1. Inversion recovery.
Inversion recovery. (A) Inversion of the sum longitudinal magnetisation vector following an 180° radiofrequency (RF) pulse. A further 90° RF pulse flips the recovering sum vector into the transverse plane allowing a signal to be obtained. The magnitude of the signal is dependent on the amount of T1 recovery that had occurred before the 90° pulse and, hence, on the inversion time (time between the 180° and 90° pulses). (B) T1 relaxation curves for fat and water demonstrating the recovery of longitudinal magnetisation following an 180° RF pulse. Application of a 90° RF pulse at the null point leads to signal suppression of a chosen tissue. This figure is only reproduced in colour in the online version.
Stuart Currie et al. Postgrad Med J 2013;89:
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