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Polar frontal artery

The polar frontal artery is a small but clinically significant branch of the anterior cerebral artery, supplying the most anterior portions of the frontal lobes, particularly the frontal pole region. It plays an essential role in vascularizing the cortical areas involved in higher cognitive functions. Its identification on imaging, though sometimes challenging due to its size and anatomical variability, can be important in surgical planning and the assessment of cerebrovascular diseases.

Synonyms

  • Frontopolar artery

  • Polar artery of the frontal lobe

  • Polar branch of the anterior cerebral artery (ACA)

  • Rami polares frontales (Latin)

Origin and Course

  • Most commonly arises from the A2 segment (post-communicating segment) of the anterior cerebral artery (ACA), though it can sometimes originate from the A1 segment or from the callosomarginal artery.

  • The artery courses anteriorly and superiorly toward the frontal pole (the most anterior part of the frontal lobe).

  • Typically, it runs parallel or slightly above the genu of the corpus callosum.

  • It may give off small cortical branches that supply the most rostral portions of the superior, middle, and inferior frontal gyri.

  • There can be significant anatomic variability; sometimes, the polar frontal artery is duplicated or even absent.

Function / Vascular Territory

  • Supplies the frontal pole (the anterior tip of the frontal lobe).

  • Perfuses parts of the superior, middle, and inferior frontal gyri.

  • Plays a role in nourishing cortical regions responsible for executive function, decision making, and aspects of personality.

MRI Appearance

  • On MR angiography (MRA), the polar frontal artery appears as a small, thin-caliber vessel arising from the ACA and projecting toward the anterior interhemispheric fissure and the frontal pole.

  • It may not always be well-visualized on standard-resolution MRA, especially if it is small or hypoplastic.

  • High-resolution 3D-TOF MRA may improve its visualization.

  • No abnormal MRI signal is typically associated with the vessel itself, but infarction or ischemia in its territory would show cortical diffusion restriction and signal change in the frontal pole.

CT Appearance

  • Not typically visualized on non-contrast CT due to its small size.

  • May be seen on CT angiography (CTA) as a fine branch off the ACA running toward the frontal pole.

  • Infarction in its territory may result in focal hypoattenuation in the anterior frontal lobe cortex on CT in the setting of acute ischemia.

  • The artery is more reliably assessed with post-contrast or high-resolution CTA imaging, but often not separately described unless specifically evaluated.

MRI images

Polar frontal artery MRI T2 sagittal image

MRI images

Polar frontal artery MRI TOF axial image

CT image

Polar frontal artery ct image