Magnetic resonance imaging method and device achieving water/fat separation

1. A magnetic resonance imaging method achieving water/fat separation, the method comprising:

for each scanning layer of multiple scanning layers, operating a magnetic resonance data acquisition unit to execute a turbo spin echo BLADE artifact correction sequence to acquire original data for an in-phase image and original data for an opposite-phase image;

in a processor, reconstructing an in-phase image on the basis of the original data for the in-phase image, and reconstructing an opposite-phase image on the basis of the original data for the in-phase image and the original data for the opposite-phase image; and

in said processor, calculating water and fat images on the basis of the reconstructed in-phase images and the reconstructed opposite-phase images of the multiple scanning layers, and making the in-phase image and the opposite-phase image available at an output of the processor as respective data files, wherein calculating water and fat images comprises:

on the basis of spatial information corresponding to multiple two-dimensional in-phase images and opposite-phase images, the multiple two-dimensional in-phase images and opposite-phase images arranging to form one three-dimensional in-phase image and one three-dimensional opposite-phase image;

subjecting the three-dimensional in-phase image and three-dimensional opposite-phase image to phase correction; and

calculating water and fat images on the basis of the phase-corrected in-phase images and the phase-corrected opposite-phase images of the multiple scanning layers.

2. The method as claimed in claim 1 , comprising reconstructing an in-phase image on the basis of the original data for the in-phase image by:

subjecting strips of the original data for the in-phase image to phase correction, rotation correction, translation correction and a fast Fourier transform to obtain the in-phase image.

3. The method as claimed in claim 2 , comprising subjecting strips of the original data for the in-phase image to phase correction by:

subjecting a strip of the original data for the in-phase image to a window operation to obtain a first processing result;

subjecting the first processing result to a two-dimensional fast Fourier transform, to obtain window data of the in-phase image;

subjecting the strip of original data for the in-phase image to a two-dimensional fast Fourier transform, to obtain a second processing result;

removing the phases of the window data of the in-phase image from the second processing result to obtain a third processing result; and

subjecting the third processing result to a two-dimensional inverse fast Fourier transform to obtain a correction result.

4. The method as claimed in claim 1 , comprising reconstructing an opposite-phase image on the basis of the original data for the in-phase image and the original data for the opposite-phase image by:

subjecting strips of the original data for the opposite-phase image to phase correction, rotation correction, translation correction and a fast Fourier transform to obtain the opposite-phase image.

5. The method as claimed in claim 4 , comprising subjecting strips of the original data for the opposite-phase image to phase correction by:

subjecting a strip of the original data for the opposite-phase image to a two-dimensional fast Fourier transform, to obtain a first processing result;

subjecting a strip of the original data for the in-phase image corresponding to the strip of original data for the opposite-phase image to a window operation, to obtain a second processing result;

subjecting the second processing result to a two-dimensional fast Fourier transform, to obtain window data of the strip of original data for the in-phase image;

removing the phases of the window data of the strip of original data for the in-phase image from the first processing result, to obtain a third processing result; and

subjecting the third processing result to a two-dimensional inverse fast Fourier transform, to obtain a correction result.

6. A magnetic resonance imaging device achieving water/fat separation, the device comprising:

a magnetic resonance data acquisition unit;

a control unit configured to operate the acquisition unit, for each scanning layer of multiple scanning layers, to execute a turbo spin echo BLADE artifact correction sequence to acquire original data for an in-phase image and original data for an opposite-phase image;

a processor comprising a first reconstruction unit configured to reconstruct an in-phase image on the basis of the original data for the in-phase image;

said processor comprising a second reconstruction unit configured to reconstruct an opposite-phase image on the basis of the original data for the in-phase image and the original data for the opposite-phase image;

said processor comprising a calculation unit configured to separately calculate water and fat images on the basis of the reconstructed in-phase images and the reconstructed opposite-phase images, and to make the in-phase image and the opposite-phase image available at an output of the calculation unit as respective data files; and

said calculation unit being configured to calculate said water and fat images by, on the basis of spatial information corresponding to multiple two-dimensional in-phase images and opposite-phase images, arranging the multiple two-dimensional in-phase images and opposite-phase images to form one three-dimensional in-phase image and one three-dimensional opposite-phase image, and subjecting said three-dimensional in-phase image and said three-dimensional opposite-phase image to phase correction, and calculating the water and fat images based on the phase-corrected in-phase images and the phase-corrected opposite-phase images of the multiple scanning layers.

7. The device as claimed in claim 6 , wherein the first reconstruction unit comprises:

a first phase correction sub-unit configured to subject strips of the original data for the in-phase image to phase correction;

a first rotation correction sub-unit configured to subject phase-corrected strips of the original data for the in-phase image to rotation correction;

a first translation correction sub-unit configured to subject rotation-corrected strips of the original data for the in-phase image to translation correction; and

a first conversion sub-unit configured to subject translation-corrected strips of the original data for the in-phase image to a fast Fourier transform.

8. The device as claimed in claim 7 , wherein the first phase correction sub-unit comprises:

a first module configured to subject strips of the original data for the in-phase image to a window operation to obtain a first processing result;

a second module configured to subject the first processing result to a two-dimensional fast Fourier transform, to obtain window data of the in-phase image;

a third module configured to subject strips of the original data for the in-phase image to a two-dimensional fast Fourier transform, to obtain a second processing result;

a fourth module configured to remove the phases of the window data of the in-phase image from the second processing result to obtain a third processing result; and

a fifth module configured to subject the third processing result to a two-dimensional inverse fast Fourier transform to obtain a correction result.

9. The device as claimed in claim 6 , wherein the second reconstruction unit comprises:

a second phase correction sub-unit configured to subject strips of the original data for the in-phase image to phase correction;

a second rotation correction sub-unit configured to subject phase-corrected strips of the original data for the in-phase image to rotation correction;

a second translation correction sub-unit configured to subject rotation-corrected strips of the original data for the in-phase image to translation correction; and

a second conversion sub-unit configured to subject translation-corrected strips of the original data for the in-phase image to a fast Fourier transform.

10. The device as claimed in claim 9 , wherein the second phase correction sub-unit comprises:

a sixth module configured to subject strips of the original data for the opposite-phase image to a two-dimensional fast Fourier transform to obtain a first processing result;

a seventh module configured to subject strips of the original data for the in-phase image corresponding to the strips of the original data for the opposite-phase image to a window operation to obtain a second processing result;

an eighth module configured to subject the second processing result to a two-dimensional fast Fourier transform, to obtain window data of the strips of the original data for the in-phase image;

a ninth module configured to remove the phases of the window data of the strips of the original data for the in-phase image from the first processing result to obtain a third processing result; and

a tenth module configured to subject the third processing result to a two-dimensional inverse fast Fourier transform to obtain a correction result.

11. The method as claimed in claim 1 , comprising phase-correcting the three-dimensional in-phase image and the three-dimensional opposite-phase image using a three-dimensional region growing algorithm.