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.

An adaptive real-time radial k-space sampling trajectory (ARKS) can respond to a physiologic feedback signal to reduce motion effects and ensure sampling uniformity. In this adaptive k-space sampling strategy, the most recent signals from an ECG waveform can be continuously matched to the previous signal history, new radial k-space locations c were determined, and these MR signals combined using multi-shot or single-shot radial acquisition schemes. The disclosed methods allow for improved

The invention relates to a method for generating MR images (10, 20) of an object in its environment within a region of interest, said object executing motion comprising a plurality of moving phases within a period of time. According to several aspects of the invention, the method comprises the steps of: —providing a first dataset pertaining to one of the moving phases of the object (Si); —generating a first image (10) of a region of interest from the first dataset (S2); —identifying a dynamic region (12) and a static region (14) inside the first image (10), wherein the regions (12, 14) are predominantly dynamic or static respectively within the periodeperiod of time (S3); —editing the first image (10) by masking out the dynamic region (14) (S4); —performing an inverse Fourier transformation of the edited first image (16) showing the remaining static region (14) (S5); —providing a second dataset pertaining to one of the moving phases of the object (S6); —subtraction of the inverse Fourier transformation of the edited first image (16) with the remaining static region (14) from the second dataset (S7); —performing a Fourier transformation on the subtracted second dataset (18) (S8); and —generating a second image (20) of a reduced region of interest with respect to the region of interest of the first image (10), which reduced region of interest includes the dynamic region (12) (S9). The invention further relates to a corresponding MRI system for generating MR images of an object in its environment within a region of interest.

According to one embodiment, an image processing apparatus includes a storage unit configured to store data of a series of slice images associated with a region including a target region of an object, a first rest period specifying unit configured to specify a first rest period based on a change between images of the series of slice images, and a second rest period specifying unit configured to specify a second rest period shorter than the first rest period by tracking the target region on a plurality of slice images corresponding to the specified first rest period or a rest period enlarged from the first rest period.

Some aspects of the present disclosure relate to systems and methods for free-breathing cine DENSE MRI using self-navigation. In one embodiment, a method includes acquiring magnetic resonance data for an area of interest of a subject, wherein the acquiring comprises performing sampling with phase-cycled, cine displacement encoding with stimulated echoes (DENSE) during free-breathing of the subject; identifying, from the acquired magnetic resonance data, a plurality of phase-cycling data pairs corresponding to matched respiratory phases of the free-breathing of the subject; reconstructing, from the plurality of phase-cycling data pairs, a plurality of intermediate self-navigation images; performing motion correction by estimating, from the plurality of intermediate self-navigation images, the respiratory position associated with the plurality of phase-cycling data pairs; and reconstructing a plurality of motion-corrected cine DENSE images of the area of interest of the subject.

3D cine MR angiography systems and methods are disclosed for use during the steady state intravascular distribution phase of ferumoxytol. The 3D cine MRA technique enables improved delineation of cardiac anatomy in pediatric patients undergoing cardiovascular MRI.

In a method and magnetic resonance (MR) apparatus for determining a fraction of scar tissue in the myocardium of an examination person, magnetization of nuclear spins is prepared by radiation of a preparation pulse in the myocardium, and MR signals are acquired for multiple MR images while the magnetization returns to equilibrium. The multiple MR images are brought into registration with each other, so a movement of the heart between MR images is compensated. T1 times are determined using this sequence of compensated MR images. Different MR template images with different contrasts are calculated at different times after radiation of the preparation pulse, using the calculated T1 times. A myocardial contour is determined using one of the template images that has a first contrast. Scar tissue in the myocardium is determined using another template image that has a second contrast that differs from the first contrast.

Embodiments relate to acquiring magnetic resonance (MR) images with suppressed residual blood signal in the early cardiac phases, leading to images with a preferred dark-blood appearance throughout the entire cardiac cycle, which improves accuracy of subsequent post-processing algorithms. The acquisition of the desired blood suppressed tissue images is achieved through a double inversion recovery pulse in DENSE sequences. The double inversion recovery pulse is applied after an electrocardiogram (ECG) trigger at a beginning point of a repetition time period, followed by a displacement encoding module at an inversion time during the repetition time period and a readout module comprised of a plurality of frames during a remainder of the repetition time period. The displacement encoding module applies a labelling process on the tissue, while the readout module applies an un-labelling process. The readout module comprises an imaging sequence adapted to acquire DENSE images.

A method for creating a first MRI image and a second MRI image is provided. A first echo is read out. A second echo is read out. The first echo readout is used to generate a first image set, with each image pixel being a first linear combination of the first species and the second species. The second echo readout is used to generate a second image set, with each image pixel being a second linear combination of the first species and the second species. The first image set and second image set are combined to obtain a first combined image containing only the first species and a second combined image containing only the second species, comprising combining the first image set and the second image set to generate two pairs of solutions and using a mathematical optimization to choose a correct pair of solutions.

Systems and methods for generating MRI images of the lungs and/or airways of a subject using a medical grade gas mixture comprises between about 20-79% inert perfluorinated gas and oxygen gas. The images are generated using acquired .sup.19F magnetic resonance image (MRI) signal data associated with the perfluorinated gas and oxygen mixture.