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Left lobe of liver

The left lobe of the liver is one of the two major anatomical lobes of the liver, separated from the right lobe by the falciform ligament on the diaphragmatic surface and by the left sagittal fissure (containing the ligamentum teres and ligamentum venosum) on the visceral surface. It extends across the midline into the left hypochondrium and epigastrium, forming a triangular shape. The left lobe is smaller than the right and is subdivided into segments II, III, and IV according to Couinaud’s classification. Segment IV (quadrate lobe) lies adjacent to the gallbladder fossa. The left lobe plays a critical role in hepatic metabolism, detoxification, and bile production, and is commonly involved in partial hepatectomy and liver transplantation (left lobe graft).

Synonyms

  • Lobus hepatis sinister

  • Sinistral lobe of liver

  • Left hepatic lobe

Function

  • Contributes to bile production and secretion

  • Performs detoxification and metabolism of nutrients, drugs, and toxins

  • Involved in glycogen storage and glucose regulation

  • Supports protein synthesis and coagulation factor production

  • Plays a role in immunological defense through Kupffer cells

Arterial Supply

  • Supplied by the left hepatic artery, a branch of the proper hepatic artery (from the common hepatic artery of the celiac trunk)

Venous Drainage

  • Portal inflow via the left portal vein

  • Hepatic venous outflow primarily through the left hepatic vein, draining into the inferior vena cava

Nerve Supply

  • Parasympathetic innervation: from the anterior vagal trunk (left vagus nerve)

  • Sympathetic innervation: from the celiac plexus

  • Provides autonomic regulation of hepatic blood flow and bile secretion

MRI Appearance

T1-weighted images:

  • Left lobe parenchyma demonstrates homogeneous intermediate signal intensity

  • Fatty infiltration increases signal (hyperintense), while fibrosis decreases it (hypointense)

  • Vessels appear as signal voids unless contrast is used

T2-weighted images:

  • Normal parenchyma shows mildly hyperintense signal relative to muscle

  • Cysts and fluid collections appear bright hyperintense

  • Fibrosis, iron deposition, or cirrhosis appear hypointense

STIR (Short Tau Inversion Recovery):

  • Suppresses fat, highlighting edema, inflammation, or lesions

  • Pathology such as tumors or abscesses appears hyperintense against suppressed fat background

T1 Post-Contrast (Gadolinium-enhanced):

  • Left lobe enhances homogeneously in arterial and portal venous phases

  • Focal lesions show characteristic enhancement patterns (e.g., hemangiomas, HCC, metastases)

  • Useful for vascular mapping and lesion characterization

CT Appearance

Non-contrast CT:

  • Parenchyma appears as homogeneous soft tissue density (slightly denser than muscle)

  • Fatty infiltration appears hypodense, calcifications or fibrosis appear hyperdense

Contrast-enhanced CT (CECT):

  • Arterial phase: left hepatic artery and branches opacify

  • Portal venous phase: parenchyma enhances uniformly, and lesions demonstrate specific enhancement patterns

  • Hepatic venous phase: left hepatic vein drains into the IVC, visible as enhancing outflow tracts

  • Excellent for evaluating vascular anatomy, cirrhosis, tumors, and preoperative mapping

MRI images

Left lobe of liver AXIAL CT image -img-00000-00000

MRI images

Left lobe of liver coronal CT image -img-00000-00000_00001

MRI images

Left lobe of liver MRI AXIAL IMAGE