Method and apparatus for the correction of magnetic resonance scan data

A magnetic resonance (MR) apparatus, comprising:

• an MR data acquisition scanner;
• a computer configured to operate said MR data acquisition scanner having a basic magnetic (B0) field therein, while an examination subject is situated therein, in the scanner to acquire a first correction data set, by executing an echo planar data acquisition sequence, from a first correction sub-volume of a correction volume of the examination subject, said first correction data set having a content for use in execution of a correction algorithm that compensates for inhomogeneities in said B0 field;
• said computer being configured to operate the MR data acquisition scanner, with said B0 field therein, while the examination subject is situated therein, to acquire a second correction data set having a content for use in execution of said correction algorithm, by executing said echo planar data acquisition sequence, from said first correction sub-volume, with the second correction data set being acquired phase-shifted with respect to the first correction data set, and with the first correction data set and the second correction data set being acquired immediately in succession;
• said computer being configured to determine a first item of correction information from said first correction data set and said second correction data set by executing said correction algorithm;
• said computer being configured to operate the MR data acquisition scanner, with said B0 field therein, while the examination subject is situated therein, to acquire a third correction data set having a content for use in execution of said correction algorithm, by executing said echo planar data acquisition sequence, from a second correction sub-volume of said correction volume;
• said computer being configured to operate the MR data acquisition scanner, with said B0 field therein, while the examination subject is situated therein, to acquire a fourth correction data set having a content for use in execution of said correction algorithm, by executing said echo planar data acquisition sequence, from said second correction sub-volume, with the fourth correction data set being acquired phase-shifted with respect to the third correction data set, and with the third correction data set and the fourth correction data set being acquired in immediate succession;
• said computer being configured to determine a second item of correction information from said third correction data set and said fourth correction data set by again executing said correction algorithm;
• said computer being configured to operate said MR data acquisition scanner, with said B0 field therein, while said examination subject is situated therein, to acquire MR scan data from an examination volume of said examination subject;
• said computer being configured to correct effects of said inhomogeneities in said B0 field on said MR scan data by applying said first item of correction information and said second item of correction information to said MR scan data, and thereby obtaining corrected MR scan data;
• and
• said computer being configured to make the corrected MR scan data available in electronic form as a data file from said computer.

A non-transitory, computer-readable data storage medium encoded with programming instructions, said storage medium being loaded into a computer of a magnetic resonance (MR) apparatus that comprises an MR data acquisition scanner having a basic magnetic (B0) field therein, said programming instructions causing said computer to:

• operate said MR data acquisition scanner, while an examination subject is situated therein, to acquire a first correction data set, by executing an echo planar data acquisition sequence, from a first correction sub-volume of a correction volume of the examination subject, said first correction data set having a content for use in execution of a correction algorithm that compensates for inhomogeneities in said B0 field;
• operate the MR data acquisition scanner, with said B0 field therein, while the examination subject is situated therein, to acquire a second correction data set having a content for use in execution of said correction algorithm, by executing said echo planar data acquisition sequence, from said first correction sub-volume, with the second correction data set being acquired phase-shifted with respect to the first correction data set, and with the first correction data set and the second correction data set being acquired immediately in succession;
• determine a first item of correction information from said first correction data set and said second correction data set by executing said correction algorithm;
• operate the MR data acquisition scanner, with said B0 field therein, while the examination subject is situated therein, to acquire a third correction data set having a content for use in execution of said correction algorithm, by executing said echo planar data acquisition sequence, from a second correction sub-volume of said correction volume;
• operate the MR data acquisition scanner, with said B0 field therein, while the examination subject is situated therein, to acquire a fourth correction data set having a content for use in execution of said correction algorithm, by executing said echo planar data acquisition sequence, from said second correction sub-volume, with the fourth correction data set being acquired phase-shifted with respect to the third correction data set, and with the third correction data set and the fourth correction data set being acquired in immediate succession;
• determine a second item of correction information from said third correction data set and said fourth correction data set by again executing said correction algorithm;
• operate said MR data acquisition scanner, with said B0 field therein, while said examination subject is situated therein, to acquire MR scan data from an examination volume of said examination subject;
• correct effects of said inhomogeneities in said B0 field on said MR scan data by applying said first item of correction information and said second item of correction information to said MR scan data, and thereby obtaining corrected MR scan data;
• and
• make the corrected MR scan data available in electronic form as a data file from said computer.