Role of multidetector computed tomography (MDCT) in evaluation of main and right portal vein branching patterns and its clinical significance

Abstract

Introduction: Knowledge of the normal portal vein anatomy and its variations is imperative for various hepatic interventional procedures and liver surgeries like during creation of transjugular intrahepatic portosystemic shunt (TIPS), partial hepatectomy and Liver transplantation. Aims and Objective: The aim of our study was to determine and analyse the spectrum of variations in the main and right portal vein anatomy and their prevalence in Indian population using MDCT. Materials and Methods: Triple phase abdomen CT of 688 patients done on a 64 slice MDCT scanner between February 2012 and March 2014, were retrospectively evaluated by two radiologists independently. Out of these, 500 patients met the inclusion criteria. Axial images of portal and venous phase along with the maximum-intensity-projection and volume rendered images were reviewed and branching patterns of main and right portal vein were recorded. Results: Normal portal vein anatomy was present in 67% of the patients. Main portal vein (MPV) variations were seen in 15.2% of the patients. The most common variant was Z-type pattern (7.6%). Next common was trifurcation pattern (6.6%). Right portal vein (RPV) variations were seen in 17.8% of patients and the most common pattern was early segmental branching (6.8%). Other RPV branching variations were RPV trifurcation (3.6%), RPV quadrification (3.6%), and superior-inferior division (1.4%). Miscellaneous branching variations of RPV were seen in 2.4% of all patients. Conclusion: Variations in the main portal vein and right portal vein anatomy are quite common and can be clearly detected with MDCT. Keywords: Portal vein branching, Portal vein MDCT, MPV variation, RPV variation.