Sonazoid超声造影定量分析早期诊断胆道闭锁的实验研究

Biliary atresia(BA) is a fatal neonatal disease characterizing of the obliteration of varying length of both intrahepatic and extrahepatic bile ducts.Early diagnosis and timely surgical intervention of BA could obtain a better outcome.However,until now there is a lack of an effective tool to early identify BA among jaundice infants.Our previous studies had showed: the diameter of liver artery in patients with BA was signficantly larger than those without BA and the number of kupffer cells in patients with BA was significantly higher than in the controls;Sonazoid microbubbles could be specifically phagocytized by kupffer cells in liver;The phagocytosis of kupffer cells would discrease in a fibrotic liver,which could be detected as the dicrease of enhancement in liver on Contrast Enhanced Ulrtasound,this enhancement difference between normal liver and fibrotic liver could be precisely measured by quantitative analysis. On the basis of these previous findings, this study is planning to build up a Rotavirus induced BA model with Balb/c murine,then to use quantitative Contrast Enhanced Ultrasound by sonazoid to evaluate the change of the blood flow perfusion and the kupffer cell number of the BA model, further to illustrate the correlation between which and liver fibrosis during the BA process,for discussing the value of quantitative Contrast Enhanced Ultrasound by Sonazoid in early diagnosis of BA and supplying theoretical support for the clinical application of Contrast Ehanced Ultrasound by Sonazoid in early diagnosis of BA.

胆道闭锁（Biliary Atresia,BA）是新生儿期一种以不同程度的肝内外胆道闭塞为特征的致死性疾病，早期外科干预能显著改善预后。目前临床上缺乏可靠的早期诊断工具。我们前期工作发现：BA的肝动脉较非BA的肝动脉增粗,BA肝脏的库否细胞含量较非BA增多；Sonazoid微泡能被肝脏库否细胞特异性吞噬；肝纤维化时库否细胞吞噬功能减退，表现为超声造影增强减低，利用定量方法可以精确量化。本研究拟在此基础上构建胆道闭小鼠模型，运用Sonazoid超声造影定量方法评价胆道闭锁病程中肝脏血管相和kupffer相的增强强度变化，以现代免疫组织化学技术为金标准分析超声增强强度与肝脏血流灌注变化﹑kupffer细胞数量变化及其肝脏纤维化的内在联系，探讨肝kupffer细胞增多引起胆道闭锁的可能机制，建立Sonazoid超声造影定量分析早期诊断胆道闭锁的方法和标准，为BA的早期诊断提供理论依据。

胆道闭锁是新生儿期一种以不同程度的肝内外胆道闭塞为特征的致死性疾病。早期诊治能在减少医疗花费的同时显著改善预后。目前临床上缺乏可靠的早期诊断工具。本项目通过Sonazoid超声造影定量分析比较大鼠结扎胆道致胆道闭锁模型与对照组之间血管相和Kupffer相肝脏增强强度随时间变化情况，探讨超声造影定量分析早期评价结大鼠结扎胆道后其肝动脉增生、肝内Kupffer细胞增多的能力, 并采用盲法读片的方式检验造影定量分析正确识别胆道闭锁的诊断效能。结果显示，采用Image J软件定量测量Sonazoid超声造影图像血管相肝包膜下血流像素比和Kupffer相增强强度灰度值，在大鼠结扎胆道后第3天，即可以在血管相和kupffer细胞相分别检测到其增强强度较未结扎胆道大鼠明显增强，差异有统计学意义（p＜0.05）。利用定量分析数据制作ROC曲线分析，得到术后3天血管相天肝包膜下血管像素比较术前差值＞0.078 dB及造影剂注入后3min时增强强度较术前增加＞6.0dB时为诊断最佳值，以此标准诊断胆道闭锁的敏感度为80%（16/20），特异度为100%（4/4），阳性预测值为（16/16）100%，阴性预测值为（4/8）50%，准确率为（20/24）83.3%。kupffer细胞的增多与病理染色计数的符合率达90%（18/20）。因此，本项目的结论认为，Sonazoid超声造影定量分析可以早期反映胆道结扎前后大鼠肝脏血流动力学的变化和Kupffer细胞数量的变化。这一发现，有可能为胆道闭锁早期无创诊断提供新的思路。