1. Brain stem and Cerebellar Imaging
Prepared by Dr. Sarah Kamal
Lecturer of Radio-diagnosis .
Neurophychiatry block – Course Name and No.
6/29/2019

2. Learning objectives
Students at the end of the lecture will be able to:
• Identify radiological anatomy of brain stem and cerebellum.
• Compare CT and MRI imaging of brain stem and cerebellum.
• Recognize the imaging findings in common diseases involving brain stem and cerebellum.
اسم ورقم المقرر – Course Name and No.
6/29/2019

3. There are three major divisions of the brain, with each division having specific functions. The major divisions of the brain are the forebrain (prosencephalon), midbrain (mesencephalon), and hindbrain (rhombencephalon).
Prosencephalon : Forebrain
- Diencephalon thalamus, hypothalamus
- Telencephalon cerebrum
2. Mesencephalon – Midbrain
3. Rhombencephalon : Hindbrain
- Metencephalon pons and cerebellum Myelencephalon medulla oblongata •
MRI brain sag T1WI
1-midbrain
2-pons
3-medulla oblongata
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6/29/2019

4. Brainstem: Three parts from superior to inferior: 1- midbrain 2- pons
3- medulla oblongata •
Connects cerebral hemisphere with spinal cord
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6/29/2019

5. اسم ورقم المقرر – Course Name and No.
6/29/2019

6. Midbrain: Radiological Features: • At the level of circle of Willis
Anteriorly two cerebral peduncles separated
by interpeduncular fossa
• Posteriorly four rounded prominences (superior and inferior colliculi)
اسم ورقم المقرر – Course Name and No.
6/29/2019

7. MRI of the brain, T1WI sagittal view. 1, Lateral ventricle.
2, Caudate nucleus. 
3, Thalamus.
4, Midbrain. 
5, Oculomotor nerve (III). 
6, Pons.
MRI of the brain, T1-weighted axial view.
1, Substantia nigra.
 2, Tegmentum. 
3, Tectum. 
4, Cerebral peduncle
اسم ورقم المقرر – Course Name and No.
6/29/2019

8. Pons: Radiological Features:
• The bulbous anterior part consists mainly of fibers
continuous on each side with middle cerebellar
peduncle
• Basilar artery lies in groove anteriorly (black color)
• Posterior surface of the pons forms the upper part of
the floor of the 4th ventricle.
• Bony anterior relation:
clivus centrally and petrous temporal bones laterally
At the leve of petrous bone. Basilar artery in white color indicates infarction of the artery.
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6/29/2019

9. 3- middle cerebellar peduncle2 3 1 1
P- pons
1- 4th ventricle
2- basilar artery
3- middle cerebellar peduncle
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6/29/2019

10. Medulla oblongata: Radiological Features:
• MRI imaging of the medulla gives superior
images to CT due to lack of bony artifact
• The ventral median fissure is seen anteriorly
with the pyramid laterally
• The 4th ventricle is seen posteriorly
اسم ورقم المقرر – Course Name and No.
6/29/2019

11. Cerebellum: Radiological Anatomy:
• Cerebellum is connected to the brainstem by three pairs of Cerebellar Peduncles:
Superior connected to the midbrain
Middle connected to the pons
inferior connected to medulla oblongata
• The two cerebellar hemisphere connected in midline by Vermis.
• Flocculus is a small ventral portion of the hemisphere
• Tonsils are the most inferior part of the hemispheres that lie close to the midline
• The superior vermis can be seen between occipital lobes on section through the thalamus.
اسم ورقم المقرر – Course Name and No.
6/29/2019

12. Radiological Features:
• On axial Ct & MRI the cerebellum is separated from the pons by the 4th ventricle and connected to the pons on each side by middle cerebellar peduncle, it is bounded anteriorly by petrous temporal bone
• On higher slices it is separated from temporal and
occipital lobes antero-laterally by tentorial margins, tentorium can be seen on contrast enhanced studies
owing to the contained superior petrosal sinus.
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6/29/2019

13. اسم ورقم المقرر – Course Name and No.
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14. vermis tonsil flocculus اسم ورقم المقرر – Course Name and No.
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15. 1-Acute infarction due to basilar artery thrombosis
Common diseases of brainstem & cerebellum:
1-Acute infarction due to basilar artery thrombosis
Axial ct brain showing Hyper dense basilar artery denoting basilar artery thrombosis
اسم ورقم المقرر – Course Name and No.
6/29/2019

16. Acute bilateral pontine infarction (arrow) as a result of acute basilar occlusion shown on diffusion weighted MRI
Axial computed tomography scan showing bright (hyperdense) region (arrow) consistent with an acute basilar thrombus
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6/29/2019

17. 2-Medulloblastoma (common in children)
Mass in the 4th ventricle and the midline of cerebellum
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18. 3-Ependymoma
Mass with areas of calcification in the 4th ventricle extending through foramen magnum
Sagital MRI T1WI contrast
Axial MRI T1WI contrast
Coronal MRI T1WI contrast
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19. 4-Hemangioblastoma
Mass in the cerebellar hemisphere compressing the 4th ventricle and tonsils through the foramen magnum
Sagital MRI T1WI
Axial MRI T2WI
Coronal MRI T1WI contrast
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20. 5-Cavernous angioma
Sagital MRI brain T1WI showing a mass with mixed intensities from hyper to hypo in the caudal pons suggesting cavernous angioma
اسم ورقم المقرر – Course Name and No.
6/29/2019

21. 3-Ependymoma 5-Cavernous angioma Mass in caudal pons
2-Medulloblastoma
Mass in the 4th ventricle(child) and the midline of cerebellum
3-Ependymoma
Mass with calcification in the 4th ventricle extending through foramen magnum
4-Hemangioblastoma
Mass in the cerebellar hemisphere compressing the 4th ventricle and tonsils through the foramen magnum
5-Cavernous angioma
Mass in caudal pons
اسم ورقم المقرر – Course Name and No.
6/29/2019

22. 6-Cerebellar tuberculosis
Axial MRI T1 with contrast
well defined semi oval mass with outer enhancement on contrast administration. Diagnosis: Tuberculous mass in the left cerebellar hemisphere)
Axial MRI T2WI
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6/29/2019

23. 7-Dandy-Walker malformation:
Rare congenital malformation that involves the cerebellum and fourth ventricle.
Dandy-Walker malformation is characterized by
1-agenesis or hypoplasia of the cerebellar vermis
2- cystic dilatation of the fourth ventricle
3- enlargement of the posterior fossa.
MRI sagittal T1WI Showing:1- large posterior fossa cyst ,2-The hypoplastic vermis is everted over the posterior fossa cyst (long arrow). 3-The cerebellar hemispheres and brainstem (b) are hypoplastic.
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6/29/2019

24. Axial T2WI MRI Brain scan that shows 1-hydrocephalus, a large cerebrospinal fluid cyst in the posterior fossa,2- thinned occipital bone (arrows), 3- hypoplastic cerebellar hemispheres with a winged appearance (c).
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25. Thank you
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