Motion artifact minimization

Claim 1

A method of reducing respiratory motion artifacts generated while acquiring magnetic resonance imaging (MRI) data of a subject, said method comprising the steps of: subjecting the subject to a large static magnetic field, determining a normal maximum amplitude of the subject's respiration cycle measuring from the subject's back to the subject's thorax, dividing the normal maximum amplitude of the respiration cycle into a number of respiration cycle intervals, assigning a preferred phase encoding gradient pulse amplitude to each of the intervals, using a multi-dimensional data acquisition scan sequence with one dimension determined by phase encoding gradient pulses to obtain signals from the subject for use in acquiring magnetic resonance images, determining the respiration cycle interval at a time for use of one of said phase encoding gradient pulses, selecting the assigned preferred phase encoding gradient pulse amplitude to be used according to the determined respiration cycle interval of the subject at the time for use of the one of said phase encoding gradient pulses, selecting another assigned preferred phase encoding gradient pulse, if the previously selected assigned preferred phase encoding gradient pulse has already been used, and said last named selecting step including acquiring data using a next sequential unused phase encoding gradient pulse in place of the previously selected assigned preferred phase encoding gradient pulse up to a next sequential unused phase encoding gradient pulse that has an amplitude that is different than the first selected assigned preferred phase encoding gradient pulse amplitude by X %.

Claim 2

A method of reducing respiratory motion artifacts generated while acquiring magnetic resonance imaging (MRI) data of a subject, said method comprising the steps of: subjecting the subject to a large static magnetic field, determining a normal maximum amplitude of the subject's respiration cycle measuring from the subject's back to the subject's thorax, dividing the normal maximum amplitude of the respiration cycle into a number of respiration cycle intervals, assigning a preferred phase encoding gradient pulse amplitude to each of the intervals, using a multi-dimensional data acquisition scan sequence with one dimension determined by phase encoding gradient pulses to obtain signals from the subject for use in acquiring magnetic resonance images, determining the respiration cycle interval at a time for use of one of said phase encoding gradient pulses, selecting the assigned preferred phase encoding gradient pulse amplitude to be used according to the determined respiration cycle interval of the subject at the time for use of the one of said phase encoding gradient pulses, selecting another assigned preferred phase encoding gradient pulse, if the previously selected assigned preferred phase encoding gradient pulse has already been used, and said last named selecting step including acquiring data using a next sequential unused phase encoding gradient pulse in place of the previously selected assigned preferred phase encoding gradient pulse up to a next sequential unused phase encoding gradient pulse that has an amplitude that is different than the first selected assigned preferred phase encoding gradient pulse amplitude by X %.