MRI of cholangiocarcinoma

Abstract

Cholangiocarcinomas are the second most common primary hepatobiliary tumors after hepatocellular carcinomas. They can be categorized either based on their location (intrahepatic/perihilar/extrahepatic distal) or their growth characteristics (mass-forming/periductal-infiltrating/intraductal) because they exhibit varied presentations and outcomes based on their location and or pattern of growth. The increased risk of cholangiocarcinoma in PSC necessitates close surveillance of these patients by means of imaging and laboratory measures; and because currently surgical resection is the only effective treatment for cholangiocarcinoma, the need for accurate pre-operative staging and assessment of resectability has emphasized the role of high quality imaging in management. Today magnetic resonance imaging (MRI) is the modality of choice for detection, pre-operative staging and surveillance of cholangiocarcinoma.

Multimodality imaging of intrahepatic cholangiocarcinoma

“…Compared with MRI, CE-CT has a limited ability to detect spread of tumor along bile ducts (8). MRI excels at this task due to its superior soft tissue contrast and is therefore considered the imaging modality of choice for diagnosis and staging of cholangiocarcinoma.…”

“…Perihilar intrahepatic cholangiocarcinomas arise from the confluence of the right and left hepatic bile ducts, accounting for 50-60% of cases. Distal extrahepatic cholangiocarcinomas arise from the bile duct below the level of the cystic duct insertion down to the ampulla of Vater (8). The anatomic location of the tumor is an important consideration for treatment planning and often reflects the clinical symptomatology (2).…”

“…Morphology is a useful indicator of the tumor's behavior and clinical outcome, often dictating the surgical approach (1,2,8). The massforming subtype invades the hepatic parenchyma, spreading along portal venous channels (1).…”

“…The periductal-infiltrating subtype grows longitudinally along the bile duct walls, spreading via lymphatic vessels. The intraductal subtype proliferates focally within the biliary duct lumen, leaving the wall intact (1,2,4,8). While all three subtypes may occur at an intrahepatic location, certain morphologies predominate at certain sites.…”

Preoperative Radiologic Evaluation of Cholangiocarcinoma

“…Moreover, biliary stent insertion can cause mural thickening and enhancement mimicking the tumor spread due to postinverventional inflammatory changes, which may cause overstaging of disease extent particularly on MR imaging. 15,28 If imaging is performed after biliary drainage, radiologists should be careful not to overestimate the tumor extent (Fig. 2).…”