3.0T MR Diffusion Tensor Imaging On Normal Cervical Spinal Cord And Cervical Spondylotic Myelopathy:Clinical Study

Part one:The preliminary study of3.0T MR diffusion tensor imaging on normal cervical spinal cordObjectiveTo explore the application of diffusion tensor imaging(DTI) in normal cervical spinal cord with3.0T MR scanner, and to investigate the anisotropy and diffusion characteristics of normal cervical spinal cord by measuring the values of apparent diffusion coefficient ADC), fractional anisotropy(FA), λ1, λ2and λ3.To explore the characteristics of diffusion tensor tractography(DTT) in normal cervical spinal cord.Materials and MethodsThirty-four subjects undergone MR examination,including19cases male and15cases female, aged from19to80years with an average43.4years. They were divided into three age groups:less than40years old for the young group(13cases),40-59years old middle-aged group(12cases),60years and over the older group(9cases). There were no clinical signs and symptoms, and no neurological diseases or disorders, which affecingt the central nervous system.Routine T1WI FLAIR, FRFSE-XL T2WI and axial DTI of cervical spinal cord were performed in all the subjects by using GE Signa EXCITE3.0T MR machine with head and neck joint coil. DTI scanning was performed using ASSET technique combined with single-shot spin echo-echo planar imaging sequence, with diffusion sensitivity gradient in fifteen different directions, diffusion weighting coefficient b=1000s/mm2. The range of scanning is from the top edge of C1to the lower edge of T1, with a saturated zone in front of it, and scanner time of4’26".All the data of DTI were analyzed with functool software. The values of ADC, FA, λ1,λ2and λ3were measured at C2/3, C3/4, C4/5and C5/6levels of normal cervical spinal cord. Regions of interest (ROIs) shoud included the entire cervical spinal cord(grey matter and white matter).Diffusion tensor tractography of normal cervical spinal cord were obtained.All the data were analyzed with SPSS13.0statistical package. The values of ADC, FA, λ1, λ2and λ3at the same level were compared with Independent-Sanmples T Test(Equal variances assumed) or Satterthwaite T’Test(Equal variances not assumed) between men and women.The values of ADC, FA, λ1,λ2and λ3among different levels and different age groups were compared with ANOVA for the repeated measures and One-Way ANOVA.If there were no statistical difference,the parameters were multiple compared. The statistically significant difference was set at P<0.05.ResultThe ADC, FA and diffusion tensor tractography images of all the normal cervical spinal cord displayed well.1.There were no statistical difference in values of ADC, FA, λ1,λ2and λ3at the same level between men and women(P>0.05).2.There were no statistical difference in values of ADC, FA, λ1, λ2and λ3at C2/3, C3/4, C4/5and C5/6levels of normal cervical spinal cord(P>0.05).But the FA values had a downward trend from C3/4to C5/6level. 3.There were no statistical difference in values of ADC, FA, λ1, λ2and λ3among the three different age group(P>0.05).4.There were statistical difference between the values of λ1and λ2(P<0.05), values of λ1and λ3(P<0.05), there were no statistical difference between the values of λ2andλ3(P>0.05),and2λ1>λ2+λ3.5.The normal parameters values of ADC, FA, λ1,λ2and λ3in normal cervical spinal cord were aquired(X±S).6.The normal cervical spinal cord demonstrated homogenous red tissue in crania-caudal direction on diffusion tensor tractography.Conclusion1. DTI and DTT can be well applied in cervical spinal cord with3.0T MR scanner, and the normal parameters of ADC, FA,λ2, λ2and λ3in normal cervical spinal cord were obtained. This can provides important reference information for clinical research of studies about pyramidal tract-related diseases.2. There were no statistically significant gender differences in the diffusion and anisotropy of the same level. The anisotropy and diffusion characteristics were nearly the same among different levels of normal cervical spinal cord. Age did not significantly affect the diffusion and anisotropy of normal cervical spinal cord. The normal cervical spinal cord was a cylindrical diffusive tissue along nerve fiber.3.3.0T MRI DTT can clearly and intuitively display white matter tracts in3D.Part two:The Preliminary clinical study of3.0T MR diffusion tensor imaging on cervical spondylotic myelopathyObjectiveTo explore the application of diffusion tensor imaging(DTI) in cervical spondylotic myelopathy with3.0T MR scanner, and to investigate the anisotropy and diffusion characteristics of cervical spondylotic myelopathy by measuring the values of apparent diffusion coefficient(ADC), fractional anisotropy(FA),λ1, λ2and λ3. To explore the characteristics of diffusion tensor tractography(DTT) in cervical spondylotic myelopathy.Materials and MethodsSixty-four patients with cervical spondylotic myelopathy undergone MR examination, including35cases male and29cases female, aged from24to76years with an average51.7years. They were divided into three groups based on the changes of spinal cord compression on routine MRI images. In Group A(21cases), only the cervical dural sac was compressed.In Group B(32cases), the cervical spinal cord was compressed, but without abnormal signal intensity. In Group C(11cases), the cervical spinal cord was obviously compressed with hyperintense on T2WI.All the patients were undergone routine MRI and DTI examination (same with part one). All the data of DTI were analyzed with functool software. The values of ADC,FA, λ1,λ2and λ3were measured at the most serious compressed level. Regions of interest (ROIs) shoud included the entire cervical spinal cord (grey matter and white matter). Diffusion tensor tractography of cervical spinal cord were obtained.All the data of DTI were analyzed with SPSS13.0statistical package.Using the nomal adluts in part one as control group(group E),the values of ADC,FA,λ1,λ2and λ3among the control group and group A, B and C were compared with One-Way ANOVA. If there were no statistical difference, the parameters were multiple compared. The statistically significant difference was set at P<0.05.Result:1.There were statistical difference in values of ADC, FA,λ1,λ2and λ3among the control group E and group A, B, C(P<0.05).2.There were no statistical difference in values of ADC, FA,λ1, λ2and λ3between the group E and the group A(P>0.05). 3.There were statistical difference in values of ADC, FA, λ1,λ2and λ3between the control group E and group B, C respectively(P<0.05).4.There were statistical difference in the values of ADC, FA, λ1,λ2and λ3among group A, B, C respectively(P<0.05).5. The changes of the cervical spinal cord on the compression level of group A, B, C could be demonstrated clearly by the maps of ADC, FA, λ1,λ2, λ3. Diffusion tensor tractography could show the distortion and break of cord on the compression levels.Conclusion1. There were statistical difference in values of ADC, FA, λ1, λ2and λ3between the control group and group B(P<0.05). This indicates that DTI is more sensitive than routine MRI in evaluating the early and mildly spondylosis-related changes of the cervical spinal cord.2.There were statistical difference in values of ADC, FA, λ1, λ2and λ3among group A, B, C respectively(P<0.05). This indicates that the changes in the values of ADC, FA, λ1, λ2and λ3can reflect the degree of cervical spinal cord injury.3.3.0T MR DTT can intuitively display the extent of cord compression and damage which is helpful for estimating prognosis.4. DTI will be a useful supplement of conventionally MRI in examing spinal cord injury. It may play an important role in making plans preoperationly, making reasonable forecast postoperationly and estimat evaluating prognosis.