Wisconsin Alumni Research Foundation

Leland Stanford Junior University

General Electric Company

Beth Israel Deaconess Medical Center, Inc.

Scott Brian Reeder

Huanzhou Yu

Diego Hernando

Charles McKenzie

Jean Helen Brittain

Norbert Joseph Pelc

Nathan Samuel Artz

Angel R Pineda

Xiaoke Wang

Ann Shimakawa

Matthew Robert Smith

Daiki Tamada

Samir Sharma

Charles Anthony Mistretta

Brian A Hargreaves

John C Perry

Walter Francis Block

Reed Frederick Busse

Garry Evan Gold

Ethan K Brodsky

Brian J Soher

Oliver Wieben

Zhifei Wen

Roberta Marie Strigel

Anja Brau

Catherine Judith Moran

Valentina Taviani

Aziz Hatim Poonawalla

Roberta M Strigel

A system and method are provided for producing at least one of an image or a map of a subject includes controlling a magnetic resonance imaging (MRI) system to perform a pulse sequence that includes a phase increment of an RF pulse selected to induce a phase difference between two echoes at different echo times (TE). The method also includes controlling the MRI system to acquire MR data corresponding to at least the two echoes at different TEs, deriving a static magnetic field (B0) map of the MRI system using the MR data corresponding to the two echoes, and using the B0 map and MR data from at least one of the two echoes, generate a map of T2 of the subject.

System and method for quantitative mapping with magnetic resonance imaging

A system and method are provided for controlling a magnetic resonance imaging (MRI) system. The method includes performing a gradient echo pulse sequence that includes a phase increment of an RF pulse of the gradient echo pulse sequence selected to encode diffusion information into a phase of MR signals. The method also includes controlling the plurality of gradient coils and the RF system to acquire the MR signals as MR data, processing the MR data to determine MR signals corresponding to diffusion in the subject when acquiring the MR signals, and generating at least one of an image or a map of the subject indicating the diffusion in the subject from the MR data.

System and method for diffusion mapping using phasemodulated magnetic resonance imaging

A system and method are provided for controlling a magnetic resonance imaging system to perform a gradient echo pulse sequence that includes varying a phase of an RF pulse of the gradient echo pulse sequence between repetitions and acquire complex MR data. The method includes processing the complex MR data to determine signal contributions from transverse relaxation (T2) in the subject, generating a quantitative T2 map of the subject using the signal contributions from T2 in the subject, and displaying the quantitative T2 map.

System and method for determining patient parameters using radio frequency phase increments in magnetic resonance imaging

A system and method for assessing tissue properties of a subject within a region of interest (ROI) using a magnetic resonance imaging (MRI) system includes acquiring chemical-shift-encoded imaging data of the ROI. The method also includes determining, from imaging data a proton density water fraction (PDWF) map and quantifying, using the PDWF map, a property of tissue within the ROI. The method further includes generating, using the PDWF map, a report indicating the quantified property of the tissue. The tissue may include fibroglandular tissue (FGT).

System and method for assessing tissue properties using magnetic resonance imaging

A phantom for use with magnetic resonance imaging ('MRI') and, in particular, for calibrating quantitative diffusion MRI is provided. In general, the phantom includes a solution composed of a solvent that has diffusivity value higher than that of water, and a solute that when added to the solvent reduces the diffusivity of the solution. By varying the combined concentration of the solvent and solute, the diffusivity of the solution can be controlled to fall within a range of diffusivity values found in biological tissues in a variety of different physiological conditions or tissue environments.

Phantom for quantitative diffusion magnetic resonance imaging

A system and method are provided for determining B1 inhomogeneities or creating a T1 map of a subject using a magnetic resonance imaging (MRI) system that is corrected for an influence of a presence of fat and a presence of iron in the subject on T1 weighting. The method includes controlling the MRI system using a single pulse sequence to acquire, from the subject, a plurality of datasets with varied T1 weighting created by varying at least one of a repetition time (TR) and a flip angle (FA) for repetitions of the single pulse sequence. The method also includes using an MR signal model and the plurality of datasets, estimating B1 inhomogeneities or generating a T1 map of the subject that is corrected for an influence of a presence of fat and a presence of iron in the subject on T1 weighting in the plurality of datasets.

System and method for confounder-corrected T1 measures using MRI

Phantoms for use in magnetic resonance imaging ('MRI') and, in particular, for use in quantifying fat concentration, iron concentration, or both, are provided. The phantoms are constructed to accurately reflect in vivo magnetic resonance signal behavior in the presence of both fat and iron. The phantoms described here can thus be used for phantom-based validation of MRI techniques for the joint quantification of fat and iron concentration, for phantom-based validation of MRI techniques for quantifying fat concentration in the presence of iron overload, and for phantom-based validation of MRI techniques for quantifying iron concentration given the confounding presence of fat.

Phantom for iron and fat quantification magnetic resonance imaging

A system and method for assessing magnetic susceptibility of tissue of a subject using a magnetic resonance imaging (MRI) system to acquire chemical-shift-encoded, water-fat separated data. From the water-fat separated data, separated water and fat images, as well as a magnetic field inhomogeneity map are used to estimate the magnetic susceptibility within tissue.

System and method for assessing susceptibility of tissue using magnetic resonance imaging

An object-based approach is used to initialize the magnetic field inhomogeneity estimation for chemical species separation, such as water-fat separation, and other imaging applications. For example, a susceptibility distribution in the subject being imaged is estimated from images reconstructed from single-echo or multi-echo k-space data and used to initialize the magnetic field inhomogeneity estimation. This approach can be applied to any complex-based chemical shift encoded chemical species separation technique and to other imaging applications, such as susceptibility-weighted imaging and quantitative susceptibility mapping. The field map can also be used to correct for image distortions and to generate magnetic field shimming values.

System and method for object-based initialization of magnetic field inhomogeneity in magnetic resonance imaging

Systems and methods for simultaneously acquiring three-dimensional data from multiple different frequency bins with a magnetic resonance imaging ('MRI') system, and without frequency-encoding gradients, are provided. A multiband radio frequency ('RF') pulse is used to excite spins associated with multiple different resonance frequency offsets, and a fully phase-encoded acquisition is used to acquire data, which may be spectrally-resolved data, from magnetic resonance signals formed in response to the multiband RF pulse.

System and method for fully phase-encoded magnetic resonance imaging using multiband radio frequency excitation

A system and method for acquiring spectrally-resolved three-dimensional data with a magnetic resonance imaging ('MRI') system without frequency-encoding gradients are provided. An MRI system is directed to produce a radio frequency ('RF') pulse that rotates net magnetization about an axis, after which a first phase-encoding gradient is established along a first direction, a second phase-encoding gradient is established along a second direction that is orthogonal to the first direction, and a third phase-encoding gradient is established along a third direction that is orthogonal to the first and second directions. Spectrally-resolved data are acquired at a point in k-space that is defined by the first, second, and third phase-encoding gradients, and is acquired by sampling a magnetic resonance signal at a plurality of time points during a period of time in which no magnetic field gradients are established by the MRI system.

System and method for spectrally-resolved three-dimensional magnetic resonance imaging without frequency-encoding gradients

Described here is a system and method for estimating apparent transverse relaxation rate, R*, while simultaneously performing chemical species separation (e.g., water-fat separation) using magnetic resonance imaging ('MRI'). A homodyne reconstruction of k-space datasets acquired using a partial k-space acquisition is used and the chemical species separation of the resultant images takes into account the spectral complexity of the chemical species in addition to magnetic resonance signal decay associated with transverse relaxation. Full resolution maps of R* are thus capable of being produced while also allowing for the production of images depicting the separated chemical species that are corrected for transverse relaxation associated signal decays.

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A system and method for accelerated magnetic resonance imaging (MRI) using spectral sensitivity information are provided. The MRI system is used to acquire k-space data from a subject that when positioned in the main magnetic field of the MRI system causes inhomogeneities in the main magnetic field. Spectral sensitivity information is derived from the acquired k-space data. In general, the spectral sensitivity information relates specific resonance frequencies to distinct spatial locations in the main magnetic field of the MRI system. One or more images of the subject may be reconstructed from the acquired k-space data using the produced spectral sensitivity information to spatially encode the acquired k-space data. By using the spectral sensitivity information to provide spatial-encoding, the data acquisition can be accelerated, for example, by undersampling k-space. In addition, using the provided system and method, clinically viable images can be obtained in the presence of severe off-resonance.

System and method for accelerated magnetic resonance imaging using spectral sensitivity

A method for producing parametric maps using a magnetic resonance imaging (MRI) system is provided. The MRI system is used to acquire k-space data from a field-of-view. A series of images is reconstructed from the acquired k-space data, and a confidence map is produced using the k-space data. The confidence map depicts regions in the field-of-view that are affected by error sources. A parametric map is produced using the reconstructed series of images and the produced confidence map. Values in the parametric map associated with regions in the field-of-view depicted in the confidence map as being affected by error sources are not computed, thereby reducing errors in the parametric map.

System and method for magnetic resonance imaging parametric mapping using confidence maps

A magnetic resonance imaging ('MRI') system and method for producing an image of a subject with the MRI system in which signal contributions of water and fat are separated are provided. A plurality of in-phase echoes formed at a plurality of different echo times are sampled to acquire k-space data. The in-phase echoes include signal contributions from water and fat that are in-phase with each other. The signal contributions from water and fat are then separated by fitting only those echo signals that are in-phase echo signals to a signal model that models a fat spectrum as including multiple resonance peaks. From these signal contributions, an image of the subject depicting a desired amount of signal contribution from water and a desired amount of signal contribution is produced.

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Middleton, WI, United States of America

Scott Brian Reeder