Stroke & Interventional Radiology

Question 1

“Density” vs. “Hypodensity” on CT/MRI

Answer 1

• Hypodensity: Dark
• Dense: Light

Question 2

Appearance of infarcts on CT

Answer 2

• Confined to a vascular territory
• 1-6 hours loss of gray matter density
• 6 hours - 4 days: progressive swelling and hypodensity
• 4 -14 days: return towards normal density and volume
• 14 days on: varying degrees of hypodensity and volume loss

Question 3

Appearance of infarcts on MRI

Answer 3

• 1 hour – 10 days: bright on diffusion weighted imaging
• Swelling and increased signal on FLAIR and T2-weighted scans follows same pattern as swelling ang and low density on CT
• DWI great for small infarcts and telling new from old

Question 4

Usefull CT scans in workup of acute infarcts

Answer 4

• Non-contrast CT scan ==>
• CT perfusion scan ==>
• head and neck angiogram

Question 5

Benefits of using CT scans in workup of acute infarcts

Answer 5

• CT is fast
• MRI has size restrictions + can’t be used on people with metal implants
  
  • No pt.s are excluded from CT scanner

Question 6

Perfusion CT procedure + information provided

Answer 6

• give bolus of contrast, see timing of bolus to get to different locations at the brain.
• High dose radiation study, lots of contrast and continuous exposure for 1 minute.
• Results = cerebral blood volume and time to start/time to peak maps.
  
  • Used in qualitative manner.
  • Look for delays in time to start/peak.

Question 7

CT Angiogram procedure + results information

Answer 7

• IV contrast bolus and take thin sections through anatomy
• look for arteries that may be the cause of the infarction

Question 8

Tx of acute infarcts

Answer 8

• IV thrombolytics, stent/catheter
• Primary/secondary prevention: treat HTN, DM, hypercholesterolemia
• Tertiary treatment → reducing long term effects of acute stroke