Topics

Topic

design image
Carotid cistern

The carotid cistern is a cerebrospinal fluid (CSF)-filled space located at the base of the brain, surrounding the supraclinoid segment of the internal carotid artery (ICA) as it courses through the subarachnoid space. It is considered one of the major basal cisterns and plays a vital role in accommodating the ICA, as well as associated neurovascular structures, including portions of cranial nerves and small vessels. Anatomically, the carotid cistern lies lateral to the optic chiasm, medial to the uncus of the temporal lobe, and superior to the cavernous sinus. Its boundaries and relationships are clinically significant, especially in the context of aneurysms, tumors, and other pathologies involving the ICA and surrounding structures.

Synonyms

  • Lateral carotid cistern

  • Supraclinoid cistern

  • Cistern of the internal carotid artery

Function

  • Provides a CSF-filled space that cushions and protects the supraclinoid segment of the internal carotid artery.

  • Allows passage and movement of the ICA, cranial nerves (notably portions of cranial nerves II and III), and small perforating vessels.

  • Facilitates distribution and flow of CSF between adjacent cisterns (optic, chiasmatic, and interpeduncular cisterns).

  • Serves as an important surgical landmark during neurosurgical approaches to the anterior cranial fossa and parasellar region.

MRI Appearance

  • T1-weighted Imaging:

    • The carotid cistern appears as a well-defined region of low signal intensity (dark) due to the presence of CSF.

    • The internal carotid artery within the cistern appears as a flow void (black) or may show flow-related enhancement, depending on imaging parameters.

    • The surrounding brain parenchyma and cranial nerves have intermediate to high signal.

  • T2-weighted Imaging:

    • The cistern is hyperintense (bright) due to the high water content of CSF.

    • The internal carotid artery appears as a flow void (black) within the bright CSF.

    • Well-defined margins between the cistern and adjacent brain structures.

  • FLAIR (Fluid-Attenuated Inversion Recovery):

    • The CSF in the carotid cistern is typically suppressed (appears dark), making it easier to identify abnormal signal intensity (such as blood or proteinaceous fluid).

    • Any pathological lesions (e.g., subarachnoid hemorrhage, infection) within the cistern may appear hyperintense (bright).

CT Appearance

  • The carotid cistern is visualized as a hypodense (dark) area lateral to the suprasellar cistern, outlining the course of the supraclinoid internal carotid artery.

  • The ICA itself appears as a round or oval hyperdense (bright) structure due to its blood content, especially after contrast administration.

  • Calcifications, hemorrhage, or masses in this region may be readily identified, potentially displacing or obliterating the cistern.

  • The margins of the carotid cistern are best seen in thin-section axial or coronal images, especially with high-resolution CT.

MRI images

Carotid cistern axial mri 3t image

MRI images

Carotid cistern coronal mri 3t image

CT image

Carotid cistern CT axial anatomy image -img-00001-00001