3.0T磁共振扩散张量成像在脊髓型颈椎病的应用研究

The Clinical Application of 3.0 T MR Diffusion Tensor Imaging in Diagnosing Cervical Spondylotic Myelopathy

目的利用扩散张量成像（DTI）评价脊髓型颈椎病患者颈髓损伤情况。方法选取34名健康志愿者（对照组E组）和64例脊髓型颈椎病患者（实验组）行颈髓常规MRI和DTI扫描。对照组选取C2/3-C5/6椎间盘层面颈髓进行分析，按年龄分为青年组、中年组、老年组。分析不同颈髓层面间、不同年龄组间颈髓ADC、FA、λ1、λ2、λ3值的差异。根据受压最严重层面颈髓改变情况，将实验组分为A、B、C三组，分析对照组、实验组间各参数值的差异。对各组进行颈髓纤维束成像。结果男女间同一层面、不同层面间、不同年龄组间颈髓各参数值差异无统计学意义（P〉0．05）；λ1与λ2、λ3差异有统计学意义（P〈0．001；P〈0．001），λ2与λ3差异无统计学意义（P=0．997）。获得正常成人颈髓各参数值。E组与A组间各参数值差异无统计学意义（P〉0．05）；E组与B、C两组间、各实验组间各参数值差异有统计学意义（P〈0．05）。且从A组到V组，ADC、λ2、λ3值呈升高趋势，λA、λ1值呈降低趋势。DTT图能清晰、直观地显示正常颈髓及受压颈髓纤维束改变情况。结论DTI能反映常规MRI发现不了的颈髓早期轻度的损伤改变；ADC、FA、λ1、λ2、λ3值改变的程度可以反映颈髓损伤的程度。

Objective To evaluate the extent of cervical spinal injury in patients with cervical spondylotic myelopathy by using magnetic resonance diffusion tensor imaging （DTI）. Methods Cervical routine MRI and DTI were performed in 34 healthy volunteers （control group） and 64 patients with cervical spondylotic myelopathy （study group）. The values of ADC, FA, λ1, λ2,λ3 were measured at C2/3 - C5/6 levels for the control group. And the subjects were divided into three groups according to the age ： young group, middle-age group and aged group. The values of ADC, FA, λ1, λ2 and λ3 at the same cervical level were measured and compared with each other groups by using independent samples t test （ Equal variances assumed） or Satterthwaite t test （Equal variances not assumed）. Based on the severity of spinal cord compression the patients of the study group were divided into three groups： group A, B and C. The differences in the parameters, including ADC, FA, λ1, λ2 and λ3 , between the study group and the control group were analyzed. Diffusion tensor tractography （DT＇F） were performed for all groups. Results No statistically significant differences in parameter values at the same level as well as among the different levels and different age groups existed between men and women （ P 〉 0.05 ）. The difference was statistically significant between λ1 and λ2 （P 〈 0. 001 ） and between λ1 and λ3 （P 〈 0. 001 ） , while the difference was not statistically significant between λ2 and λ3 （ P = 0. 997 ）. The differences in all parameters were statistically significant between the control group and group B as well as between the control group and group C （ P 〈 0.05 ）. From group A to group C, the values of ADC,λ2 and λ3 exhibited an increasing tendency, while the values of FA and λ1 showed a decrea- sing tendency. Both the normal spinal cord and the extent of spinal cord compression could be clearly demonstrated on 3.0 T MR DTT. Conclusion DTI is more sensitive than routine MRI in revealing the early and mild spondylosis-related changes of the cervical spinal cord. And the changes in the values of ADC, FA, λ1, λ2 and λ3 can reflect the degree of cervical spinal cord injury.