Method of minimizing dead-periods in magnetic resonance imaging pulse sequences and associated apparatus

Abstract

A method of minimizing dead-periods in magnetic resonance imaging pulse sequences employs a specimen disposed within magnetic field, a source of RF signals, a receiver for receiving signals from the specimen responsive to RF pulses and emitting respective output signals. A computer is provided for receiving the output signals from the receiver and establishing image information which may be displayed. 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 a 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 and employing the waveform to design a trapezoidal waveform using the calculated minimum dead-period. The method is particularly advantageous when employed in oblique magnetic resonance imaging. The method may also be employed with velocity-encoded or flow-compensated pulse sequences by employing first gradient moments in the information processing, in addition to the starting and ending gradient levels and the zeroeth moments. For other types of pulse sequences, the zeroeth moment and other higher moments may be employed. Associated apparatus is also disclosed.

Dependencies are inferred from the claim text.