METHOD OF MINIMIZING DEAD-PERIODS IN ORDER TO OBTAIN HARDWARE OPTIMIZED GRADIENT WAVEFORMS

摘要

A method of minimizing dead-periods in magnetic resonance imaging pulse sequences employs a specimen disposed within magnetic field (6), a source of RF signals (2), a receiver (8) for receiving signals from the specimen responsive to RF pulses and emitting respective output signals. A computer (12) is provided for receiving the output signals from the receiver and establishing image information which may be displayed (16). For the dead-period, the minimum and maximum phase encoding step, the scan plane gradient pulse for the slice, phase encoding and readout directions are determined and the moments contained within the dead-period waveform is determined. The values are transformed into gradient amplifier coordinates and the minimum dead-period based on the dead-period waveform is determined. The dead-period is employed in establishing a hardware optimized waveform which may be trapezoidal. The trapezoidal waveform is preferably established by for each phase encoding step determining the starting and ending gradient levels and the moments contained within the dead-period waveform using the calculated minimum dead-period.