Magnetic Resonance Innovations, Inc.

Spintech, Inc.

Mr Innovations, Inc.

Other

E Mark Haacke

Jaladhar Neelavalli

Yu-Chung Norman Cheng

Yingbiao Xu

Wei Feng

Yongsheng Chen

Yi Wang

Ching-Yi Hsieh

Juergen Reichenbach

Systems and methods for high-resolution STAGE imaging can include acquisition of relatively low-resolution k-space datasets with two separate multi-echo GRE sequences. The multi-echo GRE sequences can correspond to separate and distinct flip angles. Various techniques for combining the low-resolution k-space datasets to generate a relatively high-resolution k-space are described. These techniques can involve combining low-resolution k-space datasets associated with various echo types. The STAGE imaging approaches described herein allow for rapid imaging, enhanced image resolution with relatively small or no increase in MR data acquisition time.

Systems and methods for enhancement of resolution for strategically acquired gradient echo (stage) imaging

Systems and methods for enhancement of resolution for strategically acquired gradient echo (STAGE) imaging

Variable flip angle techniques with constraints for reconstructing MR images include a processor generating a Tmap representing a spatial distribution of Twithin an anatomical region using a first MR dataset corresponding to a first flip angle (FA) and a second MR dataset corresponding to a second FA. The processor can estimate a first and second transmit RF field maps by scaling the Tmap by a first constant value of Tassociated with a first tissue type and a second constant value of Tassociated with a second tissue type, respectively. The processor can generate a third transmit RF field map using the first and second transmit RF field maps, and use the third transmit RF field map to construct MR images of the anatomical region. Weighted subtraction images can be created with improved contrast-to-noise ratio compared to images of the first and second MR datasets.

Systems and methods for strategically acquired gradient echo imaging

In this disclosure, a process of imaging a target object using magnetic resonance (MR) includes an MRI scanner scanning the target object using a first transmit RF pulse. A processor associated with the MRI scanner can acquire magnitude and/or phase data associated with a first RF signal produced (or echoed) by the target object responsive to the MRI scan. The processor can determine a second transmit RF pulse for use to scan the target object based on the acquired data and according to a given phase criterion. The phase criterion can be configured to enforce mitigation of a phase distribution estimated based on the acquired data.

Method and apparatus for magnetic resonance imaging with radio frequency pulses generated according to phase criteria

A method of nuclear magnetic resonance imaging of an object is disclosed, the method including: receiving MR data including magnitude and phase information generated using an MR scan having a series of different echo times; generating one or more measured MR images based on the MR data; and processing the measured MR images to generate unaliased or substantially unaliased phase information for at least one pixel in the image.

Catalytic multiecho phase unwrapping scheme

A method is disclosed including: receiving a time resolved series of magnetic resonance (MR) images of an imaged region of a subject; processing the images to generate comparison data by comparing a temporal behavior of a reference region of the MR images to at least one other region of the MR images; an generating an output based on the comparison data. The method may be applied in a variety of contexts, including perfusion weighted imaging, determination of T2*, and other time series functions.

Tissue similarity mapping

A method of generating a susceptibility map of an object utilizes a regularizing inverse function, oversampling k-space, removing external phase noise and rapid phase change effects, accounting for the known geometry of the object, and using modified SWI phase data to generate reasonable susceptibility maps and digital images therefrom, such as SWI images. The inventors refers to the inventive methods set forth herein as Susceptibility Weighted Imaging and Mapping (SWIM).

Method of generating nuclear magnetic resonance images using susceptibility weighted imaging and susceptibility mapping (SWIM)

The present invention provides a method of handling rapid phase aliasing in magnetic resonance images arising from local magnetic susceptibility differences. The methods of the present invention can be used to estimate the field effects within an object arising from the interfaces of regions having differences in magnetic susceptibilities, and to subtract out the resulting phase from the original or source phase data prior to any further phase processing. The methods of the present invention also include a process of accurately determining the susceptibility values of multiple voxel regions based on the geometry of such regions.

Geometry based field prediction method for susceptibility mapping and phase artifact removal

A method comprises digitally representing a volume of space as a plurality of voxels and assigning real and imaginary values derived from magnetic resonance imaging data of the space to each of the voxels. Furthermore, the method comprises a steps of calculating a first complex summation of the real and imaginary values of a first set of the voxels, and calculating a second complex summation of the real and imaginary values of a second set of the voxels. Each set of voxels represents a different region of the volume of space. The regions are concentric. The method also comprises steps of using the first and second summations, along with another value quantitatively calculated from the magnetic resonance imaging data, to calculate a value that is dependent upon the approximate magnetic moment of an object within the volume of space, and digitally representing and storing said value.

Method of and software application for quantifying objects in magnetic resonance images via multiple complex summations

A method of removing noise while preserving signal in nuclear magnetic resonance images combines steps of performing a magnitude threshold filter and performing a phase threshold filter on the image data. Preferably, a magnitude and phase connectivity algorithm is applied to pixels that fail to meet either the magnitude or phase thresholds.

Complex threshold method for reducing noise in nuclear magnetic resonance images

Segmented echo planar nuclear magnetic resonance imaging is performed using an iterative correction method that corrects or suppresses geometric distortion in the image domain caused by off-resonance phase discontinuities in the phase encoding direction. The iterative correction method can be performed in a single scan by providing extra gradients in the pulse sequence to generate an extra transverse magnetization echo from the pulse. Additionally, the iterative correction method can be performed using a separate non-segmented double-echo scan in combination with data obtained using a conventional segmented echo planar imaging pulse sequence.

Iterative method for correction of geometric distortion resulting from phase evolution during segmented echo planar nuclear magnetic resonance imaging and apparatus therefor

A method for magnetic resonance imaging is described.

Susceptibility weighted imaging

A method of complex image reconstruction from partially acquired data in two or more dimensions is presented. This method uses an iterative multidimensional transformation to reconstruct a magnetic resonance image. The method of this invention abandons the theory that complex conjugation is necessary to reconstruct a complex image from partially acquired data and, instead, utilizes a phase constraint to make the solution determinable using a multidimensional transformation technique. This method of image reconstruction allows magnetic resonance images to be reconstructed by acquiring only one-half of the k-space data.

Method of MRI image reconstruction from partially acquired data in two or more dimensions using a multidimensional inverse transform technique

The echo time in an MR pulse sequence is optimized in accordance with the application desired. Advantageously, the echo time is selected to cause a partial volume signal cancellation from veins as compared with background tissue, and the MR pulse sequence is of a velocity-compensated type. MR data are acquired from gradient echoes. Multiple echoes may be used to extract information (such as volume content and susceptibility) about the material under investigation.

Application-specific optimization of echo time in MR pulse sequences for investigating materials with susceptibilities different from that of the background in which they are embedded

Growing community of inventors

Detroit, MI, United States of America

E Mark Haacke