Development of contrast-enhanced virtual MR cholangioscopy: a feasibility study

The purpose of this study was to examine the feasibility of contrast-enhanced virtual MR cholangioscopy (CE VMRC). Intraluminal views of the extrahepatic biliary tree were generated in ten patients undergoing abdominal MRI post mangafodipir trisodium administration employing coronal 2.5-mm 3D fast low-angle shot (FLASH) images (TR 6.8 ms, TE 2.3 ms, matrix 195 x 512) with fat saturation and a commercially available software. Contrast-enhanced VMRC was compared with single-shot turbo spin-echo T2-weighted MR cholangiography (T2 MRC) in terms of ductal visualization and artifact presence, utilizing a five-point grading scale. Four anatomic segments were evaluated: the intra- and extra-pancreatic segment of the common bile duct (CBD), and the cystic duct and the area of hepatic duct bifurcation. Both CE VMRC and T2 MRC depicted 38 of 40 segments. There were no significant differences between CE VMRC and T2 MRC in ranking ductal segments visualization (p=0.27). The high contrast between intraluminal fluid and extraluminal tissues facilitated the generation of endoscopic views. Contrast-enhanced virtual MR cholangioscopy is a feasible technique providing endoscopic views of the CBD. Initial results show correlation of CE VMRC with projectional MR cholangiography. (orig.)