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Umbilical artery

The umbilical arteries are paired vessels that play a vital role in fetal circulation, transporting deoxygenated blood from the fetus to the placenta. They arise from the internal iliac arteries in the fetus and course along the anterolateral abdominal wall to reach the umbilical cord.

After birth, the distal portions of the umbilical arteries become obliterated, forming the medial umbilical ligaments, which are fibrous cords seen on the internal aspect of the anterior abdominal wall. However, the proximal segments remain patent in the adult and continue to give rise to superior vesical arteries, supplying the upper portion of the urinary bladder.

Clinically, the umbilical artery is important in fetal Doppler studies, where it is used to assess placental blood flow and fetal well-being. In adults, its remnant course is an important surgical landmark in pelvic and bladder surgeries.

Synonyms

  • Arteria umbilicalis

  • Fetal umbilical vessel

  • Medial umbilical ligament (postnatal remnant)

Function

  • Fetus: carries deoxygenated blood from fetus to placenta

  • Adult: proximal patent portion supplies the urinary bladder via superior vesical arteries

  • Surgical landmark: medial umbilical ligament guides pelvic dissections

MRI Appearance

T1-weighted images:

  • In fetus: umbilical artery lumen appears as a flow void within cord structures

  • In adult: proximal patent segment visible as small hypointense flow void near bladder base; distal fibrous remnant appears as low-signal cord (medial umbilical ligament)

T2-weighted images:

  • Normal patent lumen: signal void

  • Medial umbilical ligament (obliterated segment): low signal intensity band along anterior abdominal wall

  • Perivascular edema or inflammation appears hyperintense

STIR:

  • Suppresses fat, making the artery or ligament more conspicuous

  • Helps detect fibrosis, hematoma, or infection along ligament

T1 Fat-Suppressed Post-Gadolinium:

  • Patent proximal portion enhances brightly with gadolinium

  • Medial umbilical ligament remains non-enhancing (fibrous tissue)

  • Useful for identifying tumor encasement, vascular anomalies, or bladder pathology

MRA Pelvis with Gadolinium:

  • Demonstrates origin from internal iliac artery, proximal patent portion, and bladder branches

  • Detects vascular anomalies, stenosis, or tumor-related neovascularity

  • In fetuses: highlights umbilical artery within the cord and placenta

CT Appearance

Non-contrast CT:

  • Adult: proximal segment may be visible as a small tubular density near bladder base

  • Distal obliterated segment (medial umbilical ligament): fibrous band along anterior abdominal wall

CT Post-Contrast:

  • Enhances the patent proximal portion from internal iliac artery

  • Distal medial umbilical ligament remains unenhanced

  • Useful in pelvic surgical mapping or trauma

CTA (CT Angiography):

  • Provides excellent visualization of origin, course, and branches of patent segment

  • Maps relationship to bladder and anterior abdominal wall

  • In trauma: detects active extravasation from pelvic injuries

  • In fetus: umbilical arteries within cord can be visualized when contrast is used in maternal-fetal studies (rare in practice, replaced by Doppler US and MRI)

CT VRT 3D image

Umbilical artery CT 3D VRT anatomy image

CT image

Umbilical artery CT axial image MRI axial anatomy image-img-00000-00000

MRI image

Umbilical artery MRI axial image MRI axial anatomy image-img-00000-00000