Ex vivo examination of the pancreas by intraductal ultrasonography (IDUS).

Pancreas specimens from humans (seven normal autopsy specimens, one surgical resection specimen containing a 15 mm microcystic adenoma in the pancreatic head) were examined by intraductal ultrasonography using flexible, high-resolution ultrasonic catheters (20 MHz, 4.8 and 6.0 French diameter). The catheters were easily inserted into the pancreatic duct in all specimens. The ultrasonographic tissue pattern could be correlated with the histological findings in tissue cross-sections at defined positions. A high degree of resolution was achieved in the differentiation of blood vessels, duct system elements, fibrotic tissue, fatty tissue and pancreatic tissue with a varying fat content. At an average distance of 5.5 mm, structures as small as 0.1 mm could be discriminated. No evidence of ductal trauma due to insertion of the catheters was found either on subsequent radiographic studies or on histologic examination. Clinical studies using this probe during ERCP are necessary to clarify whether intraductal ultrasonography could contribute to the diagnosis of small pancreatic lesions and to the differentiation of indeterminate ductal stenoses.