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

BRAIN STEM AND CEREBELLUM (CNS Block, Radiology)

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

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

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

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

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

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

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

Pons.. MRI Sagittal T1 MRI axial T2 3 1 1  4th ventricle 2  basilar artery 3  middle cerebellar peduncle

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

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

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

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

Cerebellum.. Cerebellar Vermis

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

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

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

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

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

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

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

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

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

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 (396-404)

Thank You