Abstract: An apparatus and method process magnetic resonance image (MRI) data and other data from a subject, including image data corresponding to at least one of angiographic data, four-dimensional blood flow, neurological blood flow, abdominal blood flow, and peripheral blood flow in the subject, and applies a compressed sensing (CS) reconstruction method utilizing a complex difference of the image data as a sparsifying transform for imaging of at least one of blood flow and magnetic resonance angiography to output a reconstructed image of the blood flow and magnetic resonance angiography, in the subject with increased processing speed and having high accuracy. The apparatus receives the MRI data of the fluid flow from an MRI device. The processor operates predetermined software, receives the MRI data, and applies the CS reconstruction method to generate the reconstructed image. An output device outputs the reconstructed image of the fluid flow.

Abstract: Systems and methods for adaptively registering images acquired with different contrast-weightings using a magnetic resonance imaging (“MRI”) system. For instance, motion is estimated as global affine motion refined by a local non-rigid motion estimation algorithm that simultaneously estimates the motion field and intensity variations among the images being registered. The images registered with the described systems and methods can be used for improved tissue characterization.

Abstract: A magnetic resonance imaging (MRI) system and methods are provided for producing images of a subject. In some aspects, a method includes identifying a point in the cardiac cycle, performing an inversion recovery (IR) pulse at a selected time point from the pre-determined point, and sampling a k-space segment at an inversion time from the IR pulse that is substantially coincident with the pre-determined point. The method also includes repeating the IR pulse and k-space sampling for multiple inversion times, and multiple segments of k-space, in an interleaved manner, to generate datasets having T1-weighted contrasts determined by their respective inversion times. The method further includes reconstructing three-dimensional (3D) spatially-aligned images using the datasets, and generating a T1 recovery map by combining the 3D images. In some aspects, a prospective/retrospective scheme may be used to obtain data fully sampled in the center of k-space and randomly undersampled in the outer regions.

Abstract: A method and apparatus for reducing scan time, eddy currents and image factors in dynamic magnetic resonance (MR) imaging associated with at least a portion a k-space. The method includes scanning at least a portion of the k-space with an Echo-Planar Imaging (EPI) pulse sequence technique, acquiring a randomly under-sampled k-space; and reconstructing the under-sampled k-space utilizing a constrained reconstruction technique. A dynamic image is constructed of the at least a portion of the k-space based on EPI and the randomly undersampled k-space techniques to each segment of the EPI pulse sequence technique.

Abstract: A system and method for controlling a magnetic resonance imaging (MRI) system to acquire images of a subject having inconsistencies in a cardiac cycle of the subject. The process includes receiving an identification of a predetermined point in a cardiac cycle of the subject and, thereupon, performing a saturation module configured to dephase magnetization within a region of interest (ROI) from before the predetermined point. The process also includes performing an inversion module configured to invert spins within the ROI and acquiring medical imaging data from the subject. A delay is inserted between the performance of the saturation module and the performance of the inversion module, wherein a duration of the delay is configured, with the saturation module, to control evidence in the medical imaging data of inconsistencies in the cardiac cycle of the subject by controlling a magnetization history of tissue in the ROI.

Abstract: A magnetic resonance (MR) image processing system includes a data collection unit that acquires image data from a target region of an object. A navigator unit acquires a motion signal indicating motion comprising motion of at least a portion of an object. A data processing unit derives k-space data for a k-space data array from the acquired image data, by acquiring k-space data for a first portion of the k-space from the acquired image data in response to the motion signal indicating motion is within a predetermined range and acquiring k-space data for a second portion of the k-space from the acquired image data irrespective of the predetermined range.

Abstract: A method for reconstructing an image of a subject from undersampled image data that is acquired with an imaging system, such as a magnetic resonance imaging system or computed tomography system, is provided. From the acquired undersampled image data, an image of the subject is reconstructed and used to guide further image reconstruction. For example, a low resolution image is reconstructed from a portion of the undersampled image data, such as from a portion corresponding to the center of k-space when MRI is used. From this image, a number of similarity clusters are produced and processed. The processing may be by hard thresholding, Wiener filtering, principal component pursuit, or other similar techniques. These processed similarity clusters are then used to reconstruct a final, target image of the subject using, for example, a weighted average combination of the similarity clusters.

Abstract: An apparatus and method process magnetic resonance image (MRI) data and other data from a subject, including image data corresponding to at least one of angiographic data, four-dimensional blood flow, neurological blood flow, abdominal blood flow, and peripheral blood flow in the subject, and applies a compressed sensing (CS) reconstruction method utilizing a complex difference of the image data as a sparsifying transform for imaging of at least one of blood flow and magnetic resonance angiography to output a reconstructed image of the blood flow and magnetic resonance angiography, in the subject with increased processing speed and having high accuracy. The apparatus receives the MRI data of the fluid flow from an MRI device. The processor operates predetermined software, receives the MRI data, and applies the CS reconstruction method to generate the reconstructed image. An output device outputs the reconstructed image of the fluid flow.

Abstract: A method for motion correction using coil arrays, termed “MOCCA,” is provided, in which coil-dependent motion-related signal variations are employed to determine information related to motion in two and three directions. With such a method, navigator echoes are not required, nor is the acquisition of additional data required to resolve complex motions in more than one direction. The motion estimation and compensation method provided by MOCCA is also applicable to applications of cardiac, respiratory, and other physiological self-gating techniques.

Abstract: A system and method for producing an image of a subject with a magnetic resonance imaging (MRI) system using an adaptive gating window with constant gating efficiency is provided. Navigator data is acquired from the subject and used to produce a gating window having a defined gating efficiency value. Image data is acquired with the MRI system while measuring a position of an anatomical location within the subject. Image data is accepted or rejected based on whether the measured anatomical location is within the gating window. The gating window is updated using the measured position of the anatomical location such that a substantially constant gating efficiency value is maintained. Imaging is repeated with the updated gating window, after which the gating window is again updated. When the desired amount of image data has been acquired, an image of the subject is reconstructed.

Abstract: A system and method for non-contrast enhanced pulmonary vein magnetic resonance imaging substantially suppresses the signal from cardiac tissue adjacent to the left atrium and pulmonary vein is provided. Significant conspicuity of the left atrium and pulmonary vein versus adjacent anatomical structures is produced. In this manner, more accurate measurements of pulmonary vein ostia size are facilitated, as well as more accurate registration of imaging volumes with a radiofrequency ablation catheter during pulmonary vein isolation procedures. In addition, more robust three-dimensional volume views of the left atrium and pulmonary vein are produced without the administration of contrast agents.

Abstract: A method for free-breathing magnetic resonance imaging (MRI) using iterative image-based respiratory motion correction is provided. An MRI system is used to acquired k-space data and navigator data from a subject. The k-space data is then sorted into a plurality of data bins using the navigator data. A motion correction parameter is estimated for each data bin and is applied to the respective k-space data in that bin. The corrected k-space data segments are then combined to form a corrected k-space data set, from which an image is reconstructed. The process may be iteratively repeated until an image quality metric is optimized; for example, until an image sharpness measure is sufficiently maximized.

Abstract: A method for motion correction using coil arrays, termed “MOCCA,” is provided, in which coil-dependent motion-related signal variations are employed to determine information related to motion in two and three directions. With such a method, navigator echoes are not required, nor is the acquisition of additional data required to resolve complex motions in more than one direction. The motion estimation and compensation method provided by MOCCA is also applicable to applications of cardiac, respiratory, and other physiological self-gating techniques.

Abstract: A method and system for magnetic resonance imaging comprises applying at least one radiofrequency magnetization transfer (MT) pulse to a coronary venous region of a subject positioned within a magnetic field, and acquiring magnetic resonance imaging data from the coronary venous region to produce an image of a coronary venous structure. This technique can be utilized as part of a 3D free-breathing, ECG-triggered gradient-echo Cartesian acquisition of the coronary region. One or more magnetization transfer (MT) preparation pulses are used to enhance the contrast between venous blood and myocardium. The MT preparation results in myocardial signal suppression without any significant signal loss in the arterial or venous blood so as to maintain venous blood signal-to-noise ratio while improving contrast between myocardium and veins. The image of a coronary venous structure can be acquired in connection with an interventional cardiovascular procedure, such as a cardiac resynchronization therapy.

Abstract: A method for motion correction using coil arrays, termed “MOCCA,” is provided, in which coil-dependent motion-related signal variations are employed to determine information related to motion in two and three directions. With such a method, navigator echoes are not required, nor is the acquisition of additional data required to resolve complex motions in more than one direction. The motion estimation and compensation method provided by MOCCA is also applicable to applications of cardiac, respiratory, and other physiological self-gating techniques.

Abstract: In one aspect, a method of inducing nuclear magnetic resonance (NMR) signals from a region of an object having at least a portion of at least one pulmonary vein using at least one coil adapted to emit electromagnetic signals to induce an NMR effect is provided. The method comprises operating the at least one coil to provide at least one imaging sequence at an effective off-resonance frequency adapted to cause NMR signals to be emitted from the at least one pulmonary vein, and detecting at least some of the NMR signals to obtain NMR data corresponding to the at least one pulmonary vein.

Abstract: A method for reconstructing an image of a subject from undersampled image data that is acquired with an imaging system, such as a magnetic resonance imaging system or computed tomography system, is provided. From the acquired undersampled image data, an image of the subject is reconstructed and used to guide further image reconstruction. For example, a low resolution image is reconstructed from a portion of the undersampled image data, such as from a portion corresponding to the center of k-space when MRI is used. From this image, a number of similarity clusters are produced and processed. The processing may be by hard thresholding, Wiener filtering, principal component pursuit, or other similar techniques. These processed similarity clusters are then used to reconstruct a final, target image of the subject using, for example, a weighted average combination of the similarity clusters.

Abstract: A method for motion correction using coil arrays, termed “MOCCA,” is provided, in which coil-dependent motion-related signal variations are employed to determine information related to motion in two and three directions. With such a method, navigator echoes are not required, nor is the acquisition of additional data required to resolve complex motions in more than one direction. The motion estimation and compensation method provided by MOCCA is also applicable to applications of cardiac, respiratory, and other physiological self-gating techniques.

Abstract: A system and method for non-contrast enhanced pulmonary vein magnetic resonance imaging substantially suppresses the signal from cardiac tissue adjacent to the left atrium and pulmonary vein is provided. Significant conspicuity of the left atrium and pulmonary vein versus adjacent anatomical structures is produced. In this manner, more accurate measurements of pulmonary vein ostia size are facilitated, as well as more accurate registration of imaging volumes with a radiofrequency ablation catheter during pulmonary vein isolation procedures. In addition, more robust three-dimensional volume views of the left atrium and pulmonary vein are produced without the administration of contrast agents.

Abstract: Adiabatic pulses that define an amplitude modulation and a frequency modulation are applied in a sequence of pulses to obtain a T2 weighted magnetic resonance image. Such an adiabatic T2 prep sequence typically includes a first 90° pulse, an even number of adiabatic pulses, and a second 90° pulse. Adiabatic pulses can be selected based on function pairs, or can be defined numerically. A magnetic resonance imaging (MRI) system includes a library of adiabatic pulse waveforms, and is configured to select a waveform and apply an RF magnetic field based on the selected pulse waveform.