目的 探讨超声造影（contrast-enhanced ultrasonography，CEUS）定量评估肝纤维化程度的可行性，筛选与纤维化程度密切相关的造影定量参数。方法 将79例慢性乙肝患者根据病理分级（Scheuer评分系统）分为轻度纤维化组（S0、S1期，26例）、中度纤维化组（S2、S3期，24例）和重度纤维化组（S4期和临床肝硬化，29例），分别进行超声造影检查并采集1 min的动态影像供脱机分析。于肝动脉、门静脉、肝实质和肝静脉等4个感兴趣区获得相应的时间-强度曲线及灌注时间参数［到达时间（arrival time，AT）和达峰时间（time to peak，TTP）］、灌注强度参数［峰值强度（peak intensity，PI）、强度增量（increased signal intensity，ISI）和曲线下面积（area under curve，AUC）］，计算肝动-静脉渡越时间（hepatic artery to hepatic vein transit time，HA-HVTT）、门静脉-肝静脉渡越时间（portal vein to hepatic vein transit time，PV-HVTT）及肝实质-肝静脉渡越时间（parenchyma to hepatic vein transit time，PA-HVTT），比较各参数与肝纤维化程度的相关性。结果 肝静脉AT随肝纤维化程度的加重而缩短（P<0.05），其余部位的灌注时间参数与纤维化程度无相关性。肝内渡越时间HA-HVTT、PV-HVTT和PA-HVTT与纤维化程度均呈负相关（r=-0.510 7，r=-0.764 5，r=-0.403 2；P=0.000），其中PV-HVTT在3组间均有差异（P<0.05）。灌注强度参数中仅门静脉的PI、ISI和肝实质的ISI与纤维化程度有一定的相关性（r=-0.431 0，r=-0.460 8，r=-0.280 3；P=0.013 6）。结论 超声造影定量分析可获得肝内微循环灌注的多种参数，其中肝内渡越时间与肝纤维化程度密切相关，尤其PV-HVTT可间接评估肝纤维化程度。

Objective To investigate the feasibility of contrast-enhanced ultrasonography (CEUS) in the evaluation of liver fibrosis and screening of quantitative parameters. Methods According to the Scheuer scoring system for staging liver fibrosis, 79 patients with chronic hepatic B virus infection were divided into mild fibrosis (S0 and S1, n=26), moderate fibrosis (S2 and S3, n=24) and cirrhosis (S4 and clinical evident cirrhosis, n=29) groups. All patients were examined with CEUS and the dynamic images of CEUS (at least 1 minute) were analyzed off-line. Regions of interest (ROI) were drawn separately in hepatic artery, portal vein, liver parenchyma and hepatic vein to get time intensity curve and quantitative parameters including arrival time (AT), time to peak (TTP), peak intensity (PI), increased signal intensity (ISI) and area under curve (AUC). Intrahepatic transit time was calculated as the difference in arrival time between hepatic artery (HA) and HV (HA-HVTT), between PV and HV (PV-HVTT), and between PA and HV (PA-HVTT). All the parameters were compared with the severity of liver fibrosis. Results The AT of hepatic vein decreased as the increase of liver fibrosis (P<0.05), the AT and TTP of other ROIs showed no correlation with the stage of fibrosis. Intrahepatic transit times (HA-HVTT, PV-HVTT and PA-HVTT) correlated negatively with the development of fibrosis (r=-0.510 7, r=-0.764 5 and r=-0.403 2, P=0.000). PV-HVTT showed a statistical difference between each two groups (P<0.05). The parameters of PI, ISI and AUC showed little relationship with the severity of fibrosis except that the PI and ISI of portal vein and ISI of liver parenchyma correlated with the progression of fibrosis (r=-0.431 0, r=-0.460 8 and r=-0.280 3, P=0.013 6). Conclusions Quantitative analysis of CEUS can provide reliable information of hepatic hemodynamic changes non-invasively. Intrahepatic transit time, especially PV-HVTT, is closely correlated with the stage of fibrosis.