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Umbilical vein

In the adult, the “umbilical vein” no longer functions as a vein. After birth it closes (obliterates) and becomes a fibrous cord called the round ligament of the liver (ligamentum teres hepatis).

Origin

  • Before birth (fetal life): the umbilical vein originates at the placenta and carries oxygenated, nutrient-rich blood toward the fetus.

  • After birth (adult): once the umbilical cord is clamped, flow stops and the vessel fibroses. Its adult remnant is the ligamentum teres hepatis.

Course (adult anatomy)

  • The fibrous remnant runs from the umbilicus upward in the free edge of the falciform ligament.

  • It travels to the inferior surface of the liver, heading toward the region of the left portal vein (near the porta hepatis).

  • In short: umbilicus → falciform ligament → liver.

MRI Appearance

T1-weighted images:

  • Fetal umbilical vein lumen: intermediate-to-low signal

  • Postnatal remnant (ligamentum teres): low signal fibrous band along falciform ligament

T2-weighted images:

  • Fetal/neonatal patent umbilical vein: typically a flow void (dark lumen) on routine T2 FSE/SSFSE due to flowing blood. Slow or turbulent flow can make the lumen intermediate rather than bright. Wharton’s jelly in the cord remains T2 hyperintense, which helps the dark vessel stand out.

  • Postnatal remnant (ligamentum teres): a uniformly low-signal fibrous band along the falciform ligament; adjacent edema/inflammation (if present) appears T2 hyperintense.

STIR:

  • Suppresses fat, improving visualization of the umbilical vein against surrounding abdominal fat

  • Fibrotic remnant remains dark, whereas perivascular edema (in pathology) appears hyperintense

T1 Fat-Saturated (Pre-contrast):

  • Fetal umbilical vein lumen shows intermediate signal

  • Distinguishes vein course from suppressed fat planes

T1 Fat-Saturated Post-Contrast (Gadolinium):

  • Enhances fetal umbilical vein and intrahepatic branches in utero or neonatal imaging

  • Postnatal remnant (ligamentum teres) does not enhance significantly

MRI Non-Contrast 3D Imaging:

  • Useful for mapping fetal circulation, ductus venosus, and portal connections

  • Postnatally, demonstrates the fibrous ligamentum teres in 3D reconstructions

CT Appearance

CT Pre-Contrast:

  • Fetal vein: visualized as a low-density vascular channel in cord and abdomen

  • Postnatal: ligamentum teres appears as a fibrous soft-tissue band within falciform ligament

CT Post-Contrast:

  • Fetal umbilical vein enhances brightly as a vascular structure entering the left portal vein

  • Postnatal remnant remains non-enhancing fibrous tissue

  • In portal hypertension, may re-canalize and appear as an enhancing collateral

CT Venography (fetal or neonatal):

  • Maps course of umbilical vein, ductus venosus, and portal system

  • Detects vascular anomalies, recanalization, or collateral formation in adults with cirrhosis

MRI image

umbilical vein MRI coronal anatomy image -img-00000-00000

MRI image

umbilical vein MRIsagittal anatomy image -img-00000-00000

CT image

umbilical vein CT axial anatomy image -img-00000-00000