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@AmitJoshi-fu4ir 3 күн бұрын
Add Fourier transform and K space lecture.
@MRIPhysicsEXPLAINED 2 күн бұрын
Right around the corner, stay tuned!
@oscarlubega 4 күн бұрын
this is amazing work...... and i have seen many teachings on ADC/DWI
@MRIPhysicsEXPLAINED 2 күн бұрын
Glad to hear it was helpful and thanks for commenting!
@PrashathSiva 6 күн бұрын
❤
@MRIPhysicsEXPLAINED 4 күн бұрын
😊
@franciscofernandomoralessa8344 6 күн бұрын
Thanks for this amazing set of lectures; Question... in the Noa image when the hand pokes the vectors I understand in whats its said that only after the poking of the protons start to precess, or that move already exist before the stimulation?
@MRIPhysicsEXPLAINED 4 күн бұрын
Hello, thanks for commenting and great question! While the individual protons will have some baseline spin like all atoms and particles, they are not precessing all together as one. We need to impart them with some angular energy with our RF pulse to get them precessing as one unit together. Hope this helps!
@kalogerakisbookings1336 7 күн бұрын
Great work!
@MRIPhysicsEXPLAINED 4 күн бұрын
Thank you! Cheers!
@Theextremepessimist 16 күн бұрын
I have to watch these videos more than once.
@MRIPhysicsEXPLAINED 12 күн бұрын
Me too 😂
@palpytine 17 күн бұрын
Well, now, you just had to go and introduce FLAIR. As I'm sure you must be aware, that now means you're contractually obliged to cover *all* the common inversion recovery sequences.
@MRIPhysicsEXPLAINED 12 күн бұрын
😂 It's been a lingering around in the back of my mind somewhere, but first have to wrap up this diffusion weighted imaging series! Next up, DTI
@TaejinMin-q3p 18 күн бұрын
This is EPIC!
@MRIPhysicsEXPLAINED 17 күн бұрын
😂
@EriqHover 21 күн бұрын
niceee
@MRIPhysicsEXPLAINED 18 күн бұрын
Thanks for watching!
@tsrmstefanobiagini Ай бұрын
Great video, could you make a video about difference between monopolar and bipolar dwi and on the meaning of 3 scan 4scan 3diagonal gradients (siemens) Thank you!!
@MRIPhysicsEXPLAINED Ай бұрын
Will definitely put it on my radar, thanks for watching and commenting! Nearing the final stages of the next lecture on DTI, should be a good one so stay tuned!
@Pendergeist Ай бұрын
I really vibe with these videos and your sense of humor
@MRIPhysicsEXPLAINED Ай бұрын
Thank you! Hopefully can bring a little entertainment to an otherwise dry subject!
@t1relaxation Ай бұрын
I noticed that the T1 relaxation times are constant. So does the MRI tech choose the TR time only to control TE or does the tech choose both TR and TE? I'm taking the ARRT test in December 2024
@MRIPhysicsEXPLAINED Ай бұрын
In general, the chosen TR time will affect T1 image contrast, and the chosen TE time will affect T2 image contrast and these values will remain constant for that sequence. For most sequences, these parameters are all ready chosen and optimized so the technologist simply picks the appropriate "protocol" to run. However, you can certainly manually go in and change the values of TE and TR, albeit this will change the contrast of the picture and you'll likely get an angry call from your local radiologist :)
@jakobthomsen1595 Ай бұрын
Wow, that's fascinating! Thanks for explaining this!
@MRIPhysicsEXPLAINED Ай бұрын
My pleasure!
@jakobthomsen1595 2 ай бұрын
Really cool 🙂
@MRIPhysicsEXPLAINED 2 ай бұрын
Thanks again for commenting!
@jakobthomsen1595 2 ай бұрын
cool 🙂
@MRIPhysicsEXPLAINED 2 ай бұрын
Thank you!
@jakobthomsen1595 2 ай бұрын
Great video series! Ok, so if I understand correctly the magnetization recovery process can be described (omitting constants) by a differential equation f'(t)=1-f(t) where t is time, f'(t) is the re-magnetization rate which is proportional to 1-f(t) i.e. the difference missing to "fully magnetized", where f(t) is the current magnetization proportion (1 meaning 100% magnetized). Because the constant 1 vanishes when taking the derivative f'(t) must be -f(t) which means it must be the exponential function with negative exponent: f'(t) = -e^-t and f(t) = e^-t, because the exponential function is the only function that is its own derivative. And to account for the re-magnetization speed or respectively the re-magnetization time we introduce a scaling factor 1/T1. Which gives us the full formula 1 - e^(-t/T1). And because this function approaches 1 i.e. full re-magnetization only in the limit t -> infinity, we choose some finite time instead. With t/T1 = 0 meaning full de-magnetization the next obvious choice is to choose t/T1 = 1 i.e. t = T1 which gives us 1-e^-1 = 1-0.37 = 0.63 approximately. Phew, I think I got the math part 🙂
@MRIPhysicsEXPLAINED 2 ай бұрын
You got it my friend! With those math skills you might want to get into this teaching hobby as well!
@sameerchandorkar365 2 ай бұрын
Thanks
@MRIPhysicsEXPLAINED 2 ай бұрын
Wow thank you so much!! Your support really means a lot, working on the next lecture now as we speak so stay tuned!
@jakobthomsen1595 2 ай бұрын
Very well explained! BTW the 63% looks suspiciously like 1-exp(-1)
@MRIPhysicsEXPLAINED 2 ай бұрын
Thanks for commenting! I actually did a deep dive on this 63% and did a little segment on it in the Q&A video here, check if out if you'd like to learn more kzfaq.info/get/bejne/acCaoJSo2qzTZoE.html
@jakobthomsen1595 2 ай бұрын
@@MRIPhysicsEXPLAINED Neat!
@minakshi2412 2 ай бұрын
Great video.. you made it super interesting to learn, thank you!
@MRIPhysicsEXPLAINED 2 ай бұрын
Awesome to hear it helped, thanks for commenting!
@julessoto137 2 ай бұрын
STRONG WORK. Thank you
@MRIPhysicsEXPLAINED 2 ай бұрын
Thanks for watching and commenting!
@DrMdAbdulHafeezMalik 2 ай бұрын
It was easiest explanation I have encountered till now ,Plz post more videos
@MRIPhysicsEXPLAINED 2 ай бұрын
More are in the works!
@DrMdAbdulHafeezMalik 2 ай бұрын
Thank you y
@MRIPhysicsEXPLAINED 2 ай бұрын
Glad it helps and thanks for the comment!
@MRIPhysicsEXPLAINED 3 ай бұрын
LINK TO CLINICAL FLOW CHART 👇👇👇 radiofreedia.org/approach-to-abnormal-restricted-diffusion/
@Obscure121gw 3 ай бұрын
Local AM radio stations operate between 540 and 1700 kHz, not 68 MHz. FM radio stations operate between 88 and 108 MHz which is slightly higher than your example of a 1.5T magnetic field.
@MRIPhysicsEXPLAINED 3 ай бұрын
Thanks for the comment. This (should have been) already corrected with a caption that pops up during this segment saying the band is analog TV and into the FM range.
@sehrish9847 3 ай бұрын
Waiting for more videos.Excellent explanation.
@MRIPhysicsEXPLAINED 3 ай бұрын
Thank you! More videos are in the works!
@KokebGebremeskel 3 ай бұрын
This is truly Amazing! Thank you so much!
@MRIPhysicsEXPLAINED 3 ай бұрын
Thanks for watching and commenting!
@interwebzful 3 ай бұрын
that was good
@MRIPhysicsEXPLAINED 3 ай бұрын
Thank you!
@keegansimyh 3 ай бұрын
Question: how were we able to localize in the Z-X plane before when we were also using gradient magnetic fields in both these axes?
@MRIPhysicsEXPLAINED 3 ай бұрын
Hello, check out the lectures on slice selection kzfaq.info/get/bejne/rJ6aipt8lt-Re3k.html and frequency encoding kzfaq.info/get/bejne/er-aZLZ9s9bUgYE.html where we go in-depth on how to localize the signal in the Z and X dimensions in you haven't already. If you still have questions let me know!
@keegansimyh 3 ай бұрын
@@MRIPhysicsEXPLAINED I'm confused about why we don't get the same problem at 7:55 in the Z-X plane. I can see that using frequency gradient in the X and Y axes causes the same frequencies to repeat and thus we can't resolve along (x+y=c). But why do we not get the same problem when using frequency gradient in both the Z and X axes? How are we still able to resolve voxels along those diagonals?
@MRIPhysicsEXPLAINED 3 ай бұрын
The beautiful thing about the slice select gradient technique is that we don't have to resolve the signal in the z direction, the gradient is turned on along the z-axis so that when we apply our RF pulse and tune it to the region of the body of interest along the z-axis, we know all the signal we receive is coming from that slice alone. We simply just then turn off the z-axis gradient, the protons in the slice fall back into precession at the Larmor frequency, and the problem then turns simply into localization along the x and y axes for which we do the frequency encoding and phase encoding techniques. Now in 3D MRI acquisition we do replace this slice select gradient technique with a true image encoding gradient along the z-axis, but that will require a little extra knowledge to understand which we'll cover in future lectures 🙂
@RayJacobsenJr 3 ай бұрын
As an MRI Field Service Engineer, it is my job to ensure that all the intricate MRI Physics are functioning properly every day. I'm grateful for the "MRI Physics EXPLAINED" channel on KZfaq, now I can direct people with questions to this resource. Your efforts are much appreciated, please continue to create valuable content.
@MRIPhysicsEXPLAINED 3 ай бұрын
Thank you for the comment and for keeping these amazing machines running! We've got a whole set of advanced lectures coming that will get into some engineering topics so stayed tuned!
@josephdays07 3 ай бұрын
Hello, Great job👍💯. I have developed a new methodoloy to do Wavelet Transform, Uncertainty Principle Graph, X-rays..... I have wrote about it. These theories you can use in Quantum Physics: And with these theories I haved solved Prime Numbers and Riemann's Hypotesis. It applies to MRI... kzfaq.info/get/bejne/pciBo7Wr1ardgnU.htmlsi=Fb0fiSavner-XHER kzfaq.info/get/bejne/e5-EedVit7LRdXU.htmlsi=b4FTZxePO7kChF8- kzfaq.info/get/bejne/jspoiZyEuZe2dJs.htmlsi=hEZSejrw5V6Yk-mB kzfaq.info/get/bejne/ppaKlpyg07G1YIU.htmlsi=nb0yLS3_CoLnRS6L kzfaq.info/get/bejne/aauSqdyhz5ubZ3k.htmlsi=7iiGMVKOcnQlXiIo www.amazon.com/s?k=jos%C3%A9+mauricio+orellana+d%C3%ADaz&crid=9Y4AJXKYABD3&sprefix=Jos%C3%A9+maur%2Caps%2C294&ref=nb_sb_ss_ts-doa-p_1_9
@MRIPhysicsEXPLAINED 3 ай бұрын
Hello, thank you for sharing!
@MRIPhysicsEXPLAINED 3 ай бұрын
LINK TO CLINICAL FLOW CHART 👇👇👇 radiofreedia.org/approach-to-abnormal-restricted-diffusion/
@karlitadr11 3 ай бұрын
Thank you, I appreciate your pedagogy and humor!!🧠😂💯 KEEP IT GOING!!!
@MRIPhysicsEXPLAINED 3 ай бұрын
Much thanks!! Check out the channel this weekend for a NEW lecture!
@matiaswindsor5793 3 ай бұрын
Why is it called "planar"?
@MRIPhysicsEXPLAINED 3 ай бұрын
That is a good question! "The echo-planar imaging (EPI) technique, proposed by Mansfield, overcomes this limitation by determining a complete two-dimensional image matrix in a single experiment. As the name implies, the method uses signal echoes to simultaneously acquire signal from the whole two-dimensional (planar) imaging slice."
@matiaswindsor5793 3 ай бұрын
@@MRIPhysicsEXPLAINED Thank you very much!
@m7mdmeedo 3 ай бұрын
Great job 👏
@MRIPhysicsEXPLAINED 3 ай бұрын
Thank you! Cheers!
@farahsamer7130 4 ай бұрын
You're a genius! thank you so much
@MRIPhysicsEXPLAINED 3 ай бұрын
Thanks for commenting and glad it helped!
@WalterPine 4 ай бұрын
lol ceo jocks
@MRIPhysicsEXPLAINED 3 ай бұрын
🤭
@WalterPine 4 ай бұрын
Hospital finances are important for the CEO LOL your hilarious 🤣 😂
@MRIPhysicsEXPLAINED 3 ай бұрын
Thanks for putting up with my bad jokes and I apologize if you're a CEO ha!
@WalterPine 4 ай бұрын
Thank you so much, can you lecture on the parameters: fov, matrix and tr that influence time?
@MRIPhysicsEXPLAINED 3 ай бұрын
We briefly get into factors that affect imaging time in the Spin-Echo lecture kzfaq.info/get/bejne/rLFmg8h0tdazfI0.html and Turbo/Fast Spin Echo kzfaq.info/get/bejne/kL1nl9pe37Kdj4E.html if you haven't checked those out already but will keep the other factors in mind for future lectures. Thanks for commenting and supporting the channel, really appreciate it!
@lucaya 4 ай бұрын
Great. Thank you!
@MRIPhysicsEXPLAINED 4 ай бұрын
Glad it was helpful!
@samgatin 4 ай бұрын
Hello from Kazan, Russia! Big thanks for your videos!!!
@MRIPhysicsEXPLAINED 4 ай бұрын
Hello there and thanks for commenting! Cheers from the USA my friend!
@lucaya 4 ай бұрын
Amazing!!! Best MRI lectures on KZfaq!
@MRIPhysicsEXPLAINED 4 ай бұрын
Too kind! Thanks so much for commenting and the support!
@lucaya 4 ай бұрын
Your lectures are the best on KZfaq yet. Thanks a million!
@MRIPhysicsEXPLAINED 4 ай бұрын
Too kind! Thank you so much for watching and commenting!
@vohuynhminhtuanvng 4 ай бұрын
🎉🎉🎉 thanks. It's very understandable. Could we have video about Steady state, Mister?
@MRIPhysicsEXPLAINED 4 ай бұрын
Great suggestion! Will look into it, do you use this sequence a lot in your daily work?
@vohuynhminhtuanvng 4 ай бұрын
@@MRIPhysicsEXPLAINED yes. In my hospital it's used to do a quick check of the abdomen. And it's also used in Cardiac study. It was called "Trufisp" in Siemen app. Thank you from the bottom of my heart. You help me so much! At school, I was just only taught about the surface of this such as listing the name of some sequence but not diving into it.
@MRIPhysicsEXPLAINED 4 ай бұрын
@@vohuynhminhtuanvng Awesome, so glad to hear the videos are helping! Will keep the steady state topic in mind for future videos!
@MinaRahmani-dh4nx 4 ай бұрын
Your videos are awesome!!
@MRIPhysicsEXPLAINED 4 ай бұрын
Thank you!!
@vohuynhminhtuanvng 5 ай бұрын
Thanks so much. 🎉 I have some stuck with this kind of knowledge. I have been reading many lectures about MRI. Could I ask you some question, Mister? 1. Some of people said that: The flip angle is determined by proportion of spin state "up and down" after exciting pulse. Is that correct? 2. After 90 RF pulse, a number of spin up will be equal to spin down. The spins which is resonated will be in phase. It is explained by quantumn machenics. But it seems to confuse me. Maybe is there something force them to be in phase? Also I don't know why 180 RF pulse cause it too. Somewhere in the internet, they explained understandably in the vector frame that the fast spin will catch up the lag spin and despend on the direction you put 180 pulse in. But when i try to apply it into the picture of spin-state, it makes me impossible to understand. 3. About 180 RF pulse in spin echo, after 90 exciting pulse, the transverse magnetization will gain conherence a little bit then dephasing with T2* decay. When we do a series of another 180 RF pulse, we have some coherence peaks. However, they gradually descrease magnitude and when we connect these peaks, we have T2 Decay. What make these peaks become smaller and smaller after 180 RF pulses. 4. After 90 RF pulse, we add a RF 180F Pulse. Now the vector B1 maybe >180? Is that mean the more spin up state becomes spin down? Could you do me a favor? 😭 I stuck with these problems a few days.
@MRIPhysicsEXPLAINED 5 ай бұрын
Thanks for the comment and great questions my friend! I think you are getting at a really frustrating point in that yes all of the physics governing magnetic resonance imaging are indeed covered by the laws of quantum mechanics, but trying to visualize what is going on at the quantum level is near impossible and for good reason! If the position and spin are mere statistical quantities resolved at measurement, how can we truly know their precise number and position/orientation? I think at best we can say a statistical number of these spins will be more aligned with the magnetic field B0 than randomly, our RF pulse will imbue a statistically higher number of these spins with a coherent precessional frequency and flip angle to produce a signal and so forth. But I think the visuals we use to depict these in a classical sense still hold a great degree of truth of what's going on. As to question #3, what makes the peaks become smaller is the ever increasing disorder of the system that begins as soon as we apply our initial RF pulse. Think of it like friction in the real world, we will always have irrecoverable energy loses with any system we put energy into whether it be your car or an MRI machine (excluding semiconductors!). We actually talk about this in the Turbo-Fast Spin Echo here: kzfaq.info/get/bejne/kL1nl9pe37Kdj4E.html Hope this helps!
@vohuynhminhtuanvng 5 ай бұрын
@@MRIPhysicsEXPLAINED I'm really grateful to you. Hope your channel would be well-known ❤️❤️❤️
@kanamala 5 ай бұрын
Probably one of the best mr teachers out there. Thanks so much dude.
@MRIPhysicsEXPLAINED 5 ай бұрын
Too kind! Thanks for watching and commenting!
@lucaya 5 ай бұрын
Excellent
@MRIPhysicsEXPLAINED 5 ай бұрын
Thank you!
@9678willy 5 ай бұрын
lettice
@MRIPhysicsEXPLAINED 5 ай бұрын
😂