University of Virginia Patent Foundation

Beth Israel Deaconess Medical Center, Inc.

Michael Salerno

Yang Yang

Craig H Meyer

Frederick H Epstein

Xiao Chen

Xue Feng

Christopher M Kramer

John P Mugler, Iii

James R Brookeman

Li Zhao

Xiaoying Cai

Zhixing Wang

Kelvin Chow

Daniel Stuart Weller

Changyu Sun

Wei Huang

Adrienne E Campbell-Washburn

A computerized system and method of modeling myocardial tissue perfusion can include acquiring a plurality of original frames of magnetic resonance imaging (MRI) data representing images of a heart of a subject and developing a manually segmented set of ground truth frames from the original frames. Applying training augmentation techniques to a training set of the originals frame of MRI data can prepare the data for training at least one convolutional neural network (CNN). The CNN can segment the training set of frames according to the ground truth frames. Applying the respective input test frames to a trained CNN can allow for segmenting an endocardium layer and an epicardium layer within the respective images of the input test frames. The segmented images can be used in calculating myocardial blood flow into the myocardium from segmented images of the input test frames.

System and method for fully automatic LV segmentation of myocardial first-pass perfusion images

Systems and methods for performing ungated magnetic resonance imaging are disclosed herein. A method includes producing magnetic resonance image MRI data by scanning a target in a low magnetic field with a pulse sequence having a spiral trajectory; sampling k-space data from respective scans in the low magnetic field and receiving at least one field map data acquisition and a series of MRI data acquisitions from the respective scans; forming a field map and multiple sensitivity maps in image space from the field map data acquisition; forming target k-space data with the series of MRI data acquisitions; forming initial magnetic resonance images in the image domain by applying a Non-Uniform Fast Fourier Transform to the target k-space data; and forming reconstructed images with a low rank plus sparse (L+S) reconstruction algorithm applied to the initial magnetic resonance images.

Systems and methods for spiral-in-out low field MRI scans

Some aspects of the present disclosure relate a method for magnetic resonance imaging, which can include acquiring, by applying an imaging pulse sequence, magnetic resonance data associated with a region of interest of a subject. The imaging pulse sequence can include a plurality of RF pulses configured to generate a desired image contrast, and an outer-volume suppression (OVS) module to attenuate the signal outside the region of interest. The method can further include reconstructing, from the acquired magnetic resonance data, a plurality of reduced field of view (rFOV) magnetic resonance images corresponding to the region of interest.

Reduced field-of-view perfusion imaging with high spatiotemporal resolution

A computerized method of reconstructing acquired magnetic resonance image (MRI) data to produce a series of output images includes acquiring a multiband k-space data set from a plurality of multiband slices of spiral MRI data; simultaneously acquiring a single band k-space data set comprising respective single band spiral image slices that are each associated with a respective one of the multiband slices in the multiband k-space data set; using the single band k-space data set, for each individual multiband slice, calculating a respective calibration kernel to apply to the multi-band k-space data set for each individual multiband slice; separating each individual multiband slice from the multiband k space data set by phase demodulating the multi-band k-space data using multiband phase demodulation operators corresponding to the individual multiband slice and convolving phase demodulated multi-band k-space data with a selected convolution operator to form a gridded set of the multi-band k-space data corresponding to the individual multiband slice.

Multiband spiral cardiac MRI with non-cartesian reconstruction methods

In some aspects, the disclosed technology relates to reducing respiratory-induced motion artifacts for accelerated imaging. In one embodiment, magnetic resonance data may be acquired for an area of a subject containing the heart. The acquired data may include motion-corrupted data due to respiration of the subject. From the acquired data, an image may be independently reconstructed for each of a plurality of time frames, with each time frame corresponding to one of a plurality of heartbeats. A region containing the heart of the subject may be automatically detected in the reconstructed images, and rigid motion registration may be performed on the region of the reconstructed images containing the heart. Based on the rigid motion registration, a linear phase shift for motion correction may be determined. The linear phase shift may be applied to the motion-corrupted data to produce linear phase-shifted data, and a k-t image reconstruction may be performed on the linear phase-shifted data to produce motion-corrected images.

Systems and methods for reducing respiratory-induced motion artifacts for accelerated imaging

Systems and methods for simultaneous multi-slice imaging. In one embodiment, a method for magnetic resonance imaging of a region of interest of a subject includes simultaneously exciting multiple, different slice locations corresponding to a region of interest of a subject using a radio-frequency (rf) pulse, for obtaining multiple slices. The excitation phase is modulated between acquisitions using a phase cycling scheme configured to create signal cancellation of all but one slice of the multiple excited slices from the different slice locations. The method also includes applying an imaging pulse sequence using a spiral k-space trajectory to acquire image data from the multiple slices, for an image or series of images of the region of interest; and reconstructing, from the multiple slices, images of the region of interest, wherein the reconstructing recovers unaliased images from the different slice locations.

Systems and methods for simultaneous multi-slice imaging

In one aspect, the disclosed technology relates to a method which, in one example embodiment, includes acquiring magnetic resonance imaging data for a plurality of images of the heart of a subject during free breathing of the subject. The method also includes generating an additional plurality of images with high tissue-blood contrast over the region of interest, and selecting a subset of images from the plurality of images, based upon a pre-determined quality metric of image similarity, to be used for non-rigid image registration. The method also includes aligning the subset of images by non-rigid image registration using a combination of the plurality of images and the additional plurality of images, and creating a parametric map from the aligned images.

Free-breathing parameter mapping with high-contrast image registration

Some aspects of the present disclosure relate to accelerated imaging using variable-density sampling and compressed sensing with parallel imaging. In one embodiment, a method includes acquiring magnetic resonance data associated with a physiological activity in an area of interest of a subject. The acquiring includes performing accelerated variable-density sampling with phase-contrast displacement encoding. The method also includes reconstructing, from the acquired magnetic resonance data, images corresponding to the physiological activity in the area of interest. The reconstructing includes performing parallel imaging and compressed sensing.

Systems and methods for accelerated imaging using variable density sampling and compressed sensing with parallel imaging

Some aspects of the present disclosure relate to systems and methods for three-dimensional spiral perfusion imaging. In one embodiment, a method for perfusion imaging of a subject includes acquiring perfusion imaging data associated with the heart of a subject. The acquiring includes applying an imaging pulse sequence with a three-dimensional stack-of-spirals trajectory. The method also includes reconstructing perfusion images from the acquired perfusion imaging data. The reconstructing includes parallel imaging and motion-guided compressed sensing. The method also includes determining, from the reconstructed perfusion images, absolute perfusion values based on time-intensity relationships to quantify myocardial blood flow of the heart of the subject, and generating a quantitative volumetric perfusion flow map based on the determined absolute perfusion values.

Systems and methods for three-dimensional spiral perfusion imaging

Systems and methods for Cartesian dynamic imaging are disclosed. In one aspect, in accordance with one example embodiment, a method includes acquiring magnetic resonance data for an area of interest of a subject that is associated with one or more physiological activities of the subject and performing image reconstruction comprising Kalman filtering or smoothing on Cartesian images associated with the acquired magnetic resonance data. Performing the image reconstruction includes increasing at least one of spatial and temporal resolution of the Cartesian images.

Systems and methods for cartesian dynamic imaging

Some aspects of the present disclosure relate to systems and methods for accelerated dynamic magnetic resonance imaging (MRI). In an example embodiment, a method includes acquiring undersampled MRI data corresponding to a set of images associated with an area of interest of a subject, and separating an image of the set of images into image regions. The method also includes performing motion tracking for each of the image regions, grouping the motion-tracked image regions into clusters, and applying a sparsity transform to the clusters, to form sparsity-exploited, transformed image regions. The method further includes forming a set of merged images from the plurality of sparsity-exploited, transformed image regions, and updating the set of merged images based on data fidelity, to form an updated set of estimated images.

Systems and methods for accelerated dynamic magnetic resonance imaging

A system and method for providing a dark-blood technique for contrast-enhanced cardiac magnetic resonance, improving visualization of subendocardial infarcts or perfusion abnormalities that may otherwise be difficult to distinguish from the bright blood pool. In one technique the dark-blood preparation is performed using a driven-equilibrium fourier transform (DEFT) preparation with motion sensitizing gradients which attenuate the signal in the ventricular cavities related to incoherent phase losses resulting from non-steady flow within the heart. This dark-blood preparation preserves the underlying contrast characteristics of the pulse sequence causing a myocardial infarction to be bright while rendering the blood pool dark. When applied to perfusion imaging, this dark-blood preparation will help eliminate artifacts resulting from the juxtaposition of a bright ventricular cavity and relatively dark myocardium.

Motion-attenuated contrast-enhanced cardiac magnetic resonance imaging system and method

A system and method for using hyperpolarized noble gases together with an appropriately designed and optimized magnetic resonance imaging pulse sequence to rapidly acquire static or dynamic magnetic resonance images. The strong magnetic resonance signal from hyperpolarized gases, combined with the present magnetic resonance imaging technique, presents the opportunity for the imaging of gases with both high spatial and high temporal resolution. One potential application for such a method is the direct, dynamic visualization of gas flow, which would be extremely useful for characterizing a variety of fluid systems. In the medical field, one such system of substantial importance is the lung. The system and method provides for visualizing regional ventilatory patterns throughout the respiratory cycle with high temporal and high spatial resolution. The low sensitivity to susceptibility artifacts permits good image quality to be obtained in various orientations. Depending on the application, temporal resolution can be traded for anatomical coverage. Such application of dynamic imaging of the lung using hyperpolarized gases will provide unique information on the physiology and pathophysiology of the lung, and has the potential for many clinically-relevant applications.

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Charlottesville, VA, United States of America

Michael Salerno