血管位置及血管与声轴角度对HIFU表面消融效果影响的体模实验

Effect of blood vessels at different locations and angle between blood vessel and sonic axis on HIFU peripheral ablation

目的探讨靶区内血管位置及血管与声轴角度对HIFU表面消融效果的影响。方法将56块含血管的仿组织体模分为A组(血管位置)和B组(血管角度),A组按血管中心与HIFU表面消融最深层面(顶面)距离d分为A_1(d=0)、A_2(d=10mm)、A_3(d=20mm)亚组,B组按血管长轴与声轴之间夹角角度α分为B_1(0~5°)、B_2(60°~65°)、B_3(90°~95°)、B_4(115°~120°)亚组。另设A_4、B_5亚组为空白对照组。测量各组血管内径、管壁厚度,观察辐照后损伤形态,计算能效因子(EEF)。结果 A、B各亚组间血管内径、管壁厚度差异均无统计学意义(P均>0.05)。损伤形态:A_1、B_1亚组靶区完全消融,无残留;余各亚组血管深侧靶区有残留。A组中A_4亚组、A_1亚组、A_2亚组(由小到大排列)EEF两两比较差异均有统计学意义(P均<0.05),A_1与A_3亚组差异无统计学意义(P>0.05);B组中B_5亚组、B_2亚组、B3亚组(由小到大排列)EEF两两比较差异均有统计学意义(P均<0.05),B_2亚组与B_4亚组、B_5亚组与B_1亚组的EEF差异无统计学意义(P均>0.05)。结论血管中心距HIFU表面消融最深层面10mm、靶区内血管与声轴角度90°~95°对靶区消融影响最大,效率最低,消融时应注意调整以提高消融效率。

Objective To investigate the effect of blood vessels at different locations and angles between blood vessel and sonic axis within the target area on HIFU peripheral ablation. Methods Totally 56 phantoms containing rabbit thoracic aorta were divided into group A （different vessel locations） and B （different vessel angles）. According to the distance （d） between the blood vessel center and the deepest （top） layer of the peripheral scanning, group A was divided into A1 （d=0）, A2 （d=10 mm）, A3 （d=20 mm） subgroups. According to the angle （α） between the vessel long axis and the acoustic axis, group B was divided into B1 （α=0-5°）, B2 （α=60°-65°）, B3 （α=90°-95°）, B4 （α=115°-120°） subgroups. A4, B5 subgroups were set as the control groups. The vessel diameter and vessel wall thickness were measured. The lesion morphology was observed and the energy efficiency factor （EEF） was calculated. Results There was no significant difference in vessel diameter and vessel wall thickness in both group A and B （all P〉0.05）. There was no residual area in the target area of A1, B1 subgroup, while there was residual area in the target area of the other subgroups. EEF of group A in ascending order were A4, A1, A2 subgroup, and statistically significant differences in pairwise comparisons （all P〈0.05） except for A1 and A3 subgroup （P〉0.05）. EEF of group B in ascending order were B5, B2, B3 subgroup, respectively, and statistically significant differences in pairwise comparisons （all P〈0.05） except for B2 and B4, B5 and B1 subgroup （both P〉0.05）. Conclusion It is 10 mm that the distance between the blood vessel center and the deepest （top） layer of the peripheral scanning, and 90°-95° that the angle between the vessel long axis and the acoustic axis has the greatest influence on the ablation of the target area.