Choi et al. MATERIALS AND METHODS The database of our institution’s organ transplantation center relating to the period November 1999 to July 2002 was searched for LDLT donors. The 357 identified had un- dergone partial hepatic resection after selection on the ba- sis of an adequate technical study involving (1) two-phase dynamic CT for the evaluation of liver parenchyma, liver volume, and the anatomy of hepatic vessels; (2) Doppler US for the evaluation of liver parenchyma and the anato- my and status of hepatic vascular flow; (3) plain chest radi- ography to determine current thoracic disease. Liver was defined as ‘normal’ if there was neither a history nor clini- cal findings of hepatic or other systemic disease (based on laboratory, US, CT or pathological findings). All donors underwent intraoperative cholangiography to determine the presence or absence of anatomic variation in IHD branching patterns; the cholangiograms obtained were ade- quate in 308 donors, an ‘adequate’ image being defined as one in which there was opacification of every second-order IHD. Eight donors were excluded because of difficulty in determining the branching patterns of IHDs due to their in- complete opacification. Our eventual study group com- prised 300 donors, 229 men and 71 women aged 16 60 (mean, 30) years. For intraoperative cholangiography, a 3- to 5- Fr catheter was used prior to lobectomy or segmentectomy of the donor’s liver. After cholecystectomy and clamping of the proximal common bile duct, 25 30mL of meglumine, an ionic contrast material (Telebrix 30; Guerbet, France), was injected through the cystic duct to opacify the IHDs. Using a mobile X-ray imaging unit (Shimadzu MU-125M; Shimadzu, Tokyo, Japan), two anteroposterior plain radi- ographic images of the right upper abdomen were ob- tained. If these failed to depict all IHDs, additional antero- posterior images were acquired until the branching pattern of the IHDs was identified. Intraoperative cholangiograms were retrospectively eval- uated by two radiologists (T.K.K., J.W.C.), and a consensus was reached as to the to branching pattern of the right an- terior segmental duct (RASD), right posterior segmental duct (RPSD), and the presence or absence of a first-order branch of the left hepatic duct (LHD) and an accessory he- patic duct. In each subtype, we also measured the length of the first order branch of the right hepatic duct (RHD). RESULTS The branching patterns of IHDs were classified as one of seven types (Fig. 1). The anatomy of type 1 is typical, i.e. a common hepatic duct is formed by fusion of the RHD and Fig. 1. Schematic drawing of IHD anato- my. Type 1 is typical. Type 2 involves triple confluence, the simultaneous emp- tying of the RASD, RPSD and LHD into the CHD. In type 3, the RPSD drains anomalously, and in type 4, the RHD drains into the cystic duct. In type 5, an accessory duct is present, and in type 6, segments II and III drain individually into the RHD or CHD. Type 7 shows unclas- sified or complex variation. R=right hepatic duct, L=left hepatic duct, RA=right anterior segmental duct, RP=right posterior segmental duct, C=cystic duct, Acc=accessory duct 86 Korean J Radiol 4(2), June 2003