Comparison of ARFI and SWE elastography techniques in evaluating radiofrequency ablation range

doi:10.3969/j.issn.1002-7386.2018.11.009

Abstract：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.