Magnetic resonance method and apparatus to correct image distortions in diffusion-weighted imaging

摘要

In a magnetic resonance (MR) apparatus and an operating method for the apparatus, image distortions are corrected that occur in exposures of diffusion-weighted MR images of an examination subject.;A diffusion-weighted image is acquired using a first acquisition process.;Another diffusion-weighted reference image is acquired using a second acquisition process that is different than the first acquisition process.;The second acquisition process causes significantly smaller eddy current-dependent image distortions than the first acquisition process given the same b-value.;Correction parameters to correct the image distortions of the diffusion-weighted image are determined by comparing the diffusion-weighted image with the reference image in order to determine the correction parameters such that the diffusion-weighted image can be converted into the reference image with the aid of the correction parameters.

主权项

1. A method of correcting image distortions that occur in diffusion-weighted magnetic resonance (MR) images of an examination subject, comprising the steps of:
operating an MR data acquisition unit in order to implement a first diffusion-weighted MR data acquisition procedure, comprising diffusion-weighting that is characterized by a b-value, in order to acquire a diffusion-weighted image of an examination subject, said diffusion-weighted image of said examination subject comprising image distortions that are dependent on eddy currents that arise as a result of implementation of said first diffusion-weighted MR data acquisition procedure, said diffusion-weighted image of the examination subject comprising a diagnostic content exhibiting a contrast; operating said MR data acquisition unit in order to implement a second diffusion-weighted data acquisition procedure in order to acquire a diffusion-weighted reference image, said second diffusion-weighted MR data acquisition procedure being different from said first diffusion-weighted MR data acquisition procedure and comprising diffusion-weighting that is characterized by a b-value, said second diffusion-weighted MR data acquisition procedure causing smaller eddy current-dependent distortions in said diffusion-weighted reference image, at a same b-value, then said image distortions in said diffusion-weighted image of said examination subject; providing said diffusion-weighted image of said examination subject and said diffusion-weighted reference image into a computerized processor and, in said computerized processor, automatically comparing the diffusion-weighted reference image with the diffusion-weighted image of the examination subject in order to determine contrast-maintaining correction parameters and applying said correction parameters to the diffusion-weighted image of the examination subject in order to correct the distortions in said diffusion-weighted image of the examination subject by converting the diffusion-weighted image of the examination subject into the diffusion-weighted reference image while preserving said diagnostic content of the diffusion-weighted image of the examination subject; and making the corrected diffusion-weighted image of the examination subject available in electronic form at an output of the computerized processor.