No abstract

Magnetic resonance (MR) imaging of the pancreas has undergone a major change because of its capability of providing noninvasive images of the pancreatic ducts, cross-sectional images of the parenchyma analogous to computed tomography (CT) images, and angiographic depiction of blood vessels. Recent technical issues include the use of half-Fourier T2-weighted pulse sequences and the administration of secretin for MR cholangiopancreatography (MRCP). Secretin improves pancreatic duct and side-branch delineation and the detection of anatomic variants such as pancreas divisum. It allows monitoring of pancreatic flow dynamics and evaluation of pancreatic exocrine function. Although contrast material--enhanced CT is still considered the standard of reference in severe acute pancreatitis and for the detection of calcifications in chronic pancreatitis, in patients referred for suspicion of pancreatic disease or with recurrent acute pancreatitis, MR imaging and secretin-enhanced MRCP are useful after unenhanced CT suggests the cause of disease. In advanced inflammatory disease, MR imaging and secretin-enhanced MRCP are useful for planning surgery or therapeutic endoscopy and for follow-up studies after therapy. MR imaging in combination with secretin-enhanced MRCP and MR angiography is useful in identifying pancreatic malignancies and in establishing resectability.

The aim of our study was to prepare in vitro a pineapple juice (PJ) solution labeled with a minimal gadolinium concentration working as a negative contrast agent in heavily T2-weighted imaging and to assess that solution in vivo as a negative oral contrast agent for magnetic resonance cholangiopancreatography (MRCP). Three PJs were compared in vitro according to their T2. Increasing concentrations of gadolinium (Gd)-DOTA in PJ were assessed in vitro for T2 reduction. Single-shot turbo spin echo T2-weighted MR cholangiopancreatograms were obtained for 35 patients with suspected biliopancreatic duct disease, before and after ingestion of the PJ/Gd-DOTA solution. Signal intensity (SI) measurements of gastroduodenal lumens, pancreatobiliary ducts, and image quality scores were obtained systematically before and after contrast ingestion. The in vitro selected Gd-DOTA concentration in the PJ was 2.76 mmol/l. Ingestion of 180 ml of PJ labeled with 1 ml of Gd-DOTA eliminated efficiently the gastroduodenal SI in MRCP, improving significantly the rates of complete visualization of the pancreatobiliary ducts (P<0.01) and the MRCP image quality scores (P<0.05). All patients easily ingested the contrast solution and found the solution palatable. PJ labeled with gadolinium constituted an efficient and convenient negative oral contrast agent for MRCP.

Although the diagnostic performances of US and multi-detector row CT are comparable, more inconclusive images were obtained with US.