This article, by Itoh S et al , in the September issue of the AJR, shows how MDCT (using 4-slice) can depict the pancreatico-biliary ductal anatomy exceptionally well. This allows the diagnosis of the abnormal channel, especially in patients with choledochal cysts.
Because of the superior spatial resolution with multi-slice scanners, it is highly likely that the results with MSCT for this particular purpose, will be better than MRCP.
We have had a similar experience on our 64-slice CT. This is a child with a choledochal cyst (Fig. 1), where the abnormal pancreatico-biliary channel is extremely well seen (Figs. 2, 3).