DTI及T2 mapping对腰椎间盘退变的诊断价值

目的：探讨磁共振扩散张量成像(DTI)表观扩散系数(ADC)、各向异性分数(FA)以及 T2 mapping T2值定量评估腰椎间盘退变程度的价值。方法健康志愿者12例,男8例,女4例；慢性下腰痛患者28例,男15例,女13例；年龄19~70岁。行腰椎MRI矢状位T2 WI、DTI、T2 mapping成像。对 L1~S1椎间盘进行Pfirrminn退变分级,测量各腰椎间盘髓核 ADC 值、FA 值以及T2值并分析其与不同腰椎间盘退变分级的相关性,比较 ADC值、FA值以及T2值对腰椎间盘退变的诊断价值。结果腰椎间盘的平均ADC值、T2值与Pfirrminn分级呈显著负相关关系,相关系数分别为r=-0.779,r=-0.708(P<0.001)；FA值与Pfirrminn分级呈正相关关系,但是相关关系不密切(相关系数r=0.474,P<0.001)。结论 DTI和T2 mapping可以定量评估腰椎间盘的退变程度,其诊断价值为 ADC 值最高,T2值次之,FA 值较差。

Value of diffusion tensor imaging and T2 mapping to assess lumbar intervertebral disc degeneration

Objective To investigate the value of ADC and FA of diffusion tensor imaging(DTI)and T2 value of T2 mapping for assessing lumbar intervertebral disc degeneration.Methods 12 cases of healthy volunteers(8 males and 4 females),28 cases of patients with chronic low back pain(15 males and 13 females,19-70 years old)were performed lumbar spine MRI,DTI and T2 mapping to obtain ADC,FA and T2 value.Intervertebral discs were classified according to the Pfirrmann grading.The correlations of different degeneration grade with ADC,FA and T2 value were analyzed.The diagnostic value of ADC,FA and T2 values of lumbar intervertebral disc degeneration were compared. Results Both ADC value and T2 value were significantly negative correlated with lumbar intervertebral disc degeneratic Pfirrminn grading(r=-0.779,r=-0.708,P<0.001).FA value were positively correlated with Pfirrminn grading(r=0.474,P<0.001), the correlation was not closely.Conclusion DTI and T2 mapping can be effectively used to quantitatively evaluate the degeneration degree of lumbar intervertebral disc,the diagnostic value of ADC was the highest,followed by T2 ,and FA was the worst.