Introduction to Clinical MRI Physics (part 1 of 3)
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- čas přidán 1. 06. 2024
- Intended audience: radiology residents and fellows, medical students, or anyone who is interested in learning basic MRI physics conceptually. No complex equations or formulas. It is also helpful for those who are seeking the cure to their insomnia.
---- Contents ----
0:00 - Intro
3:06 - Basic definitions
5:35 - MR active atoms
7:23 - Hydrogen proton / spin
9:09 - Larmor frequency and equation
11:19 - Longitudinal and transverse magnetization
12:57 - Resonance
14:33 - Longitudinal relaxation and T1 relaxation time
19:39 - Transverse relaxation and T2 relaxation time
22:52 - T2*, echo, and Spin Echo technique
32:27 - T1 and T2 weighted imaging
this is the best mri physics lecture i have stomped upon i had to leave a comment after the random question cause it just reminded me that i watched 13ish minutes without realizing
Mri Technologist here for 20 years. I've seen lots of videos TRYING to simplify Mri Physics. This is by far the best of them all. R u sure you're a Radiologist, and not a Physics Professor? 😜Just kidding. Excellent video. Thanks.
Ha ha, I wish I'm smart enough to be a physicist; just try to learn it to better my clinical understanding. I'm allergic to complex equations. :) I'm glad it helps. Thanks.
20 years ,love it ?
I am a third-year radiology resident preparing for the core exam now. This is the best physics lecture on MRI that I have seen. I have learned more from your lectures than from reading the war machine chapter. I would love to see more videos from you.
That's great to hear, thanks. This hobby site started with me finding a place to store lectures for my residents, but happy to know it's also helping residents elsewhere. Best luck on core exam, and you're almost there! Let me know if you guys have any neuro Q's.
wait, your technologist that do your exam knows more physics than you?
@@neuroradish Your Videos helped me so much!!!!!!!!!! Thank you so much
This has to be the best explanation of MRI physics on YT. Thank you!
I TOTALLY AGREE!! I've seen several videos trying to explain this and by far, this is the BEST explanation!!! There is light at the end of the tunnel for me!!
This is such a great lecture - equivalent to reading numerous textbooks. Thank you so much for posting it!
Spectacular. Thank you!
The Kennedy thing you did should be an example in every textbook on the topic: how to make students remember numbers
This has been the best source on MRI physics so far. Thank you!
I'm a nuclear tech starting MRI cross-training. I'm left to teach myself the physics and this video has helped a ton. Thank you
literally the most clear explanation of MRI physics on YT! Thank you for your great video!
I looked at all 3 parts I’m a MRI Technologist of 17 years, just looking for refresh the basics. Thank you great lecture well explained.
I never write comments. But this is literally the best MRI lecture on CZcams. Thank you so much.
It is the best out there , have looked a lot nothing informative like this one
Thank you so much for uploading!
Amazing lecture! Thank you very much
Best explanation of MRI I have found. Thanks.
This was great. I am working on my thesis and was having a hard time understanding how MRI works. This video was exactly what I needed.
Omg 😱 it's the best introduction that I ever see about this topic. Thx so much.
Crisp & to the point. Excellent
Great lection. Thank you
Thank you so much for this. I was just not getting the physics part in mri. You made it so easy to understand. God bless ❤
Thank you for this amazing video! I can finally understand this topic
great video ! Very useful
Man, what a beautiful video! Perhaps a bit fast for those who have not seen the subject before. But the visualization is wonderful. Top job!
The best video for MRI learners....
10/10....
Thanks for posting such lectures
how a super and super well explained video... I think its the BEST ONE .. Thank you a lot for the animations and well explaination...
Best MRI physics EVER. You should expand the topics and build on those videos as is the best attempt to explain a rather complex topic that stops thousands of doctors to understand better that modality.
Excellent lecture! Hands down and this is coming from a Prof! you nailed it.
Thank you for this!
Simply wonderful!
Excellent, thanks
Great explanation👌
fantastic lecture
Awesome lecture, pls continue your videos with mri
That was very helpful thank u ❤️❤️
you make MRI physics a lot easier to understand. thank you for making this great video!
Uni textbooks explanation makes me cry. your explanation makes me cry in joy. 😅
its a very good more than books for sure
Brilliant
Please do similar basic videos on Ultrasound, CT scan physics and Gamma imaging. Muchh needed. Thanks:)
Bro you should go teach masters for radiology, impressive explanation, thank you so much !
Thank you very much
Sir plz post more videos on mri physics this one is awesome…
This is an absolutely fantastic introduction to MR. Easy to understand and clinically relevant. Wish I would have come across it during my core review a few months ago.
best lecture
Thanku so much
Thanks!
Very nice overall presentation. TR introduction was a bit lacking
Thank you so much
Sir. is it possible to share the power point file of the lecture??
34:15
Isnt the X axis - time? As if when do we acquire the signal and not give the 90 degree pulse? Shoudlnt it be Te (or time of acquisition) and not Tr. in your explanation?
In my understanding the difference in contrast of T1 relaxation with short TR should be explained by relative short horizontal magnetization vector of water in contrast with longer vector of fat after the second 90 degree pulse. With short Tr more water protons become higher energy state than fat protons, thus the net transvese magnetization is lower of water than of fat, and thus the signal that we measure at point of echo will be stronger of fat than of water.
With increasing TR (time of second 90 degree pulse) the difference between horizontal magnetization dicreases and thats why we loose contrast.
I got some question: if I have well understood, both T1 and T2 'come from' the same phenomena, which is having the RF pulse taken away. In the T1 case we have how fast longitudinal magnetisation recover its 63%, in T2 we have how fast spins are losing their 37% of phase (than lose the trasversal magnetisation). They're even influenced by each other, as you say rightly that you put, for instance, a long TR in a T2 weighted image not to have the T1 'contribution' in it.
1) why can't I acquire both the two weighted images with only one scan as both need the RF to be ruled out?
2) in my RMN I usually work on the TE is fixed and I can only change the TR, regardless is a T1 or a T2. Why is that?
3) if I want to get more images out of a certain scan the only thing I can do is get an higher TR. Why is that? What does the TR have to do with the amount of images you can get out of a scan?
Thanks
Thanks for video. definitely,
"I wanted to ask something;
In a magnetic field where no external pulse signal is applied, would a proton making a precession spin at the larmor frequency send out electromagnetic waves?"
I was just going to ask; however, I saw that you explained this very clearly in your video. You really explained it very clearly. Thank you.
Thanks. I'm glad it's helpful. I assume a proton precessing at larmor frequency would produce EM waves but negligible for clinical MRI.
@@neuroradish thanks a lot.
@@neuroradish Thank you for your answer that got me excited. Can you unpack your thoughts on this matter? This could be the beginning of a research for me.
@@ahmetozdemir7173 I'm afraid it's beyond the scope of my understanding. At the end of the day, I'm just trying to simplify a complex subject such as MRI physics for my day-to-day clinical practice.
In your demonstration showing different contrasts between fat and CSF along their respective T1 recovery curves (graph at roughly 33:47), I am confused as to why you say the signal is strongest when the contrast is smallest considering both have regained most of their longitudinal magnetization by then? I thought signal was strongest when in the transverse plane? Is it just that T1 increases over time and that T2 decreases? Maybe thats why Im getting confused?
Does the external magnetic field influence the spin as well as the precession or just the precession? I guess my question is, is spin influenced by this process or is this just an unchanging quality of the atom?
The precession axis is perpendicular to the z axis. After the 90 degree RF pulse, the protons are flipped to the x axis. Wouldn’t the precession plane now be perpendicular to the x axis?
When we say introduce an 90° RF pulse and 180 °,,,the aspect of angles what are they and their importance
Kindly clarify for me
Hi doctor, in 7:53 is the nuclear spin direction in the wrong way? thank you.
Hi. To be perfectly honest, I'm a clinical radiologist not a physicist, and admittedly have a limited knowledge in quantum physics. I would only see those drawings as for illustration purposes. Sort of a lay person's approach to a much more complex topic.
@@neuroradish I'm currently in cleerkship and struggling with MRI, thank you for your video. Does your video cover the MRI knowledge enough for clerkship and non-radiologist residency? I thought memorizing different disease with different pulse sequence finding is hard, without understanding the physics of MRI; However it is very difficult...
@@user-wr9ks3tf4n If you understand these basic MRI physics principles, it is more than enough for radiology clerkship. In fact, this is mostly for radiology residents and what they need to know for their board exam. Unfortunately, I don't think there is an easy way to study or memorize what a particular pathology looks like on what sequences. There are just too many pathologies. For vast majority of radiologists and experience clinicians, it is down to the "muscle memory". You need to look at the images over and over again. My advice is to look at as many images/sequences as you can for a particular disease, rather than just trying to memorize a list or read from a textbook that only shows a few selective images. You need to look at the entire study, repeatedly. Also, rather than trying to study too many diseases at once, pick one or few pathologies that you are not familiar with yet (maybe something you come across during your clerkship, or you heard about in an interesting presentation), then look up as many examples as you can, study it a little in depth, and look at the entire study (all sequences) for that one disease. We learn radiology by seeing the entire study, not just reading few pictures with arrows that points to the findings. I find that when I try to learn too many pathologies at once just by reading a textbook, different pathologies start to bland in with each. Don't get discourage! You'll get there.
@@neuroradish thank you for your detailed response doctor! I will get your advice and trying to look as much image as possible in one disease.
12:46 Can air resistance be ignored in this question?
The real Lenard McCoy is Deforest Kelly!
Indeed. R.I.P. Deforest...
Sir can i get this ppt
Can I get the slides please
I had 3T abdominal mri with contrast done a month ago , 6 h later I started with muscle twitching, pins and needles , ringing ears , internal vibrations , light headaches , tingle in my spine area . Nobody knows why . I google mri can provoked PNS . Is that possible that after a month I still have symptoms?
Dear o dear, that sounds bad. Did they investigate the contrast?
@@jacobvandijk6525 well they stated you pee the contrast in 48 h . I did Urine test to measure gadolinium. Pending results . They also stated that PNS only occurred while you’re in the scanner . They cleaned their hands .
"in indiana lots of fat" lmao!!!
"transverse decay much faster than longitudinal recovery"
I can’t see anything
For to do the wavelet transform or Function Wave i am not requiere the complex number or Fourier series. Just I need the new methodoly I discovered.I left this video to compare:
czcams.com/video/3Ebvypj577E/video.html