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Topic

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Simple lobule (HVI) of cerebellum

The simple lobule (HVI) is a small lobule of the posterior lobe of the cerebellum, located between the primary fissure and the posterolateral fissure. It is part of the hemispheric region of the cerebellar posterior lobe and plays a key role in coordination of voluntary movements, fine motor control, and balance.

The HVI is involved in integration of proprioceptive information and coordination of distal limb movements, particularly of the upper extremities. It communicates extensively with the deep cerebellar nuclei (primarily dentate and interposed nuclei) and the cerebral cortex via the cerebellar peduncles, forming essential loops for motor planning and execution.

Function

  • Coordinates fine voluntary movements

  • Maintains balance and posture

  • Integrates sensory input from muscles and joints

  • Contributes to motor learning and timing

  • Supports coordination of upper limb and hand movements

Synonyms

  • Lobulus simplex

  • HVI lobule of cerebellum

  • Posterior cerebellar lobule HVI

MRI Appearance

T1-weighted images:

  • Appears as intermediate signal intensity gray matter forming the cortical ribbon of the cerebellar hemisphere

  • Surrounded by high signal intensity white matter of the cerebellar core

  • Well-delineated fissures separating it from adjacent lobules

T2-weighted images:

  • Cortical gray matter of the simple lobule appears hyperintense relative to the white matter, highlighting cerebellar folia

  • Fissures appear as low signal clefts separating lobules

  • Useful for assessing cortical atrophy, demyelination, or focal lesions

STIR (Short Tau Inversion Recovery):

  • Cortical folia of HVI show intermediate signal

  • Edema, inflammation, or infarcts appear hyperintense, aiding in detection of stroke, tumor, or demyelinating lesions

T1 Post-Contrast (Gadolinium-enhanced):

  • Normal simple lobule shows no significant enhancement

  • Pathological conditions (tumor, abscess, inflammation) demonstrate variable enhancement along cortical or subcortical areas, highlighting abnormal tissue

CT Appearance:

  • Appears as gray matter of intermediate density surrounded by hyperdense white matter of cerebellar core

  • Fissures and folia may be subtle, best seen on high-resolution CT

  • Useful for detecting hemorrhage, mass lesions, calcifications, or trauma

  • Posterior fossa reconstruction can demonstrate the lobule’s relationship to the vermis and cerebellar hemispheres

MRI images

Simple lobule (HVI) of Cerebellum mri sag image -img-00000-00000