Topics

Topic

design image
Postcentral sulcus

The postcentral sulcus is a prominent groove found in the parietal lobe of the human brain. Located parallel and posterior to the central sulcus, it forms the posterior boundary of the postcentral gyrus, which contains the primary somatosensory cortex. This sulcus plays an important anatomical role as a landmark in both clinical and radiological neuroanatomy. It helps distinguish the somatosensory cortex from the remainder of the parietal lobe and is crucial for identifying adjacent gyri on imaging.

Synonyms

  • Posterior central sulcus

  • Sulcus postcentralis (Latin)

Function

  • Serves as the posterior boundary of the postcentral gyrus (primary somatosensory cortex, Brodmann areas 3, 1, and 2).

  • Anatomical landmark for orientation in neurosurgery and neuroimaging.

  • Aids in distinguishing the primary somatosensory cortex from the superior and inferior parietal lobules.

Arterial Supply

  • Supplied predominantly by branches of the middle cerebral artery (MCA), especially its cortical branches.

  • Occasionally receives minor supply from the anterior cerebral artery (ACA) via its parietal branches.

Venous Drainage

  • Drained mainly by superficial cortical veins that empty into the superior sagittal sinus.

  • Some drainage also occurs via the superior anastomotic vein (vein of Trolard) and the inferior anastomotic vein (vein of Labbé), connecting to the transverse sinus.

MRI Appearance

  • T1-weighted Images:

    • The postcentral sulcus appears as a hypointense (dark) linear structure separating the postcentral gyrus from the remainder of the parietal lobe.

    • Surrounding gray matter (cortex) appears isointense to slightly hyperintense relative to white matter.

  • T2-weighted Images:

    • The sulcus is hyperintense (bright) due to the presence of CSF (cerebrospinal fluid) within the groove.

    • Clear demarcation of adjacent gyri, aiding anatomical localization.

  • FLAIR Sequence:

    • On FLAIR, CSF signal is suppressed, so the postcentral sulcus appears hypointense (dark).

    • The sulcus may be less visible compared to T2, but FLAIR is useful for detecting pathology (such as edema or gliosis) adjacent to the sulcus, as these will appear hyperintense against the suppressed CSF background.

CT Appearance

  • The postcentral sulcus appears as a hypodense (dark) line due to the presence of CSF, similar to other sulci.

  • Less conspicuous than on MRI but can be identified as a linear low-density groove posterior to the central sulcus, especially in the absence of mass effect or edema.

MRI images

Postcentral sulcus MRI 3T axial image

MRI images

Postcentral sulcus MRI 3Tsagittal image