前交叉韧带及其损伤的弥散张量成像观测

Diffusion tensor imaging observation of the anterior cruciate ligament and its injury

目的为前交叉韧带损伤的定量诊断提供影像学数据。方法选取膝关节弥散张量成像扫描的检查正常者100例和单侧前交叉韧带撕裂伤患者100例,在工作站划分前交叉韧带不同部位及损伤处的感兴趣区,测量感兴趣区的各向异性分数(FA)值和表观弥散系数(ADC)值,生成纤维示踪图像。比较前交叉韧带不同部位和损伤处与正常组相应部位的FA值和ADC值。结果前交叉韧带的上端、上中部、中部、下中部、下端的FA值和ADC值差异有统计学意义(P<0.05),FA值随前交叉韧带部位自上而下逐渐降低呈负相关,ADC值则逐渐增高呈正相关;其中组间比较的上端与上中部的FA值和ADC值差异无统计学意义(P>0.05),其他部位之间的FA值和ADC值差异均有统计学意义(P<0.05)。前交叉韧带损伤处与正常组相应部位的FA值和ADC值分别为(0.449±0.039)、(0.577±0.064)和(2.564±0.227)×10-3mm2/s、(1.324±0.160)×10-3mm2/s,差异有统计学意义(P<0.05),前交叉韧带损伤处的FA值低于正常组,ADC值则高于正常组。结论弥散张量成像的FA值、ADC值与前交叉韧带的部位和损伤程度密切相关,纤维示踪成像可以直观显示前交叉韧带及损伤处的三维形态,为前交叉韧带损伤的微细结构变化提供了客观影像诊断依据。

Objective To provide imaging data for quantitative diagnosis of anterior cruciate ligament injury.Methods All 100 cases with normal knee joint and 100 cases of unilateral anterior cruciate ligament laceration were selected by diffusion tensor imaging scanning.At the workstation,the regions of interest in the different position of anterior cruciate ligament and its injury were divided,the fractional anisotropy(FA)values and apparent diffusion coefficient(ADC)values of the regions of interest were measured,and the tractography images were generated.The Fa values and ADC values were compared in different position of the anterior cruciate ligament,damaged position of anterior cruciate ligament and corresponding position of normal group.Results There were significant differences in the FA values and ADC values of the anterior cruciate ligament among the upper ends,upper-middle position,middle position,lower-middle position and lower ends(P<0.05),the FA values was negatively correlated with the decrease of anterior cruciate ligament from top to bottom,while the ADC values was positively correlated with the increase of anterior cruciate ligament.There was no significant difference in the FA values and ADC values between the upper ends and middle-middle position of the groups(P>0.05),and it was significant difference in the FA values and ADC values among the other positions(P<0.05).The FA values and ADC values of the anterior cruciate ligament injury and corresponding position of the normal group were(0.449±0.039),(0.577±0.064)and(2.564±0.227)×10-3 mm2/s,(1.324±0.160)×10-3 mm2/s respectively,there was significant difference(P<0.05),the FA values of anterior cruciate ligament injury was lower than that of normal group,while the ADC values was higher than that of the normal group.Conclusion The FA values and ADC values of diffusion tensor imaging are closely related to the position of anterior cruciate ligament and damage degree,the tractography imaging can visualize the three-dimensional morphology of anterior cruciate ligament and its damage position,it can provide an objective imaging diagnosis basis for the changes of the microstructure of anterior cruciate ligament injury.