Introducing MRI: The Spin Echo Pulse Sequence (31 of 56)
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- čas přidán 22. 09. 2014
- www.einstein.yu.edu - The thirty-first chapter of Dr. Michael Lipton's MRI course covers The Spin Echo Pulse Sequence. 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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I am a radiology resident and I think you are the best lecturer for MRI I have ever encountered
This lecture is great! It answers all the questions I had when reading MR books and watching other lectures. Thanks a lot!
This is the most helpful introduction for MR for Radiologists and residents. Thank You so much. I watched a lot of explanations, none were as helpful 🙏🙏
thanks for the in-depth lectures!
you make so much sense, thank you !
thank you so much! this really helped...answered my question that i was search for soo long!
In decoupling scheme in case of 13C we apply 90 degree pulse to of H what is does actually?
when we adding the rephasing pulse with Gsl at 180
why the second half of this pulse do not change its polarity (as we do in frequency encoding)
So at around 18:40 when he speaks about applying the frequency encoding gradient twice, he mentions that the spins would then be back in phase before we sample in order generate the most signal. If that is the case, what even is the point of applying the frequency encoding gradient? How I understand it, the amount of dephasing caused by this gradient is how we do spatial localization. Could someone help me with this please?
Wonderful lecture. Very detailed and understandable. I am very appreciate it.
Great class. Better than my teachers
Doesn't the 180° RF pulse also cause the difference caused by the phase encoding gradient to rephase and we lose spatial information? Why do we not apply the phase encoding gradient after the 180° RF pulse?
I think the 180° pulse is just enough to recover the inherent phase change during T2 and nothing more. So the extra difference from the phase encoding gradient will still remain
@18:49 it should be 180 pulse instead of 90 pulse!!
awsome
In spinn echo sequence, What does the 90 and 80 degree - pulse do?
18.50: Where does this 90 degree pulse comes from? Isn't this 180 degree pulse that we give Dr. Lipton?
What is TE ?
Time to Echo. The point where our spins are back in phase due to the 180 pulse. It's the point where we sample as we have the most signal here. The earlier videos in the series explain it in good detail.
@@markplatt1708 hey thanks for reply
Where r u from ?
Could u please clear my one another dout
Can anyone tell me the note or frequency of the magnetic vibrations, because it effects me either emosional puts me in fight to flight mode, ive always had problems with magnetic and vibration all my life, but i have to have an mri and i just carnt do it and was wondering in i could custom my self with the frequency by using vibration bowls or some thing, i have this problem with alot of vibration sounds in my everyday life, dise this make sence to anyone
Sounds solly but even cats vibration can cause sedition or anger in me
Silly not solly
If I didn’t hear it wrong, that student was asking : “why we add 180 degree RF?”. The answer is : the 180 degree RF is to strengthen the echo effect of the first RF. Heres why. The first RF maneuver is to “distort” the proton in an alignment ‘phase surface’ that is orthogonal to its ‘original or relaxed’ phase surface. The second RF maneuver didn’t move the ‘distorted’ proton out of the phase surface, rather,
“tightening” the ‘distorted’ proton while keeping it on the same ‘phase surface’. - that’s why the second RF has to be 180 degree. Once the ‘targeted protons’ or ‘tissues’ are ‘distorted’ and ‘tightened’, then, the ‘returning to their original/relaxed phase’ or ‘echo’ of the “manipulated” protons will give out stronger “echo”. The second ‘maneuver’ of Protons can be considered as a genius idea of the physicist.
subtitles, please! :(