Method and magnetic resonance apparatus for generating a weighting matrix for reducing artifacts with parallel imaging

A magnetic resonance (MR) apparatus comprising:

• an MR acquisition scanner comprising a plurality of reception coils, each having an associated reception channel;
• a computer configured to operate said MR data acquisition scanner to acquire a reference dataset of a recording volume of an examination subject situated in the MR data acquisition scanner, with said reference dataset being entered into a memory organized as k-space so that said reference dataset completely fills at least one segment of k-space;
• said computer being configured to determine a first subregion of the recording volume, in which at least one component of the MR data acquisition scanner has a lower homogeneity than in a second subregion of the recording volume;
• said computer being configured to determine a first reception channel, among said plurality of reception channel, that supplies, to said computer, acquired signals having a higher signal intensity in said first subregion than others of said plurality of reception channels;
• said computer being configured to use said reference dataset to calculate a weighting matrix in which said first reception channel is given a lower weighting than said other reception channels;
• said computer being configured to operate said MR data acquisition scanner in order to acquire MR diagnostic data from said recording volume with parallel imaging, wherein respective MR diagnostic datasets are individually acquired by said plurality of reception coils and provided to the computer respectively via said plurality of reception channels, and enter said diagnostic MR data into said memory organized as k-space;
• said computer being configured to apply said weighting matrix to said diagnostic MR data in k-space acquired with said parallel imaging, in order to determine points in k-space that were not filled in said parallel imaging;
• and
• said computer being configured to reconstruct image data from said diagnostic MR data and the points in k-space determined with said weighting matrix, and to make the image data available from the computer in electronic form, as a data file.

A non-transitory, computer-readable data storage medium encoded with programming instructions, said storage medium being loaded into a computer system of a magnetic resonance (MR) apparatus comprising an MR data acquisition scanner having a plurality of reception coils, each with an associated reception channel, said programming instructions causing said computer system to:

• operate said MR data acquisition scanner to acquire a reference dataset of a recording volume of an examination subject situated in the MR data acquisition scanner, with said reference dataset being entered into a memory organized as k-space so that said reference dataset completely fills at least one segment of k-space;
• determine a first subregion of the recording volume, in which at least one component of the MR data acquisition scanner has a lower homogeneity than in a second subregion of the recording volume;
• determine a first reception channel, among said plurality of reception channel, that supplies, to said computer, acquired signals having a higher signal intensity in said first subregion than others of said plurality of reception channels;
• use said reference dataset to calculate a weighting matrix in which said first reception channel is given a lower weighting than said other reception channels;
• operate said MR data acquisition scanner in order to acquire MR diagnostic data from said recording volume with parallel imaging, wherein respective MR diagnostic datasets are individually acquired by said plurality of reception coils and provided to the computer respectively via said plurality of reception channels, and enter said diagnostic MR data into said memory organized as k-space;
• apply said weighting matrix to said diagnostic MR data in k-space acquired with said parallel imaging, in order to determine points in k-space that were not filled in said parallel imaging;
• and
• reconstruct image data from said diagnostic MR data and the points in k-space determined with said weighting matrix and make the image data available from the computer in electronic form, as a data file.