一、超声(US)在肝癌诊断中的价值 US具有无创、价廉、使用方便、分辨率高、病灶定位准确等优点,可作为肝硬化患者筛查肝细胞癌的有效手段和肝癌术前诊断的首选影像学技术。但肝癌的超声表现变化甚大且缺少特异性,大肝癌主要表现为高低混杂的不均匀回声,若其周围出现低回声环、声晕或镶嵌声波等对肝癌诊断有较大帮助。小肝癌(直径<3cm)主要表现为均匀低回声,常规灰阶超声检查由于某些等回声病变周围缺乏包膜和声晕,肝硬化或退变结节与低回声的小肝癌又很相似,极易导致漏诊。因此有肝硬化史的肝癌,二维US的灵敏度仅为50％～80％,对小肝癌检出敏感性更低。彩色多普勒US可观察病变内部和边缘回声及血流分 First, the value of US in the diagnosis of liver cancer US has the advantages of noninvasive, inexpensive, easy to use, high resolution, accurate positioning of the lesion can be used as an effective screening of patients with cirrhosis of hepatocellular carcinoma and preoperative diagnosis of liver cancer The preferred imaging technology. However, the manifestations of hepatocellular carcinoma vary greatly and lack of specificity. Large hepatocellular carcinoma (HCC) is mainly characterized by heterogeneous echoes of high and low echoes. If there are hypoechoic rings around it, acoustic halo or inlaid acoustic waves may be of great help in the diagnosis of HCC. Small hepatocellular carcinoma (diameter <3cm) is mainly characterized by low hypoechoic echo. Conventional grayscale ultrasound is similar to low hypoechoic hepatocellular carcinoma due to the lack of envelope and sound halo around some isoelectronic lesions. Easily lead to missed diagnosis. Therefore, a history of liver cirrhosis, two-dimensional US sensitivity of only 50% to 80%, the detection of small liver cancer is less sensitive. Color Doppler US observes the internal and peripheral echoes and blood flow in the lesion