1. IMAGING MODALITIES
Computerized Tomography
Magnetic Resonance Imaging

2. Advantages of C.T Detection of calcification and calvarial defects
No contraindication

3. Disadvantages of CT Use of ionizing radiation
Reaction to iodinated contrast
Nephrotoxicity

4. Advantages of MRI No radiation Excellent soft tissue resolution
Multiplanar imaging

5. Limitations of MRI
Hyperacute bleed
Evaluation of calcification

6. Contraindications for MRI
Cochlear implants
Cardiac pace maker
Neuro stimulator

7. Lissencephaly Most severe of neuronal migrational abnormalities
Generalized paucity of gyral and sulcal
formation
Vertically oriented sylvian fissures

8. Torch Infections Toxoplasmosis Rubella Cytomegalovirus - Most common
cause of congenital CNS infection
Herpes simplex virus

9. Focal cortical dysplasia
Common location – temporal lobes
Expanded gyrus with abnormally oriented
sulci and thickened cortex
Subcortical white matter hyperintensity
Surgical excision of dysplastic focus when
possible is often curative

10. Cortical dysplasia – Balloon Cell Type of Taylor
Focal cortical thickening
Blurring of the gray-white matter junction
Hyperintensity (on T2-weighted images) of
subcortical white matter often tapering
toward the ventricle

11. Unilateral megalencephaly
Hamartomatous overgrowth of a part or whole of cerebral hemisphere
Ipsilateral migrational defects
Hypoplastic / hyperplastic white matter
Intractable seizures, hemiplegia and severe developmental delay

12. Peri-Sylvian syndrome
Anomalous cortical development overlying
underdeveloped sylvian fissures
Dorsal perirolandic extension of sylvian
fissures

13. Septo-optic dysplasia (de Morsier syndrome)
Partial or complete absence of septum
pellucidum
Squared off appearance of frontal horns
Hypoplasia of optic nerves and chiasm
( 40-80%)
Hypoplasia of hypothalamus

14. Tuberous sclerosis (Bourneville disease)
Incidence :10,000-50,000
Inheritance
-- autosomal dominant
-- low penetrance
-- chromosomes: 9, q ; 11, ??

15. Clinical - “classic” triad of:
Tuberous sclerosis
Clinical - “classic” triad of:
> Papular facial lesions
> seizures
> mental retardation- 50% of patients

16. Tuberous sclerosis CNS lesions Non- CNS lesions - Subependymal nodules
- Giant cell astrocytoma
- Cortical tubers
- White matter lesions
Non- CNS lesions
- Skin, kidneys, cardiovascular,
Liver, spleen, pancreas and
Musculoskeletal

17. Sturge-weber syndrome (Encephalotrigeminal angiomatosis)
Inheritance : none
Clinical : port wine stain in CN - V distribution

18. Sturge-weber syndrome
Aetiology
- Normal cortical venous drainage fails to develop
Pathology
- Leptomeningeal angiomatous vascular plexus with secondary dystrophic cortical changes

19. Sturge-weber syndrome
Calcification
Atrophy
Enlarged med, sub-epen veins
Ocular lesions

20. Periventricular leukomalacia
Commonly seen in premature infants
Ischemic lesions are most obvious in parieto-occipital regions
Paucity of white matter in the parieto-occipital regions
Indentation of the lateral ventricles

21. Hippocampus Mean volumes: Hippocampal sclerosis: 1.46+0.60cu.cm
Right Left
Male cu.cm cu.cm
Female cu.cm cu.cm
Hippocampal sclerosis: cu.cm

22. Hippocampus Normal: NAA/Cho:1.20 + 0.27 Hippocampal sclerosis:

23. Hippocampus T2 Relaxometry Mean T2 time:110-115ms
Prolonged in Hippocampal sclerosis

24. Dysembryoplastic Neuroepithelial Tumor
Slow growing superficial lesions usually within temporal lobe but always supratentorial
Focal cortical lesion , hypointense on T1 &
hyperintense on T2 Wt.images
Surgery is curative