Interactive magnetic resonance cholangiography (MRC) with adaptive averaging

PURPOSE: To implement and evaluate a technique for adaptively averaging 2D magnetic resonance cholangiography (MRC) images obtained using an interactive imaging system with a view to improving image quality at reduced fields of view (FOVs).

MATERIALS AND METHODS: Images were obtained using an interactive implementation of a single-shot half-Fourier rapid acquisition with relaxation enhancement (RARE) technique. Software was developed for adaptively averaging images, and an evaluation was performed in a phantom and a cohort of 10 patients referred for standard MRC. Adaptively averaged and standard single-shot MRC images were evaluated with respect to their ability to demonstrate the common bile duct and main left and right intrahepatic duct branches.

RESULTS: In all patient studies there was no difference in the ability of either the adaptive technique or the standard single-shot method to demonstrate the common bile duct and the main left and right intrahepatic duct branches. However, in seven of the 10 patient studies the adaptive technique provided better visualization of the peripheral bile duct system (P = 0.035; sign test). There was no difference in the diagnostic confidence of the two techniques (P = 0.32, Wilcoxon signed-rank test).

CONCLUSION: Adaptive averaging of MRC images obtained using an interactive imaging paradigm significantly improves visualization of peripheral intrahepatic ducts.