2022 Volume 49 Issue 3 Pages 193-204
As ultrasound (US) is simple and minimally invasive, it is widely used for mass screening. However, since conventional US screening focused on mass lesions and indirect findings such as the dilated extrahepatic bile duct and main pancreatic duct, the detection rate of pancreatic cancer was low, and most detected lesions were advanced. Although there is still no definition of early-stage pancreatic cancer, Stage 0 and Stage 1A pancreatic cancers less than 10 mm are considered pancreatic cancers with good prognosis. To detect these lesions, it is useful to perform detailed examinations and regular follow-up for high-risk individuals who have multiple risk factors for pancreatic cancer. It is also the role of US to identify high-risk individuals who show a dilated main pancreatic duct or cystic lesion. The pancreas is sometimes difficult to visualize not only because of its complicated anatomical location but also because of its susceptibility to obesity and gastrointestinal gas. Although the pancreatic head is a common site of pancreatic cancers with good prognosis, it is important to pay attention to lesions in the groove region and uncinate process, which are often not accompanied by indirect findings. To minimize poorly visualized areas, positional changes such as right and left decubitus, sitting and standing positions, and the liquid-filled stomach method should be applied. Furthermore, employing magnified observation with high-frequency transducers for the detailed examination and follow-up of high-risk individuals could detect smaller mass lesions and abnormalities of the pancreatic ducts.
