Imaging and staging of biliopancreatic malignancy: role of ultrasound.
Most patients with a pancreatic head carcinoma, periampullary carcinoma or a cholangiocarcinoma of the liver hilum (Klatskin tumor) present with obstructive jaundice and therefore ultrasound often is the first imaging modality. Visualization is sufficient in more than 90% of cases for adequate diagnosis and staging. Even most small papillary tumors can be diagnosed with conventional abdominal ultrasound. In pancreatic head and periampullary carcinoma vascular involvement is the most important determinant for local irresectability and can often be assessed by color Doppler US. An abnormal pulsed Doppler signal obtained from the portal venous system due to severe narrowing or occlusion is highly suspicious for major involvement and irresectability of the tumor. However, a normal pulsed Doppler signal does not exclude involvement, if the tumor has continuity with the vessel with interruption of the hyperechoic tumor vessel interface. Enlarged lymph nodes are not a major diagnostic parameter, because a reliable differentiation between reactive and malignant lymph nodes is generally not possible. Very tiny liver and peritoneal metastases are missed by abdominal US and only detectable by laparoscopy and/or laparascopic US. In cholangiocarcinoma of the liver hilum extensive biliary and vascular involvement are considered the most important factors for determining irresectability. Portal venous involvement can be assessed by color Doppler US with a high accuracy (91%). Although cholangiography (ERCP and PTC) is considered the best imaging modality in detecting proximal extension of the tumor into the biliary system US can provide useful additional information. If dilated ducts are seen without clear communication among each other within a liver lobe, extension of the tumor into the segmental bile ducts can be concluded. We consider color Doppler US, a valuable tool for preoperative imaging and staging of biliopancreatic malignancy.
Smits
N J
NJ
Department of Radiology, Academic Medical Center, Amsterdam, The Netherlands.
Reeders
J W
JW
D001650:Bile Duct Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology; D018281:Cholangiocarcinoma / Q000000981:diagnostic imaging* / Q000473:pathology; D006801:Humans; D008113:Liver Neoplasms / Q000556:secondary; D008207:Lymphatic Metastasis; D009367:Neoplasm Staging; D010190:Pancreatic Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology; D014463:Ultrasonography