1. Part2 infection and tumor
Neuro
Part2 infection and tumor

2. Infection
Meningitis
Cerebritis, encephalitis
Brain abscess

3. Meningitis Most common CNS infection Adult: Pneumococci
Routes of infection:
- Hematogenous spread
- Local extension from extracerebral infection
- Direct implantation Hematogenous

4. Meningitis NCCT Normal (early stage)
Increased density in subarachnoid space
(exudate in CSF space)
Dilatation of ventricular system
(communicating + obstructive type hydrocephalus)

5. Meningitis
CECT
Leptomeningeal enhancement

6. CECT
Leptomeningeal enhancement: sylvian,interpeduncular, folia of cerebellum

7. Meningitis Complication Hydrocephalus Subdural effusion / empyema
Cerebritis / cerebral abscess
Ependymitis
Arterial / venous thrombosis

8. 3 1 2 5
Hydrocephalus 4

9. precontrast
Brain abscess
Enhancing wall
Post contrast

10. Tuberculous Infection
Hematogenous spread (Lung)
1) Meningitis
2) Tuberculoma

11. TB meningitis Imaging: NCCT: Thick fibroexudate in basal cistern
Impaired CSF absorption → hydrocephalus
Imaging:
NCCT:
Obliteration of basal cistern by exudative content
Ventricular system dilatation
Hypodense areas of cerebral infarction (basal gg. and thalamus)

12. TB meningitis
CECT:
Leptomeningeal enhancement thick in cistern

13. Tuberculoma Associated with TB meningitis about 50%
Solitary 70%, multiple 30-60%
Location:
- Adult: basal ganglia
- Children: cerebellum
- gray-white junction

14. Tuberculoma Findings: NCCT Iso-hyperdense lesion with edema CECT
Nodular, ring or irregular enhancement

15. Chest: infiltration

16. TB meningitis with Tuberculoma
NCCT
CECT

17. TB meningitis with Tuberculoma
CECT

18. Cerebritis/abscess
Neonate, infant : occurs as complication from bacterial meningitis
Location:
- Corticomedullary junction
- Frontal and parietal lobes are most common
4 stages: early-late cerebritis (0-2 wks)
early-late abscess (2-4wks)

19. Imaging Cerebritis: NCCT Ill-define hypodensity area CECT
Increase enhancement area or
gyral enhancement

20. Imaging
Abscess:
Well-defined hypodensity (fluid density) with ring enhancement, surrounding vasogenic edema
Ring enhancement of brain abscess
Uniform thickness
Thin wall

21. Ring enhancement Abscess Metastasis
Primary tumor (anasplastic astro-GBM)
Resolving hematoma
Subacute infarction
neurocysticercosis

22. Brain Tumor
Is there a mass lesion?
Is it intra-axial or extra-axial?

23. Extra-axial Vs Intra-axial

24. Imaging Intra-axial Extra-axial Round shaped Surrounding by parenchyma
No bony change
Vasogenic edema
Extra-axial
Broad- based
Attachment to meninges, bone
Adjacent bony changes
Ipsilateral widening of CSF cleft
Pushing mass effect
Buckling gray-white matter

25. Broad-based lesion, Buckling, less edema
Meningioma
Extra-axial

26. Intra-axial
Glioblastoma

27. Brain metastasis Parenchyma: corticomedullary junction Leptomeningeal
skull

28. Brain metastasis NCCT Hypodense
Hyperdense (GI tract, choriocarcinoma, melanoma, leukemia, lymphoma)
Isodense (rare)
Surrounding vasogenic edema
Multiple lesions

29. Brain metastasis CECT Increased enhancement - nodular
- ring enhancement (thick, irregular wall)
Leptomeningeal enhancement

30. Parenchymal metastases
NECT
CECT
Parenchymal metastases

31. Metastasis
Leptomenigeal metastasis