Topics

Topic

design image
Portal vein branch to liver segment I

The portal vein branch to liver segment I supplies the caudate lobe of the liver. Unlike other hepatic segments, the caudate lobe often has a dual blood supply, receiving branches directly from both the right portal vein and the left portal vein. These segment I branches penetrate the posterior aspect of the liver near the porta hepatis and distribute within the caudate parenchyma, ensuring independent perfusion.

Anatomically, this vascular arrangement explains the relative resistance of the caudate lobe to ischemia or cirrhosis, as it can maintain perfusion from either side. This also makes it a key site for caudate hypertrophy in cirrhosis and an important surgical consideration in caudate lobectomy, transplantation, and tumor resections.

Synonyms

  • Segment I portal vein branch

  • Caudate lobe portal branch

  • Portal supply of segment I

Function

  • Provides portal venous inflow to the caudate lobe

  • Maintains dual perfusion from both right and left portal veins

  • Plays a role in the relative sparing of caudate lobe in cirrhosis

  • Serves as a critical anatomical landmark in hepatic surgery and transplantation

MRI Appearance

T1-weighted images:

  • Segment I portal vein branches appear as flow voids (dark tubular structures) against intermediate liver parenchyma

  • Seen near the posterior hilum adjacent to the IVC

T2-weighted images:

  • Appear as flow voids surrounded by intermediate liver signal

  • Pathology (thrombus or tumor thrombus) shows intraluminal intermediate-to-high signal

STIR:

  • Fat suppression enhances visualization of segment I branches

  • Detects perivascular edema, inflammation, or tumor infiltration

T1 Fat-Saturated (Pre-contrast):

  • Lumen appears as intermediate signal intensity standing out against suppressed fat

  • Allows clear differentiation from surrounding hepatic tissue

T1 Fat-Saturated Post-Contrast (Gadolinium):

  • Portal vein branches enhance brightly and homogeneously during the portal venous phase

  • Useful in detecting stenosis, thrombosis, or neoplastic invasion

MRV (Magnetic Resonance Venography):

  • Provides a non-invasive 3D map of portal venous system, highlighting segment I branches from both right and left portal veins

  • Essential in pre-transplant evaluation, caudate lobectomy planning, and vascular anomaly detection

CT Appearance

CT Pre-Contrast:

  • Segment I portal branches appear as linear soft-tissue densities in caudate region, difficult to separate from liver parenchyma

CT Post-Contrast:

  • Branches opacify in portal venous phase, supplying the caudate lobe posterior to the hilum and near the IVC

  • Demonstrates dual origin from right and/or left portal vein

CTV (CT Venography):

  • Gold standard for detailed portal venous anatomy

  • 3D reconstructions highlight segment I portal branches and their dual supply

  • Indispensable for hepatic surgery, transplantation planning, and caudate lobe tumor resections

CT images

Portal vein branch to liver segment I CT axial image 1

CT images

Portal vein branch to liver segment I CT axial image