Imaging method and device for water/fat separation in magnetic resonance imaging
AssigneeSiemens Aktiengesellschaft
InventorCong Zhao
Life of this patent
Estimating the term…
Abstract
In an imaging method and device for water/fat separation in MRI using a two-point Dixon FSE sequence, each refocusing RF pulse corresponds to two readout gradients of the same polarity, each being center-divided into a smaller rear part and a larger front part, and one rephasing gradient of opposite polarity. In running the FSE sequence, each echo signal acquired is subjected to an FFT, to reconstruct an image with water and fat in phase and an image with water and fat in opposed phases. Data of each echo signal are subjected to a partial Fourier transform; and the in-phase water/fat image and the opposite-phase water/fat image are subjected to a water/fat separation algorithm, to obtain a pure water image and a pure fat image.
Claims11
An imaging method for water/fat separation in magnetic resonance imaging, said method comprising:
- operating a magnetic resonance scanner to execute a fast spin echo sequence based on the two-point Dixon method, in which an RF excitation pulse is emitted followed by at least one refocusing RF pulse;
- operating said magnetic resonance scanner in said fast spin echo sequence to activate, after each RF refocusing pulse, two readout gradients of the same polarity and one rephasing gradient of opposite polarity between said two readout gradients, with each of said two readout gradient producing an echo signal having an echo center;
- operating said magnetic resonance scanner in said fast spin echo sequence to cause each of said two readout gradients to be divided into a front part and a rear part by the echo center of the echo signal produced thereby, with a rear part of a front readout gradient of said two readout gradients being smaller in area than a front part thereof, and with a front part of a rear readout gradient of said two readout gradients being smaller in area than a rear part thereof;
- in a processor, subjecting each echo signal acquired to a fast Fourier transform, so as to reconstruct an image with water and fat in phase and an image with water and fat in opposed phases, wherein data of each echo signal is further subjected to a partial Fourier transform;
- and
- in said processor, subjecting the image with water and fat in phase and the image with water and fat in opposed phases to a water/fat separation algorithm, to obtain a pure water image and a pure fat image at an output of said processor.
A magnetic resonance imaging apparatus comprising:
- a magnetic resonance scanner;
- a control computer configured to operate the magnetic resonance scanner to execute a fast spin echo sequence based on the two-point Dixon method while an examination subject is situated in the magnetic resonance scanner;
- said control computer being configured to operate said magnetic resonance scanner in said fast spin echo sequence to emit an RF excitation pulse followed by at least one refocusing RF pulse;
- said control computer being configured to operate said magnetic resonance scanner in said fast spin echo sequence to activate, after each RF refocusing pulse, two readout gradients of the same polarity and one rephasing gradient of opposite polarity between said two readout gradients, with each of said two readout gradient producing an echo signal having an echo center;
- said control computer being configured to operate said magnetic resonance scanner in said fast spin echo sequence to cause each of said two readout gradients to be divided into a front part and a rear part by the echo center of the echo signal produced thereby, with a rear part of a front readout gradient of said two readout gradients being smaller in area than a front part thereof, and with a front part of a rear readout gradient of said two readout gradients being smaller in area than a rear part thereof;
- a processor configured to subject each echo signal acquired to a fast Fourier transform, so as to reconstruct an image with water and fat in phase and an image with water and fat in opposed phases, wherein data of each echo signal is further subjected to a partial Fourier transform;
- and
- said processor being configured to subject the image with water and fat in phase and the image with water and fat in opposed phases to a water/fat separation algorithm, to obtain a pure water image and a pure fat image at an output of said processor.
Dependencies are inferred from the claim text.