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Anterior calcarine sulcus

The anterior calcarine sulcus is the anterior segment of the calcarine sulcus, a prominent medial cortical sulcus of the occipital lobe. It forms a major anatomical landmark of the primary visual cortex and separates the cuneus superiorly from the lingual gyrus inferiorly.

This region is of particular importance in neuroanatomy, functional neuroimaging, epilepsy evaluation, and localization of visual field deficits.

Synonyms

  • Anterior calcarine fissure

  • Anterior calcarine cortex region (functional context)

Location

  • Situated on the medial surface of the occipital lobe

  • Represents the anterior portion of the calcarine sulcus

  • Extends posteriorly from the parieto-occipital sulcus

  • Runs horizontally and slightly downward

  • Forms the medial boundary between the cuneus (superiorly) and lingual gyrus (inferiorly)

  • Located superior to the splenium of the corpus callosum

MRI appearance

T1-weighted images:

  • Normal sulcus: Well-defined cortical indentation with gray–white matter contrast

  • Cortex: Intermediate signal intensity

  • White matter: Higher signal relative to cortex

T2-weighted images (including 3T MRI):

  • Sulcus: Appears as a CSF-filled cleft with high signal intensity

  • Banks of sulcus: Normal cortical thickness and signal

  • 3T advantage: Improved delineation of sulcal depth and cortical layering

FLAIR:

  • Normal: CSF signal suppressed, sulcus appears dark

  • Cortex: Normal intermediate signal

Diffusion-weighted imaging (DWI):

  • Normal cortex: No diffusion restriction

Post-contrast T1-weighted images:

  • Normal: No enhancement of cortex or sulcal margins

CT appearance

Non-contrast CT:

  • Sulcus: CSF-density cleft on medial occipital surface

  • Cortex: Poor gray–white differentiation compared with MRI

Post-contrast CT:

  • Normal: No enhancement

MRI image

MRIAnterior calcarine sulcus axial anatomy image -img-00000-00000