NMR and MRI

[Gamma Girl]

Why does a sample in an NMR spectrometer spin, but in an MRI, the magnet spins?

[John Cuthber]

Do you know why they spin in ether case?

[Gamma Girl]

The different spin states creates different energy differences for NMR due to different frequencies.

[studiot]

What is 'the sample' in each case?

 

What does each technique measure?

[Gamma Girl]

The sample is a molecule. MRI deals with magnets like in CAT scans.

[studiot]

 

 

in CAT scans.

 

Isn't that the answer you require, or do hospital patients spin where you come from?

[Gamma Girl]

No

Elaborate, please.

Actually, I understand now. Thank-you again.

[BenSCBSc]

Hi, I am actually running measurements at the moment using 400 MHz 1H NMR spectroscopy. The purpose of spinning the sample is to average the effect of inhomogeneities (unevenness, deviation from a uniform field) in the main magnetic field.