The document covers central nervous system (CNS) pathology, focusing on radiological findings and imaging modalities. It details terminologies for X-ray, CT, ultrasound, and MRI, along with their respective indications for investigating CNS conditions. Additionally, it highlights common pathologies and emergencies identifiable through radiological imaging.

1. CHS 3111: CENTRAL NERVOUS
SYSTEM (CNS) PATHOLOGY
Dr. Erem Geoffrey
Lecturer, Radiology Department
School of Medicine

2. Learning objectives
To learn the different terminologies used to describe
CNS radiological findings
To describe the different imaging modalities and
their indications, in investigation of the CNS
To describe the radiological anatomy of the CNS at
the different imaging modalities

3. Learning objectives
To describe the common pathology of the CNS as
demonstrated on radiological imaging
To identify emergencies of the CNS that are
demonstrable on radiological imaging

4. Common terminologies used to
describe CNS radiological findings
Plain X-ray
Opacity: opaque/dense area on an X-ray- appears
white
Sclerosis: Thickening & increase in bone density-
appears white
Radiolucency: Non opaque area on an X-ray- appears
as dark/ black area

5. Terminologies cont.
CT scan
Hypodense: Area with a lower density in comparison to another
area-appears dark/black
Hyperdense: Area with a higher density in comparison to
another area-appears bright/white
Isodense: Area with same density in comparison to another
area-similar appearance

6. Terminologies cont.
Ultrasound scan
Echogenicity: Intensity of echoes reflected by tissues
or structures from inside the body
Hyperechoic: An area with higher intensity echoes in
comparison to another area-appears brighter
Hypoechoic: An area with lower intensity echoes in
comparison to another area-appears darker/blacker
Anechoic: An area with no echoes-appears black
Isoechoic: An area with same/similar echo intensity in
comparison to another area-similar appearance

7. Terminologies cont.
MRI
Hyperintense: areas which appear birght on MRI
Hypointense: areas which appear black

8. Radiological imaging modalities for investigation
of CNS & their indications
Plain X-ray: Skull & spine X-rays
Indications:
Infections & inflammatory diseases
Trauma
Neoplasm
Foreign body

9. Imaging modalities & indications cont.
Ultrasound
Indications:
 Evaluation of intracranial diseases & anomalies in children with
open anterior fontanelle: e.g. hydrocephalus, intraventricular
haemorrhage, subdural effusion, various congenital anomalies
such as Dandy-Walker cyst
 Evaluation for spinal dysraphism in neonates & young infants

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11. Imaging modalities & indications cont.
CT scan/ MRI
Indications
Infections & inflammatory diseases
Congenital anomalies of CNS
Trauma
Neoplasm

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14. Imaging modalities & indications cont.
Radionuclide imaging
Indications:
Functional studies e.g brain perfusion
Angiography
Indications:
Pts with stroke/cerebral infarcts
Pts with transient ischaemic disease
Preoperative evaluation e.g. in pts with certain
tumours

15. Normal Skull X-rays (SXR)
Lateral view AP view

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Sella turcica
Anterior clinoid process
Posterior clinoid process
Tuberculum sellae
Dorsum sellae
Dr. Erem

17. Normal CT anatomy of brain
23: Interhemispheric fissure
24: Head of caudate nucleus
25: Lentiform nucleus
(globus pallidus & putamen)
26: Thalamus
27: Atrium of lateral
ventricles
28: Anterior limb of internal
capsule
29: corpus callosum (body)
30: Posterior limb of internal
capsule

18. Anatomy
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19. Anatomy….
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20. Normal CT anatomy of brain: level of
basal ganglia

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23. Brain CT scan: posterior fossa tumour

24. Brain CT scan: brain abscess

25. Brain CT scan: right subdural
haemorrhage

26. Brain CT scan: infarct

27. Brain CT scan: skull fractures

28. Brain MRI

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34. Conventional myelogram CT myelogram

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36. Emergencies of CNS that demonstrable are
on radiological imaging
Trauma:
Spinal injury with cord compression
Intracranial haemorrhages
Cardiovascular diseases
Stroke especially haemorrhagic
Increased intracranial pressure
Tumours
Infection with brain oedema