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Lateral frontobasal artery

The lateral frontobasal artery, also known as the orbitofrontal artery, is an important cortical branch of the anterior cerebral artery (ACA). It predominantly supplies blood to the lateral and inferior aspects of the frontal lobe, specifically the orbitofrontal cortex. Due to its location and territory, it plays a critical role in supporting functions associated with behavior, decision-making, and olfaction. Its identification on imaging is essential, especially in the context of ischemic stroke or vascular malformations in the frontal lobe.

Synonyms:

  • Lateral frontobasal artery

  • Orbitofrontal artery

  • Orbitofrontal branch of the anterior cerebral artery (ACA)

  • Arteria orbitofrontalis (Latin)

Origin and Course:

  • Origin:

    • Arises from the A2 segment of the anterior cerebral artery, usually just distal to the anterior communicating artery.

  • Course:

    • Passes anterolaterally, running along the inferior (orbital) surface of the frontal lobe.

    • Travels parallel to the olfactory tract and the gyrus rectus.

    • Supplies the lateral orbital gyri and parts of the inferior frontal gyrus.

    • May anastomose with small branches from the middle cerebral artery (MCA) on the basal surface of the frontal lobe.

Function / Vascular Territory:

  • Supplies blood to:

    • Lateral and inferior portions of the orbitofrontal cortex (basal frontal lobe).

    • Part of the inferior frontal gyrus, especially the orbital gyri.

    • Involved in perfusion of brain regions responsible for decision-making, emotional regulation, olfaction, and aspects of personality.

MRI Appearance:

  • Best visualized on high-resolution, contrast-enhanced MR angiography (MRA).

  • Seen as a small vessel branching off the ACA, curving anterolaterally towards the base of the frontal lobe.

  • On conventional MRI sequences, its territory can be inferred if there is infarction or abnormal perfusion in the lateral orbitofrontal region.

  • May be involved in acute ischemia presenting as restricted diffusion in the orbitofrontal cortex.

CT Appearance:

  • Not usually visualized on non-contrast CT due to its small caliber.

  • CT angiography (CTA) can show it as a tiny branch of the ACA, best seen in thin-slice, high-resolution images.

  • Indirect signs such as hypodensity in the orbitofrontal cortex may suggest its involvement in the case of infarction.

  • In the context of subarachnoid hemorrhage, it may be a source if an aneurysm arises near its origin.

MRI images

Lateral frontobasal (orbitofrontal) artery coronal 3t image