T2-weighted MRI high signal in cervical spondylotic myelopathy is associated with dynamic change

The cervical spine's mobility affects the compression level of the cervical cord which varies with dynamic positioning. High signal on MRI T2-weight imaging (MRI-T2WI) of the cervical cord indicates a poorer prognosis. This study investigates the relationship between high-signal intensity on MRI-T2WI and cervical dynamic change using kinematic MRI. The objective of this study was to explore changes in the degree of cervical spinal cord compression during flexion-extension motions and identify risk factors linked to the occurrence of high signals. We collected data on patients who underwent surgical treatment for cervical spondylotic myelopathy (CSM) in our department from 2023 to 2024. Patients were classified into two groups based on high-intensity signal presence: the high-signal group and non-high-signal group. Using kinematic MRI, the area and width of cervical cord compression in the responsible segment were measured in the axial and sagittal positions. Differences between the two groups were assessed using univariate analysis, binary logistic analysis, receiver operating characteristic (ROC) curve, and restricted cubic spline (RCS) regression model. A total of 40 patients in the high-signal group and 30 in the non-high-signal group were included in the study. There was no significant difference in baseline characteristics between two groups. The degree of cord compression was remarkably increased in both groups with cervical ranging from flexion to extension. Additionally, the neutral position and extension compression degrees (area and width) were significantly greater in the high-signal group than in the non-high-signal group, indicating that stenosis is a risk factor for high-signal occurrence. Furthermore, the degree of dynamic compression change of kinematic MRI was significantly higher in the high-signal group compared to the non-high-signal group. Statistical analysis confirmed that cervical dynamic change was an independent risk factor for high-signal occurrence. The RCS curve demonstrated that the incidence of high signal significantly increased when the compression degree of extension/flexion exceeded 1.4. Cervical cord compression worsens with cervical dynamic change from flexion to extension. The degree of compression change is considered a risk factor for high signals on MRI-T2WI. An extension/flexion value greater than 1.4 indicates an increased likelihood of a high-signal occurrence.