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Artery to angular gyrus anatomy

The artery to the angular gyrus is a terminal cortical branch of the posterior cerebral circulation, supplying the angular gyrus—a key region at the parietal-temporal-occipital junction involved in language, number processing, spatial cognition, and memory. Its precise vascularization is vital for higher cognitive functions, and its compromise may lead to profound neurological deficits. Recognition of this vessel and its territory on imaging is crucial for clinicians assessing cerebrovascular events, neurodegenerative disorders, and planning neurosurgical interventions.

Synonyms

  • Angular artery (when referring to the cerebral branch, not the facial artery)

  • Angular gyrus branch of the middle cerebral artery (MCA)

  • Posterior parietal artery (context dependent, but can refer to branches supplying this area)

Origin

  • Most commonly arises from the terminal branches of the middle cerebral artery (MCA), specifically the inferior division of the MCA.

  • Occasionally, small contributions from distal branches of the posterior cerebral artery (PCA) may supply this region.

  • Rare anatomical variants may exist, including accessory supply from leptomeningeal collaterals.

Course

  • The artery courses laterally from the insular region along the Sylvian fissure.

  • It continues over the superior temporal gyrus towards the parietal lobe.

  • Reaches and supplies the angular gyrus, located at the posterior end of the superior temporal sulcus, near the junction of the temporal, parietal, and occipital lobes.

  • The artery ramifies into smaller branches over the cortical surface of the angular gyrus.

Function

  • Supplies oxygenated blood to the angular gyrus and adjacent cortical regions.

  • Supports language comprehension, reading and writing, arithmetic processing, spatial orientation, memory retrieval, and aspects of attention and perception.

  • Ischemia or infarction in this vascular territory can result in Gerstmann syndrome (agraphia, acalculia, finger agnosia, left-right disorientation) and aphasic symptoms.

MRI Appearance

  • Normally, the artery to the angular gyrus is not visualized as a discrete structure on standard MRI sequences due to its small caliber.

  • On high-resolution MR angiography (MRA) or AI enhanced 3T images, distal branches of the MCA may be identified, with the cortical branches seen extending to the parietal convexity.

  • Acute infarcts in this vascular territory appear as areas of restricted diffusion (bright on DWI, dark on ADC) in the angular gyrus.

  • Chronic infarcts show cortical atrophy and encephalomalacia in the supplied area.

  • Perfusion MRI may show decreased perfusion in cases of vascular compromise.

CT Appearance

  • The artery itself is not visualized on non-contrast CT due to its small size.

  • CT Angiography (CTA) can occasionally demonstrate the distal MCA cortical branches; the artery to the angular gyrus may be inferred if the distal inferior MCA territory is opacified.

  • Acute infarct presents as loss of gray-white matter differentiation, cortical hypodensity, or subtle effacement of sulci in the angular gyrus region.

  • Chronic infarct appears as focal encephalomalacia or volume loss in the angular gyrus area.

MRI images

Artery to angular gyrus MRI 3T axial image

MRI images

Artery to angular gyrus MRI 3T coronal image