Early diagnosis of pancreatic cancer by routine CT scanning; significance of the pancreatic bile duct scanning

Early recognition of dilated tail-side pancreatic duct and liver-side bile duct is one of the main diagnostic goals for an early diagnosis of pancreatic cancer. In order to attain these objectives, a new scanning method involving Target Volume Scan for the pancreas as a routine CT scanning modality has been devised. The picturing capability of this imaging method for the pancreatic bile duct and its role in the early diagnosis of pancreatic cancer are discussed. In phantom experiments, clinical experiments and clinical applications, the pancreatic duct within the pancreas body and the intra-hepatic bile duct, which were expanded into a cylindrical form of pure circular cross section with a diameter greater than 2 mm, have been pictured as continuous, linear, low-density regions. Similarly, the pancreatic duct within the pancreas head and the choledoch duct with diameters greater than 3 mm have also been pictured as low-density circular areas. In healthy pancreatic bile ducts, the tail section of the pancreas head and the intra-hepatic bile duct do not appear in scans, and although 70% of healthy choledoch ducts have been pictured, many deformed lumens have been observed in cross section. The conditions for obtaining successful images of lumens depended upon the degree of intra-lumen filling with either pancreatic juice or bile rather than the diameter of the lumen. Consequently, pancreatic cancer, which causes changes in the pancreatic duct and bile duct lumen, can be detected as a discontinuity in the image of the lumen obtained in the Target Volume Scan, regardless of the cancer, suggesting that the Target Volume Scan could be an important diagnostic imaging tool for the early detection of pancreatic cancer.