公开(公告)号：WO2021259494A1

公开(公告)日：2021-12-30

申请号：PCT/EP2020/068061

申请日：2020-06-26

Applicant: MAX-PLANCK-GESELLSCHAFT ZUR FÖRDERUNG DER WISSENSCHAFTEN E. V.

Inventor： FRAHM, Jens ,  VOIT, Dirk ,  KALENTEV, Oleksandr

IPC: G01R33/563 ,  G01R33/48 ,  G01R33/483 ,  G01R33/561 ,  G01R33/4824 ,  G01R33/4835 ,  G01R33/5611 ,  G01R33/56341

Abstract: A method for creating sequences of diffusion-weighted magnetic resonance (MR) images of an object under investigation, wherein each of said sequences of MR images represents the same series of cross-sectional slices covering a volume of the object, comprises the steps of (a) providing multiple sequences of sets of image raw data being collected with the use of at least one radiofrequency receiver coil of a magnetic resonance imaging (MRI) device, wherein each set of image raw data includes a plurality of data samples being generated with a combined diffusion-weighted spin-echo and single-shot stimulated-echo sequence with diffusion-encoding gradients having at least two different strengths and at least three different directions, wherein one of the sequences of sets of raw data is generated with diffusion-encoding gradients of zero strength or lower strength and further sequences of sets of raw data are generated with diffusion-encoding gradients of higher strength, (b) subjecting the sequence of sets of image raw data generated with diffusion-encoding gradients of zero strength or lower strength to a regularized nonlinear inverse reconstruction process to provide a sequence of MR images with no or lower diffusion weighting, and (c) subjecting the sequences of sets of image raw data with diffusion-encoding gradients of higher strengths to a linear inverse reconstruction process to provide sequences of MR images with higher diffusion weighting, each of the images representing one of the cross-sectional slices and being created by using the sensitivity of the at least one receiver coil determined in step (b) for the same cross-sectional slice. Furthermore, an MRI device for creating a sequence of diffusion-weighted MR images of an object under investigation is described.

公开(公告)号：WO2022022836A1

公开(公告)日：2022-02-03

申请号：PCT/EP2020/071673

申请日：2020-07-31

Applicant: MAX-PLANCK-GESELLSCHAFT ZUR FÖRDERUNG DER WISSENSCHAFTEN E. V.

Inventor： FRAHM, Jens ,  VOIT, Dirk ,  KALENTEV, Oleksandr

IPC: G01R33/563 ,  G01R33/48 ,  G01R33/483 ,  G01R33/561 ,  G01R33/56

Abstract: A method for creating multiple sequences of diffusion-weighted magnetic resonance (MR) images of an object is described, wherein each of said sequences of MR images represents the same series of contiguous cross-sectional slices covering a volume of the object. The method comprises (a) providing multiple sequences of sets of image raw data being collected with the use of at least one radiofrequency receiver coil of a magnetic resonance imaging device, wherein each set of image raw data includes data samples being generated with a combined diffusion-weighted spin-echo and single-shot stimulated-echo sequence with diffusion-encoding gradients, (b) subjecting a sequence of sets of image raw data generated with diffusion-encoding gradients of zero strength or lower strength to a regularized nonlinear inverse reconstruction process to provide a sequence of coil sensitivities and MR images with no or lower diffusion weighting, and (c) subjecting all se- quences of sets of image raw data with diffusion-encoding gradients of zero or lower strength as well as of higher strength to a regularized linear inverse reconstruction process, to provide a sequence of MR images with no or lower diffusion weighting and a sequence of MR images with higher strength, each of the MR images representing one of the cross-sectional slices and being created by using the sensitivity of the at least one receiver coil determined in step (b) for the same cross-sectional slice and in dependency on a difference between a current image content estimation and an image content estimation of a neighboring cross-sectional slice. Furthermore, an MRI device for creating a sequence of diffusion-weighted MR images of an object is described.