In helical dynamic computed tomography (CT), images are rapidly and continuously acquired during a single breath hold, resulting in improved spatial resolution and the elimination of motion artifacts. Multi–detector row CT is the latest advancement in CT technology and is now more readily available than in the past. The increased speed and narrower collimation of multi–detector row CT, together with the use of intravenously administered contrast material, improves visualization of the portal vein. Among the most common variants of the portal vein are trifurcation, right anterior portal branch arising from the left portal vein and right posterior portal branch arising from the main portal vein. Agenesis of the right or left portal vein is the most frequently reported congenital anomaly