Department of Radiology, University of California San Francisco, 505 Parnassus Ave, Box 0628, M-372, San Francisco, CA 94143-0628, USA.
Radiographics. 2009 Oct;29(6):1669-88. doi: 10.1148/rg.296095514.
Magnetic resonance (MR) imaging and computed tomography (CT) can be useful in the diagnosis of biliary disease, with both modalities allowing detailed evaluation of the biliary tract. Careful interrogation of the images is critical, regardless of modality. The identification of dilated bile ducts necessitates evaluation for strictures or filling defects, which is best performed with thin-section imaging. Smooth, concentric short-segment strictures favor a benign cause, whereas abrupt, eccentric long-segment strictures favor a malignancy. At MR imaging, extrabiliary entities such as crossing vessels or metallic clip artifact may mimic strictures and should not be mistaken for disease. A stone is the most common biliary filling defect and may occur in the absence of dilated ducts. Stones commonly have a lamellated, geometric shape and are found in a dependent portion of the duct. Identification of bile duct wall thickening raises concern for cholangitis or malignancy. Improved diagnosis of biliary disease can be achieved with a knowledge of the benefits and limitations of modern MR and CT cholangiographic techniques, including the use of biliary-excreted contrast material and of various postprocessing techniques. Familiarity with the radiologic appearances of the duct lumen, wall, and surrounding structures is also important for accurate image interpretation. The rapidly evolving technology for both MR imaging and CT of the biliary tract will continue to present radiologists with opportunities as well as challenges.
磁共振成像（MR）和计算机断层扫描（CT）可用于胆道疾病的诊断，两种方法都可以对胆道进行详细评估。无论采用哪种方法，仔细检查图像都至关重要。发现胆管扩张后，需要评估是否存在狭窄或充盈缺损，这最好通过薄层成像来完成。胆管狭窄呈光滑、同心的短节段时，多提示良性病变，而胆管狭窄呈突然、偏心的长节段时，则多提示恶性病变。在 MR 成像中，交叉血管或金属夹伪影等胆管外病变可能会模拟狭窄，不应误诊为疾病。结石是最常见的胆管充盈缺损，可在无胆管扩张的情况下出现。结石通常呈层状、几何形状，位于胆管的下垂部位。胆管壁增厚提示胆管炎或恶性肿瘤。了解现代 MR 和 CT 胆系成像技术的优缺点，包括使用胆汁排泄对比剂和各种后处理技术，可提高胆道疾病的诊断水平。熟悉胆管管腔、管壁和周围结构的影像学表现，对于准确解读图像也很重要。胆道的 MR 成像和 CT 技术发展迅速，这为放射科医生带来了机遇，也带来了挑战。
