# US 11,112,476 B2 · Method of extracting information about a sample by nuclear magnetic resonance measurements > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,112,476 B2 - Document ID: US11112476B2 - Status: Granted - Kind: B2 - Application number: 16/065,086 - Filed: 2016-12-22 - Published: 2019-01-10 - Granted: 2021-09-07 - Earliest claimed: 2015-12-29 - Assignees: CR Development AB - Applicants: CR Development AB - Inventors: Daniel Topgaard; Samo Lasic - Web page: https://patentgrep.com/patent/US11112476B2 ## CPC - G01R 33/543: {Control of the operation of the MR system, e.g. setting of acquisition parameters prior to or during MR data acquisition, dynamic shimming, use of one or more scout images for scan plane prescription (G01R33/546 takes precedence)} - A61B 5/055: involving electronic [EMR] or nuclear [NMR] magnetic resonance, e.g. magnetic resonance imaging - G01N 24/08: by using nuclear magnetic resonance (G01N24/12 takes precedence) - G01R 33/448: {Relaxometry, i.e. quantification of relaxation times or spin density (G01R33/50 takes precedence)} - G01R 33/56341: {Diffusion imaging} - G06F 17/18: for evaluating statistical data {, e.g. average values, frequency distributions, probability functions, regression analysis (forecasting specially adapted for a specific administrative, business or logistic context G06Q10/04)} - A61B 5/4064: {Evaluating the brain (for intracranial pressure A61B5/031; for cerebral blood gases A61B5/14553; using EEG A61B5/369)} - A61B 2576/026: for the brain - G01N 24/081: {Making measurements of geologic samples, e.g. measurements of moisture, pH, porosity, permeability, tortuosity or viscosity} - G01R: MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES (indicating correct tuning of resonant circuits H03J3/12) - A61B: DIAGNOSIS; SURGERY; IDENTIFICATION (usefulness limited to only animals A61D) - G01N: INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES (measuring or testing apparatus or processes other than immunoassay, involving enzymes or microorganisms C12M, C12Q) - G06F: ELECTRIC DIGITAL DATA PROCESSING (computer systems based on specific computational models G06N) ## 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, the information including nuclear relaxation and diffusion characteristics for the sample. ## Claims ### Claim 1 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 first subset of said plurality of measurements, and at least one measurement of said first subset includes a gradient pulse sequence comprising a diffusion-encoding tensor representation with more than one non-zero eigenvalue, and wherein at least a second 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, the information including nuclear relaxation and diffusion characteristics for the sample, wherein extracting the information includes estimating a representation of a probability distribution indicating a probability to find a particular combination of nuclear relaxation characteristics and diffusion characteristics in the sample, the combination including: a longitudinal and/or a transverse relaxation rate, and one or more of: an isotropic diffusion, an anisotropic diffusion, and an orientation of a diffusion tensor, wherein the probability distribution is estimated by determining a solution to an equation relating echo signals resulting from said plurality of measurements to a product of a kernel and the probability distribution, wherein components of the kernel are based on an acquisition parameter and a diffusion or a relaxation characteristic. ### Claim 2 (depends on 1) The method according to claim 1, wherein said at least one parameter of a gradient pulse sequence is varied between measurements to provide different diffusion encoding in the sample. ### Claim 3 (depends on 1) The method according to claim 1, wherein said at least one parameter of a gradient pulse sequence is varied between measurements to encode for different levels of signal attenuation. ### Claim 4 (depends on 1) The method according to claim 1, wherein one or more of a modulation of a gradient pulse sequence, a maximum gradient amplitude, and an orientation of the diffusion encoding are varied between measurements. ### Claim 5 (depends on 1) The method according to claim 1, wherein at least a third subset of the measurements include encoding for different levels of signal attenuation due to transverse relaxation and/or longitudinal relaxation. ### Claim 6 (depends on 1) The method according to claim 1, wherein the nuclear relaxation characteristics of the extracted information includes an estimate of a transverse relaxation rate and/or a longitudinal relaxation rate for the sample. ### Claim 7 (depends on 1) The method according to claim 1, wherein the diffusion characteristics of the extracted information include estimates of the elements of a diffusion tensor representing diffusion for a component in the sample. ### Claim 8 A method of determining diffusion characteristics of a biological sample including water using magnetic resonance measurements, 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, varying at least one parameter of a gradient pulse sequence comprising a diffusion-encoding tensor representation with more than one non-zero eigenvalue, encoding for different levels of magnetic resonance signal attenuation due to nuclear relaxation, and extracting information including a probability distribution indicating a probability to find a particular combination of nuclear relaxation characteristics and diffusion characteristics in the sample, the combination including: a longitudinal and/or a transverse relaxation rate, and one or more of an isotropic diffusion and an anisotropic diffusion. ### Claim 9 (depends on 8) The method of claim 8, wherein the probability distribution is estimated by determining a solution to an equation relating echo signals resulting from the plurality of measurements to a product of a kernel and the probability distribution, wherein components of the kernel are based on an acquisition parameter and a diffusion or a relaxation characteristic. ### Claim 10 (depends on 8) The method of claim 8, wherein the at least one parameter of a gradient pulse sequence is varied between measurements to provide different diffusion encoding in the sample. ### Claim 11 (depends on 8) The method of claim 8, wherein the at least one parameter of a gradient pulse sequence is varied between measurements to encode for different levels of signal attenuation. ### Claim 12 (depends on 8) The method of claim 8, wherein the measurements include one or more of a modulation of a gradient pulse sequence, a maximum gradient amplitude, and an orientation of the diffusion encoding. ### Claim 13 (depends on 8) The method of claim 8, wherein the measurements include encoding for different levels of signal attenuation due to transverse relaxation or longitudinal relaxation. ### Claim 14 (depends on 8) The method of claim 8, encoding for different levels of signal attenuation due to transverse relaxation and longitudinal relaxation. ### Claim 15 (depends on 8) The method of claim 8, further comprising estimating a transverse relaxation rate and/or a longitudinal relaxation rate for the sample. ### Claim 16 (depends on 8) The method of claim 8, wherein the diffusion characteristics of the extracted information include estimates of the elements of a diffusion tensor representing diffusion for a component in the sample.