Infection

Question 1

What is the pathognoic apprearance of HSV infection (herpes simplex virus)?

Answer 1

The areas of abnormality in the temporal lobe and insula abruptly end at the lateral putamen,which is characteristically spared. MR is frequently able to detect asymmetric bilateral temporal lobe involvement.

Question 2

Imaging features of ventriculitis/ependymitis?

Answer 2

The key to the diagnosis is subependymal enhancement

Choroid plexus enhancement has been reported. Periventricular calcification can be seen on CT after neonatal ventriculitis. Purulent ependymitis can be bright on DWI.
Enhancement of the ependyma is also observed in lymphoma (the most likely diagnosis in patients infected with HIV with subependymal enhancement.

Question 3

Imaging features of subdural empyema

Answer 3

Features of subdural empyema are those of extracerebral
collections over the convexities and within the interhemispheric
fissure, which on magnetic resonance (MR) display
isointensity on T1WI and high signal on T2WI/FLAIR, and
on CT show an isodense to low density extra-axial mass (Fig.
6-3). Empyema may be distinguished from subdural effusion
on DWI if restricted diffusion is identified in the former; that
is, empyemas are hyperintense on DWI (low apparent diffusion
coefficient [ADC] value), whereas sterile effusions are
low intensity on DWI and have ADCs similar to those of CSF.

Question 4

ToRCHs infections?

Answer 4

congenital infections

toxoplasmosis (2nd MC)
rubella
cytomegallo virus (MC)
herpes
syphillis

Question 5

CNS presentations of TB?

Answer 5

TB Granuloma or meningitis