| 摘要 |
The present invention discloses a method for removing at least one part of a MR brain image, said part representing non-brain tissue of the MR brain image, the method comprising the steps of:
- generating a static magnetic field capable of aligning moments of nuclei of a target to be imaged with a direction parallel with said static magnetic field magnetic;
- generating at least one excitation radio frequency pulse (±) capable of exciting atom nuclei of said target being magnetized by said static magnetic field, and capable of deflecting said moments of nuclei from said direction of the static magnetic field;
- generating for a first and a second predefined time period at least a first and a second magnetic field gradient, each capable of magnetizing said atom nuclei of the target and each designed for determining positional or spatial information of the excited atom nuclei of the target, the first and the second magnetic field gradient being oppositely directed magnetic field gradients;
- for each generated magnetic field gradient acquiring a current signal, respectively at a first time of echo TE 1 after the excitation radio frequency pulse (±) and at a second time of echo TE 2 after said radio frequency pulse (±), by means of induction coils designed for surrounding said target and capable of generating said current signal from the deflection of the nuclei moments according to induction;
- reconstructing the MR brain image of an internal structure of the target from said current signal by means of computational processing of said current signal;
characterized in that
- the first time of echo TE 1 and the second time of echo TE 2 are adjusted for correlating a second and first time of echo difference ”TE = TE 2 -TE 1 with a fat and water mutual resonance frequency difference ´, and in that a fat and a water information encoded in the current signal and resulting from said correlation of the second and first time of echo difference ”TE with the fat and water mutual resonance frequency difference is used as additional input source into a multispectral analysis method for removing said at least one part representing non-brain tissue. |
