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Purpose:To explore the application of diffusion tensor imaging（DTI）as a quantitive analsis in normal cervical spinal cord with 3.0T MR scanner, and to obtain the standard apparent diffusion coefficient（ADC）values, fractional anisotropy（FA）values,the values ofλ1,λ2,λ3 in the normal cervical spinal cord.To explore the characteristic of fiber tracking in the normal cervical spinal cord.Methods:Conventional T2WI,T1WI and axial DTI of cervical spinal cord were performed in 21 healthy volunteers who were divided into three age groups （less than 30 years,31 to 60 years,over 60 years）by using GE EXCITEⅡ3.0T MR.Normal cervical spinal cord of these healthy volunteers were demonstrated on conventional T2-weighted imaging.A four-channel NV-full coil was accepted.SE EPI sequence was selected in DTI,fifteen non collinear directions and b=1000 s·mm-2were selected according to the preliminary study of DTI(5,10,15,20,25 non collinear directions were selected,and b values were 600、1000、1500、2000、2500 s·mm-2respectively) in five normal volunteers,the thickness was 4mm with no gap and 28 slices,the range of scanning is from C1 to C7.All the data of DTI were analyzed with GE functool 3.0 software,and which were corrected by a certain procedure to reduce the artifact and distortion of DTI.The values of ADC,FA,λ1,λ2 andλ3 were measured at C2-C3,C4-C5 and C6-C7 levels of the cervical spinal cord according to ADC map,FA map and b=0 map in the healthy volunteers.Regions of interest（ROIs）included the cervical spinal cord.The data of DTI were analyzed with a software package SPSS 11.0.Fiber tracking of the healthy volunteers were performed by using a functool software of GE Company.Results:High quality maps of ADC,FA,λ1,λ2,λ3 and fiber tracking of cervical spinal cord were obtained in 21 normal volunteers.There were no statistically significant in values of ADC（F=0.04,P＞0.957）,FA （F=0.56,P＞0.576）,λ1（F=1.02,P＞0.368）,λ2（F=0.77,P＞0.468）andλ3 （F=0.15,P＞0.859）at C2-C3,C4-C5 and C6-C7 levels of normal cervical spinal cord.There were also no statistically significant in values of ADC(F=2.23,P=0.117,FA（F=0.11,P=0.899）,λ1（F=1.33,P=0.288）、λ2（F=0.11,P=0.901）andλ3（F=1.86,P=0.185）among the three different age groups.The average values of ADC,FA,λ1,λ2 andλ3 in 21 healthy volunteers were 0.784±0.083 10-3mm2/s,0.721±0.027,1.509±0.145, 0.416±0.094,0.411±0.102 respectively.There were statistically significant differences in values ofλ1,λ2 andλ3（F=1871.41,P=0）, The values ofλ1 was more thanλ2（Q=74.75,P＜0.01）andλ3（Q=75.10, P＜0.01）,There was no statistically significant between the values ofλ2 andλ3（Q=0.347,P＞0.05）.Conclusion:The normal cervical spinal cord was a cylindrical diffusive tissue in crania-caudal direction.The values of ADC,FA,λ1,λ2 andλ3 were sensitive indices for quantitative analysis of the strength of diffusion cervical spinal cord.The fiber tracing was a usfull tool to demonstrate the white matter tracts and nervi spinales. Purpose:To explore the application of diffusion tensor imaging（DTI）as a quantitive analysis method in cervical spondylosis with 3.0T MR,and to analyze the characteristics of values of the apparent diffusion coefficient（ADC）,fractional anisotropy（FA）,λ1,λ2,λ3 and of the fiber tracking in patients with cervical spondylosis.Methods:Eighty-four patients with cervical spondylosis were performed FSE T2WI,FSE T1WI and axial DTI by using GE EXCITEⅡ3.0T MR scanner.Eighty four patients were divided into four groups based on the cord being compressed or not,the extent of cord compression and the compressed cord with or without definite hyperintensity whithin it on T2-weighted imaging,In Group A,it was shown that only the dura mater spinalis was compressed.In Group B,it was shown that the cervical spinal cord was compressed,without high signal intensity in it.In Group C,it was shown that the cervical spinal cord was compressed with suspected high signal intensity on the compression site.In Group D,it was shown that the cervical spinal cord was compressed with significant high signal intensity in it.The four-channel NV-full neck coil and SE EPI sequence were selected in DTI.Fifteen non collinear directions and b=1000 s·mm -2were selected.The thickness was 4mm with no gap.Slices=28.Range of scanning is from C1 to C7.The data of DTI were postprocessed with GE functool 3.0 software,and which were corrected by a certain procedure to reduce artifact and distortion of DTI.The values of ADC,FA,λ1,λ2 andλ3 in healthy volunteers and patients were analyzed with a software package of SPSS 11.0.Regions of interest（ROIs）of 10mm2 were set on the compression sites in group A,B and on the high signal regions in group C,D based on the T2WI.Fiber tracking was performed in the patients with a functool software of GE Company.Results:The changes of the cervical spinal cord on the compression sites could be demonstrated by the maps of ADC,FA,λ1,λ2,λ3.Fiber tracking could show the distortion of cord on the compression sites.ANOVA（analysis of variance）and Q test（Newman-Keuls,P＜0.05 was considered statistically significant）were used to compare the mean values of ADC,FA,λ1,λ2 andλ3 between the control group and the group A,B,C,D.Between the control group and the group A,there were no statistically significant differences in values of ADC（Q=1.451,P＞0.05）and FA（Q=1.999,P＞0.05）,λ1 （Q=1.137,P＞0.05）,but there were statistically significant differences in values ofλ2（Q=3.039,P＜0.05）andλ3（Q=2.982,P＜0.05）. There were statistically significant differences in values of ADC,FA,λ1,λ2 andλ3（P＜0.01）between the control group and group B,C,D respectively.Conclusion:The values of ADC,FA,λ1,λ2 andλ3 were sensitive indices for evaluating the early spondylosis-related changes of the cervical spinal cord.The subtle structure damages of cervical spinal cord in cervical spondylosis can be quantitatively analyzed in early stage by DTI compared with conventional T2-weighted imaging.Distortions of compressed spinal cords which was compressed by cervical spondylosis were showed clearly by fiber tracking.
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