Comparison of axial and sagittal spinal cord motion measurements in degenerative cervical myelopathy

Abstract

Background and Purpose:The timing of decision-making for a surgical intervention in patients with mild degenerative cervical myelopathy (DCM) is challenging. Spinal cord motion phase contrast MRI (PC-MRI) measurements can reveal the extent of dynamic mechanical strain on the spinal cord to potentially identify high-risk patients. This study aims to determine the comparability of axial and sagittal PC-MRI measurements of spinal cord motion with the prospect of improving the clinical workup.Methods: Sixty-four DCM patients underwent a PC-MRI scan assessing spinal cord motion. The agreement of axial and sagittal measurements was determined by means of intraclass correlation coefficients (ICCs) and Bland-Altman analyses. Results:The comparability of axial and sagittal PC-MRI measurements was good to excellent at all cervical levels (ICCs motion amplitude: .810-.940; p < .001). Significant differences between axial and sagittal amplitude values could be found at segments C3 and C4, while its magnitude was low (C3: 0.07 ± 0.19 cm/second; C4: −0.12 ± 0.30 cm/second). Bland-Altman analysis showed a good agreement between axial and sagittal PC-MRI scans (coefficients of repeatability: minimum −0.23 cm/second at C2; maximum −0.58 cm/second at C4). Subgroup analysis regarding anatomic conditions (stenotic vs. nonstenotic segments) and different velocity encoding (2 vs. 3 cm/second) showed comparable results. Conclusions:This study demonstrates good comparability between axial and sagittal spinal cord motion measurements in DCM patients. To this end, axial and sagittal PC-MRI are both accurate and sensitive in detecting pathologic cord motion. Therefore, such measures could identify high-risk patients and improve clinical decision-making (ie, timing of decompression).

Spinal cord motion and CSF flow in the cervical spine of 70 healthy participants

“…When comparing spinal cord motion obtained by sagittal versus axial measurements, mid‐centered sagittal measurements showed slightly, but significantly higher values The velocity curves also qualitatively differed in terms of temporal dispersion, range and duration of the main velocity peaks. Although the applied sequences and processing methods were widely identical, current data suggest that sagittal and axial measurements of spinal cord motion cannot be directly compared, which contrasts with a previous report 38 . While technical factors such as partial volume effects need to be considered, it could be speculated that this difference may even reflect intramural anatomical variations, as the values represent the average of all voxels included: sagittal (mid‐centered) assessments included larger proportions of the central canal, while axial (cross‐sectional) assessments include a higher proportion of voxels belonging to lateral spinal cord tissues that are closer to adherent structures (radices and ligaments).…”

“…Although the applied sequences and processing methods were widely identical, current data suggest that sagittal and axial measurements of spinal cord motion cannot be directly compared, which contrasts with a previous report. 38 While technical factors such as partial volume effects need to be considered, it could be speculated that this difference may even reflect intramural anatomical variations, as the values represent the average of all voxels included: sagittal (mid-centered) assessments included larger proportions of the central canal, while axial (cross-sectional) assessments include a higher proportion of voxels belonging to lateral spinal cord tissues that are closer to adherent structures (radices and ligaments). This may explain the slightly lower values and temporal dispersion in axial assessments.…”

Influence of preprocessing, distortion correction and cardiac triggering on the quality of diffusion MR images of spinal cord

“…Our results confirm this hypothesis, as the images themselves are not appreciably different (i.e., artifacts not overly prevalent) and the derived indices are also not different (i.e., if outliers exist, they do not change final DTI fit). It is important to emphasize that these results may not generalize at all times, particularly pathology where increased motion has been observed in cervical myelopathies [53, 54] and stenosis [55], and similar quality assurance should be performed prior to removing triggering for a given study.…”

Spinal cord motion assessed by phase-contrast MRI - An inter-center pooled data analysis

“…Both imaging protocols comprised high-resolution T2-weighted sequences and sagittal 2D phase-contrast MRI sequences covering the entire cervical spine. Further details of imaging protocols and the different processing methods have been reported separately ( Hupp et al, 2019 , Hupp et al, 2021 Mar , Pfender et al, 2022 , Wolf et al, 2021 , Wolf et al, 2021 ). Key features were summarized in Table 1 .…”