Abstract: Inventive technology is directed to diffusion weighted magnetic resonance measurements. In an embodiment, a method for performing a diffusion weighted magnetic resonance measurement on a sample includes operating a magnetic resonance scanner to apply a diffusion encoding sequence to the sample. The method also includes operating the magnetic resonance scanner to acquire from the sample one or more echo signals. The diffusion encoding sequence includes a diffusion encoding time-dependent magnetic field gradient g(t) with non-zero components gl(t) along at least two orthogonal directions y and z, and a b-tensor having at least two non-zero eigenvalues, the magnetic field gradient comprising a first and subsequent second encoding block.

Abstract: According to a first aspect of the present inventive concept, there is provided a method for performing a diffusion weighted magnetic resonance measurement on a sample, the method comprising: operating a magnetic resonance scanner to apply a diffusion encoding sequence to the sample; and operating the magnetic resonance scanner to acquire from the sample one or more echo signals; wherein the diffusion encoding sequence comprises a diffusion encoding time-dependent magnetic field gradient g(t) with non-zero components gl(t) along at least two orthogonal directions y and z, and a b-tensor having at least two non-zero eigenvalues, the magnetic field gradient comprising a first and subsequent second encoding block, wherein an n-th order gradient moment magnitude along direction l ? (y, z) is given by Mnl(t)|=|?0tgl(t?)t?n dt?| and the first encoding block is adapted to yield, at an end of the first encoding block: along said direction y, |Mny(t)|?Tn for each 0?n?m, where Tn is a predetermined n-th order threshold

Abstract: According to an aspect of the present inventive concept, there is provided a method of extracting information about a sample, the method comprising: performing a plurality of magnetic resonance measurements on the sample, each measurement including subjecting the sample to an encoding sequence, at least a part of the sequence being adapted to encode a magnetic resonance signal attenuation due to nuclear relaxation and diffusion, wherein at least one parameter of a gradient pulse sequence is varied between at least a subset of said plurality of measurements, and at least one measurement of said subset includes a gradient pulse sequence having a diffusion-encoding tensor representation with more than one non-zero eigenvalue, and wherein at least a subset of said plurality of measurements include encoding for different levels of magnetic resonance signal attenuation due to nuclear relaxation; and extracting information about the sample from signals resulting from said plurality of magnetic resonance measurements

Abstract: According to an aspect of the present inventive concept there is provided a method of performing diffusion weighted magnetic resonance measurements on a sample, the method comprising: performing a plurality of diffusion weighted magnetic resonance measurements on the sample, wherein said plurality of measurements includes: a first measurement with a first diffusion encoding sequence having a tensor representation with three non-zero eigenvalues, a second measurement with a second diffusion encoding sequence, and a third measurement with a third diffusion encoding sequence, wherein the second and the third diffusion encoding sequence have different spectral content.

Abstract: According to an aspect of the present inventive concept there is provided a method of performing diffusion weighted magnetic resonance measurements on a sample, the method includes performing diffusion weighted magnetic resonance measurements on the sample, where the measurements include a first measurement with a first diffusion encoding sequence having a first diffusion weighting tensor representation B1 with at least two non-zero eigenvalues and a second measurement with a second diffusion encoding sequence having a second diffusion weighting tensor representation B2 with at least two non-zero eigenvalues.

Abstract: The present invention discloses a method for magnetic resonance (MR) imaging comprising acquiring at least two MR images with different motion-weighting originating from a RF and gradient pulse sequence causing signal attenuation from diffusion but not flow (flow-compensated data); acquiring at least two MR images with different motion-weighting originating from a RF and gradient pulse sequence causing signal attenuation from diffusion and flow (non-compensated data); performing a model fit to the flow-compensated and non-compensated data in which at least one of the adjustable parameters are constrained to be the same for both sets of data; and obtaining quantitative information on microscopic flow by extracting at least one parameter of the intravoxel incoherent motion (IVIM) effect from the model fit, said method being directed to diffusion-perfusion.

Abstract: A method for MRI includes performing an MRI experiment on a material to acquire an echo attenuation data set using a gradient modulation scheme comprising 1D diffusion encoding and to acquire an echo attenuation data set using a gradient modulation scheme comprising 2D diffusion encoding, determining respective first-order deviations ?2 from mono-exponential decay in said echo attenuation data sets, and generating MRI parameter maps or MR image contrast based on said first-order deviations ?2.

Abstract: According to an aspect of the present inventive concept there is provided a method of performing diffusion weighted magnetic resonance measurements on a sample, the method comprising: performing a plurality of diffusion weighted magnetic resonance measurements on the sample, wherein said plurality of measurements includes: a first measurement with a first diffusion encoding sequence having a tensor representation with three non-zero eigenvalues, a second measurement with a second diffusion encoding sequence, and a third measurement with a third diffusion encoding sequence, wherein the second and the third diffusion encoding sequence have different spectral content.

Abstract: According to an aspect of the present inventive concept there is provided a method of performing diffusion weighted magnetic resonance measurements on a sample, the method comprising: performing diffusion weighted magnetic resonance measurements on the sample, wherein said measurements includes: a first measurement with a first diffusion encoding sequence having a first diffusion weighting tensor representation B1 with at least two non-zero eigenvalues, a second measurement with a second diffusion encoding sequence having a second diffusion weighting tensor representation Bz with at least two non-zero eigenvalues, wherein the first tensor representation B1 and the second tensor representation Bz have a same number of non-zero eigenvalues, the eigenvalues of the first tensor representation B1 matching the eigenvalues of the second tensor representation Bz, and wherein the first and the second diffusion encoding sequences are configured to present a matching average spectral content, and to present a diff

Abstract: The present invention describes a method for quantifying microscopic diffusion anisotropy and/or mean diffusivity in a material by analysis of echo attenuation curves acquired with two different gradient modulations schemes, wherein one gradient modulation scheme is based on isotropic diffusion weighting and the other gradient modulation scheme is based on non-isotropic diffusion weighting, and wherein the method comprises analyzing by comparing the signal decays of the two acquired echo attenuation curves.

Abstract: The present invention describes a method for magnetic resonance (MR) and/or MR imaging, comprising acquisition of signals and MR images originating from a RE and gradient sequence causing isotropic diffusion weighting of signal attenuation, wherein the isotropic diffusion weighting is achieved by one time-dependent dephasing vector q(t) having an orientation, wherein the isotropic diffusion weighting is proportional to the trace of a diffusion tensor D, and wherein the orientation of the time-dependent dephasing vector q(t) is either varied discretely in more than three directions in total, or changed continuously, or changed in a combination of discretely and continuously during the gradient pulse sequence, 0?t?echo time, where t represents the time. The method may be performed during a single shot (single MR excitation).

Abstract: According to an aspect of the present inventive concept, there is provided a method of extracting information about a sample, the method comprising: performing a plurality of magnetic resonance measurements on the sample, each measurement including subjecting the sample to an encoding sequence, at least a part of the sequence being adapted to encode a magnetic resonance signal attenuation due to nuclear relaxation and diffusion, wherein at least one parameter of a gradient pulse sequence is varied between at least a subset of said plurality of measurements, and at least one measurement of said subset includes a gradient pulse sequence having a diffusion-encoding tensor representation with more than one non-zero eigenvalue, and wherein at least a subset of said plurality of measurements include encoding for different levels of magnetic resonance signal attenuation due to nuclear relaxation; and extracting information about the sample from signals resulting from said plurality of magnetic resonance measurements

Abstract: The present invention discloses a method for magnetic resonance (MR) imaging comprising acquiring at least two MR images with different motion-weighting originating from a RF and gradient pulse sequence causing signal attenuation from diffusion but not flow (flow-compensated data); acquiring at least two MR images with different motion-weighting originating from a RF and gradient pulse sequence causing signal attenuation from diffusion and flow (non-compensated data); performing a model fit to the flow-compensated and non-compensated data in which at least one of the adjustable parameters are constrained to be the same for both sets of data; and obtaining quantitative information on microscopic flow by extracting at least one parameter of the intravoxel incoherent motion (IVIM) effect from the model fit, said method being directed to diffusion-perfusion.

Abstract: The present invention discloses a method for magnetic resonance (MR) imaging comprising: acquiring at least two MR images with different motion-weighting originating from a RF and gradient pulse sequence causing signal attenuation from diffusion but not flow (flow-compensated data); acquiring at least two MR images with different motion-weighting originating from a RF and gradient pulse sequence causing signal attenuation from diffusion and flow (non-compensated data); performing a model fit to the flow-compensated and non-compensated data in which at least one of the adjustable parameters are constrained to be the same for both sets of data; and obtaining quantitative information on microscopic flow by extracting at least one parameter of the intravoxel incoherent motion (IVIM) effect from the model fit, said method being directed to diffusion-perfusion.

Abstract: The present invention describes a method for quantifying microscopic diffusion anisotropy and/or mean diffusivity in a material by analysis of echo attenuation curves acquired with two different gradient modulations schemes, wherein one gradient modulation scheme is based on isotropic diffusion weighting and the other gradient modulation scheme is based on non-isotropic diffusion weighting, and wherein the method comprises analyzing by comparing the signal decays of the two acquired echo attenuation curves.

Abstract: According to an aspect of the present inventive concept there is provided a method for quantifying isotropic diffusion and/or anisotropic diffusion in a sample, the method comprising: performing diffusion weighted magnetic resonance measurements on the sample using diffusion encoding magnetic gradient pulse sequences Gi=1. . . m, wherein each magnetic gradient pulse sequence Gi is generated such that a diffusion encoding tensor bi for the magnetic gradient pulse sequence Gi has one to three non-zero eigenvalues, where bi=Formula (I), qi(t) is proportional to Formula (II) and t is an echo time.

Abstract: The present invention describes a method for magnetic resonance (MR) and/or MR imaging, comprising acquisition of signals and MR images originating from a RE and gradient sequence causing isotropic diffusion weighting of signal attenuation, wherein the isotropic diffusion weighting is achieved by one time-dependent dephasing vector q(t) having an orientation, wherein the isotropic diffusion weighting is proportional to the trace of a diffusion tensor D, and wherein the orientation of the time-dependent dephasing vector q(t) is either varied discretely in more than three directions in total, or changed continuously, or changed in a combination of discretely and continuously during the gradient pulse sequence, 0?t?echo time, where t represents the time. The method may be performed during a single shot (single MR excitation).

Abstract: The present invention describes a method for magnetic resonance (MR) and/or MR imaging, comprising acquisition of signals and MR images originating from a RF and gradient sequence causing isotropic diffusion weighting of signal attenuation, wherein the isotropic diffusion weighting is achieved by one time-dependent dephasing vector q(t) having an orientation, wherein the isotropic diffusion weighting is proportional to the trace of a diffusion tensor D, and wherein the orientation of the time-dependent dephasing vector q(t) is either varied discretely in more than three directions in total, or changed continuously, or changed in a combination of discretely and continuously during the gradient pulse sequence, 0?t?echo time, where t represents the time. The method may be performed during a single shot (single MR excitation).

Abstract: According to an aspect of the present inventive concept there is provided a method for quantifying isotropic diffusion and/or anisotropic diffusion in a sample, the method comprising: performing diffusion weighted magnetic resonance measurements on the sample using diffusion encoding magnetic gradient pulse sequences Gi=1 . . . m, wherein each magnetic gradient pulse sequence Gi is generated such that a diffusion encoding tensor bi for the magnetic gradient pulse sequence Gi has one to three non-zero eigenvalues, where bi=Formula (I), qi(t) is proportional to Formula (II) and t is an echo time.

Abstract: The present invention describes a method for quantifying microscopic diffusion anisotropy and/or mean diffusivity in a material by analysis of echo attenuation curves acquired with two different gradient modulations schemes, wherein one gradient modulation scheme is based on isotropic diffusion weighting and the other gradient modulation scheme is based on non-isotropic diffusion weighting, and wherein the method comprises analyzing by comparing the signal decays of the two acquired echo attenuation curves.