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Claustrum

The claustrum is a thin, irregular sheet of gray matter located deep within the cerebral hemispheres, nestled between the insular cortex medially and the putamen laterally. Although its exact function remains partially understood, the claustrum is believed to play a key role in integrating multisensory information and coordinating consciousness. Its unique location and complex connectivity make it a structure of interest in neuroanatomy and radiology.

ANATOMY & LOCATION

  • The claustrum is a slender, subcortical structure situated between the external capsule (laterally) and the extreme capsule (medially).

  • It lies parallel to the insular cortex and is separated from the putamen by the external capsule.

  • It is composed predominantly of gray matter.

FUNCTION

  • Thought to be involved in the integration of sensory inputs across various modalities.

  • Suggested to play a role in consciousness, awareness, and cognitive processing.

  • May participate in attention and the coordination of cortical activity.

  • Connectivity studies show extensive links with almost all regions of the cortex, supporting its role as a relay or integrator.

MRI APPEARANCE

  • T1-weighted MRI:

    • The claustrum appears isointense to hyperintense  relative to surrounding gray matter.

    • Its thin shape may make it challenging to distinguish clearly, especially if image resolution is low.

  • T2-weighted MRI:

    • The claustrum demonstrates isointense  to the adjacent cortex.

    • Slightly more conspicuous than on T1, but still subtle due to its slender morphology.

  • FLAIR MRI:

    • The claustrum is typically isointense to the adjacent cortex on FLAIR sequences.

    • Lesions, edema, or pathological processes may cause it to appear hyperintense, but in normal conditions, it blends with surrounding tissues.

CT APPEARANCE

  • On non-contrast CT, the claustrum is generally not well-visualized due to its small size and similar attenuation to other gray matter.

MRI images

Claustrum mri 3t axial image

MRI images

Claustrum mri 3t coronal image