Introducing MRI: Phase Contrast MRA (45 of 56)
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- เผยแพร่เมื่อ 6 ก.ย. 2024
- www.einstein.yu... - The forty-fifth chapter of Dr. Michael Lipton's MRI course covers Phase Contrast MRA. Dr. Lipton is associate professor radiology at Albert Einstein College of Medicine and associate director of its Gruss Magnetic Resonance Research Center.
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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 ?
Do you still use phase contrast for assessing flow in the brain? Why not the much faster and better time of flight?
@@richardthomas4112 time of flight 3D is for angiography.
@@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.
How does change in phase along the gradient bring about contrast for image formation
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.