声脉冲辐射力弹性成像技术评价牛肝组织射频消融的实验研究

Visualization of radiofrequency ablation treated lesions on bovine liver ex vivo using acoustic radiation force impulse elastography

目的探讨声脉冲辐射力弹性成像(ARFI)的声触诊组织定性成像(VTI)和声触诊组织定量技术(VTQ)评价离体牛肝组织内射频消融灶的可行性。方法应用VTQ检测射频消融前、中、后正常牛肝组织、消融灶中心及消融灶外周的组织硬度。消融后分别采用灰阶超声及VTI测量计算消融灶体积,并与大体标本比较。结果灰阶超声、VTI和大体标本测量消融灶平均体积分别为(13143.29±452.79)mm3、(17258.42±428.47)mm3、(17540.69±310.52)mm3。灰阶超声与VTI、大体标本比较差异均有统计学意义(均P<0.05),VTI与大体标本比较差异无统计学意义,两者之间具有较好的相关性(r=0.921,P<0.05)。VTQ检测牛肝组织消融前、中、后的横向剪切波速度(SWV)平均值分别为(1.72±0.17)m/s、(4.96±0.40)m/s、(9.00±0.00)m/s,三者比较差异均有统计学意义(均P<0.05)。消融后消融灶外周的SWV平均值为(2.76±0.65)m/s,与消融灶中心及正常牛肝组织的SWV值比较差异均有统计学意义(均P<0.05)。结论 ARFI的VTI定性及VTQ定量技术有望成为评价肝组织内射频消融灶形态及大小的有效方法。

Objective To investigate the feasibility of evaluating the radiofrequency ablation （RFA） treated lesions in bovine liver with virtual touch tissue imaging （VTI） and virtual touch tissue quantification （VTQ） of acoustic radiation force impulse（ ARFI ）. Methods Tissue stiffness was evaluated by VTQ before, during and after performing RFA. The volume of RFA- lesions which measured by gray-scale ultrasound and VTI were compared with the measurements obtained from pathologic examination. Results The average volumes of RFA-lesions measured on gray-scale ultrasound, VTI and pathologic findings were （13 143.29 ±452.79）mm3, （17 258.42 ±428.47）mm3, （17 540.69±310.52）mm3, respectively. There was significant difference among gray-scale, VTI and pathology （P〈0.05）. There was no significant difference between the measurements detected by VTI and pathology with better correlation （r=0.921 ,P〈0.05）. The mean shear wave velocity （SWV） of RFA-lesions before, during and after RFA was （1.72 ±0.17）m/s, （4.96 ±0.40）m/s, （9.00± 0.00）m/s,respectively. The data showed significant difference （all P〈0.05 ）. Compared to the normal tissues and the center of RFA-lesions, the average SWV value was （2.76 ± 0.65）m/s which was markly increased in the boundary of RFA-lesions. Conclusion ARFI could be a promising and reliable method for evaluating the shape and size of the RFA-lesions during RFA procedure.