MR cholangiopancreatography: comparison between two-dimensional fast spin-echo and three-dimensional gradient-echo pulse sequences.
The purpose of our study was to perform a prospective comparative analysis of three-dimensional (3D) steady-state free precession (SSFP) and two-dimensional (2D) fast spin-echo (FSE) imaging in the evaluation of 26 patients with suspected bile duct obstruction. SSFP and highly T2-weighted FSE sequences were obtained for each patient in multiple planes. Both sequences were reviewed independently and results were compared with findings from direct cholangiography (n = 17) or from a combination of sonography and CT (n = 9). The extrahepatic bile duct [EHBD] and intrahepatic bile duct [IHBD] were dilated in 32% and 54% of patients, respectively. The EHBDs were visualized in 44% of patients with SSFP, versus in 96% with FSE. One or more IHBD segments were seen in 42% of the SSFP sequences and in 100% of the FSE sequences. A portion of, or the entire, pancreatic duct was seen in 23% of the SSFP sequences and in 65% of the FSE sequences. Our findings lead us to conclude that T2-weighted FSE sequences are superior to SSFP sequences in visualizing the biliary tree and pancreatic duct and that they should replace gradient-echo sequences in MR cholangiopancreatography.