声辐射力脉冲成像技术定量评价兔肝缺血后弹性改变的实验研究

目的 运用声辐射力脉冲成像(acoustic radiation force impulse,ARFI)技术评价兔肝门脉主干及肝固有动脉同时阻断后的弹性改变.方法 通过同时阻断肝门脉及肝固有动脉的方法建立兔肝缺血模型,运用ARFI技术分别于肝缺血前(T0)及缺血后5 min(T1)、20 min(T2)、30 min(T3)对兔右肝同一部位进行检查,测量肝缺血过程中肝组织的弹性;在相应时间点测定血清门冬氨酸氨基转移酶(AST)、丙氨酸氨基转移酶(ALT)水平,以及肝穿刺活检;最后进行统计分析.结果 T2兔右肝ARFI测值即组织剪切波速度(Vs)明显高于T0,差异有统计学意义(P＜0.05),T3兔右肝Vs明显高于T2,差异有统计学意义(P＜0.05);T2血清AST、ALT水平稍高于T0,但差异无统计学意义(P＞0.05),T3血清AST、ALT水平明显高于T2,差异有统计学意义(P＜0.05);组织学观察在T2、T3可见兔肝缺血损伤病理改变.结论 ARFI技术定量分析缺血肝组织弹性改变能在较早期准确、客观地反映肝缺血损伤的严重程度.

Quantitative assessment of ischemic liver's elastic changes in rabbits using acoustic radiation force impulse (ARFI)

Objective To evaluate the change of elasticity of rabbit liver following portal inflow vessels occlusion using acoustic radiation force impulse (ARFI). Methods Twelve Japanese white big ear rabbits were used to establish total hepatic vascular exclusion animal models by occluding the portal inflow vessels. The elasticity of rabbits' right liver was detected during the stages of baseline(T0), 5 min(T1),20min(T2) ,30min (T3)after occluding the portal inflow vessels using ARFI respectively. The elasticity of rabbit liver, levels of serum's aspartate aminotransferase (AST), alanine aminotransferase (ALT) and historical results of hepatic tissue during different stage were compared. Results Shear wave velocity(Vs)of rabbits' right livers in T2 was significantly higher than that in T0 ( P ＜0.05) and Vs of rabbits' right livers in T3 was significantly higher than that in T2 ( P ＜0.05). No significant differences of serum's AST,ALT levels between T2 and T0 were found,while the Vs of rabbit live in T2 was slightly higher than that in T0 (P＞0.05), serum's AST, ALT levels in T3 were significantly higher than that in T2 ( P ＜0.05).Historical changes of liver ischemia and injury were observed in T2 and T3 with light microscopy. Conclusions The liver ischemia and injury severity can be accurately and objectively evaluated using ARFI.