graywhite contrast and differences between individual WM tracts.…”

Age-related changes of the diffusion tensor imaging parameters of the normal cervical spinal cord

“…2). The ROI-based measurement has been shown to be valuable and reproducible for the measurements of DTI parameters [16,17].…”

Relationships between quantitative spinal cord MRI and retinal layers in multiple sclerosis

“…15,16 DTI indices were calculated from DT eigenvalues. 17 To delineate regions of interest (ROIs) outlining the SC axial cross-section, an automated reproducible segmentation protocol was applied to MT off images and transferred to DTI/MTR maps (figure 2). 18 DTI maps from 8 patients and the MTR map from one patient were excluded because of inadequate image quality.…”