Imaging spectrum of cerebellar pathologies: a pictorial essay

Abstract

The cerebellum is a crucial structure of hindbrain which helps in maintaining motor tone, posture, gait and also coordinates skilled voluntary movements including eye movements. Cerebellar abnormalities have different spectrum, presenting symptoms and prognosis as compared to supratentorial structures and brainstem. This article intends to review the various pathological processes involving the cerebellum along with their imaging features on MR, which are must to know for all radiologists, neurologists and neurosurgeons for their prompt diagnosis and management.

Keywords: Cerebellar Diseases; Cerebellum; Magnetic Resonance Imaging.

Figure 1

5-year old male patient with Dandy-Walker variant. Axial T2 weighted (A), T1 weighted (B) and sagittal T2 weighted (C) MR images showing widely separated & hypoplastic cerebellar hemispheres (A, B) and hypoplastic vermis (C).

Figure 2

6-year old boy with joubert syndrome. Axial non-contrast CT images of the brain showing dilated batwing-shaped fourth ventricle (A), hypoplastic vermis (A, B) in addition to thickened and elongated superior cerebellar peduncles with deep interpeduncular fossa (A, B) giving molar-tooth appearance.

Figure 3

40-year old man with Lhermitte-duclos disease. Axial T1 (A) & T2 weighted (B) MR images showing a well defined mass in left cerebellar hemisphere with hypointense signal on T1 and hyperintense signal on T2 weighted sequences along with isointense and hyperintense striations within it. There is evidence of mass effect on the fourth ventricle.

Figure 4

(A, B) One and a half year old male child with chiari-2 malformation. Sagittal T2 weighted images of the cervicodorsal spine including craniocervical junction showing evidence of caudal displacement of the cerebellar vermis and medulla with spina bifida and meningomyelocele in the lower dorsal spine. There is presence of syringohydromyelia as well in the dorsal spinal cord.

Figure 5

60-year old man with bilateral PICA infarcts. Axial FLAIR sequence (A) showing hyperintensity involving bilateral posterior inferior cerebellar hemispheres corresponding to territory of posterior inferior cerebellar artery which shows acute diffusion restriction on diffusion weighted sequence (B).

Figure 6

20-year old male patient with scrub typhus cerebellitis. Axial FLAIR sequence (A) of MRI of the brain showing diffuse hyperintensities involving both cerebellar hemispheres with compression of fourth ventricle leading to obstructive hydrocephalus. Parasagittal T2 weighted sequence (B) showing hyperintensities involving grey matter of cerebellar hemisphere with compressed fourth ventricle and tonsillar herniation. Axial contrast enhanced T1 weighted MR (C) showing diffuse leptomeningeal enhancement in bilateral cerebellum and axial diffusion weighted sequence (D) showing restricted diffusion in the same location.

Figure 7

40-year old man with metronidazole toxicity. Axial FLAIR (A) and coronal T2 (B) sequence of MRI of the brain showing symmetric hyperintensities involving bilateral dentate nuclei of the cerebellum. Axial diffusion weighted sequence (C) showing mild diffusion restriction in bilateral dentate nuclei.

Figure 8

40-year old female patient with olivopontocerebellar atrophy. Axial T2 weighted image (A) of the brain showing diffuse atrophy of the cerebellum and pons with hot cross bun sign in pons. Axial FLAIR sequence (B) showing hyperintensity in bilateral middle cerebellar peduncles with pontocerebellar atrophy.

Figure 9

9-year old boy with pilocytic astrocytoma. Axial T2 (A) and postcontrast T1 (B) weighted images of the brain showing a large well defined cystic lesion with mural nodule which is mildly hyperintense on T2 weighted image (A) seen involving left cerebellar hemisphere and vermis with thick irregular intense enhancement of the wall of the cyst and the mural nodule.

Figure 10

7-year old boy with medulloblastoma. Axial T1 (A) and coronal T2 (B) weighted image of the brain showing a well defined homogenous mass with hypointense signal on T1 (A) and mildly hyperintense signal on T2 (B) weighted sequences in the vermis with mass effect on fourth ventricle causing obstructive hydrocephalus. Axial diffusion weighted sequence (C) showing restricted diffusion within the mass. Axial post contrast T1 weighted sequence (D) showing moderate enhancement of the lesion with nonenhancing necrotic area anteriorly at the periphery. Sagittal post contrast T1 weighted image (E) of the dorsolumbar spine showing diffuse leptomeningeal spread.