Liver Anatomy Tutorial Overview

In the past, liver resections were made according to what could be told about liver segment anatomy from the surface view. This has several drawbacks. First, anatomic variations may produce errors in identifying the vascular inflow, outflow, and biliary drainage of individual liver segments, thus opening the possibility of leaving non-viable tissues. Second, exact location of tumor relative to the vessels that outline the segments is difficult to determine from surface views and often precise resections cannot be done (i.e. more liver is taken than is necessary).

This has led to the use of the Couinaud classification of liver anatomy [Couinaud] which divides the liver into eight independent segments each with its own vascular inflow, outflow, and biliary drainage. Resections along these planes diminishes the chances of leaving non-viable tissue or damaging viable tissue. [Gazelle].

The purpose of this tutorial is to:

Help participants learn the Couinaud classification of liver segments using rotating maximum intensity projections and shaded-surface views of reconstructed 3-D data sets acquired from contrast-enhanced spiral CT examinations of normal livers.

Use the concepts learned from the 3-D CT data to help sonologists and surgeons learn to define the Couinaud segments using ultrasound, a modality which can be used intraoperatively.

Fig 1-1Anterior and posterior view of liver showing 3-dimensional reconstructions of helical CT scan data in shaded surface projections which have been segmented according to the Couinaud classification (dotted line represents the course of the portal vein which is sometimes used to to divide segment IV into segments IVa and IVb).

Fig 1-2 Shaded-Surface 3D reconstructions of the liver segments viewed in the transverse plane at the level of the rostral part of the liver and inferiorly from the caudal surface.

Last modified: Wed Jun 2 11:48:05 CDT