The Image Diagnostic Classification of Mr T2 Increased Signal Intensity in Cervical Spondylotic Myelopathy: Clinical Evaluation Using Quantitative and Objective Assessment

STUDY DESIGN A prospective imaging study. OBJECTIVE The study investigated whether the classification of increased signal intensity (ISI) using magnetic resonance imaging (MRI) reflects the severity of symptoms in patients with cervical spondylotic myelopathy (CSM). SUMMARY OF BACKGROUND DATA Although the ISI on MRI in patients with CSM is observed, the degree of ISI has not been examined. The association between ISI and the surgical outcomes in cervical myelopathy remains controversial. METHODS A total of 505 consecutive patients with CSM (311 males; 194 females) were enrolled. The mean age was 66.6 years (range, 41-91 yrs), with an average postoperative follow-up period of 26.5 ± 12.5 months. The ISI was classified into three groups based on sagittal T2-weighted MRI as follows: Grade 0, none; Grade 1, light (obscure); and Grade 2, intense (bright). Pre- and postoperative neurological status was evaluated using the Japanese Orthopedic Association scoring system for cervical myelopathy (JOA score) and quantifiable tests, including the 10-s grip and release test (10-s G&R test) and the 10-s step test. RESULTS The preoperative MRI showed 168 patients in Grade 0, 169 patients in Grade 1, and 168 in Grade 2, with no age differences among three groups. Grade 2 patients had a longer duration of symptom compared with the other grades. Grade 0 patients had a better postoperative JOA score and recovery rate compared with the other grades. The preoperative and postoperative scores in the G&R test and steps were better in the Grade 0 patients compared with the other grades. Grade 1 and 2 patients had similar outcomes and recovery rates. CONCLUSION ISI on MRI in patients with CSM was prospectively classified into three grades. The ISI grading was not associated with the preoperative severity of myelopathy and outcomes. LEVEL OF EVIDENCE 2.