超声造影在周围神经挤压伤检测中的应用价值

Value of Contrast-enhanced Ultrasound in Detection of Peripheral Nerve Crush Injury

目的评估超声造影(CEUS)在周围神经挤压伤检测中的应用价值。方法采用随机数字表法将30只新西兰白兔随机分为正常对照组,坐骨神经挤压伤术后3d,2、4、8周组,每组6只。采用常规高频超声、超声能量多普勒成像(PDUS)、CEUS及组织病理学共同检测受损坐骨神经组织内部的形态结构及血流灌注情况。结果常规超声结果显示,术后8周的神经内径与正常对照组差异无统计学意义[(1.14±0.15)mm比(0.92±0.11)mm;t=4.72,P=0.86]。对神经血流灌注的分析显示,PDUS在神经损伤后急性期(术后3d)敏感度较高,可显示损伤神经内部的细微血流信号,但在术后4、8周显示血流欠佳。CEUS可清晰显示神经损伤后3d及2、4、8周的微循环灌注情况,并通过时间-强度曲线下面积、达峰时间和峰值强度定量发现术后3d挤压伤处神经血流灌注显著增多,而后随时间变化逐渐减少。组织病理学检查结果显示,术后8周的中位累积OD值为12035.6(10566.3,14805.8),仍明显低于正常对照组的18784.8(15904.5,21103.5)(H=6.10,P=0.0003)。结论常规超声及PDUS难以充分评估神经损伤后不同时期的微循环灌注。CEUS可在损伤神经的任何时期对其内部微血流灌注情况进行定量评估,为间接评估神经再生情况提供更多的信息。

Objective To explore the value of contrast-enhanced ultrasound(CEUS)in the detection of peripheral nerve crush injury.Methods Thirty New Zealand white rabbits were randomly divided into normal control group and sciatic nerve crush injury group(which included 3-day,2-week,4-week,and 8-week groups after operation).The morphological structure and blood perfusion of the injured sciatic nerves were detected by high-frequency ultrasound,power Doppler ultrasound(PDUS),CEUS,and histopathology.Results Conventional ultrasound revealed that the internal diameter of nerves showed no significant difference between the 8-week group and the control group[(1.14±0.15)mm vs.(0.92±0.11)mm;t=4.72,P=0.86].Analysis of nerve blood perfusion showed that PDUS had a high sensitivity in displaying fine blood flow signal inside the injured nerve in the acute stage of inflammation(3-day group)but not good enough in the 4-and 8-week groups.CEUS could clearly show the microcirculation perfusion in the 3-day,2-week,4-week,and 8-week groups,and analyses of the area under the curve,the peak time,and the peak intensity showed that the nerve blood perfusion increased significantly 3 days after operation and then decreased gradually.Histopathological examination showed that the median cumulative OD value was 12035.6(10566.3,14805.8)8 weeks after operation,which was still significantly lower than that 18784.8(15904.5,21103.5)in the normal control group(H=6.10,P=0.0003).Conclusions Conventional high-frequency ultrasound and PDUS can not adequately evaluate the microcirculation perfusion in different periods after nerve injury.CEUS can quantitatively evaluate the microvascular perfusion of injured nerve at any period and provide more information for indirect evaluation of nerve regeneration.