应用超声造影分析兔脑死亡状态下肝微血流灌注定量参数，探讨评估脑死亡供肝的新方法。

制备兔脑死亡组（15只）和对照组（5只）模型并维持状态达8 h，对脑死亡组和对照组于模型制备完成后0 h、4 h、8 h进行肝超声造影检查和微血流灌注定量分析，定量参数包括曲线下面积（AUC）、峰值强度（Peak）、达峰时间（Tp）、平均渡越时间（MTT）。采用t检验比较脑死亡组与对照组0 h、4 h、8 h肝超声造影定量参数AUC、Peak、Tp及MTT的差异，同时进行肝功能和病理检查。

脑死亡状态下，13只兔（13/15，86.7%）AUC值呈逐渐下降趋势，15只（15/15，100%）兔的Peak值呈逐渐下降趋势。建模后0 h脑死亡组Peak值高于对照组［（66.1±9.1）% vs （54.9±7.3）%］，建模后8 h脑死亡组Peak值低于对照组［（44.9±10.3）% vs （68.5±2.9）%］，且差异均具有统计学意义（t=-11.276，P=0.032；t=-10.395，P=0.001）；建模后4 h，脑死亡组和对照组的Peak值比较，差异无统计学意义（P＞0.05）。建模后8 h，脑死亡组AUC值小于对照组［（2591.7±732.7）%s vs（4520.0±182.8）%s］，差异有统计学意义（t=-18.762，P=0.001）；建模后0 h、4 h，脑死亡组和对照组的AUC值比较，差异均无统计学意义（P均＞0.05）。建模后0 h、4 h、8 h，脑死亡组和对照组Tp值和MTT值比较，差异均无统计学意义（P均＞0.05）。

兔脑死亡状态下肝微血流灌注量下降，超声造影可作为评估脑死亡供肝的有效方法。

To analyze the quantitative parameters of hepatic microperfusion by contrast-enhanced ultrasound in rabbits with brain death, in order to explore a new method for evaluating the donor liver of individuals with brain death.

Rabbits with brain death (n=15) were prepared by surgery and maintained for 8 hours, and rabbits undergoing sham operation were used as controls (n=5). Contrast-enhanced ultrasonography and quantitative analysis of microblood flow were performed in the two groups at 0 h, 4 h, and 8 h after modeling. The quantitative parameters included area under the curve (AUC), peak intensity (PI), peak time (Tp), and average transit time (MTT). The t-test was used to compare the differences of liver contrast-enhanced ultrasound quantitative parameters AUC, PI, Tp, and MTT between the two groups at different time points. Liver function and pathology were evaluated at the same time.

Under the condition of brain death, the AUC values of 13 rabbits (13/15, 86.7%) showed a gradually downward trend, and the PI values of 15 rabbits (15/15, 100%) showed a gradually downward trend. At 0 h after modeling, the PI value of the brain death group was significantly higher than that of the control group [(66.1±9.1)% vs (54.9±7.3)%, t=-11.276, P=0.032], and at 8 h, the PI value of the brain death group was significantly lower than that of the control group [(44.9±10.3)% vs (68.5±2.9)%, t=-10.395, P=0.001]; at 4 h, there was no significant difference in the PI value between the two groups (P＞0.05). Eight hours after modeling, the AUC value of the brain death group was significantly lower than that of the control group [(2591.7 ±732.7)%s vs (4520.0 ±182.8)%s, t=-18.762, P＜0.001], but there was no significant difference at 0 h and 4 h (P＞0.05). At 0 h, 4 h, and 8 h after modeling, there was no significant difference in the Tp scores and MTT values between the two groups (P＞0.05).

The amount of hepatic microperfusion decreases in rabbits with brain death, and contrast-enhanced ultrasound can be used as an effective method to evaluate the donor liver of individuals with brain death.