1. Brainstem & Cerebellum
Dr. Sajjad Hussain
Faculty in Neuroradiology
Department of Radiology and Medical Imaging
King Saud University / King Khalid University Hospital

2. BRAIN STEM AND CEREBELLUM
(CNS Block, Radiology)

3. Lecture Objectives.. Identify radiological anatomy Compare CT and MRI
At the end of the lecture, students will be able to:
Identify radiological anatomy
Compare CT and MRI
Recognize main imaging findings in common diseases

4. Brain Divisions.. I Prosencephalon – Forebrain
Diencephalon thalamus, hypothalamus
Telencephalon cerebrum
II Mesencephalon – Midbrain
III Rhombencephalon - Hindbrain
Metencephalon pons and cerebellum
Myelencephalon medulla oblongata

5. Brain Stem..
Three parts from superior to inferior: 1 midbrain 2 pons 3 medulla oblongata Connects cerebral hemispheres with spinal cord, and indirectly to cerebellum 1 2 3

6. Midbrain.. Radiological Features: CT+ MRI T2WI
At the level of circle of Willis
Anteriorly two cerebral peduncles (or crus cerebri) separated by interpeduncular cistern
Posteriorly four rounded prominences (superior and inferior colliculi)
In center, tegmentum of midbrain
CT+
MRI T2WI

7. Midbrain.. 1 Superior colliculus 2 Inferior colliculus
MRI Sagittal T1WI
MRI axial T2WI 1 2 3 4
1 Superior colliculus 2 Inferior colliculus
3 Cerebral peduncle 4 Interpeduncular cistern

8. Midbrain.. Internal features:
Substantia nigra separates crus cerebri ventrally from tegmentum posteriorly. Red nuclei are dorsal to substantia nigra at the level of superior colliculi

9. Pons.. Radiological Features:
The bulbous anterior part consists mainly of fibres continuous on each side with middle cerebellar peduncle
Basilar artery lies in groove anteriorly
Posterior surface of pons forms upper part of floor of 4th ventricle
Adjacent bones:
Clivus anteriorly in midline
Petrous part of temporal bones laterally

10. Pons.. MRI Sagittal T1 MRI axial T23 1
1  4th ventricle 2  basilar artery
3  middle cerebellar peduncle

11. Medulla oblongata.. Radiological Features:
MRI of medulla gives better images than CT due to bony artefact on CT
Ventral median fissure is seen anteriorly with pyramids laterally
4th ventricle is seen posteriorly
CT axial with contrast
medulla
MRI axial T2

12. Cerebellum..
Radiological Features: On axial Ct & MRI, cerebellum is separated from pons by 4th ventricle in midline and connected to pons laterally on each side by middle cerebellar peduncle On higher slices it is separated from temporal and occipital lobes anterolaterally by tentorium cerebelli, which can be seen on contrast enhanced studies p
CT+
Petrous bone
cerebellum
tentorium
Middle cerebellar peduncle

13. Cerebellum.. Radiological Features: T2 MRI
Cerebellum is connected to brainstem by 3 pairs of cerebellar peduncles:
Superior  midbrain
Middle  pons
Inferior  medulla oblongata
Two cerebellar hemisphere with midline vermis
Flocculus is a small ventral portion of the hemisphere
Tonsils are the most anterior inferior parts of hemispheres that lie close to midline
flocculus
vermis
tonsil
T1 MRI
axial CT
tonsil

14. Cerebellum.. Radiological features: CT+
The superior vermis can be seen between occipital lobes on section through thalamus.
Superior vermis

15. Cerebellum..
Cerebellar Vermis

16. of brainstem & cerebellum..
Common diseases
of brainstem & cerebellum.. CT
MRI axial FLAIR
MRI axial T2WI
Hyperdense
basilar artery
Acute infarction due to basilar artery thrombosis

17. of brainstem & cerebellum..
Common diseases
of brainstem & cerebellum..
Diffusion sequence
Acute infarction due to basilar artery thrombosis

18. of brainstem & cerebellum..
Common diseases
of brainstem & cerebellum..
Sag MRI T1WI
axial MRI T2WI
axial MRI T1WI contrast
Brain stem glioma

19. of brainstem & cerebellum..
Common diseases
of brainstem & cerebellum..
Sag MRI T1WI contrast
axial MRI T2WI
axial MRI T1WI contrast
Medulloblastoma

20. of brainstem & cerebellum..
Common diseases
of brainstem & cerebellum..
Sag MRI T1WI contrast
axial MRI T1WI contrast
Coronal MRI T1WI contrast
Ependymoma

21. of brainstem & cerebellum..
Common diseases
of brainstem & cerebellum..
Sag MRI T1WI
axial MRI T2WI
Coronal MRI T1WI contrast
Hemangioblastoma

22. of brainstem & cerebellum..
Common diseases
of brainstem & cerebellum.. CT
Sag MRI T1WI
axial MRI T2WI
axial MRI SWI
Cavernous angioma

23. of brainstem & cerebellum..
Common diseases
of brainstem & cerebellum..
axial MRI T2WI
axial MRI T1 contrast
Cerebellar tuberculosis

24. of brainstem & cerebellum..
Common diseases
of brainstem & cerebellum..
axial MRI T1 contrast
TB meningitis with multiple tuberculomas

25. Reference book and the relevant page numbers..
Stephanie Ryan, “Anatomy for Diagnostic imaging”, 2nd Edition, Pages 61-66
Jamie Weir, Peter Abraham, “Imaging Atlas of Human Anatomy” 3rd Edition, Pages 34-41
Peter Armstrong, “diagnostic imaging ”,
5th Edition, Pages ( )

26. Thank You