Patients have an ultrasound if they experience painless obstructive jaundice, which is caused by compression or ingrowth of the distal common bile duct.
The level of obstruction should be determined.
In patients with a pancreatic head tumor, typically dilatation of the common bile duct and pancreatic duct (double duct sign) is seen, which is very suggestive for a mass in the pancreatic head, even in the absence of a visible mass.
The tumor itself usually presents as a hypoechoic mass (seen below).