von Herbay A, Kühnel J, Frieling T, Häussinger D
Department of Gastroenterology, Hepatology and Infectious Diseases, University of Düsseldorf, Moorenstrasse 5, D-40225 Düsseldorf, Germany.
J Clin Ultrasound. 1999 Oct;27(8):426-32. doi: 10.1002/(sici)1097-0096(199910)27:8<426::aid-jcu3>3.0.co;2-x.
The intrahepatic "parallel channel sign" on gray-scale sonograms is generally interpreted as representing dilated bile ducts, but it may also be caused by enlargement of intrahepatic arteries. This study was performed to evaluate the incidence of misinterpretation of the parallel channel sign without color Doppler sonography and the characteristics of patients in whom misinterpretation of the parallel channel sign is likely to occur.
A total of 1,100 patients were examined by sonography. All patients with a parallel channel sign on gray-scale sonograms underwent color Doppler sonography. In addition, laboratory values related to cholestasis were measured.
The parallel channel sign was observed in 57 patients (5.2%). In 35 (61%) of these patients, color Doppler sonography revealed blood flow in both lumina, indicating that the parallel channel sign was not caused by enlarged bile ducts. Eighty-six percent of this group had nonbiliary liver disease; the enlarged hepatic artery branches were associated with liver cirrhosis in 63% of this group. Color Doppler sonography confirmed that the other 22 patients (39%) had an enlarged intrahepatic bile duct.
Use of color Doppler sonography can help avoid misinterpretation of the parallel channel sign, especially in patients with nonbiliary liver disease.
灰阶超声图像上的肝内“平行管道征”通常被解释为代表胆管扩张，但它也可能由肝内动脉增粗引起。本研究旨在评估在未使用彩色多普勒超声的情况下平行管道征误判的发生率，以及可能发生平行管道征误判的患者特征。
对1100例患者进行超声检查。所有灰阶超声图像上出现平行管道征的患者均接受彩色多普勒超声检查。此外，还测量了与胆汁淤积相关的实验室值。
57例患者（5.2%）出现平行管道征。在这些患者中，35例（61%）彩色多普勒超声显示两个管腔内均有血流，表明平行管道征并非由胆管扩张所致。该组86%的患者患有非胆汁性肝病；该组63%的患者肝动脉分支增粗与肝硬化有关。彩色多普勒超声证实，另外22例患者（39%）肝内胆管扩张。
使用彩色多普勒超声有助于避免平行管道征的误判，尤其是在非胆汁性肝病患者中。
