Usefulness of contrast-enhanced ultrasonography for biliary tract disease.

Conventional ultrasonography (US) for biliary tract disease shows high time and spatial resolution. In addition, it is simple and minimally invasive, and is selected as a first-choice examination procedure for biliary tract disease. Currently, contrast-enhanced US (CEUS), which facilitates the more accurate assessment of lesion blood flow in comparison with color and power Doppler US, is performed using a second-generation ultrasonic contrast agent. Such agents are stable and provide a timeline for CEUS diagnosis. Gallbladder lesions are classified into three types: gallbladder biliary lesion (GBL), gallbladder polypoid lesion (GPL), and gallbladder wall thickening (GWT). Bile duct lesions can also be classified into three types: bile duct biliary lesion (BBL), bile duct polypoid lesion (BDPL), and bile duct wall thickening (BDWT). CEUS facilitates the differentiation of GBL/BBL from tumorous lesions based on the presence or absence of blood vessels. In the case of GPL, it is important to identify a vascular stalk attached to the lesion. In the case of GWT, the presence or absence of a non-contrast-enhanced area, the Rokitansky-Aschoff sinus, and continuity of a contrast-enhanced gallbladder wall layer are important for differentiation from gallbladder cancer. In the case of BDWT, it is useful to evaluate the contour of the contrast-enhanced medial layer of the bile duct wall for differentiating IgG4-related sclerosing cholangitis from primary sclerosing cholangitis. CEUS for ampullary carcinoma accurately reflects histopathological findings of the lesion. Evaluating blood flow in the lesion, continuity of the gallbladder wall, and contour of the bile duct wall via CEUS provides useful information for the diagnosis of biliary tract disease.

Contrast-enhanced US of ampullary carcinoma: correlations with pathological findings.

PURPOSE: To investigate the utility of contrast-enhanced transabdominal ultrasonography (CEUS) in the diagnosis of ampullary cancer (AC). METHODS: In 12 patients with AC, the presence of tumor enhancement, histological type, amount of connective tissue in cancer, and tumor growth pattern were evaluated. The correlation between the tumor growth pattern and enhancement shape, that between the enhancement pattern and surrounding tissue, and the presence of pancreatic infiltration were evaluated. The depth of cancer invasion was mucosa in five patients, within Oddi's sphincter in four, beyond the duodenum but not to the pancreas in two, and pancreatic invasion less than 5 mm in one. RESULTS: The tumor was enhanced in 11 patients but not in the patient with much connective tissue in the tumor. Enhancement was observed in all patients with the intraluminal papillary or mixed type, but not in those with the periductal invasive type. The enhancement shape was predominantly round or irregular in the intraluminal papillary type and predominantly serrated in the mixed type. The enhancement shape differed among the growth patterns. The normal pancreatic parenchyma around the tumor was enhanced in all patients, and pancreatic infiltration was regarded as absent when there was a continuous unenhanced area between the tumor and pancreatic parenchyma. CONCLUSION: CEUS correlates with pathological findings of ampullary cancer.