Malformations

Question 1

What is Cognard definitions used for?

Answer 1

Dural atriovenous malformations.

Question 2

What is the meaning of Cognard typ 4?

Answer 2

Location of fistula:
-Cortical
Presence of cortical venous drainage:
-Yes. drains into cortical veins and not into sinus.
Direction of flow:
Does not need to be addressed for grade IV.
Presence of venous ectasia:
-Yes. Drainage WITH presence of venous ectasia.