[Problem of spectral attenuated with inversion recovery fat suppression method with respiratory-gated]

The purpose of this study was to investigate the effect of fat suppression when we use respiratory-gated spectral attenuated with inversion recovery (SPAIR) method with respiratory-gated. We experimented on phantom and in-vivo study using simulated wave of respiratory-gated SPAIR at 1.5 tesla and 3.0 tesla. As a result, the effect of fat suppression becomes wrong with longer intervals of inspiration and expiration by wave of respiratory-gated. The signal intensity also varies with each slice. This result had the same trend on phantom and in-vivo study. The longitudinal magnetization of fat becomes a stable state when SPAIR pulse is shot more than once. However, the SPAIR method with respiratory-gated collect signal before the longitudinal magnetization of fat to be stable state, and fat suppression effect becomes bad, because the inversion time does not match the null point of the fat. Therefore, when we use SPAIR method with respiratory-gated it always causes bad fat suppression.