Hepatic arterial anatomy: demonstration of normal supply and vascular variants with three-dimensional CT angiography.

Three-dimensional (3D) helical computed tomographic (CT) angiography is a promising method of determining vascular anatomy. This technique is useful in delineating the arterial anatomy of the liver, demonstrating the normal anatomy and vascular variants in a highly visual fashion. The "typical" hepatic arterial anatomy occurs in only 55% of the population, and numerous variants exist; the standard classification system for hepatic arterial anatomy includes 10 variations. After helical scanning, postprocessing with reconstruction algorithms such as shaded surface display and maximum-intensity projection provides highly graphic, easily understandable views of vascular anatomy. The 3D CT angiograms, with their global view of the anatomy and inherent advantage of volumetric rotation of the vascular system, are useful to surgeons and others with limited experience in interpreting axial anatomy. Determination of hepatic arterial anatomy with 3D CT angiography has already been shown to be clinically useful in patients being evaluated for liver transplantation.