System for adjusting a magnetic field for MR and other use

A system for automatically dynamically compensating for inhomogeneity and variability in an MR imaging device magnetic field resulting from patient anatomical variation and other sources, comprising:

• an MR imaging compensation system for automatically,
• acquiring at least three MR data sets representing luminance intensity values of individual image elements comprising a corresponding plurality of different image versions of at least a portion of a first imaging slice of patient anatomy including fat and water components,
• for an individual image element of said image elements, employing said at least three MR data sets in iteratively solving a corresponding at least three simultaneous nonlinear equations to calculate local frequency offset associated with magnetic field inhomogeneity at the individual image element location and comprising a difference between proton spin frequency at the location and a nominal proton spin frequency,
• deriving data representing an electrical signal to be applied to magnetic field generation coils to substantially compensate for determined offset frequencies at a plurality of individual locations including at said individual element location;
• and
• a magnetic field generation coil for generating a magnetic field in response to applying said electrical signal to substantially compensate for the magnetic field inhomogeneity at said individual image element location.

A method for automatically dynamically compensating for inhomogeneity and variability in an MR imaging device magnetic field resulting from patient anatomical variation and other sources, comprising the activities of:

• acquiring a plurality of MR data sets representing luminance intensity values of individual image elements comprising a corresponding plurality of different image versions of at least a portion of a first imaging slice of patient anatomy including fat and water components;
• for an individual image element of said image elements, employing said plurality of MR data sets in solving a corresponding plurality of simultaneous nonlinear equations to calculate local frequency offset associated with magnetic field inhomogeneity at the individual image element location and comprising a difference between proton spin frequency at the location and a nominal proton spin frequency;
• deriving data representing an electrical signal to be applied to magnetic field generation coils to substantially compensate for determined offset frequencies at a plurality of individual locations including at said individual element location;
• and
• generating a magnetic field in response to applying said electrical signal to substantially compensate for the magnetic field inhomogeneity at said individual image element location.