Diagnosis of the pancreatic diseases by intraductal ultrasound of the pancreas--with special reference to clinical cases difficult to diagnose differentially pancreatic diseases by the endoscopic retrograde pancreatography

We examined the usefulness of the intraductal ultrasound (IDUS) examinations by comparing the IDUS images with the endoscopic retrograde (ER) pancreatograms. We inserted an IDUS probe with 30 MHz at frequency transpapillary into the main pancreatic duct (MPD) in 105 cases with pancreatic diseases (30 cancers, 30 mucin-producing tumor, 3 islet cell tumor, 1 pancreatic serous cyst adenoma, 1 pancreatic teratoma, 1 pancreatic solid and cystic tumor and 39 chronic pancreatitis). All 105 cases were performed ER pancreatography. Sixty-four of 105 cases (22 cancers, 20 mucin-producing tumor, 3 islet cell tumor, 1 pancreatic serous cyst adenoma, 1 pancreatic teratoma, 1 pancreatic solid and cystic tumor and 16 chronic pancreatitis) were operated and the IDUS images were compared with the corresponding histopathological sections. The usefulness of the IDUS examinations of the pancreatic diseases were the following cases; differential diagnosis between benign and malignant cases with localized stenosis of the MPD, differential diagnosis of the cases with displacement of the MPD, and the diagnosis of the intraductal extent and of invasion of the tumor in the mucin-producing tumor of the pancreas with the dilation of the MPD. IDUS examinations are performed by the IDUS probe with high frequency, so the indications of the IDUS examinations are to detect the small lesions in the pancreas.