Abstract: ［Abstract］Objective To explore the diagnosis value of diffusion tensor imaging in patients with cervical spondylotic myelopathy.
Methods Thirty-seven patients with cervical spondylotic myelopathy were recruited in this study and anterior cervical discectomy and fusion were performed in all patients. According to preoperative different degree of signal intensity ratio(SIR), patients were divided into three groups: 11 cases in group A SIR<1.32, 12 cases in group B SIR 1.32-1.68, 14 cases in group C SIR>1.68. Clinical information, FA value, Japanese Orthopaedic Association(JOA) scores and detailed limb function scores were collected to compared among three groups. The correlation between JOA scores and FA value was identified by Pearson correlation analysis.
Results Operations were successfully performed in all patients of three groups. There was no significant difference in surgical time, bleeding, rate of cerebrospinal fluid leakage among three groups(P＞0.05). The FA value was lower in group C than in group A and B(P＜0.05). JOA score was higher in last follow-up visit than preoperative in three groups, while it was lower in group C than group A and B at both preoperative and last follow-up visit. The JOA scores improvement rate was lower in group C than group A(P＜0.05). Walking time of 6 m of normal step was shorter in follow up than preoperative in three groups(P＜0.05), while it was longer in group C than group A and B at both preoperative and follow up. Walking time of 6 m of maximum step was longer in group B than group A before operation and at last follow-up visit, it was longer in group B than group A. In three groups, walking time of 6 m of maximum step was shorter at last follow-up visit than preoperative(P＜0.05). Before operation, five consecutive sitting time was longer in group C than group A and B. At last follow-up visit, five consecutive sitting time in group B was longer than group A and it was longer in group C than groups A and B. Five consecutive sitting time was shorter in last follow-up visit than preoperative in three groups(P＜0.05). In three groups, times of continuously hold loose fist in 10 s was greater at last follow-up visit than preoperative(P＜0.05), while at preoperative and last follow-up visit, times of continuously hold loose fist in 10 s was less in group C than group A. There was positive correlation between preoperative JOA scores(P＜0.05), JOA scores improvement rate(P＜0.05) and FA value.
Conclusion FA value shows satisfactory diagnosis value in cervical spondylotic myelopathy patients with increased SIR in cervical spinal cord. FA value is closely related to clinical outcomes after surgery.

Key words: cervical spondylosis, signal intensity ratio of T2WI in spinal cord, diffusion magnetic resonance imaging