Ultrasound diagnosis of masses elevating the inferior vena cava.

The inferior vena cava is frequently involved in diseases of the abdomen and retroperitoneum. Critical evaluation of this vessel's course can greatly help in determining the origin of an adjacent mass. Ultrasound was used to divide the inferior vena cava into three parts. A vector type principle was applied to masses anteriorly displacing the vena cava, and the location of the mass was compared to the particular portion of the cava most affected. With this approach, it was often possible to determine what structures a mass may have originated from.