Imaging

Question 1

FLAIR MRI

Answer 1

Fluid attenuation inversion recovery

CSF is attenuated and made dark
Abnormalities are bright

Question 2

DWI MRI

Answer 2

Diffusion weighted imaging

Sensitive to small and early strokes

Detects movement of water protons
Detects areas of ischemia through the lack/slowing of intracellular water diffusion and random movement of water protons, appears bright

Question 3

Water movement in areas of ischemia AND method to detect

Answer 3

Na/K pumps shut down
Na builds up intracellularly
Water follows concentration gradient into cell
Movement of water is restricted
Appears bright on DWI

Question 4

Gadolinium

Answer 4

Contrast used in MRI
Lights up blood vessels, good for looking at vascular structure and breakdown in BBB
[e.g., tumors, abscesses, inflammation (herpes simplex encephalitis, multiple sclerosis, etc.)].

Question 5

Benefits of MRI over CT scans

Answer 5

No ionizing radiation
Visualization of blood flow and cryptic vascular malformations
Detects demyelenating disease
No beam-hardening artifacts, making posterior fossa more easily visualized

Question 6

Benefits of CT scans over MRI

Answer 6

Rapid testing

Don’t have to worry about MRI compatible equipment

Question 7

Visualization of a clot in CT

Answer 7

Hyperdense area of blood vessel (brighter)

Confirmed with CTA

Question 8

CTP

Answer 8

CT perfusion

Shows differentiation between penumbra and the infarct core

Useful in assessing for treatment (Ex/ patient with small core and large penumbra will most likely benefit from reperfusion therapy)