Relaxation

Relaxation is the process in which spins release the energy received from a radiofrequency pulse. MRI signal is influenced, among other factors, by different types of relaxation:

Relaxation causes MR signal to recover in the longitudinal direction according to the time constant T1 (Figure 1) or decay in the transverse plane according to the time constant T2 (Figure 2).

The differences in relaxation between different tissues form the basis of image contrast (signal to noise ratio) in MRI.

See also

Imaging physics

Article information

rID: 22554
Synonyms or Alternate Spellings:

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Cases and figures

  • Figure 1: MR relaxation curves
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  • Figure 2: MR relaxation curves
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