DTI成像技术在犬急性期脊髓损伤模型中的应用

The Application of MR Diffusion Tensor Imaging in the Acute Injured Canine Spinal Cord

目的应用MR-DTI成像技术对犬急性期脊髓损伤的表观扩散系数(ADC)及部分各向异性(FA)值进行检测,探讨MR-DTI成像技术在脊髓损伤中的应用价值。方法制作犬脊髓损伤模型。脊髓损伤前及脊髓损伤模型造模成功30 min后分别进行磁共振FSE和DTI检查(FSET2WI,DTI b=500 s/mm2,扩散敏感梯度方向=15,测量脊髓损伤前、后脊髓的ADC值及FA值。结果脊髓损伤前ADC值为(0.97±0.18)×10-3mm2/s,FA值为0.58±0.10;脊髓损伤后ADC值升高为(1.16±0.16)×10-3mm2/s(t=1.676,P=0.07>0.05),FA值降低为0.34±0.06(t=4.512,P=0.002<0.05)。结论在脊髓损伤急性期ADC值升高不明显,FA值明显降低,DTI技术可以为急性期脊髓损伤的诊断提供有价值的信息。

Objective To observe the apparent diffusion coemcients （ADCs） and fractional anisotropy （FA） value changes of a- cute injured canine spinal cord with MR diffusion tensor imaging （DTI）. Methods The canines＇ spinal cord injure model was firstly made. Before and 30 mins after injury, the MRI and DTI were examined （FSET2WI, DTI b=500 s/mm2）, direction of diffusion sen- sitive gradients being 15. The ADCs and FA value of the spinal cord were calculated. Results The ADCs and FA of normal canine spinal cord were （ 0. 97 ± 0. 18 ） ×10^-3mm2/s and 0. 58 ± 0. 10 respectively. The ADCs and FA of injured canine spinal cord were （1.16±0. 16） ×10^-3mm2/s （t=1.676, P= 0.07〉0.05） and 0.34±0.06 （t =4.512, P=0.002〈0.05 ） respectively. Conclusions The ADC is not significantly increased, but the FA is significantly decreased. DTI can provide useful information of spinal cord damage in acute spinal cord injury.