4 imaging diagnostic methods for pancreatic cancer

The four commonly used imaging examination methods for diagnosing pancreatic cancer are transabdominal ultrasound, intraductal ultrasound, intravenous ultrasound, and CT.

1. Transabdominal ultrasound examination

Food should not be consumed for 6 hours before the transabdominal ultrasound examination. 500-800 ml of water should be consumed before the examination to fill the stomach and show the pancreas. Barium contrast should not be performed the day before the examination. The image generally shows the morphological changes of the pancreas, the extent of expansion of the pancreatic duct and bile duct, the invasion of blood vessels and surrounding organs, lymph node metastasis, etc.

2. Ultrasound examination of the pancreatic duct

Intraductal ultrasound is a method of using a tiny probe with a diameter of 2 mm to be inserted into the main pancreatic duct, which can clearly display the main pancreatic duct, bile duct, and the anatomical structures around the pancreatic duct. It can also display lesions in the pancreatic duct and lesions in the parenchyma of the main pancreatic duct, and determine the degree of invasion of pancreatic cancer.

3. Intravenous ultrasound examination

The intravenous ultrasound catheter is inserted into the intrahepatic portal vein and then gradually withdrawn to observe the portal vein from the liver to the pancreas. The echo reflects the degree of damage to the portal vein: an intact echo band indicates no damage; an occluded echo band indicates damage.

4. CT examination

CT is now considered the best method for detecting pancreatic cancer and its staging, and its positive predictive value for diagnosing pancreatic cancer is >90%.

The positive predictive value for whether a tumor cannot be removed is close to 100%, and the predictive value for whether a negative tumor can be removed is close to 80%. The detection rate for early pancreatic cancer is as high as 80%.