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.