Couinaud’s Liver Segments

Couinaud segments frontal view

Sonographically the liver is usually divided into right and left lobes . However the liver is divided into 8 functional segments with the Couinaud classification (pronounced kwee-NO). Each segment has it’s own vascular and biliary supply.

The liver is divided horizontally by the portal veins and vertically by the hepatic veins.

Segment I is the caudate lobe.

Segment II and III is the superior and inferior lateral left lobe.

Segment IV is subdivided into IVa and IVb, superior and inferior and is located between the left and middle hepatic veins.

Segment V is inferior to the portal plane between the middle and right hepatic veins.

Segment VI is below the portal plane lateral to segment V/right hepatic vein.

Segment VII is located superior to segment V above the portal plane medial to the right hepatic vein.

Segment VIII s lateral to segment VII, above the portal plane between the middle and right hepatic veins.

Sagittal

  • Liver Lt Lobe
  • Liver Left Lobe segments II and III
  • Caudate lobe segment I
  • Segment I,II and III
  • Liver w/Gallbladder
  • Segment IVb, V and VI
  • Rt Liver lobe
  • Segments V, VI, VII, VIII
  • RT Liver lobe and Kidney
  • Segments V, VI, VII, VIII
Sagittal segments

Transverse

  • Transverse Lt lobe anglig cephalad
  • Segments I, II, III, IVb and V
  • Transverse Left lobe Hepatic veins
  • Segments II, IVa and VII
  • Transverse Left lobe inferior
  • Segments I, III, IVb, V
  • Transverse superior Rt lobe
  • Segments IVa VII, and VIII
Transverse segments

Sources:

https://www.acr.org/-/media/ACR/Files/Clinical-Resources/LIRADS/Chapter-3–Liver-anatomy.pdf?la=en

https://www.researchgate.net/publication/331247944_Paediatric_liver_ultrasound_a_pictorial_essay

11 thoughts on “Couinaud’s Liver Segments”

    1. This needs to be corrected and trying to change the text as little as possible.

      Segment VII is located superior to segment VI above the portal plane and lateral to the right hepatic vein

      Segment VIII is medial to segment VII above the portal vein and between the middle and right hepatic veins.

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  3. Wow this is an amazing resource. I have referred my sonography students to this page for additional Liver Segment review material. Thanks for creating and sharing this!

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  5. Thank you so much! for all the information that you provide and for all the organs too!!! from this to vascular, pedis to everything!!! thanks!! =)

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