Patent ID: 9689952
Date: 2017-06-27
CPC Classifications: G01R

Claim:
1. A method for acquiring magnetic resonance (MR) data in an examination region of an examination subject situated in a measurement region of an MR data acquisition unit, said MR data acquisition unit comprising a basic field magnet, a radio-frequency (RF) system, and a gradient coil system, said method comprising: operating said basic field magnet of said MR data acquisition unit, with said examination region situated in said measurement region, to produce a polarization field in said measurement region that gives nuclear spins in the examination region a magnetization, said polarization field having a first field inhomogeneity across said measurement region; operating said MR data acquisition unit according to an MR imaging sequence having a sequence duration and, in said MR imaging sequence, operating said RF system to radiate at least one RF pulse into the examination region that deflects said magnetization and thereby causes said nuclear spins to emit an MR signal; in said MR imaging sequence, operating said gradient coil system of said MR data acquisition unit to activate a spatially encoding magnetic field gradient that spatially codes said MR signal; operating said gradient coil system of said MR data acquisition unit to activate at least one pulsed compensation magnetic field gradient during a compensation time interval in said MR imaging sequence that is shorter than said sequence duration and that occurs relative to the radiation of the at least one RF pulse so as to make said compensation field gradient effective during said at least one RF pulse, by supplying a temporally variable current, that is varying over said sequence duration, to said gradient coil system, and configuring said at least one pulsed compensation magnetic field gradient to reduce said first field inhomogeneity during said compensation time period to a second field inhomogeneity across said measurement region that is less than said first field inhomogeneity; operating said MR data acquisition unit to detect said MR signal at least in said compensation time period; and converting the detected MR signal into an electrical signal representing raw MR data and entering said raw MR data into an electronic memory, to produce a raw data set in a form that is accessible from said electronic memory for conversion into an image of the examination region.