ARFI与SWE弹性成像技术评估射频消融范围的比较研究

摘要

Objective To explore the role of acoustic radiation force impulse imaging ( ARFI) including virtual touch tissue imagine ( VTI) and virtual touch tissue quantification ( VTQ) as well as real-time shear wave elastography ( SWE) in evaluating radiofrequency ablation range in liver of experimental pig and the difference between the two techniques. Methods Twenty fresh hepatic lobes of the pigs ( thickness:6～8 cm; length and width:more than 8 cm) were used in ultrasound-guided radiofrequency ablation ( RFA) . The changes of the acoustic image in ablation area were observed. The maximum long diameter, anteroposterior diameter, area of ablation place and VTQ were measured under ARFI imaging conditions, and the maximum long diameter, anteroposterior diameter, area of ablation place and Young 's modulus value were measured under SWE imaging conditions. Then the differences between the measured values by the two methods and the real measured value in ablation area after dissection and the differences between the hardness value in ablation area and non ablation area were observed and compared, respectively. Results Twenty RFA experiments were performed successfully. There was no significant difference in the area of lesions measured by the ARFI technique and the actual values (P>0. 05). Also there was no statistically significant difference in the area of lesions measured by the SWE technique and the actual values (P>0. 05). The maps of SWE color hardness were more delicate and clear than those of VTI hardness. Conclusion Both ARFI and SWE can accurately evaluate the shape, size and hardness in radiofrequency ablation area, while two dimensional ultrasound imaging can not do it. Moreover the map of SWE color hardness is more delicate than that of ARFI.%目的 探讨声辐射力脉冲弹性成像技术(ARFI,包括VTI及VTQ)与实时二维剪切波弹性成像技术(shear wave elastography SWE)在评估实验猪肝射频消融范围中的作用及其差异.方法 新鲜离体猪肝若干,获取厚度约6～8 cm,长、宽大于8 cm的肝叶20个,超声引导下行射频消融实验(RFA),超声实时观察消融区域声像图变化,分别测量ARFI方式下其最大长径、前后径、面积、VTQ值;SWE方式下其最大长径、前后径、面积、杨氏模量值.比较两种方式所得测量值与剖开后消融区域实测数值差异,比较消融区域硬度值与非消融区域硬度值的差异.结果 成功进行20次RFA实验,ARFI方式所测消融灶大小与实测数值差异无统计学意义(P>0.05),SWE方式所测消融灶大小与实测数值差异无统计学意义(P>0.05).两种方式所测消融区硬度值与非消融区域比较差异有统计学意义(P>0.05).SWE彩色硬度图较VTI硬度图图像细腻,层次清晰.结论 ARFI与SWE技术均能较准确评价射频消融区域的形态、大小、硬度,二维超声成像不能准确评价消融区域,SWE彩色硬度图较细腻.