Neuro-infectious + epilepsy

Question 1

Describe the 4 imaging stages of brain abscess
One (2)
Two (2)
Three (3)
Four (3)

Answer 1

Early cerebritis
- Poorly marginated
- little-to-no enhancement
Late Cerebritis
- Irregular rim enhancing lesion
- hypodense center
Early capsule
- well-defined rim-enhancing mass
- outer hypodense and inner hyperdense rim (double rim sign)
Late capsule
- Thickened capsule
- diminished hypodense cavity

Question 2

Imaging features of Herpes simplex encephalitis (2)

Answer 2

• preferential involvement of mesial temporal lobes
• If hemorrhagic, blooming on GRE/SWI

Question 3

Imaging features of Japanese Encephalitis (3)

Answer 3

• Predominant involvement of deep gray matter
• Especially bilateral thalami (though can be asymmetric)
• Spares cortices

Question 4

Imaging features of Neurocysticercosis:
Vesicular (3)
Colloidal vesicular (2)
Granula Nodular (3)
Nodular Calcified (2)

Answer 4

Vesicular:
- T1 hyperintense scolex
- Dot sign (cyst with eccentric scolex)
- No or faint enhancement
Colloidal vesicular
- T1 hyperintense with edema
- Dot sign
Granular nodular
- less edema
- cyst retracts
- enhancement persists but less marked
Nodular calcified
- no enhancement
- no edema

Question 5

Spectroscopy finding to suggest toxoplasmosis

Answer 5

Increased Lipid lactate peak