急性创伤性颈髓损伤的DTI诊断价值

An investigation on the feasibility of using DTI for the diagnosis of acute traumatic cervical spinal cord injury

目的探讨使用1.5 T磁共振扩散张量成像(DTI)对急性创伤性颈髓损伤(SCI)的诊断价值。方法选取经临床诊断为SCI的患者34例及20例正常对照组分别进行常规MRI及DTI检查。损伤组34例,选取颈髓损伤最严重平面,正常对照组选取C_(3/4)平面,分别测量损伤组和对照组FA值、ADC值,然后取平均值;统计分析采用独立样本t检验,检验水准α=0.05。结果急性颈髓损伤后颈髓FA图和ADC图信号均明显降低。颈髓损伤组FA值(0.49±0.06)较对照组(0.65±0.26)明显降低,颈髓损伤组ADC值(1.23±0.07)×10^(-3) mm^2/s较对照组(1.05±0.23)×10^(-3) mm^2/s明显升高,比较差异均有统计学意义(P均<0.001)。DTT图能够直观显示颈髓白质纤维束不同程度的稀疏、扭曲、变形、移位及断裂。结论DTI能够敏感的显示急性创伤性颈髓损伤;FA值、ADC值可作为测量SCI的敏感指标;DTT图能直观显示颈髓白质纤维束的细微损伤。

Objective To investigate the feasibility of using DTI in the diagnosis of acute traumatic spinal cord injury （SCI）. Methods 34 cases with confirmed SCI and 20 healthy volunteers were recruited for the study. Conventional MRI and DTI examination were performed on both groups. In the SCI group, the FA and ADC values of the worst level of cervical spinal cord injury were measured; in healthy volunteers the same measurement were performed at C3/4 level. Simple t test were performed for comparison with the test level of 0.05. Results The signal intensity of spinal cord after injury markedly decreased on FA map and ADC map. The FA value （0.49 ± 0.06） were declined obviously compared to control groups （0.65 ± 0.26）, and ADC value （1.23± 0.07） × 10^-3 mm^2/s increased markedly compared to normal subjects （1.05 ± 0.23） × 10^-3 mm^2/s. Statistically significant difference were found between injury group and healthy volunteers in FA value and ADC value （P 〈 0.001 ）. DTT showed sparse, distorted, deformed, displaced and fractured white matter fiber tracts in the cervical spinal cord. Conclusion Early acute traumatic SCI can be detected using DTI, and the FA values, ADC values can be used as a sensitive indicator of SCI; DTT can visually show the micro injury of white matter fiber tracts of cervical spinal cord.