T1, T2 and Proton Density Weighting | MRI Weighting and Contrast | MRI Physics Course #6

[@francochiteka7364]

small error @2:15-2:16 longitudinal recovery (63% not 67%)

[@radiologytutorials]

Thank you! Small but important 🙂 will 📌 pin this so others can see 🙏🏻

[@zer0legend109]

I was perplexed for a second, should have made some kind of annotation on the video to highlight the mistake

[@alonewanderer4697]

@@zer0legend109 Perplexed, baffled, and frankly, utterly bemused. Cmon man, it's just a typo, probably due to the fact that 1/e ~= 0.37, and so the 7 sticks around in the head when you calculate 1-1/e.

[@GaylaPybus]

I am starting MRI school in 2 weeks with zero background in this field. I purchased "MRI In Practice 5th Edition", and decided to read 3 chapters to familiarize myself with content prior to beginning class. Big mistake. I was so confused. I am a great student, but my brain is not geared to physics. Your videos are the BEST! You have a gift for teaching, and breaking it down into understandable terms. I get it now. I can speak for all MRI students when I say physics is one of the hardest parts. Thank you for caring because you did not have to conduct these videos. Best of luck to everyone going through the program and taking their licensing exam. May we be the best MRI Techs for our patients.

[@mihaimoldo]

Don't worry. I takes years for mri physics to finally click so you understand it on a fundamental level . The most important part in the beginning is to know the anatomy and the orientations, then sequences, and then parameters .

[@abhijain5933]

Best explanation of MR physics.

[@radiologytutorials]

Appreciate it! Thanks!

[@AustanStein]

Been servicing MRI machines for the past four years and your lectures are incredible thank you

[@emily-rivendell]

Thank you!! This was extremely helpful!

[@CDP-yl5jp]

Thank you for great lectures! I think I´m missing a small piece of the puzzle to understand this. Assuming we are starting from time 0 and applying the first 90 degree RF pulse, if we measure/sample the signal with short TE (for T1 weighting) i cannot understand how TR can have any impact on this measurement since it seams in the diagram TR is occurring after TE. The model does not make sense to me if there is only one repetition of RF-TE-TR with sampling at TE. In my mind for this to work the sequence of events would have to be something like RF-TE-TR-TE2 with sampling at TE2 for T1 weighting at least. In others words the T1 relaxation and subsequent 90 degree pulse (TR) must cycle at least once for the tissues to first differentiate (due to the different relaxation rates) and then be flipped in order to be measurable in the transverse plane. Am I making any sense here? Excuse the confusion.

[@عبدالرحمنسلامة-م9ص]

I was hoping he would reply to that

[@christianbehler4309]

I've had the same problem. And I think you are right. You get a T1w image when: 1. Apply a 90deg pulse. 2. Wait a long TR that we have big T1 differences in the lateral plane. 3. Apply a second 90deg pulse to flip the T1 differences in the transverse plane. 4. Measure those differences now with a very short TE.

[@mohitagrawal1382]

@@christianbehler4309 ah ok so basically we are measuring our new TE after that second 90deg pulse so we need to do a initial 90deg pulse without even needing to do a TE then start our next 90deg pulse (TR) at a different point than the initial starting point which then we can measure a TE with a different starting point which will then allow us to highlight different parts of the brain differently.

[@mudithaariyarathna7301]

I am sri lankan radiography student.This is very much help to me in my studies 😘❤

[@NoorAfshan-u2p]

you are a life saver ..God bless you ..thank you for your priceless efforts

[@radiologytutorials]

You're welcome! Thanks for watching 🥳

[@DrZubiaTarar]

The only channel for which I have turned on notifications. Sir next lecture please. Thank you.

[@radiologytutorials]

New one is out 👍🏼 thanks for your patience 🙂

[@DrZubiaTarar]

@@radiologytutorials Thank you

[@rakeshmaheshwari6754]

Fabulous, it shows your strong hold on the subject.

[@PaulAni-o6l]

Thank you so much for your well detailed explanation, I really appreciate that. Remain blessed Sir.

[@GiorgiaZilio]

Thank you very much! I am desperately trying to understand how diffusion MRI works and your videos are finally giving me at least a clear perspective on how the basic aspects of MRI works!

[@radiologytutorials]

Great to hear! Next video is on diffusion weighted imaging 🥳

[@GiorgiaZilio]

Super ! 😍Can't wait to see it!@@radiologytutorials

[@babasahebkolhal5100]

Making mri more simpler Thanks Sir for great efforts❤ Love you❤

[@radiologytutorials]

Thank you ❤️ glad they’re helpful!

[@flavianicolecamachoveliz1355]

Amazing tutorials, cheers from Ecuador

[@hanifmahmud9294]

Extraoridnary works you did Sir...there's no fitting word to say to you ..just that.. carry on🙂🙂👍👍

[@radiologytutorials]

Thank you so much Hanif 😀

[@PrettyPrettyPwnies]

This is such a clutch video and series. Thank you so much.

[@reysvignette]

I love this series! thank you so much

[@n_o_w_a_y]

YOU ARE THE BEST IN MRI LECTURES🤩

[@YonasAschalew-f4b]

We are waiting for the rest of MRI and CT Michael and thank you❤

[@radiologytutorials]

Released a new one today ❤️

[@DrZubiaTarar]

Besttt! My exam in September and hope to watch all your Physics course till then. Thank you Sir.

[@radiologytutorials]

You’re going to be great in your exam I’m sure! Keep up the hard work 🙂

[@Ruth_Grace]

You’re God sent. Thank you so much 😊

[@radiologytutorials]

You are so welcome!

[@Ehe265]

Thank you doctor for ur wonderful lectures ...waiting for the next MRI videos ...from Ethiopia ❤❤

[@radiologytutorials]

It's an absolute pleasure. I'm working hard on the next videos in the series. Hope you find them useful!

[@irishcamilledelsocorro6246]

thank you very much sir.. very helpful as we prepare for our exam.. watching from the philippines..

[@radiologytutorials]

Glad it was helpful! Best of luck for your exam. Regards from South Africa

[@lucaya]

Great lectures

[@mansurali1933]

Wonderfully explained ❤

[@asraflatif4172]

HI doctor, great lectures as usual. I have a question. Referring to the statement around 5:34 minutes are these the same as what the books are saying about leaders and laggers. Are the muscle leaders and are the CSF laggers in T2 relaxation?

[@tearsinhd1997]

Will this be helpful for my ARRT Test?

[@bedilumelesse3948]

Always u made easy my strugle!,thank you!

[@radiologytutorials]

Happy to help Bedilu!

[@abdullah7472]

Thank you very much sir for every information given to us ... I have question please Do you will give us lectures in CT scan ; mammography and flouroscopy ? Thank you again boss

[@radiologytutorials]

My pleasure. The plan is to complete MRI then move on to CT, fluoroscopy, nuclear med, mammography etc

[@abdullah7472]

❤

[@teoritsos3640]

Thanks

[@syafiqyacob]

Hi doc! Would me mind give guidance on oral cavity anatomy? I find the surrounding muscles names are so foreign n difficult to identify. 😮

[@rehabmohamed5513]

This is great ! Thanks alot I am a newly rotating doctor in radiology department and your vedios is very very helpful .. Can you suggest to me good reference for studying ..l dosnt like farr and it doesn't contain all this topics and information ..😢

[@radiologytutorials]

Thanks Mohamed. I use Bushberg - essential physics of medical imaging.

[@Will67898]

Soo, what happens with a short T2 (~500ms, =full T1 differences of tissues) and a long TE (~100ms, =full T2 differences) ? We get a super bright image? Do the tissue T1 and T2 signals cancel each other out?

[@Ruban-C-002]

Love your content ... very helpful ...

[@radiologytutorials]

I appreciate that! Thank you 😊

[@omarfarid952]

Amazing

[@jeevithar2582]

Sir what happens if we give 180 degree RF pulse after initial 90 degree RF pulse will it change anything

[@matutejohn6994]

Why are you pointing those sticks that way? I consider transverse magnetization in the horizontal plane and longitudinal magnetization in the "axial" plane, but you show it the other way.

[@caiyu538]

Great lectures. 😊

[@radiologytutorials]

Glad you like them!

[@nunya3399]

Can someone tell me why the bone is brighter than the muscle on proton density? It seems like there would be more hydrogen signal from the muscle and I don’t understand what’s causing the pixel brightness of the bone.

[@theonlycartoonnetwork]

Chai... Well detailed.

[@chazsison]

Wheres the next vids😢

[@radiologytutorials]

New one out 🙂

[@____gminton]

thank you so much sir

[@radiologytutorials]

Such a pleasure!

[@sohailkohri7269]

What a gem you are🥵🥵

[@radiologytutorials]

Thanks Sohail 🙌🏼

[@mudangayu1729]

1 question. If PDW is based basically on the number of protons available, then why is CSF but bright in PDW Brain images?

[@mudangayu1729]

Okay got it. It is actually bright, but just not as BRIGHT as in T2 weighted with long TE

[@shabnamaliak7649]

please upload the MRI Q

[@radiologytutorials]

This Friday hopefully 🤞🏼 🤞🏼

[@Ruban-C-002]

Waiting for next video.... come back

[@radiologytutorials]

I’m back 🙂

[@sunnyday8765]

Thanksssss ka❤

[@radiologytutorials]

Pleasure ❤️

[@chrisdao]

sooooo good

[@radiologytutorials]

Thanks Chris. Hope you’re well mate 🙂

[@kunjani20]

63% or 67% ?

[@radiologytutorials]

Apologies, there is a small mistake with the one diagram. 63%

[@mehboobalimehboobali5528]

❤❤

[@diegorosato2455]

I’m sorry I have a question… didn’t you say that we can directly measure T2 (transverse decay) with our first 90 degree pulse? (Eventually correcting T2* with the 180 degree pulse). Then the second set of pulse is for measuring the T1. You said in this video that to weigh a T2 image we need a very long TR and then a medium TE. But actually that goes only if we want to use the second pulse to measure T2. We could simply measure T2 in the first pulse considering that TR in this case would be equal to the time we initially apply B0 to all the protons in the first place. That goes to say that to measure T1 we absolutely must use the second pulse, but do we really need the second pulse to measure T2?

[@radiologytutorials]

Hi Diego. We only measure the signal after the 180 degree pulse (in spin echo sequences). This measurement is a reflection of the T2 decay. Where I think you might be getting confused is that we don't take separate measurements for T1 and T2. We take one measurement and depending on when we apply the RF pulse (TR interval) and when we measure (TE), the image will have either T1 or T2 weighting. There is no measuring of T1 and T2 separately because we can never measure T1 directly in the longitudinal plane. Hope this makes some sense..

[@sohailkohri7269]

Sir make videos conceptual as possible as rather than informative like others

[@radiologytutorials]

Will try my best

[@bodanamusicproduction876]

❤❤

[@AainaKohri]

❤❤

[@suhanakohri8928]

❤️❤️