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Posterior quadrangular lobule

The posterior quadrangular lobule is a cerebellar cortical subdivision located within the cerebellar hemisphere. It corresponds predominantly to lobule VI of the cerebellum and forms part of the spinocerebellum. This lobule plays an important role in coordination of voluntary limb movements, motor planning, and integration of sensory feedback.

It is frequently evaluated in neuroimaging due to its involvement in cerebellar infarction, demyelination, degeneration, and posterior fossa tumors.

Synonyms

  • Quadrangular lobule (posterior part)

  • Cerebellar lobule VI

  • Posterior quadrangular lobe

Location

  • Located on the superior surface of the cerebellar hemisphere

  • Posterior to the primary fissure

  • Anterior to the horizontal fissure

  • Lateral to the vermian declive

  • Forms the posterior portion of the quadrangular lobule

  • Superior to the cerebellar tonsil and inferior semilunar lobule

Anatomical components

  • Cerebellar cortex:

    • Molecular layer

    • Purkinje cell layer

    • Granular layer

  • Underlying white matter:

    • Arbor vitae projecting to deep cerebellar nuclei

  • Functional connections:

    • Spinocerebellar afferents

    • Corticopontocerebellar pathways via middle cerebellar peduncle

Relations

Superiorly:

  • Tentorium cerebelli

  • Occipital lobes (separated by tentorium)

Inferiorly:

  • Horizontal fissure

  • Inferior semilunar lobule

Medially:

  • Cerebellar vermis (declive)

Laterally:

  • Cerebellar hemisphere convexity

Anteriorly:

  • Primary fissure

  • Anterior quadrangular lobule

Function

  • Coordination of voluntary limb movement

  • Motor planning and timing

  • Integration of proprioceptive and cortical motor input

  • Error correction during ongoing movements

  • Contribution to posture and balance

Clinical significance

  • Cerebellar infarction: Lesions may cause ipsilateral limb ataxia and dysmetria

  • Degenerative disorders: Early involvement in spinocerebellar ataxias

  • Demyelinating disease: Frequently affected in multiple sclerosis

  • Tumors: May be involved by hemispheric cerebellar tumors or metastases

  • Post-surgical relevance: Important landmark in posterior fossa approaches

  • Alcohol-related cerebellar degeneration: Can contribute to superior cerebellar atrophy

MRI appearance

T1-weighted images:

  • Normal lobule: Intermediate signal intensity cortex with slightly hypointense white matter

  • Anatomy: Clear folial pattern with well-defined gray–white differentiation

T2-weighted images:

  • Normal cortex: Intermediate-to-slightly hyperintense signal

  • White matter: Relatively hypointense compared to cortex

  • Pathology: Hyperintensity in infarction, demyelination, edema, or gliosis

FLAIR:

  • Normal: Suppression of CSF highlights cerebellar folia

  • Pathology: Hyperintense cortical or subcortical lesions in demyelination or infarction

Diffusion-weighted imaging (DWI):

  • Normal: No diffusion restriction

  • Acute infarction: Bright restricted diffusion with low ADC values

Post-contrast T1-weighted images:

  • Normal: Minimal or no enhancement

  • Inflammation or tumor: Focal or diffuse enhancement

CT appearance

Non-contrast CT:

  • Normal: Often limited gray–white differentiation in posterior fossa

Post-contrast CT:

  • Normal: Minimal enhancement

MRI images

MRI Posterior quadrangular lobule axial anatomy image -img-00000-00000

MRI images

MRI Posterior quadrangular lobule coronal anatomy image -img-00000-00000

MRI images

MRI Posterior quadrangular lobule sag anatomy image -img-00000-00000

CT image

CT Posterior quadrangular lobule sag anatomy image -img-00000-00000