MR imaging of the pancreas: a pictorial tour.

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.