BMJ Group Medical Reference
If you have pancreas cancer, the tube that drains bile from your liver and gallbladder to your intestine may become blocked. This tube is called the common bile duct. An ultrasound scan can show whether your common bile duct is blocked.
To learn more, see More about your pancreas and bile duct.
An ultrasound scan will also show if you have lumps called gallstones, which also can block your bile duct. This can cause some of the same symptoms as pancreas cancer.
An ultrasound scanner is a machine that uses sound waves to create a picture of the inside of your body. There are two ways of doing an ultrasound scan of the area around your pancreas. External ultrasound
The doctor places an ultrasound device (or probe) on the skin of your abdomen and moves it around. This doesn't always give a good enough picture to detect changes that could be cancer in organs and tissues.Endoscopic ultrasound (EUS)
The doctor passes a thin, flexible tube through your mouth and stomach and down into the first part of your small intestine (your duodenum). The tube is called an endoscope. At the end of the tube is a light and an ultrasound device. The test is usually used to see if your cancer can be removed with surgery. It works better than an external ultrasound.  But it's not available everywhere.
If you have this type of ultrasound, you'll be given painkillers and a sedative to keep you calm. It may make you feel uncomfortable and nauseous.  You mustn't eat anything the night before.
This procedure can have side effects, such as: