LEARNING OBJECTIVES: 1) To describe the technique for contrast-enhanced US (CEUS) of the pancreas; 2) to describe CEUS findings that allow characterization and staging of pancreatic disease.

BACKGROUND : Second generation US contrast media have already proven useful in the study of the liver. The study of the pancreas is a new and promising application of CEUS.

IMAGING FINDINGS: CEUS of the pancreas shows marked early parenchymal enhancement (peak: 15-20 seconds) followed by progressive washout. Contrast-enhanced phases can be followed dynamically.

Mass-forming pancreatitis : parenchymographic enhancement. CEUS improves differential diagnosis with ductal adenocarcinoma. Ductal adenocarcinoma : poor enhancement, appears hypoechoic to the adjacent normally enhancing pancreatic tissue. CEUS improves identification, characterization and loco-regional and hepatic staging. Endocrine tumors : bright enhancement, appearing hypechoic to the adjacent normally enhancing pancreatic tissue. CEUS improves identification, characterization and loco-regional and hepatic staging. Pseudocyst : no intralesional enhancement. Serous cystadenoma : CEUS enhancement of intralesional septa improves identification of microcystic features. Mucinous cystc neoplasm : CEUS helps identify parietal nodules and septa, for the differential diagnosis with pseudocysts.

CEUS allows to study a pancreatic lesion in the arterial and venous phase for characterization and local staging, then after 120 seconds the liver can be examined for the detection of metastases.

CONCLUSION : In this comprehensive review we address the topic of CEUS of the pancreas, discussing examination technique and imaging findings for solid and cystic disease.

CEUS OF THE PANCREAS: WHY SHOULD WE DO IT?

•  US if often the first examination performed in patients with suspicion of pancreatic pathology

•  The greater accuracy of CEUS compared to baseline US can immediately result in better diagnostic workup and treatment planning

TEACHING POINTS

1: in presence of any focal pancreatic mass iso-enhancing to the normal parenchyma at CEUS, FNAC is mandatory for treatment planning.

2: any focal pancreatic mass hypo-enhancing to the normal parenchyma at CEUS should be considered a ductal adenocarcinoma until otherwise proven.

3: endocrine tumors are the first differential diagnosis for any focal pancreatic mass hyper-enhancing to the normal parenchyma at CEUS.

4: the presence of vascularized inclusions in a cystic lesion at CEUS excludes the diagnosis of pseudocyst, and the diagnosis of cystic tumor must be considered.