System and method for setting a field of view for a magnetic resonance scan

A magnetic resonance scanner comprising:

• a gradient coil arrangement configured to generate gradient fields to be used during a magnetic resonance scan for spatial encoding;
• and
• a controller configured to perform distortion correction based on a distortion map of acquired magnetic resonance data sets at least for distortions caused by imperfections in the gradient fields, the controller being configured to:
• ascertain exclusion information describing an unmapped region of an original field of view based on the distortion map for at least one first set of field-of-view parameters describing a rectangular or cuboidal original field of view, the unmapped region resulting from the distortion;
• control a user interface to display the original field of view to be set together with an anatomy of the patient to be scanned, wherein the unmapped region is displayed based on the exclusion information and/or a limitation of the field of view display for exclusion of the unmapped region is adjusted based the exclusion information;
• determine a second set of field-of-view parameters to be used for the MR scan based on the exclusion information;
• and
• control the MR scanner to perform the magnetic resonance scan using the second set of field-of-view parameters.

A computer-implemented method for setting a field of view for a magnetic resonance (MR) scan of a patient with a MR scanner including a gradient coil arrangement configured to generate gradient fields to be used during the MR scan for spatial encoding and a controller configured to perform distortion correction based on a distortion map of acquired magnetic resonance data sets at least for distortions caused by imperfections of the gradient fields, the method comprising:

• ascertaining, by the controller, exclusion information describing an unmapped region of an original field of view based on the distortion map for at least one first set of field-of-view parameters describing a rectangular or cuboidal original field of view, the unmapped region resulting from the distortion;
• determining, by the controller, a second set of field-of-view parameters to be used for the MR scan based on the exclusion information;
• and
• controlling, by the controller, the MR scanner to perform the magnetic resonance scan using the second set of field-of-view parameters, wherein:
• (a) based on examination information describing anatomical features to be shown in the MR scan, automatically checking, by the controller, whether the mapped region of this original field of view comprises all features to be shown, starting from an original field of view containing the anatomical features without considering the distortion and/or from an original field of view selected by the user;
• and, in response to the mapped region not comprising all of the anatomical features to be shown:
• automatically ascertaining, the second set of field-of-view parameters such that the mapped region of the associated field of view comprises all features to be shown, and/or generating and outputting a warning to the user;
• or
• (b) the first set of view parameters describes a used, original field of view of a previously performed magnetic resonance scan, the controller automatically evaluating an action criterion to check whether the portion of the unmapped region of the used field of view, without taking into account the distortion, exceeds a threshold value and/or whether at least one feature to be shown in the magnetic resonance scan in accordance with an item of the examination information is located at least partially in the unmapped region;
• and, in response to the action criterion being met, the second set of field-of-view parameters to be used for a magnetic resonance scan yet to take place is automatically ascertained such that the portion of the unmapped region of the used, original field of view, without taking into account the distortion, is below a further threshold value and/or the mapped region of the field of view associated with the second set of field-of-view parameters comprises all features to be shown.