How do you identify liver segments on ultrasound?

The imaging of segments is done in eight steps: (1) identify lobes; (2) identify sectors (right and left portal fissures); (3) identify the plane of superior and inferior segments (transverse fissure/liver hilum); (4) identify left sagittal fissure and the liver ligaments; (5) identify caudate lobe (posterior to …

What is the Couinaud classification?

Couinaud classification. The Couinaud classification of liver anatomy divides the liver into eight functionally indepedent segments. Each segment has its own vascular inflow, outflow and biliary drainage. In the centre of each segment there is a branch of the portal vein, hepatic artery and bile duct.

What is segment 4a?

segment 4 (IV) lies between the left and middle hepatic veins; it is subdivided into 4a (IVa) (superior) and 4b (IVb) (inferior) subsegments. easy tip: 4a is above and 4b is below the portal plane. segment 4 includes the quadrate lobe.

How do you remember Couinaud segments?

The segments are represented by the following:

  1. segment 1: (caudate): the thumb, in the palm of the hand.
  2. segment 2: index finger proximal phalanx.
  3. segment 3: index finger middle phalanx.
  4. segment 4a: middle finger proximal phalanx.
  5. segment 4b: middle finger middle phalanx.
  6. segment 5: ring finger middle phalanx.

What is segment IVb?

The IVb segment (quadrate lobe) is demarcated on the visceral surface anteriorly by the inferior edge of the liver, on the right side by the gallbladder fossa, posteriorly by the porta hepatis, and on the medial side by the fissure for the ligamentum teres (Figures 14B and 14D).

Where is segment 4b of the liver?

The middle hepatic vein divides the liver into left and right lobes. The left hepatic vein divides the left lobe into lateral (2, 3) and medial (4a, 4b) segments. The right hepatic vein divides the right lobe into anterior (5, 8) and posterior (6, 7) segments.

What is Segment 3 of the liver?

The four segments of left liver are: I (caudate); II (left lateral superior); III (left lateral inferior); and IV (left medial) [subdivided into superior (IVa) and inferior parts (IVb) by Bismuth].

What is IVb of liver?