MR cholangiopancreatography: value of axial and coronal fast Spin-Echo fat-suppressed T2-weighted sequences

To compare axial and coronal fast Spin-Echo fat-suppressed T2-weighted sequences with three-dimensional (3D) maximum intensity projection (MIP) images in patients with suspected pancreaticobiliary obstruction.

MR cholangiopancreatography (MRCP) was performed in 108 consecutive patients with a non-breath-hold, fat-suppressed, 2D, heavily T2-weighted fast spin-echo sequence in coronal plane. Axial T1- and T2-weighted images were previously obtained. In addition, 3D reconstructions of the coronal images were analysed separately by using a MIP algorithm. Both two-dimensional (2D) (axial and coronal) and 3D MIP images were separately evaluated by two readers in conference and their results were compared with that of endoscopic retrograde cholangiopancreatography, percutaneous trans-hepatic cholangiography, surgery and/or imaging follow-up. Statistical analysis of 2D and 3D MRCP images in diagnosing the level and probable cause of pancreaticobiliary obstruction were separately calculated.

106/108 of MRCP examinations were judged diagnostic by the two reviewers for adequacy of visualisation of the biliary and pancreatic ducts. Sensitivity, specificity, positive predictive value, negative predictive value and global diagnostic accuracy of 2D (axial and coronal) and 3D MRCP images in diagnosing the pancreaticobiliary obstruction were 94 and 57%,, 95 and 93%, 97 and 92%, 91 and 60%, 94 and 72% respectively.

Our results do indicate a higher global accuracy for axial and coronal fast Spin-Echo fat-suppressed T2-weighted sequences versus 3D MIP images in diagnosis of the level and probable cause of pancreaticobiliary obstruction and stress the limitations of 3D images in depiction of small intraductal pathology such as calculi and biliary neoplastic.