Collateral branches IPMTs: Secretin-enhanced MRCP

Recently, the fantastic evolution of imaging modalities (especially MR, MDCT, EUS) has raised many issues regarding the correct classification of smaller and smaller lesions, their preoperative evaluations, and indications of most appropriate treatment. However, it is still debated which technique should be employed for the diagnosis and the follow-up of intraductal papillary mucinous tumours (IPMTs). Despite the superb spatial resolution of MDCT, nowadays most of the authors agree on considering MR with magnetic resonance cholangiopancreatography (MRCP) the imaging modality of choice in studying IPMTs. In particular, MRCP is rapid, non-invasive, and accurate in detecting, localizing, and correctly classifying IPMT. The diagnostic performance of MRCP is even improved after the introduction of secretin stimulation. In fact, dynamic MRCP studies after secretin administration, besides facilitating the depiction of the structural characteristics of the lesions, make easier the detection of the communicating duct of branch duct IPMTs with the main pancreatic duct, especially if the newest high resolution 3D heavily T2-weighted sequences are utilized. Secretin stimulation is also useful in the demonstration of early changes of associated chronic pancreatitis. Consequently, we believe that secretin-enhanced MRCP is the most suitable imaging modality in the diagnosis and follow-up of IPMTs of the collateral branches.