Topics

Topic

design image
Quadrate lobe of liver

The quadrate lobe of the liver is a small, anatomically defined lobe located on the visceral (inferior) surface of the liver, between the gallbladder fossa (right) and the fissure for the ligamentum teres (left), with its posterior boundary marked by the porta hepatis.

Although traditionally described as a distinct lobe, in the modern Couinaud classification of hepatic segments, the quadrate lobe corresponds to segment IVb (inferior medial segment of the left lobe). It is functionally part of the left liver despite its position near the midline.

The quadrate lobe is clinically important because of its location adjacent to the porta hepatis, gallbladder, and ligamentum teres, making it a critical landmark in hepatobiliary surgery, liver transplantation, and radiology. It is a frequent site for metastatic disease, cholangiocarcinoma, and gallbladder carcinoma extension.

Synonyms

  • Segment IVb of liver (Couinaud classification)

  • Inferior medial segment of left lobe

  • Classical quadrate lobe

Function

  • Participates in bile secretion and metabolism as part of the left hepatic system

  • Contributes to detoxification, glycogen storage, and protein synthesis

  • Provides a key surgical landmark for gallbladder and hepatic hilar operations

Nerve Supply

  • Autonomic innervation from the hepatic plexus, derived from the celiac plexus (sympathetic) and vagal trunks (parasympathetic)

Arterial Supply

  • Supplied by the left hepatic artery (branch of proper hepatic artery)

  • Small accessory branches may arise from the middle hepatic artery

Venous Drainage

  • Hepatic veins from the quadrate lobe drain into the left and middle hepatic veins, which then enter the inferior vena cava

  • Portal venous inflow from the left branch of the portal vein

MRI Appearance

T1-weighted images:

  • Parenchyma appears as intermediate signal intensity, similar to the rest of the liver

  • Ligamentum teres appears hypointense, defining medial boundary

T2-weighted images:

  • Parenchyma appears as mildly hyperintense relative to T1

  • Pathology such as edema, cysts, or tumors appear hyperintense

STIR:

  • Suppresses fat, accentuating lesions, edema, or infiltrative processes

  • Useful for detecting inflammatory or neoplastic pathology

T1 Fat-Saturated (Pre-contrast):

  • Quadrate lobe parenchyma shows intermediate signal intensity, distinct from suppressed fat

  • Lesions (tumors, cysts) stand out more clearly

T1 Fat-Saturated Post-Contrast (Gadolinium):

  • Normal parenchyma enhances homogeneously in the portal venous phase

  • Lesions demonstrate arterial hyperenhancement, portal washout, or delayed enhancement depending on pathology (e.g., HCC, metastases)

MRI Non-Contrast 3D Imaging:

  • Provides volumetric data for surgical planning, transplant assessment, and segmental mapping

CT Appearance

CT Pre-Contrast:

  • Quadrate lobe appears isoattenuating to other hepatic segments

  • Calcifications, hemorrhage, or fat infiltration may be detected

CT Post-Contrast:

  • Homogeneous enhancement during portal venous phase in normal parenchyma

  • Lesions (HCC, metastasis, cholangiocarcinoma) appear as arterial phase hyperenhancing or hypoenhancing masses

  • Important for surgical mapping and staging

CT image

Quadrate lobe of the liver ct axial anatomy image-img-00000-00000

CT image

Quadrate lobe of the liver CT axial image

MRI image

Quadrate lobe of the liver MRI axial anatomy image-img-00000-00000

MRI image

Quadrate lobe of the liver MRI axial anatomy image-img-00000-00000_00001