MRI: excitation and recovery of spins

This animation shows how spinning hydrogen nuclei are excited by a radio pulse, and how they subsequently emit radio waves as they return to the ground state.

Category:

Science & Technology

Tags:

• MRI
• animation

[cmorethings]

nice .the hydrogen dudes should think long and hard about this.its all related

[islandbuoy4]

so nuclei emit radio waves as they return to the ground state.

and electrons emit and absorb photons to move UP or DOWN energy levels.

where do the phonons come into the picture?

[h2321]

@danejoe650 Yes. The shown relaxation only includes T1. What T2 would look like in the video would be nuclei start to point at various directions in the xy-plane. So the net magnetic moment along the y-axis would decrease gradually when more and more nuclei are out of phase with each other.

This also tells us why T1 is always longer T2. When T1 is over, there are no more horizontally aligned nuclei thus no net magnetic moment in the xy-plane.

[danejoe650]

Very helpful visualizations.

Is this T1 relaxation?

[juanpodadera1]

Great video guys...

[shahir321]

Thanks for the video..it is probably the best video on youtube about MRI.

[profesorsergio]

So amazingly good!!!. Thank you. Favourite and shared. Cheers!!!, Sergio.

[lookatcha]

excellent video:) thanx

[leotakesleo]

make more such videos!!!

by the way you have any other material that details the image formation through fourier analysis?

[cytorun]

nice animation but a little physically misleading. The spins seem to have behavior like quantized spin and net magnetization due to an ensemble of spins. Also the emission of electromagnetic waves does not just occur when an individual spin changes state but rather whenever there is oscillatory motion of the spin magnetic moment.