Dixon magnetic resonance imaging using prior knowledge

A computer program product comprising machine executable instructions for execution by a processor controlling a magnetic resonance imaging system for acquiring magnetic resonance data from a subject within an imaging zone, wherein the magnetic resonance imaging system comprises a memory for storing pulse sequence data, wherein the pulse sequence data comprises commands for acquiring the magnetic resonance data using an n point Dixon magnetic resonance imaging method, wherein n is greater than or equal to two, wherein execution of the instructions causes the processor to:

• control the magnetic resonance imaging system with the pulse sequence data to acquire the magnetic resonance data;
• construct two phase candidate maps using the magnetic resonance data according to the n point Dixon magnetic resonance imaging method, wherein each of the two phase candidate maps are in image space, wherein each of the two phase candidate maps comprise a set of voxels, and wherein each voxel has a phase map value;
• identifying a set of object voxels in the set of voxels using an object identification algorithm;
• identify a set of boundary voxels and interior voxels within the set of object voxels using a boundary identification algorithm;
• create a chosen phase candidate map in the memory, wherein the chosen phase candidate map comprises the set of voxels;
• select a chosen phase map value for at least a portion of the set of boundary voxels in the chosen phase map from the two phase candidate maps, wherein the phase map value is chosen by comparing the candidate phase map value for each of the set of boundary voxels in each of the two phase candidate maps selecting the candidate phase map value which indicates the lowest fat to water ratio;
• and
• calculate the phase map value of the object voxels according to a phase candidate selection algorithm, wherein input for the phase candidate selection algorithm comprises the two phase candidate maps and the chosen phase map value for the at least a portion of the set of boundary voxels in the chosen phase map.

A method of operating a magnetic resonance imaging system acquire magnetic resonance data from a subject within an imaging zone, wherein the method comprises the steps of:

• controlling the magnetic resonance imaging system with pulse sequence data to acquire the magnetic resonance data, wherein the pulse sequence data comprises commands for acquiring the magnetic resonance data using an n point Dixon magnetic resonance imaging method, wherein n is greater than or equal to two;
• constructing two phase candidate maps using the magnetic resonance data according to the n point Dixon magnetic resonance imaging method, wherein each of the two phase candidate maps are in image space, wherein each of the two phase candidate maps comprise a set of voxels, and wherein each voxel has a phase map value;
• identifying a set of object voxels in the set of voxels using an object identification algorithm;
• identifying a set of boundary voxels and a set of interior voxels within the set of object voxels using a boundary identification algorithm;
• creating chosen phase candidate map, wherein the chosen phase candidate map comprises the set of voxels;
• selecting a chosen phase map value for at least a portion of the set of boundary voxels in the chosen phase map from the two phase candidate maps, wherein the phase map value is chosen by comparing the candidate phase map value for each of the set of boundary voxels in each of the two phase candidate maps selecting the candidate phase map value which indicates the lowest fat to water ratio;
• and
• calculating the phase map value of the object voxels according to a phase candidate selection algorithm, wherein input for the phase candidate selection algorithm comprises the two phase candidate maps and the chosen phase map value for the at least a portion of the set of boundary voxels in the chosen phase map.