Visual diagnostics in praxis Flashcards
Why should MR be performed within 48h from surgery?
To be able to discriminate blood from remnant tumor.
Why should DWI sequences be added postoperatively?
To enable detection of perioperative ischemia
What is pseuodoprogression?
What is pseudoregression?
Can solid masses be bright on an unenhanced T1 weighted MRI?
No.
Only blood or proteinacious fluid OR Fat can be bright on an unenhanced T1 MRI.
In general, all extra-axial masses , i.e. masses outside of the brain like the pituitary gland and stalk, will enhance because they do not have a blood-brain barrier.
If you have a non-enhancing extra-axial mass, there are three possibilities. Which?
- Rapid arterial flow (eg. large blood vessel).
- No cellular tissue (eg. cyst).
- No blood supply (eg. infarcted mass
So, what is probably an extraaxial mass that has high T1 signal but no Gd enhancement representing?
That must be something with blood or high protein content or fat.
It is not
In general there are three things that are black on MRI (T1)-which?
- Air
- Bone
- Rapid flow void
type of vision defect?
- prefixed chiasm
homonymous hemianopsia