Introducing MRI: Phase Contrast MRA (45 of 56)

[@588908]

Hi,
I'm a junior MRI radiographer and I was watching you lecture about PC imaging... and It helped me a lot to understand how this technic works. But I in the daily we use this tecnic to see the venous vessel of the head... from what I see the directions of the slices is not important to the study... I just need to use the 3 directions codification of flow and the correct velocity. So If I plan the PC in the axial plane is the same as I plan it by the Sag planing. Or there is any difference at the image ?

[@couldbericher]

Do you still use phase contrast for assessing flow in the brain? Why not the much faster and better time of flight?

[@jerry5550]

@@couldbericher time of flight 3D is for angiography.

[@couldbericher]

@@jerry5550 I know. I was responding to Daniel Leitao's comment above about using phase contrast MRA for the brain. I would use TOF for the brain.

[@shashwatpriyadarshi972]

How does change in phase along the gradient bring about contrast for image formation

[@ghosttownbmw]

The use of bi-polar gradients applies a gradient in the direction of flow (x, y, z), first positive lobe to change phase of flowing blood and stationary tissue. Then, a negative lobe to the flowing blood that then moves to another direction and creating a difference in phase for flowing blood and stationary background tissue. It's this change of phase that creates a contrast.