ASC Stroke Imaging & Diagnostics 2

Question 1

On CT perfusion imaging, which map best identifies the ischemic penumbra (tissue at risk but potentially salvageable)?

Accepted Answer

Mean transit time (MTT) or Tmax map showing perfusion delay

Answer

Tmax or MTT maps highlight areas with prolonged transit time representing the ischemic penumbra, which differs from the core infarct seen on CBF maps.

Question 2

Which MRI sequence is most sensitive for detecting hyperacute subarachnoid hemorrhage within the first few hours?

Accepted Answer

Gradient echo (GRE) T2*

Answer

GRE/T2* sequences are highly sensitive to blood products due to susceptibility effects of deoxyhemoglobin, making them superior to FLAIR in the hyperacute phase.

Question 3

A patient's CTA reveals a hyperdense basilar artery sign. What does this finding indicate?

Accepted Answer

Acute thrombus within the basilar artery

Answer

A hyperdense basilar artery on non-contrast CT indicates acute thrombus and is associated with basilar artery occlusion requiring urgent intervention.

Question 4

In CT perfusion imaging, the ischemic core is best represented by which parameter threshold?

Accepted Answer

CBF < 30% of contralateral normal tissue

Answer

A CBF reduction to less than 30% of normal contralateral tissue is the widely accepted threshold for identifying irreversibly infarcted core tissue.

Question 5

Which artifact on diffusion-weighted MRI can mimic acute ischemic stroke and must be recognized?

Accepted Answer

T2 shine-through effect

Answer

T2 shine-through occurs when subacute lesions with long T2 relaxation times appear bright on DWI without true diffusion restriction, mimicking acute infarct.

(ASC) Advanced Stroke Coordinator Certification Practice Test

(ASC) Advanced Stroke Coordinator Certification Practice Test

ASC Stroke Imaging & Diagnostics 2