Evaluation of liver damage caused by brain death with real-time ultrasound elastography on Ba-Ma pig

Abstract

Objective To investigate the value of real-time ultrasound elastography (RTE) in the evaluation of liver damage caused by brain death. Methods Establish brain death model on 11 Ba-Ma pigs (either gender, weigh 30-35 kg). Ran RTE respectively before the model have been established which defined as control group, when brain death predicated, 3, 6, 9 h after brain death; one-way ANOVA test analyze of 11 parameters of different groups, correlation analysis of electronic speculum results and RTE; receiver operating characteristic (ROC) curve analyze of RTE parameters’ cut-off value. Results Among 11 parameters, the mean relative strain value within the region of interest (ROI) (MEAN), standard deviation of the relative strain value within the ROI (SD), area of low strain within the ROI (%AREA), complexity of low strain area within the ROI (COMP), skewness (SKEW), correlation (CORR) were statistically significant differences between groups (P=0.000), MEAN decreased from 117.20±8.74 to 93.30±3.76 with time (P=0.000); electronic speculum of liver tissue results show that the damage gradually irreversible with the extension of brain death time, there is significant difference between 9 h and 0 h group (P=0.027); the correlation between MEAN and electronic speculum is the highest (r=0.59, P=0.000); ROC curve analyze RTE parameters cut-off value between before and after 9 h, the critical value of MEAN is 99.82. Conclusion Liver damage of brain death gradually increased, RTE is a noninvasive method to preliminary evaluation of liver damage and has a good correlation with electronic speculum results. Key words: Real-time ultrasound elastography; Electronic speculum; Brain death animal model; Liver damage