Energy levels of nucleus in emitting radiation in MRI

[opfphysics]

Hi experts
please explain energy levels of nucleus in emitting radiation in MRI

 

[Parlyne]

MRIs don't emit radiation. They operate using an entirely magnetic effect.

 

[Drakkith]

The wiki article states: After the field is turned off, those protons which absorbed energy revert to the original lower-energy spin-down state. Now a hydrogen dipole has two spins, 1 high spin and 1 low. In low spin both dipole and field are in parallel direction and in high spin case it is antiparallel. They release the difference in energy as a photon, and the released photons are detected by the scanner as an electromagnetic signal, similar to radio waves.

I'm unsure just what they mean when they say it releases photons. Is it actually emitting radiation, or are the magnetic moments returning to their previous alignment and in the process the changing magnetic field inducing a detectable signal?

 

[granpa]

a magnetic dipole in a uniform external magnetic field will resonate at one particular frequency.

 

[sardar]

Sure, no problem. In MRI (Magnetic Resonance Imaging), the energy levels of the nucleus refer to the different energy states that the nuclei of atoms can exist in. These energy states are determined by the magnetic field strength that the nuclei are exposed to.

When a patient is placed in an MRI machine, the machine produces a strong magnetic field that aligns the nuclei of the atoms in the patient's body. This alignment causes the nuclei to have different energy levels, with the lower energy levels being more common and the higher energy levels being less common.

As the MRI machine emits radio waves, it causes the nuclei to transition between these energy levels. When the radio waves are turned off, the nuclei return to their original energy levels, emitting energy in the form of radio waves. This emitted radiation is what is detected by the MRI machine and used to create images of the patient's body.

The specific energy levels of the nuclei that are excited and emit radiation in MRI depend on the type of atom and its properties, such as its spin and magnetic moment. By analyzing the emitted radiation, we can obtain information about the structure and composition of tissues and organs in the body, allowing for the diagnosis of various medical conditions.

In summary, the energy levels of the nucleus play a crucial role in the emission of radiation in MRI, and understanding these energy levels is essential for the accurate and effective use of this imaging technique in healthcare.