腰椎间盘的扩散张量成像观测及临床应用

目的　为腰椎间盘退变导致的腰腿痛等病症的临床诊断提供影像学依据。 方法　选取脊柱腰段扩散张量成像（DTI）扫描检查正常者200例和腰椎间盘退变者100例，在工作站划分腰椎间盘和腰椎间盘退变的感兴趣区，测量感兴趣区的表观扩散系数（ADC）和各向异性分数（FA），比较不同解剖部位、年龄组腰椎间盘和不同Pfirrmann分级腰椎间盘退变的FA、ADC值。 结果　不同解剖部位腰椎间盘的FA值和ADC值均有统计学差异（P<0.05），L1~2、L2~3、L3~4椎间盘的FA值逐渐降低，L4~5、L5~S1椎间盘的FA值则逐渐增高；L1~2、L2~3、L3~4椎间盘的ADC值逐渐增高，L3~4、L4~5、L5~S1椎间盘的ADC值则无明显变化。不同年龄组腰椎间盘的FA值无统计学差异（P>0.05），ADC值有统计学差异（P<0.05），随着年龄增长ADC值逐渐降低。不同Pfirrmann分级腰椎间盘退变的FA值和ADC值均有统计学差异（P<0.05），随着Pfirrmann分级增高，FA值逐渐增高，ADC值逐渐降低。 结论　解剖部位、年龄均影响腰椎间盘的ADC值，DTI的FA值和ADC值可以定量评估腰椎间盘及其退变程度，为早期腰椎间盘退变的临床诊断提供影像学依据。

Diffusion tensor imaging observation and clinical application of the lumbar intervertebral disc

Objective　 To provide imaging basis for clinical diagnosis of the waist and leg pain caused by the lumbar intervertebral disc degeneration.　Methods　There were 200 persons with normal lumbar spine and 100 cases with lumbar intervertebral disc degeneration selected and scanned by diffusion tensor imaging (DTI). The region of interest of the lumbar intervertebral disc and the lumbar intervertebral disc degeneration was selected at workstation, and the apparent diffusion coefficient (ADC) value and the fractional anisotropy (FA) value of the region of interest were measured. The FA value and ADC value of lumbar intervertebral disc in different anatomic sites, age groups and different Pfirrmann grades of the lumbar intervertebral disc degeneration were compared.　Results　The FA value and ADC value of lumbar intervertebral discs in different anatomic sites had significant difference (P<0.05). The FA values of L1~2, L2~3 and L3~4 intervertebral discs were gradually decreased, and the FA values of L4~5 and L5~S1 intervertebral discs were gradually increased. The ADC values of L1~2, L2~3 and L3~4 intervertebral discs were gradually increased, and the ADC values of L3~4、L4~5、L5~S1 intervertebral discs were not changed significantly. There was no statistical difference in FA values among different age groups (P>0.05). There was statistical differences in ADC values (P<0.05), and the ADC values were gradually decreased with the ages. There were statistical differences in FA values and ADC values in the different Pfirrmann grades of lumbar intervertebral disc degeneration, and with the Pfirrmann gradation increasing, the FA values were gradually increased, and the ADC values were gradually decreased. Conclusions The ADC value of the lumbar intervertebral disc can be influenced by the different anatomic sites and age. The FA value and ADC value of DTI can quantitatively evaluate the degree of lumbar intervertebral disc degeneration, and provide imaging basis for clinical diagnosis of early lumbar intervertebral disc degeneration.