CT Brain Anatomy
Grey matter structures

Key points

  • The cortex, insula, basal ganglia and thalamus are the important grey matter structures

Important grey matter structures visible on CT images of the brain include the cortex, insula, basal ganglia, and thalamus.

Cerebral cortex

The cerebral cortex is a layer of grey matter formed in gyri (folds) over the entire brain surface.

Cortical grey matter - CT Brain

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Cortical grey matter

  • The grey matter of the cerebral cortex is formed in folds called gyri
  • Note that the cortex appears whiter (denser) than the underlying white matter

Insula - CT Brain

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Insula

  • The insula forms an inner surface of the cerebral cortex found deep to the Sylvian fissure

Insula - clinical significance

  • Loss of definition of the insular cortex may be an early sign of an acute infarct involving the middle cerebral artery territory

Basal ganglia and thalamus

The basal ganglia and the thalamus are important grey matter structures which are located deep to the insula.

Basal ganglia and thalamus - CT Brain

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Basal ganglia and thalamus

  • The thalamus and the basal ganglia are readily identifiable with CT
  • Basal ganglia = lentiform nucleus + caudate nucleus

Basal ganglia - clinical significance

  • Insults to the basal ganglia may result in disorders of movement

Thalamus - clinical significance

  • Insults to the thalamus may result in thalamic pain syndrome