Dong B, Chen M
Ultrasonic Laboratory, Beijing Institute for Cancer Research, Western District, China.
J Clin Ultrasound. 1987 Mar-Apr;15(3):185-90. doi: 10.1002/jcu.1870150306.
Ultrasonographic diagnosis of gallstones in the distal part of extrahepatic duct is not easy. A number of new techniques have been used by the authors to improve the detection rate of these stones. They include filling the duodenum and gastric antrum with drinking water, scanning after a fatty meal, and changing the patient's position during scanning. Ultrasound successfully identified choledocholithiasis in 78 of 104 patients for a sensitivity of 75%. There were 26 false-negative cases. The chief causes of the false negatives were obscuration of the distal duct by overlying bowel gas, missing of small stone in a nondilated bile duct, and misdiagnosis of soft pigment or an impacted stone having an atypical hypoechoic image in the distal duct as a tumor. False-positive diagnosis occurred in 32 out of 188 noncalculous cases, giving a specificity of 83%. These cases represent various hyperechoic lesions in the neck of gallbladder, cystic duct, and periampullary region. The overall diagnostic accuracy of gallstones in the extrahepatic bile duct by ultrasound was 80% (234/292).
超声诊断肝外胆管远端的胆结石并不容易。作者采用了一些新技术来提高这些结石的检出率。这些技术包括用饮用水充盈十二指肠和胃窦、在进食脂肪餐后进行扫描以及在扫描过程中改变患者体位。超声在104例患者中的78例成功识别出胆总管结石，敏感性为75%。有26例假阴性病例。假阴性的主要原因是覆盖的肠气遮挡了远端胆管、未扩张胆管中的小结石漏诊以及将远端胆管中具有非典型低回声图像的软色素结石或嵌顿结石误诊为肿瘤。188例无结石病例中有32例假阳性诊断，特异性为83%。这些病例表现为胆囊颈部、胆囊管和壶腹周围区域的各种高回声病变。超声诊断肝外胆管结石的总体诊断准确率为80%（234/292）。
