This photo gallery presents the anatomy of Cerebellum by means of MRI (T1-weighted sagittal, axial and coronal views).
The cerebellum, Latin for “little brain,” is found at the base of the hindbrain or back of the brain.
Findings showed that the cerebellum plays a vital role in maintaining balance, coordinating voluntary muscle movement, and executing motor control(1).
The cerebellum is also essential for motor learning and cognitive functions, such as speaking and understanding language(2).
Injuries or abnormalities in the cerebellum have been linked to various neurodegenerative diseases, including Parkinson’s disease, hereditary ataxia (lack of motor coordination and balance), and multiple sclerosis(3).
Gross Anatomy of the Cerebellum
The cerebellum is a large structure with two cerebellar hemispheres(4).
The hemispheres of the cerebellum are connected by a central part called the cerebellar vermis. The vermis runs along the midsagittal plane and separates the hemispheres vertically.
Finely spaced and parallel grooves cover the surface of the cerebellum or the cerebellar cortex. The tight folding of the cerebellar cortex, similar to that of an accordion, creates the parallel grooves(5).
Found underneath the cerebellar cortex are the deep cerebellar nuclei. These nuclei are embedded within a central mass of white matter called the corpus midollare or arbor vitae (tree of life)(6).
The cerebellum also has three lobes: anterior, posterior, and flocculonodular lobes.
The flocculonodular lobe is located below the posterior fissure. This cerebellar lobe is primarily connected to balance and spatial orientation(7).
The anterior lobe is found above the primary fissure, while the posterior lobe is below the primary fissure(8). Both of these lobes are concerned with the modulation of motor systems.
Cerebellar peduncles, two stalks or columns, connect the cerebellum to the brainstem.
Cerebellum and Diagnostic Medical Imaging
Different diagnostic tools for neuroimaging (brain imaging) allow doctors to observe and evaluate the parts, functions, and interactions of the brain regions, including the cerebellum(9).
Among the many neuroimaging techniques, functional magnetic resonance imaging (fMRI) and electroencephalography (EEG) are the most commonly used(10).
Other diagnostic neuroimaging techniques available include positron emission tomography (PET) and near-infrared spectroscopy (NIRS)(11).
Computed tomography (CT) scans are also used to examine the brain and diagnose injuries or issues(12).
The combination of MRI and CT scans is recommended for diagnosing pathologies or abnormalities in the posterior cranial fossa, where the cerebellum is located.
Challenges in Neuroimaging of the Cerebellum
The cerebellum’s position at the base of the skull makes it challenging to access for diagnostic imaging(13).
The cerebellum is housed in the posterior cranial fossa, one of the three distinct depressions in the cranial cavity.
The posterior cranial fossa lies between the tentorium cerebelli (a membrane roof or cover over the cerebellum) and foramen magnum (the opening where the spinal cord passes through).
The posterior cranial fossa’s formation, small dimensions, and contained structures made the depression hard to study using CT and MRI scans(14).
However, advanced MRI techniques made it possible to observe the microstructural and functional characteristics of the cerebellum(15).
High- and ultra-high-field (UHF) strength MRI scans enhance brain anatomy visualization and enable faster imaging performance.
Imaging Features of Different Cerebellar Disorders
Abnormalities or malformations in the cerebellum may result in difficulties maintaining posture and gait and coordinating voluntary movements, such as eye movements(16).
The following are examples of cerebellar malformations and their identifying features in diagnostic imaging scans:
Dandy-Walker malformation (DWM) stems from a developmental failure during the formation of the hindbrain.
Diagnostic imaging showed that DWM is characterized by an underdeveloped cerebellar vermis and enlarged posterior fossa (base of the skull)(17). MRI scans also showed widely separated cerebellar hemispheres(18).
Symptoms of Dandy-Walker include ataxia or balance and coordination issues, developmental delay, and, in some cases, enlarged head circumference.
Joubert syndrome is a rare autosomal recessive disorder that may cause developmental delay, ataxia, intellectual disability, and breathing dysregulation in children(19).
CT and MR imaging showed that, unlike normal healthy cerebella, the cerebellum of a person with Joubert syndrome has a triangular or batwing-shaped fourth ventricle(20).
Neuroimaging also shows a “molar-tooth appearance or sign” due to thickened and horizontally elongated cerebellar peduncles(21).
The fourth ventricle is an interconnected and fluid-filled cavity located in front of the cerebellum(22).
Also known as acute cerebellar ataxia, acute cerebellitis is an uncommon inflammatory disorder.
Acute cerebellitis more commonly affects children, who may show signs of acute onset ataxia, dysarthria (motor speech difficulties), and nystagmus (uncontrolled eye movements)(23).
MR neuroimaging results indicated that acute cerebellitis causes diffuse swelling of the two cerebellar hemispheres and raised intracranial pressure(24).
Radiology imaging allows doctors and students to identify malformations, injuries, and other cerebellum irregularities and diagnose cerebellar disorders.
• Harnsberger HR, Osborn AG, Ross JS, Moore KR, Salzman KL, Carrasco CR, Halmiton BE, Davidson HC, Wiggins RH. Diagnostic and Surgical Imaging Anatomy: Brain, Head and Neck, Spine. 3rd ed. Salt Lake City, Utah. Amirsys. 2007.
- Knierim, J. (2020, Oct. 20). Chapter 5: Cerebellum. Neuroscience Online. Retrieved from https://nba.uth.tmc.edu/neuroscience/m/s3/chapter05.html
- Mormina, E., Petracca, M., Bommarito, G., Piaggio, N., Cocozza, S., & Inglese, M. (2017). Cerebellum and neurodegenerative diseases: Beyond conventional magnetic resonance imaging. World journal of radiology, 9(10), 371–388. https://doi.org/10.4329/wjr.v9.i10.371
- LibreTexts. (2020, Aug. 14). 11.5A: Parts of the Cerebellum. Retrieved from https://med.libretexts.org/Bookshelves/Anatomy_and_Physiology/Book%3A_Anatomy_and_Physiology_(Boundless)/11%3A_Central_Nervous_System/11.5%3A_The_Cerebellum/11.5A%3A_Parts_of_the_Cerebellum
- Mormina, E., et al. (2017). Op. cit.
- LibreTexts. (2020, Aug. 14). Op. cit.
- Xue, G., Chen, C., Lu, Z. L., & Dong, Q. (2010). Brain Imaging Techniques and Their Applications in Decision-Making Research. Xin li xue bao. Acta psychologica Sinica, 42(1), 120–137. https://doi.org/10.3724/SP.J.1041.2010.00120
- Radiological Society of North America. (2018, June 22). Computed Tomography (CT) - Head. Radiology Info. Retrieved from https://www.radiologyinfo.org/en/info.cfm?pg=headct
- Thust, S. C., & Yousry, T. (2016). Imaging of skull base tumours. Reports of practical oncology and radiotherapy : journal of Greatpoland Cancer Center in Poznan and Polish Society of Radiation Oncology, 21(4), 304–318. https://doi.org/10.1016/j.rpor.2015.12.008
- Mormina, E., et al. (2017). Op. cit.
- Arora R. (2015). Imaging spectrum of cerebellar pathologies: a pictorial essay. Polish journal of radiology, 80, 142–150. https://doi.org/10.12659/PJR.892878
- National Organization for Rare Diseases. Dandy-Walker Malformation. Retrieved from https://rarediseases.org/rare-diseases/dandy-walker-malformation/
- Arora R. (2015). Op. cit.
- Okpe, O. (2020, Oct. 29). Fourth ventricle. Kenhub. Retrieved from https://www.kenhub.com/en/library/anatomy/the-fourth-ventricle