Abstract
An intraductal ultrasound (IDUS) probe which is inserted via the papilla into the
main pancreatic duct (MPD) was evaluated in the diagnosis of 20 patients with pancreatic
cancer. The examination was successfully performed with the probe in 17 of the patients
(85 %). Due to its high frequency (30 MHz) the probe only allowed visualization of
the ductal wall and the immediate periductal vicinity (up to about 10 mm). In 15 of
the 20 patients the tumors were surgically resected and IDUS scanning was also performed
in vitro on the resection specimens, the results being compared to those of histopathological
examination. Of these 15 patients, 13 were found to have ductal adenocarcinomas and
all but one had been unequivocally diagnosed as having such by ultrasonography (US),
computed tomography (CT), endoscopic retrograde cholangiopancreatography (ERCP) and
endoscopic ultrasonography (EUS). IDUS showed an echorich area (corresponding to cancerous
canaliculi on histopathological examination), surrounded by an echopoor area (abundant
stroma). This pattern was classified as type I. In two patients with intraductal papillary
carcinomas in whom a conclusive diagnosis was not established on US, CT, EUS or ERCP,
IDUS showed tumorous tissue with an inhomogenous echopattern outside (type II) or
within (type III) the duct. These results show that IDUS offers valuable diagnostic
information complementary to ERCP especially in cases of intraductal papillary tumors.
Whether the high resolution imaging of the duct and the paraductal tissue can be used
to differentiate between the different forms of pancreatic lesions (inflammation,
neoplasms) has to be investigated further.
