Coronal 2D MR cholangiography overestimates the length of the right hepatic duct in liver transplantation donors

Abstract

PURPOSE: To compare the length of the right hepatic duct (RHD) measured on rotatory coronal 2D MR cholangiography (MRC), rotatory axial 2D MRC, and reconstructed 3D MRC. MATERIALS AND METHODS: Sixty-seven donors underwent coronal and axial 2D projection MRC and 3D MRC. RHD length was measured and categorized as ultrashort (</=1 mm), short (>1-14 mm), and long (>14 mm). The measured length, frequency of overestimation, and the degree of underestimation between two 2D MRC sets were compared to 3D MRC. RESULTS: The length of the RHD from 3D MRC, coronal 2D MRC, and axial 2D MRC showed significant difference (p < 0.05). RHD was frequently overestimated on the coronal than on axial 2D MRC (61.2 % vs. 9 %: p < .0001). On coronal 2D MRC, four (6 %) with short RHD and one (1.5 %) with ultrashort RHD were over-categorized as long RHD. On axial 2D MRC, overestimation was mostly <1 mm (83.3 %), none exceeding 3 mm or over-categorized. The degree of underestimation between the two projection planes was comparable. CONCLUSION: Coronal 2D MRC overestimates the RHD in liver donors. We suggest adding axial 2D MRC to conventional coronal 2D MRC in the preoperative workup protocol for living liver donors to avoid unexpected confrontation with multiple ductal openings when harvesting the graft. KEY POINTS: * In living liver donors, RHD length influences the number of ductal openings. * Coronal 2D MRC overestimates the RHD length than does axial 2D MRC. * Adding axial 2D MRC to coronal 2D MRC may prevent overestimating RHD length.