MRI Physics | Magnetic Resonance and Spin Echo Sequences - Johns Hopkins Radiology

Don’t fret about learning MRI Physics! Join our proton buddies on a journey into the MR scanner's magnetic field, where they encounter radiofrequency pulses, generate echos, and combat T2* effects! We take it back to basics, focusing on the fundamentals of magnetic resonance and reviewing the components of a simple spin echo sequence.
Check out more educational resources for radiology residents and medical students at TeamRads.com
Video Outline:
0:00 Introduction
0:10 Protons
0:43 Magnetic fields
1:18 Precession, Larmor Equation
1:56 Radiofrequency pulses
3:00 Protons will be protons
3:45 Spin echo sequence
5:00 T1 and T2 time
5:51 Free induction decay
6:28 T2* effects
7:02 T2* effects (the distracted children analogy)
8:23 Spin echo sequence overview
Animation by Emily Wu, MA
Script and Narration by Erin Gomez, MD
Special thanks to the Johns Hopkins University DELTA Grant

[@michaelblankenau6598]

The people who designed and engineered MRIs are geniuses . All these analogies don’t scratch the surface on the deep understanding one must have to make sense of this technology.

[@x0xNOVAx0x]

Animator is god.

[@hermanyuen4046]

Please do more of these videos to explain other MRI sequences. Your analogies made the concepts so much more easier to understand! Please keep up the good work.

[@Haru-xn6hy]

What a PERFECT explain it is!! I’m a student studying MRI in South korea where there are a lot of headmasters who lecture MRI poorly… Thank you for your high quality video and I’ll come back when I need your help thanks a lot!!

[@ThamizhanDaa1]

This video is soo good. Like my professor tried explaining this over 3 lectures, but I didn't understand. This video made it so crystal clear. Well Done!!

[@pawanKumar-hp7zm]

Ha

[@thadreimagined9391]

You brought me back from the brink of panic. Thank you.

[@easyMRI]

The best explanation of the MRI basics ever!!!

[@common1028]

I was struggling to understand the spin echo sequence with the complicated formulas taught in class, but this just made my day :) So easy to understand with the super cute animations! Thank you sooo much!!

[@daltonbryer3171]

Huge help thanks nobody ever explains what axis things are spinning in. Please make more of these!

[@MrTian1212]

Please keep more coming!! This is so good!

[@shujatali642]

Super, can't have a better explanation than this. Amazing

[@edwardhayes5229]

That was incredible. I loved that you still used useful analogies for such a complex topic.

[@diegosoriavivas]

What an amazing job you have done! Thank you so much! This is a phenomenal video. You made this very easy to understand.

[@heddaisbingingyoutube]

I am amazed over how much more understandable this concept just became, with your illustrations and great explanations. Thank you so much!!

[@subiraa814]

Brilliant! Simply brilliant! Please make more videos like this, Dr. Erin Gomez and Emily Wu!

[@thabangmoarabi2419]

You are very comprehensive. Thank you.

[@14renukakadu28]

BEST VIDEO ON MRI AND NMR. I have been trying to understand this concept for hours. I have a much more clear understanding now. Thank Youuuu!

[@sophiaramos770]

This is amazing!! I wish there were more videos

[@ashidubey5225]

This is hands down the best explanation i've seen for this..!!!!

[@dinaalmiari264]

great video ! just summarized 105 slides of MRI in 10 minutes . Thank you

[@sehrishmomin865]

Excellent explanation

[@Gealamusic]

Thank you , this is so helpful, really impressive animation :O

[@TheLadyskittles]

Best MRI video ever!!! Please make more of thesee

[@viktorgotz1098]

great explanation.. finally. Thank you so much!

[@chuanwu6118]

This is amazing!!!! Looking for more of these!

[@REGINAESGUERRA]

Thank you! Makes so much sense for a visual learner like me! Give the animator a big applause!

[@17x30__]

At 1:58 in the video, the explanation was well done and allowed me to grasp the principles behind SPIN UP and SPIN DOWN effectively.

[@alerope6597]

Thank you very much! It was really helpful. Keep up the good work!

[@larawagner2389]

Wow this is so good! We need more

[@saisrinivas3909]

Excellent animation and beautifully explained

[@mahima5402]

beautiful video

[@appsenence9244]

Absolutely amazing video😊

[@ashleynicoleg770]

This is soooo good!

[@silviasansanocolomina9495]

thank you so much! you are amazing!

[@ellemargaret4529]

this video saved me!!! so clear, thank you

[@hollumsss]

Is there a second video yet? Thank you!! This is very informative

[@harammuneeb462]

Excellent description. 😁

[@suomynonaanonymous]

fantastic explanation, wow!!!!!!!!!

[@jawadalhajj6804]

thank you for this great video

[@amarshrivastava5363]

Sublime Explanation!

[@michaelkasembeli6074]

This was so helpful

[@Dtran4409]

that was amazing!

[@Pharaohmolo]

Incredible.

[@akekalukardjnaphai464]

Your video is very great. I’ve just understand what the multiple line symbol in phase diagram means.

[@annastark9917]

Very nicely explained

[@KaptainLuis]

Thank you!

[@samuelsimukoko3397]

This is wonderful!!

[@vanshthukral9440]

Radiologists generally dont dive that deep into the physics of imaging modalities, i am shocked to see this MD knowing everything, she must be a genius

[@bat7797]

Thank you so much

[@maximilianriemer2356]

amazing Video

[@cloudsky997]

Cutest explanation ever seen😆

[@youngdegenerate1002]

Thank you video

[@shathiskumargovindaraju1223]

great video. tq very much

[@patharnr8569]

This vdo is valuable!

[@jakobv8]

Very interesting. I recently saw a 101 video of how MRI works and it's been lingering in my mind. This gave me a reminder and further depth. It is tricky stuff, really needs to explained several times to a layman.

[@ew7512]

Yes! I'm a layperson too, but really want to get a grasp on this technology because it's so fascinating and revolutionary. Watching a variety of videos explaining it is helping me to get a good understanding.

[@brendawilliams8062]

Me too, is there attractors involved. Deep stuff

[@ianlewis4383]

I’ve met dr Gomez before and can attest that she’s a great person in general ❤ happy to hear her voice on a KZbin vid

[@fahimandfardinsofficials1312]

Nice ❤

[@selgomezbabe135]

This is super helpful!! is there another video for T2 and T2* weighting?

[@yannickhs7100]

Was about to say that 🙏 would even pay for that !

[@hasanghavidel2701]

how these protons are cute 😍, i could understand all concepts.. god bless u

[@bladox971]

Exam in just a few hours, if i pass, it'll be thanks to you

[@martinprochazka5280]

Damn what a vocab this woman has

[@ShiraRachlin]

It says more on that later at the end- is there another video in this series?

[@delfipotters3161]

at 0:24 you say a hydrogen atom is just a proton, one positron and one electron. I'm very confused why you said that. There is no positron in a hydrogen atom

[@HemaSalam]

Me too

[@MyNotSoHumbleOpinion]

She probably meant "positive proton"...

[@delfipotters3161]

@@MyNotSoHumbleOpinion Protons always have a positive charge. She hopefully meant proton, but saying positron is very wrong.

[@MyNotSoHumbleOpinion]

@@delfipotters3161 yes, I know about positive charges of protons! But considering that luckily we live without positrons, "positive proton" seems to me the homophonic word that could match the erroneous "posi-tron"!

[@acluster3411]

I guess that was jus slip of the tongue, she meant proton. She seems to know her stuff very well!

[@Blak2blue]

I clicked cuz the molecules where so happy! 🥰🥰

[@HemaSalam]

How did a positron made it here 0:25 ? Can someone explain?

[@TheLadyskittles]

Where is the next one about T1 T2 phase?

[@dhathriprasad7121]

Wow

[@talesfreitas7873]

Magnificente, but.. Did you said that a proton components are onde pósitron and onde electron? It's not wrong?

[@skybuck2000]

why do mri scan not scan the bottom nerves s2 to s5 ?!

[@princetamrac1180]

4:33 in what dimension is the spiraling along the z-axis happening? One axis is the tranverse magnetization, on the other longitudinal. What is the 3. axis to create a 3d spiraling effect? Also does the transverse magnetization flip from the "negative side" to the "positive side" back and forth in the spiral? How does that happen? Also, is the initial free induction decay with the 90° pulses not registered by the MRI and only the following 180° pulses? Thank you so much for the video. Cute little protons :D

[@ileniapessotto7211]

soooooc cute!!!!

[@npact69]

So, can you use an MRI machine to affect the spin of an entangled particle? And if you could, you use that to potentially send Binary over a great distance faster than light?

[@missmyth21]

❤

[@radhaotwani3901]

can i get notes form

[@sierraoneal3501]

God bless you 🥲

[@sammytech9464]

🤩🤩

[@kaungsithusett9017]

not assuming anything about this particular presenter, but if it were an asian mom, the RF mom character would be holding a broom

[@emald7739]

Two tissue types A and B have the same proton density and the same T1, but A's T2 is half as long as B's T2. Which of the tissues gives the highest signal on a spin echo image taken with TR=2500 ms and TE = 50 ms? And why?

[@karineibrahim5628]

B?

[@braaitongs]

When atoms are hit with rf pulse, don't the parallel and anti-parallel fall over and align causing the 90 degree magnetic alignment? Anywho, this is extreme close to the method of nullifying gravity.

[@akekalukardjnaphai464]

May I ask why T1 have to be 63% of recovery ? Where this number come from ? Is it 50% recover of total energy ?

[@ozboz1995]

It comes from time constants (please google to learn more if you're interested).. 63% is used because its 1-(1/e) for an 'increasing' constant (where e = exponential function)

[@alexpaul5a]

What is T1 though?

[@aryankhanaryankhan6562]

How H pos have poles while having no electron

[@anjalipal5077]

Mam kay aap is video ki topics ko aur ache se explain kar doge?

[@carolinateixeira6709]

2h of this from my teacher and I didn't understand half of what you explained in 10 minutes

[@shashikantvairat8073]

What's magnet

[@Livecologne]

It is a good Video, but i understand it not really because it is in englisch, in german it was easylier for me.

[@ammaralharbi7711]

I WANT MOOORRRE INFORMATION NOOOO

[@EmilMichor]

A Hydrogen Atom is a Proton and a Electron, a Positron is the opposite of an Electron, it is Antimatter and anhilate with the Electron if it could.... So I'm 30 seconds into the video and already fundamentals are wrong....

[@anastasia.2007.]

Education from Johns Hopkins? Really??? 0:23 A hydrogen atom is a proton and an electron. A proton is NOT a positron and an electron. A proton is made of quarks. A positron is an anti-electron and is not a part of a proton or a hydrogen atom. Continue to spread your misinformation and pretend you are "educating" people!

[@rutamatukaite3295]

So much mistakes. Dont recommend. H plus has no dipole side.

[@HemaSalam]

How did a positron made it here 0:25 ? Can someone explain?

[@acluster3411]

I think she ment proton.

[@Adadhable]

Yes, I wondering the same thing. What she said in the video is incorrect, and I think what she meant is "a hydrogen atom is a proton and an electron"