Hepatic segments (Couinaud classification)

Diagnosis

Hepatic segments (Couinaud classification)

History

The Couinaud classification describe the functional liver anatomy (preferred over morphological liver anatomy).

The middle hepatic vein also demarcates the true right and left lobes. The right lobe is further divided into an anterior and posterior segment by the right hepatic vein. The left lobe is divided into the medial and lateral segments by the left hepatic vein. The fissure for the ligamentum teres also separates the medial and lateral segments. The medial segment is also called the quadrate lobe. In the widely used Couinaud (or "French") system, the functional lobes are further divided into a total of eight subsegments based on a transverse plane through the bifurcation of the main portal vein. The caudate lobe is a separate structure which receives blood flow from both the right- and left-sided vascular branches.

I: Caudate

II: Superior subsegment of the lateral segment

III: Inferior subsegment of the lateral segment

IVa: Superior subsegment of the medial segment

IVb: Inferior subsegment of the medial segment

V: Inferior subsegment of the anterior segment

VI: Inferior subsegment of the posterior segment

VII: Superior subsegment of the posterior segment

VIII: Superior subsegment of the anterior segment