Anatomic variations of the intrahepatic bile ducts: analysis of magnetic resonance cholangiopancreatography in 1011 consecutive patients.

OBJECTIVES: The aim of the study was to evaluate the frequency of anatomic variations of the hepatic duct bifurcation using magnetic resonance cholangiopancreatography (MRCP). METHODS: A total of 1,160 consecutive patients, referred to our department for MRCP due to suspected pancreatobiliary disease or before liver transplantation, were reviewed retrospectively. A total of 149 patients with less than optimal results due to imaging limitations or secondary differentiations of bile duct anatomy were excluded from the study. The final study population was composed of 1,011 cases. RESULTS: Of the 1,160 patients, 149 were excluded from the analysis. Typical biliary anatomy was observed in 79.4% of cases, but female potential living liver donors more frequently presented an anatomic variation. Typical anatomy was present in 75.7% of the females and 85.3% of the males (p < 0.05). Out of the remaining 1,011 patients, 208 (20.57%) were diagnosed with different levels of various anatomic variations of the intra- and extrahepatic biliary ducts. Of the 208 cases with diagnosed variations, 204 (98.07%) and 4 (1.92%) turned out to have 1 and 2 different variations, respectively. The trifurcation variant was observed in 81 cases (8.01%), while 73 subjects (7.23%) had an aberrant right biliary duct draining into the common hepatic duct. A right dorsocaudal branch draining into the left hepatic duct was present in 42 cases (4.15%). Four cases (0.4%) had 2 different variations and 8 (0.8%) had uncommon anatomic variations. CONCLUSIONS: Typical intrahepatic biliary anatomy is present in about 80% of the inhabitants of the Aegean region of Turkey, but anatomic variants seem to be more frequent in females as compared to males. Trifurcation was the most common anatomic variation in our study population. The presence of an aberrant right hepatic duct emptying into the common hepatic duct was the second most common observation amongst our findings.

Efficacy of high resolution magnetic resonance imaging in preoperative local staging of rectal cancer.

OBJECTIVE: To assess the efficacy of high-resolution magnetic resonance imaging (HRMRI) for preoperative local staging in patients with rectal cancer who did not receive preoperative radiochemotherapy. METHODS: In this retrospective study, 30 patients with biopsy proved primary rectal cancer were evaluated by HRMRI. Two observers independently scored the tumour and lymph node stages, and circumferential resection margin (CRM) involvement. The sensitivity, specificity, the negative predictive value and the positive predictive value of HRMRI findings were calculated within the 95% confidence interval. The area under the curve was measured for each result. Agreement between two observers was assessed by means of the Kappa test. RESULTS: In T staging the accuracy rate of HRMRI was 47-67%, overstaging was 10-21%, and understaging was 13-43%. In the prediction of extramural invasion with HRMRI, the sensitivity was 79-89%, the specificity was 72-100%, the PPV was 85-100%, the NPV was 73-86%, and the area under the curve was 0.81-0.89. In the prediction of lymph node metastasis, the sensitivity was 58-58%, the specificity was 50-55%, the PPV was 43-46%, and the NPV was 64-66%. The area under the curve was 0.54-0.57. When the cut off value was selected as 1 mm, the sensitivity of HRMRI was 38-42%, the specificity was 73-82%, the PPV was 33-42%, and NPV was 79-81% in the prediction of the CRM involvement. The correlation between the two observers was moderate for tumour staging, substantial for lymph node staging and predicting of CRM involvement. CONCLUSION: Preoperative HRMRI provides good predictive data for extramural invasion but poor prediction of lymph node status and CRM involvement. CONFLICT OF INTEREST: None declared.