超声弹性成像技术评估无水乙醇诱导肝脏凝固灶的实验研究

目的探讨超声弹性成像技术评估无水乙醇诱导肝脏凝固灶的价值。方法选取新鲜离体猪肝共25个肝叶,随机分为5组,每组各5个肝叶。分别行单点、两点相距0.5cm、两点相距1.0cm、两点相距1.5cm及两点相距2.0cm注射无水乙醇,各点无水乙醇注射量均为2.0ml。注射无水乙醇前、后观察实验区常规二维超声声像图及应变力弹性成像图（EI）变化,同时运用声触诊组织定量技术（VTQ）测定实验区剪切波速度。实验结束后剖开标本,记录凝固灶的形态、范围。采用配对t检验比较注射无水乙醇前后实验区肝组织剪切波速度差异。结果无水乙醇不同注射方式可形成不同形态的凝固灶,常规二维超声下局部区域出现短暂高回声,随之迅速消散,而EI图可显示较恒定红色硬变区,比常规二维超声更接近实际凝固灶;但对于间距小于0.3cm的双凝固灶,EI图难以分辨。凝固后的肝组织剪切波速度均明显增高,与注射无水乙醇前比较差异均有统计学意义（P〈0.01）,表明凝固性坏死的肝组织硬度增加。结论超声弹性成像技术可反映肝脏凝固灶力学变化,是常规二维超声的有力补充,但细微分辨力还有待提高。

Evaluation of ethanol-induced liver coagulation with ultrasonic elastography

Objective To investigate the role of ultrasound elastography in evaluation of liver coagulation induced by absolute ethanol.Methods Absolute ethanol was injected in fresh pig liver in different patterns：at one point,two points 0.5 cm apart,two points 1.0 cm apart,two points 1.5 cm apart and two points 2.0 cm apart.The dosage of absolute ethanol at each point was 2.0 ml.Two-dimensional ultrasonic image and elasticity image were observed.Shear wave velocity was measured by virtual touch tissue quantification（VTQ）.After ultrasound examination,the liver was dissected to assess the shape and size of coagulation zone.Results Absolute ethanol could produce coagulation necrosis with different shapes by different injection patterns in local hepatic tissue.Compared to two-dimensional ultrasonic image,coagulation zone could be better observed on elasticity image.Because coagulation zone showed transient hyperechoic change on two-dimensional ultrasounic image,while appeared to be red（hard）constantly on elasticity image.However,it was difficult to distinguish two zones when the distance of them was less than 0.3 cm.After injection,the shear wave velocity of the zone increased significantly（P〈0.01）,which indicated that hepatic tissue got stiffer when coagulation necrosis occurred.Conclusions Ultrasonic elastography can provide elasticity information of coagulation zones,which was a beneficial supplement to conventional two-dimensional ultrasound.However,the resolution of elasticity image need to be improved.