Segmental anatomy of the liver: a sonographic approach to the Couinaud nomenclature.

The authors developed a simplified description of the segmental anatomy of the liver on the basis of the Couinaud nomenclature. This approach was demonstrated with normal in vivo sonographic images and livers dissected in corresponding planes. The branches of the portal vein, which lead to the center of individual segments, are used as key landmarks in the determination of segmental location. The hepatic veins, ligaments, fissures, and gallbladder are used as external boundaries of the segments.