A system and method are provided for determining a spatial distribution of susceptibility in a subject using a magnetic resonance imaging (MRI) system. The method includes directing the MRI system to acquire imaging data from an imaging volume within a subject, wherein the imaging volume is subject to both background fields (B.sub.B) originating outside the imaging volume and local fields (B.sub.L) originating from tissue within the imaging volume. The method also includes selecting a size and non-central compute point for an extended Poisson kernel to be applied to the imaging data, subtracting from a delta function to control the background fields (B.sub.B) but not the local fields (B.sub.L), and producing a susceptibility report attributable to the local fields (B.sub.L).

An information processing apparatus according to an embodiment includes a processing circuit. The processing circuit acquires a measurement field corresponding to a spatial distribution of a predetermined physical quantity in a subject of measurement. The processing circuit calculates an unknown quantity in the subject of measurement based on a first equation between the measurement field and the unknown quantity having spatial dependence, and on the acquired measurement field. The first equation is one that is acquired based on a second equation expressing a dual field divergence of which can be expressed using the measurement field, by using the measurement field and the unknown quantity, and on the Helmholtz decomposition of the dual field.

In a method and apparatus for performing magnetic resonance (MR) imaging for generating multiple T1 maps of separate regions of interest of a subject along a first spatial axis, multiple MR pulse sequences are generated, each MR pulse sequence being for imaging a respective one of the separate regions of interest of the subject. In order to generate each of the plurality of MR pulse sequences, a spatially selective preparation pulse is generated exciting the region of interest of the subject and a number of imaging sequences that follow the application of the spatially selective preparation pulse are generated. MR imaging data are acquired during the generation of the multiple imaging sequences. The multiple MR pulse sequences are generated during a period not exceeding 30 seconds.

Systems and methods for quantitative susceptibility mapping (“QSM”) using magnetic resonance imaging (“MRI”) are described. Localized magnetic field information is used when performing the inversion to compute quantitative susceptibility maps. The localized magnetic field information can include multi-resolution subvolumes obtained by segmenting, or dividing, a field shift map. In some instances, a trained machine learning algorithm, such as a trained neural network, can be implemented to convert the localized magnetic field information into quantitative susceptibility data. These local susceptibility maps can be combined to form a composite quantitative susceptibility map of the imaging volume.

A system may measure, using a measurement device, a response associated with a sample to an excitation. Then, the system may compute, using the measured response and the excitation as inputs to one of an inverse model and a predetermined predictive model, model parameters on a voxel-by-voxel basis in a forward model with multiple voxels that represent the sample. The forward model may simulate response physics occurring within the sample to a given excitation, and the model parameters may include magnetic susceptibilities of the multiple voxels. Moreover, the system may determine an accuracy of the model parameters by comparing at least the measured response and a calculated predicted value of the response using the forward model, the model parameters and the excitation. When the accuracy exceeds a predefined value, the system may provide the model parameters as an output to: a user, another electronic device, a display, and/or a memory.

Systems and methods for taking into account susceptibility deviations in magnetic-resonance-based therapy planning by a magnetic resonance tomography unit. A B0 field map is determined by the magnetic resonance tomography unit. A location blur distribution is determined from the B0 field map and from the location blur distribution in turn, a parameter of an image acquisition as a function of the location blur distribution, in such a way that an image acquisition brings about a reduced location blur with the determined parameter.

A measurement apparatus including: a static magnetic field applying part that applies a static magnetic field having a constant magnitude in a first direction to a measurement target; a plurality of current applying parts applying a plurality of AC currents oriented in a plurality of directions toward a portion of the measurement target via an electrode pair; a magnetic field detecting element that detects a magnitude of a magnetic field generated from the portion of the measurement target in response to the static magnetic field having the constant magnitude in the first direction and the plurality of AC currents; a calculating part for calculating impedance of the portion of the measurement target; and an internal information output part for generating information including an internal component of the measurement target.

State of the art systems being used for QSM reconstruction have explored prior information from both magnitude and phase data. However, the underlying assumption is that the susceptibility maps and the magnitude images have coinciding edges. Establishing the ground-truth susceptibility maps is difficult and leads to limited applicability of supervised methods. Further, with portable MRI machines becoming a reality, low-field imaging is getting more prominence, which brings in several associated challenges due to noise and external interference. The disclosure herein generally relates to magnetic resonance imaging (MRI) imaging systems, and, more particularly, to a method and system for quantitative susceptibility mapping (QSM) reconstruction in magnetic resonance imaging (MRI) systems. The system performs an iterative reconstruction of QSM, wherein in each iteration the reconstructed QSM from previous iteration is refined by comparing with a reference image generated using same subject's prior MRI data.

Various methods and systems are provided for correcting transmit attenuation of an amplifier of a transmit radio frequency (RF) coil for use in a magnetic resonance imaging (MRI) system. In one example, a method includes setting a reference value of transmit attenuation for an amplifier of a transmit radio frequency (RF) coil, acquiring a three-dimensional B.sub.1 field map with the transmit attenuation set at the reference value, determining a plurality of mean flip angles for a plurality of slice locations in a pre-scan imaging volume from the B.sub.1 field map, determining a transmit attenuation correction value for each of the slice locations based on a prescribed flip angle and the mean flip angle determined for the respective slice location, correcting the reference value of transmit attenuation with the transmit attenuation correction value at each of the slice locations to obtain a final value of transmit attenuation for each of the slice locations, and performing an MRI scan with the transmit attenuation set at the value.

A method of processing magnetic resonance (MR) data of a sample under investigation, includes the steps of providing the MR data being collected with an MRI scanner apparatus, and subjecting the MR data to a multi-parameter nonlinear regression procedure being based on a non-linear MR model and employing a set of input parameters, wherein the regression procedure results in creating a parameter map of model parameters of the sample, wherein the input parameters (initial values and possibly boundaries) of the regression procedure are estimated by a machine learning based estimation procedure applied to the MR data. The machine learning based estimation procedure preferably includes at least one of at least one neural network and a support vector machine. Furthermore, an MRI scanner apparatus is described.