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Middle occipital gyrus

The Middle Occipital Gyrus (MOG) is a prominent brain structure located in the lateral aspect of the occipital lobe. It lies between the superior and inferior occipital gyri, extending posteriorly from the parieto-occipital sulcus towards the occipital pole. The MOG plays a crucial role in visual processing, particularly in the interpretation of visual stimuli and spatial orientation. Anatomically, it is easily identified on both MRI and CT scans, making it an important landmark in neuroimaging and neurosurgery.

Synonyms

  • Middle occipital convolution

  • MOG

  • Gyrus occipitalis medius (Latin)

  • Lateral occipital gyrus (less commonly, sometimes overlaps in usage)

Arterial Supply

  • Primarily supplied by branches of the posterior cerebral artery (PCA), especially the calcarine branch and the parieto-occipital artery.

  • In some cases, minor contributions from the middle cerebral artery (MCA) via its occipital branches.

Venous Drainage

  • Venous drainage is mainly via the superior sagittal sinus and transverse sinus.

  • The superior and inferior occipital veins play a major role, draining into the superior sagittal and transverse sinuses respectively.

Function

  • Major role in visual processing (secondary visual cortex, Brodmann area 18 and 19).

  • Involved in interpretation of motion, spatial orientation, and object recognition.

  • Participates in the integration of visual information with memory and attention networks.

  • Associated with higher-order visual tasks, including the perception of complex shapes and movement.

MRI Appearance

  • T1-weighted: Appears as intermediate to low signal intensity compared to the surrounding white matter; normal anatomy is well defined.

  • T2-weighted: Demonstrates relatively high signal intensity compared to white matter; cortical ribbon is easily visualized.

  • FLAIR: Similar to T2 with increased sensitivity to pathology (e.g., gliosis, edema, demyelination), making subtle lesions more conspicuous.

CT Appearance

  • Non-contrast CT: The MOG is seen as part of the cortical gray matter of the occipital lobe; not specifically differentiated unless affected by pathology (e.g., infarction, hemorrhage).

  • The normal cortex is isodense relative to other cortical regions.

  • Pathological processes may render the gyrus hypodense (ischemia/infarct) or hyperdense (hemorrhage/calcification).

MRI images

Middle occipital gyrus mri 3t axial image

MRI images

Middle occipital gyrus mri 3t sagittal image

CT image

Middle occipital gyrus CT axial anatomy image -img-00001-00001