The invention relates to a method of Dixon-type MR imaging. It is an object of the invention to provide a method that enables efficient and reliable Dixon water/fat separation, in particular using a bipolar acquisition strategy, while avoiding flow-induced leakage and swapping artifacts. According to the invention, an imaging sequence is executed which comprises at least one excitation RF pulse and switched magnetic field gradients, wherein pairs of echo signals are generated at two different echo times (TE1, TE2) and during two or more different cardiac phases (AW1, AW2). The echo signals are acquired and phase images are reconstructed therefrom. A final diagnostic image is reconstructed from the echo signal data using water/fat separation, wherein regions of flow and/or estimates of flow- induced phase errors are derived from the phase images to suppress or compensate for flow- induced leakage and/or swapping artifacts in the final diagnostic image. Therein, flow- induced phase offsets are determined by voxel-wise comparison of the phase images associated with the different cardiac phases. Moreover, the invention relates to a MR device (1) and to a computer program to be run on a MR device (1).

In a method for measuring brain free water content, in response to an RF excitation field generated on the basis of a magnetic resonance fingerprinting sequence and applied to the brain, an equilibrium magnetization mixed term (M0) signal is acquired from radiation emitted by each excited voxel of the brain, to obtain an M0 value of each voxel of the brain; a receive coil sensitivity (RP) value of each voxel of the brain is acquired; the M0 value of each voxel of the brain is divided by the RP value of the corresponding voxel to obtain a proton density (PD) value of each voxel of the brain; a PD value of cerebrospinal fluid is taken to be a reference PD value; and the PD value of each voxel of the brain is divided by the reference PD value to obtain the free water content of each voxel of the brain. The method advantageously increases the speed and accuracy of measurement of brain free water content.

In a method for determining a fat-reduced MR image, a first MR image is provided having, apart from the other tissue constituents, MR signals from only one of the two fat constituents, the first MR image is applied to a trained ANN, which was trained by first MR training data as the input data, the training data including, apart from the other tissue constituents, MR signals from only the one of the two fat constituents, and using second MR training data as a base knowledge, the second MR training data including, apart from the other tissue constituents, no MR signals from the two fat constituents; and an MR output image is determined from the trained ANN, to which the first MR image was applied, as a fat-reduced MR image, wherein the fat-reduced MR image includes, apart from the other tissue constituents, no MR signals from the two fat constituents.

The invention provides for a magnetic resonance imaging system (100, 300, 100) for acquiring magnetic resonance data (110, 1104) from a subject (118) within an imaging zone (108). The magnetic resonance imaging system comprises a memory (136) for storing machine executable instructions (160, 162, 164, 166, 316) and pulse sequence data (140, 1102). The pulse sequence data comprises instructions for controlling the magnetic resonance imaging system to acquire magnetic resonance data according to a magnetic resonance imaging method. The magnetic resonance imaging system further comprises a processor (130) for controlling the magnetic resonance imaging system. Execution of the machine executable instructions causes the processor to: acquire (1200) the magnetic resonance data by controlling the magnetic resonance imaging system with the pulse sequence data; calculate (1202) a B0 inhomogeneity map (148) by analyzing the magnetic resonance data according to the magnetic resonance imaging method, calculate (1204) a B1 phase map (150) and/or a B1 amplitude map (1106) by analyzing the magnetic resonance data according to the magnetic resonance imaging method; and calculate (1206) a second derivative (1110) of the B1 phase map and/or a second derivative of the B1 magnitude map 1 and/or a second derivative of the B0 in homogeneity map in at least one predetermined direction. The second derivative is calculated using a corrected voxel size in the at least one predetermined direction, wherein the corrected voxel size is calculated using a correction factor calculated from the derivative of the B0 inhomogeneity map.

An MR Spectroscopy (MRS) system and approach is provided for measuring spectral information corresponding with propionic acid (PA), either alone or in combination with other measurements corresponding with other chemicals, to diagnose and/or monitor at least one of bacterial infection, such as associated with P. acnes, or conditions related thereto such as nociceptive pain associated with tissue acidity. An interfacing DDD-MRS signal processor receives output signals to produce a post-processed spectrum, with spectral regions corresponding with certain chemicals, including PA, then measured as biomarkers. A diagnostic processor derives a diagnostic value for each disc, and performs certain normalizations, based upon ratios of the spectral regions related to chemicals implicated in degenerative painful tissue pathology, such as PA and hypoxia markers of lactic acid (LA) and alanine (AL), and structural chemicals of proteoglycan (PG) and collagen or carbohydrate (CA).

A method for magnetic resonance imaging performs chemical shift encoded imaging to produce complex dual-echo images which are then applied (with imaging parameters) as input to a deep neural network to produce as output water-only and fat-only images. The deep neural network can be trained with ground truth water/fat images derived from chemical shift encoded images using a conventional water-fat separation algorithm such as projected power approach, IDEAL, or VARPRO. The chemical shift encoded imaging comprises performing an image acquisition with the MRI scanner via a spoiled-gradient echo sequence or a spin-echo sequence.

Provided herein are adipose mimic compositions for use in MRI. The compositions of the invention mimic the MRI properties of human adipose tissue, including T1 relaxation kinetics, T2 relaxation kinetics, magnetic susceptibility, and chemical shift artifact. The compositions of the invention are readily manufactured from inexpensive materials. The compositions of the invention may be used in MRI system calibration or for implementing image correction techniques such as fat suppression.

A method to compensate for chemical shift displacement includes, prior to applying an imaging pulse sequence to acquire MRI data of a subject, applying a first saturation pulse within a slice location of an imaging volume of the subject in which the MRI data is to be acquired, wherein the first saturation pulse results in a first chemical shift displacement between water and fat in a first spatial saturation band. The method also includes, prior to applying the imaging pulse sequence, subsequently applying a second saturation pulse within the slice location, wherein the second saturation pulse results in a second chemical displacement between the water and the fat in a second spatial saturation band that results in a final spatial saturation band being free of chemical shift displacement after application of the second saturation pulse, the second chemical shift displacement being different from the first chemical shift displacement.

A method for non-invasive quantification of organ fat using a magnetic resonance approach includes: constructing a detection system; connecting a detection area; detection system startup; acquiring data; analyzing data; and performing horizontal data analysis. An external computer, a radio frequency (RF) subsystem, and a portable magnet module are used to construct a system for non-invasive quantification of organ fat based on low-field nuclear magnetic resonance (LF-NMR), which causes no damage, and achieves accurate and non-invasive quantification of organ fat. Specific pulse sequences are used to excite nuclear spin in a target region to generate LF-NMR, so as to achieve “one-click” detection, which is used for fast screening of related diseases such as non-alcoholic fatty liver disease (NAFLD). The system has accurate quantification, and is easy to operate without constraints of operator qualifications.

A method of providing content related to capture of a medical image of an object is provided. The method includes acquiring at least one of information related to a state of the object and information related to a capture protocol, determining content to be provided to the object on a basis of the acquired information, and outputting the determined content.