Clinical significance of MRI T2 image classification in patients with cervical spondylotic myelopathy

Objective To study the clinical value of increased signal intensity (ISI) on MRI T2-weighted images for the severity of symptoms and surgical outcomes in patients with cervical spondylotic myelopathy (CSM). Methods One hundred and sixteen patients admitted to our department from September 2005 to June 2009 were enrolled in this study. The patients underwent MRI before cervical posterior laminoplasty and classified into grade 0 with no ISI, grade 1 with light (obscure) ISI, and grade 2 with intense (bright) ISI. The severity of CSM was scored according to the Japanese Orthopedics Association (JOA) criteria for CSM. Results Of the 116 CSM patients, 40 were classified as grade 0, 47 as grade 1, and 29 as grade 2. The disease course was(11.2±25.6) months and (36±33.7) months for grade 0 and grade 2 patients, respectively. No significant difference was found in the CSM score of grades 1-3 patients according to the JOA criteria. The lowest and highest scores of grade 0 patients were significantly higher than those of grade 3 patients before and after operation ((15.6±1.7) vs (10.6±2.0), (65.1±24.3) vs (36.1±30.3)). Conclusion ISI on T2-weighted MRI in CSM patients before operation is correlated with their age, disease course, preoperative and postoperative CSM score according to the JOA criteria. The improvement rate is the lowest for patients with the highest ISI after operation. Classification of ISI on T2-weighted MRI can be used as an indication for the prognosis assessment of CSM patients.