Introduction to MRI: Basic Pulse Sequences, TR, TE, T1 and T2 weighting

Access our CT and MRI case-based courses at navigatingradio..., which include fully scrollable cases, walkthroughs of imaging findings, and comprehensive reviews of basic and more advanced imaging studies.
Basic Pulse Sequences (gradient echo, spin echo)
Pulse sequence parameters (TR, TE)
T1 and T2 weighting

[@anncampbell6766]

NOW I CAN CHANGE MY CAREER CHOICE, THANK YOU!

[@sajjadN1]

Thank youuuuuu this is the best video of playlist. Helped me a lot.

[@karaashley9519]

wow this helped me so much… that rephasing example with the cars was so simple but i am mindblown at how much it made it make sense!! thank you!!

[@CatMedy]

thank u so much for the videos, you're best at explaining such complicated themes!😍

[@RohitPant04]

Got it finally! Thanks.

[@mohammadshahjad1637]

Thank you 🙂

[@jejojoje9521]

But, if T2 is shorter than T1, in ohter words, T2 effect decays earlier than T1 effect, how does a long TE emphasize T2 in detriment of T1? By following the logic that T2 is shorter than T1, so the more the time passes, the greater would be T1 effect in comparison with T2, right?

[@JflyG]

From an R1, thanks

[@iimeo1363]

Thank u ❤️

[@Mars_Man21]

Great video

[@Sabrina-cs8cl]

Thank you very much!!

[@KirtiSharma-tm2qr]

sir , when fat have short longitudinal relaxation time then why they relax quicker on z-axis in short TR

[@nukenuke9394]

Amezing !

[@destynhernandez-bravo6057]

Hi! These have been so helpful! By chance, do you know when the video for Fat Saturation will be posted?

[@LaserPeow]

isn't fat saturation just some inversion recovery, where you give a 180° RF impulse with specific timing for fat and apply a 90° RF puls when the fat is at a 90° angle so it wont be affected? thus the 90° RF impulse only affects every other proton that is not parallel to this impulse?

[@mrkarn8241]

is it safe to say to fire immediately a 180 pulse to have a shorter TE?

[@rianshala3565]

How does fat and water appear in gradient sequences?

[@MetalAndor]

Tissues usually have a much slower T2 time vs T1. So how come short TE isnt better for T2 times?

[@9cobil299]

If im not mistaken, it is because we want some amount of dephasing, such that fat and water will give of different signal intensity. If they are all in phase (short te), it will be harder to tell the difference in tissue composition.

[@esthermaina3825]

@@9cobil299 You are right Well out

[@WaqasAhmed-sh4cr]

Man ,its just too difficult 😢

[@Encore_22]

MRIPETCTSOURCE

[@MrSlawkie]

But wtf is echo? :(

[@amartinezsilberstein]

An RF pulse is transmitted to the tissue. The tissue absorbs part of the energy of this RF pulse. Then the tissue releases this energy in the form of another RF pulse (that has a different shape). I think this is what is referred to as "echo". It's the echo of the RF pulse transmitted by the MRI machine, that comes from the tissue that is being scanned. The tissue abrorbs the RF pulse and (kind of) releases it back so it can be received by the MRI machine.

[@LaserPeow]

the echo is the frequency of the precession of the protons that if you activate the antenna at a specific time (TE) will net you a current in the coils, which can be interpreted via an algorithm

[@TC-dw6wg]

The echo is the rf signal received back into the coil from the body. This signal is what we use to create images

[@truongvinh3108]

​@@amartinezsilberstein your comment is all i need today 😭

[@anarbay24]

Meh, video!