Method for the simultaneous detection of acceleration and velocity distribution in moving fluids

Claim 1

A method of simultaneous detection of multiple components of motion of a material within a subject comprising the steps of: a) placing said subject into a magnetic field to polarize nuclear spins; b) applying a radiofrequency (RF) pulse of a selected frequency and amplitude; c) applying a slice select magnetic field gradient in a slice select direction perpendicular to a slice desired to be imaged, simultaneously with the application of the RF pulse, thereby causing nutation of resonant nuclei, `nuclear spins` in a slice of said subject, to create transverse spin magnetization; d) applying an acceleration-encoding magnetic field gradient pulse of a selected polarity, in an acceleration-encoding direction, to said subject to cause the transverse spin magnetization to acquire an acceleration-induced phase shift; e) applying a higher-order phase encoding pulse, being a magnetic field gradient pulse of a selected amplitude which induces a phase shift proportional to velocity and is oriented in a phase encoding direction which is independent of the slice select direction and the acceleration-encoding direction f) applying a readout magnetic field gradient pulse in a readout direction substantially orthogonal to the slice-select direction; g) acquiring an MR response signal in the presence of the readout magnetic field gradient pulse; h) Fourier transforming the MR response signal to result in an intermediate data set; i) repeating steps `b`-`h` plurality, Y times, each repetition having a unique amplitude for the higher order phase encoding gradient pulse; to result in Y intermediate data sets; j) Fourier transforming the Y intermediate data sets with respect to the amplitudes of the higher order phase encoding pulse to result in a complex two dimensional (2D) transformed data set having a spatial first dimension, and a velocity second dimension, the 2D transformed data set having a plurality of complex entries with the phase of each complex entry indicating acceleration, and the amplitude indicating the number of nuclear spins at a given velocity and spatial position of the material within said subject.

Claim 2

A method of simultaneous detection of multiple components of motion of a material within a subject comprising the steps of: a) placing said subject into a magnetic field to polarize nuclear spins; b) applying a radiofrequency (RF) pulse of a selected frequency and amplitude; c) applying a slice select magnetic field gradient in a slice select direction perpendicular to a slice desired to be imaged, simultaneously with the application of the RF pulse, thereby causing nutation of resonant nuclei, `nuclear spins` in a slice of said subject, to create transverse spin magnetization; d) applying an acceleration-encoding magnetic field gradient pulse of a selected polarity, in an acceleration-encoding direction, to said subject to cause the transverse spin magnetization to acquire an acceleration-induced phase shift; e) applying a higher-order phase encoding pulse, being a magnetic field gradient pulse of a selected amplitude which induces a phase shift proportional to velocity and is oriented in a phase encoding direction which is independent of the slice select direction and the acceleration-encoding direction f) applying a readout magnetic field gradient pulse in a readout direction substantially orthogonal to the slice-select direction; g) acquiring an MR response signal in the presence of the readout magnetic field gradient pulse; h) Fourier transforming the MR response signal to result in an intermediate data set; i) repeating steps `b`-`h` plurality, Y times, each repetition having a unique amplitude for the higher order phase encoding gradient pulse; to result in Y intermediate data sets; j) Fourier transforming the Y intermediate data sets with respect to the amplitudes of the higher order phase encoding pulse to result in a complex two dimensional (2D) transformed data set having a spatial first dimension, and a velocity second dimension, the 2D transformed data set having a plurality of complex entries with the phase of each complex entry indicating acceleration, and the amplitude indicating the number of nuclear spins at a given velocity and spatial position of the material within said subject.

Claim 3

A method of simultaneous detection of multiple components of motion of a material within a subject comprising the steps of: a) placing said subject into a magnetic field to polarize nuclear spins; b) applying a radiofrequency (RF) pulse of a selected frequency and amplitude; c) applying a slice-select magnetic field gradient in a slice select direction perpendicular to a slice desired to be imaged, simultaneously with the application of the RF pulse, thereby causing nutation of resonant nuclei, `nuclear spins` in a slice of said subject, to create transverse spin magnetization; d) applying an acceleration-encoding magnetic field gradient pulse of a selected polarity, in an acceleration-encoding direction, to said subject to cause the transverse spin magnetization to acquire an acceleration-induced phase shift; e) applying a higher-order phase encoding pulse, being a magnetic field gradient pulse of a selected amplitude which induces a phase shift proportional to velocity and is oriented in a phase encoding direction which is independent of the slice-select direction and the acceleration-encoding direction f) applying a readout magnetic field gradient pulse in a readout direction substantially orthogonal to the slice-select direction; g) acquiring a first MR response signal in the presence of the readout magnetic field gradient pulse; h) repeating steps `b`-`g` to acquire a second MR response signal; i) subtracting the first MR response signal from the second MR response signal to result in a difference data set; j) Fourier transforming the difference data set to result in an intermediate data set; k) repeating steps `b`-`j` a plurality, Y times, each repetition having a unique amplitude for the higher order phase encoding gradient pulse; to result in Y intermediate data sets; l) Fourier transforming the Y intermediate data sets with respect to the amplitudes of the higher order phase encoding pulse to result in a complex two dimensional (2D) transformed data set having a spatial first dimension, and a velocity second dimension, the 2D transformed data set having a plurality of complex entries with the phase of each complex entry indicating acceleration, and the amplitude indicating the number of nuclear spins at a given velocity and spatial position of the material within said subject.

Claim 4

A method of simultaneous detection of multiple components of motion of a material within a subject comprising the steps of: a) placing said subject into a magnetic field to polarize nuclear spins; b) applying a radiofrequency (RF) pulse of a selected frequency and amplitude; c) applying a slice-select magnetic field gradient in a slice select direction perpendicular to a slice desired to be imaged, simultaneously with the application of the RF pulse, thereby causing nutation of resonant nuclei, `nuclear spins` in a slice of said subject, to create transverse spin magnetization; d) applying an acceleration-encoding magnetic field gradient pulse of a selected polarity, in an acceleration-encoding direction, to said subject to cause the transverse spin magnetization to acquire an acceleration-induced phase shift; e) applying a higher-order phase encoding pulse, being a magnetic field gradient pulse of a selected amplitude which induces a phase shift proportional to velocity and is oriented in a phase encoding direction which is independent of the slice-select direction and the acceleration-encoding direction f) applying a readout magnetic field gradient pulse in a readout direction substantially orthogonal to the slice-select direction; g) acquiring a first MR response signal in the presence of the readout magnetic field gradient pulse; h) repeating steps `b`-`g` to acquire a second MR response signal; i) subtracting the first MR response signal from the second MR response signal to result in a difference data set; j) Fourier transforming the difference data set to result in an intermediate data set; k) repeating steps `b`-`j` a plurality, Y times, each repetition having a unique amplitude for the higher order phase encoding gradient pulse; to result in Y intermediate data sets; l) Fourier transforming the Y intermediate data sets with respect to the amplitudes of the higher order phase encoding pulse to result in a complex two dimensional (2D) transformed data set having a spatial first dimension, and a velocity second dimension, the 2D transformed data set having a plurality of complex entries with the phase of each complex entry indicating acceleration, and the amplitude indicating the number of nuclear spins at a given velocity and spatial position of the material within said subject.