Correlation between diffusion tensor imaging parameters and clinical assessments in patients with cervical spondylotic myelopathy with and without high signal intensity

Study design: A cross-sectional observational study. Objectives: The aim of this study is to compare the apparent diffusion coefficient (ADC) and fractional anisotropy (FA) between patients with cervical spondylotic myelopathy (CSM) with and without high T2-weighted signal intensity, and to correlate each parameter with clinical assessments. Setting: CSM is a common cause of spinal cord dysfunction. The significance of T2 high signal intensity in the prognosis of CSM remains controversial. Methods: Diffusion tensor imaging was performed at the cervical spinal cord in 40 patients with CSM and 42 healthy subjects. Patients with high signal intensity were separated from those without high signal intensity. ADC and FA values were compared among different groups, and the correlation between each parameter and the modified Japanese Orthopedic Association (mJOA) score was examined. Results: The ADC and FA values of C2/3 differed significantly from those of C5/6 and C6/7 in healthy subjects. Patients with CSM had a higher ADC but a lower FA value than did healthy subjects. In all patients with CSM, there was a negative linear correlation between ADC and mJOA score, but FA value correlated positively with mJOA score. Secondary analysis suggested that FA value in patients with high signal intensity was lower than that in patients without high signal intensity. FA value showed a positive linear correlation with mJOA score in the patients with high signal intensity but not in the patients without high signal intensity. Conclusions: Patients with high signal intensity may have more severe spinal cord injury than patients without high signal intensity, and FA may be a useful indicator of functional status in patients with CSM with high signal intensity.