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
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.
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.
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!!
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.
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.
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. 😅
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.
@@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.
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
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?
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.
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...
@@黃紹閔 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.
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?
@@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 .
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: ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-3Ebvypj577E.html
