目的：研究急性颈髓损伤（Spinal cord injury，SCI）DTI各参数值在ASIA不同残损等级的临床应用价值。方法：回顾性分析急性SCI常规MRI T2WI高信号34例患者，48小时内行MR-DTI检查，测量病变区FA、ADC、λ∥、λ⊥值，临床采用ASIA等级标准，A级5例、B级6例、C级10例、D级13例，健康组15例相近年龄段志愿者，测量C3/4～C5/6相应椎间盘平面。采用单因素方差（ANOVA）分析DTI参数值在ASIA A~D级差异，t检验分析DWI高信号（DWI高信号区）与边缘区（T2WI高信号区）DTI参数差异。结果：A~D级与健康组比较FA、ADC、λ∥、λ⊥值均具有统计学意义（F=51.90，13.30，24.70，13.01，P＜0.001）。A级与B、C、D级两两比较FA值、ADC值、λ∥值有统计学意义（P＜0.05），FA值、λ∥值随着ASIA残损等级降低呈下降趋势，ADC值在A级降低、B~D级升高，λ⊥值升高，B级与A、C、D级两两比较差异有统计学意义（P＜0.05），A、C、D级比较差异无统计学意义（P＞0.05）。DTT显示A、B级损伤区域神经纤维束肿胀、中断，C、D级损伤区神经纤维束完整。DWI高信号区与T2WI高信号区ADC、λ∥、λ⊥值具有统计学意义（P＜0.05），FA值均降低无统计学意义（P＞0.05）。DTT显示DWI高信号区神经纤维束连续性中断。结论：FA值、λ∥值是评价急性SCI AISA不同残损等级敏感指标，ADC值越低损伤程度越重，DTT直观显示神经纤维束损伤部位和损伤程度，为临床治疗提供更多影像学证据。
Abstract
Objective: To study the clinical value of DTI in acute spinal cord injury(SCI) with different ASIA grades. Methods: A retrospective analysis of 34 acute SCI patients with conventional MRI T2WI hyperintensity was made. All patients underwent MR-DTI examination in 48 hours. According to ASIA grades, we measured the values of FA, ADC, λ∥, λ⊥in the injury area. We recruited 15 healthy volunteers of matched ages, and measured the same parameters in the corresponding level of C3/4~C5/6 intervertebral disc plane. Single factor analysis of variance(ANOVA) was applied to analyze the difference in DTI parameters in ASIA grade A to D. Independent sample t test was used to analyze DTI parameters in DWI image matching area(hyperintense on both DWI and T2WI) and mismatch area(isointense on DWI but hyperintense on T2WI) in the same patients. Results: The number of patients is 7 in grade A, 5 in grade B, 19 in grade C, and 13 in grade D. Compared with the healthy group, the A～D groups showed significant differences in FA, ADC, λ∥ and λ⊥(F=51.90, 13.30, 24.70, 13.01, P<0.001). Compared with grade B, C and D, the values of FA, ADC and λ∥ in grade A were significantly reduced by pairwise comparison(P<0.05). FA and λ∥ showed a downward trend as ASIA grade was reduced. ADC values increased in grade A, however decreased in grade B to D. As for λ⊥ elevation, by pairwise comparison, grade B showed significant difference from grade A, C and D(P<0.05). There was no significant difference between grade A, C or D in λ⊥ by pairwise comparison(P>0.05). DTT showed in injured area nerve fiber bundle swelling, distortion and interruption in grade A. The nerve fiber bundles were swelling, coarse and partially interrupted in grade B. Integrated nerve fiber bundles could be found in grade C and D. Comparing DWI match area with mismatch area, ADC, λ∥ decreased and λ⊥ increased significantly(P<0.05), whereas the changes of FA value had no difference(P＞0.05). DTT demonstrated that the nerve fiber bundle in DWI match area was interrupted. Conclusion: FA value and λ∥ value are sensitive indexes among different AISA grades in acute SCI. The lower the ADC value is, the more serious the injury is. DTT can display the position and injury extent of nerve fiber bundles, and provide more imaging evidence for clinical treatment.
关键词
脊髓损伤；磁共振成像 /
弥散
Key words
Spinal cord injuries /
Diffusion magnetic resonance imaging
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基金
山东省自然科学基金（ZR2015HM081）；山东省烟台市科技计划项目（2014WS049）。
