Methods for the simultaneous detection of multiple magnetic resonance images using phase modulated excitation

Claim 1

A method for the generation of image data from multiple portions of a subject with magnetic resonance, comprising the steps of: a) placing said subject into a magnetic field to polarize nuclear spins; b) applying to said subject a composite excitation radiofrequency (RF) pulse comprised of a series of N discrete RF pulses, each having a selected frequency and phase to nutate nuclear spins within said subject for the purpose of creating transverse spin magnetization; c) applying to said subject a composite excitation magnetic field gradient pulse substantially simultaneously with the application of the composite excitation RF pulse to constrain the creation of transverse spin magnetization to N selected portions within said subject; d) applying to said subject at a selected time after the application of the composite excitation RF pulse, a refocusing RF pulse to generate a spin echo; e) applying to said subject a refocusing magnetic field gradient pulse substantially simultaneously with the application of the refocusing RF pulse to limit the region of refocusing in said subject; f) applying to said subject at a selected time after the application of the composite excitation RF pulse, a phase-encoding magnetic field gradient pulse of a selected amplitude in a first selected direction to cause transverse spin magnetization to be dephased by an amount proportional to the location of the transverse magnetization in the first direction; g) applying to said subject at a selected time after the application of the composite excitation RF pulse, a readout dephasing magnetic field gradient pulse of a selected amplitude in a second selected direction substantially orthogonal to the first direction to cause transverse spin magnetization to be dephased by an amount proportional to the location of the transverse magnetization in the second direction; h) applying a readout magnetic field gradient pulse in the second selected direction with a polarity substantially opposite that of the readout dephasing magnetic field gradient pulse; i) detecting with a receiver operating at a selected frequency an MR response signal generated by the transverse spin magnetization in the presence of the readout magnetic field gradient pulse; j) repeating steps `b`-`i` a plurality, Y times, each repetition having a unique amplitude for the phase-encoding gradient pulse and each discrete RF excitation pulse having a phase shift proportional to the amplitude of the phase-encoding gradient pulse; and k) creating a reconstructed MR image containing MR image data from each of the N excited portions of said subject by performing a two-directional Fourier transform of the detected MR response signals.

Claim 2

A method for the generation of image data from multiple portions of a subject with magnetic resonance, comprising the steps of: a) placing said subject into a magnetic field to polarize nuclear spins; b) applying to said subject a composite excitation radiofrequency (RF) pulse comprised of a series of N discrete RF pulses, each having a selected frequency and phase to nutate nuclear spins within said subject for the purpose of creating transverse spin magnetization; c) applying to said subject a composite excitation magnetic field gradient pulse substantially simultaneously with the application of the composite excitation RF pulse to constrain the creation of transverse spin magnetization to N selected portions within said subject; d) applying to said subject at a selected time after the application of the composite excitation RF pulse, a refocusing RF pulse to generate a spin echo; e) applying to said subject a refocusing magnetic field gradient pulse substantially simultaneously with the application of the refocusing RF pulse to limit the region of refocusing in said subject; f) applying to said subject at a selected time after the application of the composite excitation RF pulse, a phase-encoding magnetic field gradient pulse of a selected amplitude in a first selected direction to cause transverse spin magnetization to be dephased by an amount proportional to the location of the transverse magnetization in the first direction; g) applying to said subject at a selected time after the application of the composite excitation RF pulse, a readout dephasing magnetic field gradient pulse of a selected amplitude in a second selected direction substantially orthogonal to the first direction to cause transverse spin magnetization to be dephased by an amount proportional to the location of the transverse magnetization in the second direction; h) applying a readout magnetic field gradient pulse in the second selected direction with a polarity substantially opposite that of the readout dephasing magnetic field gradient pulse; i) detecting with a receiver operating at a selected frequency an MR response signal generated by the transverse spin magnetization in the presence of the readout magnetic field gradient pulse; j) repeating steps `b`-`i` a plurality, Y times, each repetition having a unique amplitude for the phase-encoding gradient pulse and each discrete RF excitation pulse having a phase shift proportional to the amplitude of the phase-encoding gradient pulse; and k) creating a reconstructed MR image containing MR image data from each of the N excited portions of said subject by performing a two-directional Fourier transform of the detected MR response signals.