Feasibility of 3D navigator-triggered magnetic resonance cholangiopancreatography with combined parallel imaging and compressed sensing reconstruction at 3T.

PURPOSE To assess the feasibility of 3D navigator-triggered magnetic resonance cholangiopancreatography (MRCP) with combined parallel imaging (PI) and compressed sensing (CS). MATERIALS AND METHODS With Institutional Review Board approval, 30 consecutive patients who underwent MRCP for suspected pancreaticobiliary disease were prospectively recruited. All patients underwent 3D navigator-triggered MRCP with conventional PI alone, and with combined PI and CS using a 3T machine. The acquisition time and relative duct-to-periductal contrast ratios (RCs) at three biliary segments were quantitatively compared between the two MRCP methods. Qualitative image parameters were independently evaluated by two blinded radiologists, and were compared between two methods using the Wilcoxon signed-rank test. RESULTS The mean acquisition time of MRCP with combined PI and CS (131.87 ± 33.60 sec) was significantly shorter compared with that of MRCP with PI (253.63 ± 56.08 sec; P < 0.001). The RC obtained using MRCP with combined PI and CS at two segments was slightly lower compared to that obtained using MRCP with PI (P = 0.007 and 0.002). Both reviewers found no significant differences in duct visualization, overall image quality, and degree of artifacts between the two methods (P ≥ 0.063; P = 0.637; and P = 0.752, respectively). Lesion conspicuity and confidence in duct abnormalities were comparable between two MRCP methods in both readers (P = 0.564 and P > 0.999). CONCLUSION Combined PI and CS reconstruction is feasible for 3D navigator-triggered MRCP, providing image quality comparable to that of MRCP with PI alone, in about half the acquisition time. LEVEL OF EVIDENCE 2 Technical Efficacy: Stage 1 J. Magn. Reson. Imaging 2017;46:1289-1297.