Patent ID: 6492815
Filing Date: 2002-12-10
Classification: G01R

Abstract:
A system for evaluating the fields produced by an MRI system which comprises:a coil assembly for placement in the fields produced by the MRI system, the coil assembly including: a) a frame; b) a first pair of magnetic field induction coils mounted to the frame and disposed along a first gradient field axis, the magnetic field induction coils producing a voltage signal proportional to the rate of change in the magnetic fields produced by the MRI system to which the magnetic field induction coils are exposed; and c) a radio frequency (RF) detection coil mounted to the frame, the RF detection coil picking up RF pulses transmitted by the MRI system during an MR imaging pulse sequence and producing a voltage signal comprising RF pulses detected from the MR imaging pulse sequence produced by the MRI system; a processor connected to each of the coils in the coil assembly and being operable to sample signals produced by the coils while the MRI system is operating and to solve for and reconstruct a first gradient waveform produced by the MRI system from the sampled signals from the first pair of magnetic field induction coils and an RF pulse waveform produced by the MRI system from the sampled signal from the RF detection coil; and a display for receiving the waveforms reconstructed by the processor and displaying them.