Ultrasonographic anatomy of the caudate lobe.

The caudate lobe, like the other segments and lobes of the liver, can be defined anatomically as well as pathologically utilizing gray-scale ultrasonography. It is anatomically distinct from the left and right lobes as it has its own portal veins, hepatic arteries, hepatic veins, and bile ducts. Sonographically the limits of the caudate lobe can be defined using readily identifiable vascular landmarks such as the proximal left portal vein anteriorly, the inferior vena cava posteriorly, and the main portal vein inferiorly A wide variety of pathologic conditions that affect the caudate lobe, including cirrhosis, infection, and neoplastic lesions, can be demonstrated by ultrasonography.